WO2023115029A2 - Antibody-based depletion of il1r2-positive cells - Google Patents

Abstract

Provided herein are antibodies that deplete IL1R2-positive (IL1R2+) cells. Antibodies disclosed herein bind the extracellular domain of membrane bound IL1R2 present on the surface of a cell and cause the depletion or killing of the cell. Also disclosed herein are methods to modulate an immune response by administering an IL1R2 inhibitor (e.g., an antibody). For example, such methods can include a method of enhancing an immune response in a subject, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody to the subject, wherein the anti-IL1R2 antibody binds to the extracellular domain of membrane-bound IL1R2 present on the surface of the cell and causes the depletion or killing of the cell.

Description

ANTIBODY-BASED DEPLETION OF IL1R2-POSITIVE CELLS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims the benefit of and priority to U.S. Provisional Patent Application No. 63/291,375, filed December 18, 2021, the entire content of which is hereby incorporated by reference in its entirety for all purposes.

REFERENCE TO A SEQUENCE LISTING XML

[0002] This application contains a Sequence Listing which has been submitted electronically in XML format. The Sequence Listing XML is incorporated herein by reference. Said XML file, created on December 1, 2022, is named TBI-009WO_SL.xml and is 9,279 in size.

BACKGROUND

[0003] Interleukin- 1 receptor type 2 (IL1R2) has been reported to serve as a decoy receptor by competitive binding to ILip, thereby preventing its binding to the activating receptor IL1R1. Thus, the binding of IL1R2 to ILip blocks ILip signaling in inflammation and disease. IL1R2 overexpression is observed during ovarian, pancreatic and breast cancer tumorigenesis. IL1R2 is also expressed by immune-suppressing cells in tumors. A mechanism-of-action to target IL1R2 is via depleting ILlR2-expressing cells.

[0004] Relevant references for the above include: (1) Molgora et al., Immunol. Rev. 2018, 281, 233. (2) Zheng et al., Immunity 2013, 38, 285. (3) Laios et al., Mol. Cancer 2008, 7, 8. (4) Ma et al., Cancer Cell 2004, 5, 607. (5) Zhang et al., Adv Sci (Weinh). 2020 Jan; 7(1): 1901728.

SUMMARY

[0005] Disclosed herein are antibodies that can deplete, kill, or disable interleukin 1 receptor 2 (ILlR2)-positive cells. The present disclosure also provides methods of treating a disease by administration of an IL1R2 depleting antibody.

[0006] In one aspect, the present disclosure provides a method of enhancing an immune response in a subject in need thereof, the method comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti- IL1R2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell.

[0007] In another aspect, the present disclosure provides a method of depleting or killing a IL1R2+ cell, the method comprising contacting the cell with an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof, wherein the anti-IL!R2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of the cell and causes the depletion or killing of the cell.

[0008] In yet another aspect, the present disclosure provides a method of treating cancer in a subject, the method comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti-ILlR2 antibody or antigenbinding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell.

[0009] In certain embodiments of any of the methods, the anti-ILlR2 antibody or antigenbinding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell, prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell.

[0010] In another aspect, the present disclosure provides an isolated antibody or antigenbinding portion thereof that binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell, prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell. In some embodiments, the anti-ILlR2 antibody or antigenbinding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell, prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell.

[0011] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane portion of IL1R2. In certain embodiments, the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. [0012] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues DLHMDFKCVVHNTLSFQTLRTTVKEASS (SEQ ID NO: 1).

[0013] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues VHNTLSFQTLRTTVKEASS (SEQ ID NO: 7).

[0014] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within: a region comprising amino acid residues SFQTLRTTVKEASS (SEQ ID NO: 2), a region comprising amino acid residues DLHMDFK (SEQ ID NO: 3), or a combination thereof in a manner that prevents cleavage of membrane-bound IL1R2. In some embodiments, the cleavage of membrane-bound IL1R2 is prevented due to steric hindrance. [0015] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within: a region comprising amino acid residues SFQTLRTTVKEASS (SEQ ID NO: 2), a region comprising amino acid residues DLHMDFK (SEQ ID NO: 3), or a combination thereof. [0016] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues SFQTL (SEQ ID NO: 4).

[0017] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues CVVHNTL (SEQ ID NO: 5).

[0018] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds at or near an enzyme recognition site, wherein the enzyme recognition site comprises the amino acid sequence shown in SEQ ID NO: 4; optionally wherein binding of the said antibody or antigen-binding portion thereof prevents cleavage of membrane-bound IL1R2.

[0019] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof binds at or near an enzymatic cleavage site, wherein the enzymatic cleavage site is located within the sequence DLHMDFKCVVHNTL (SEQ ID NO: 6); optionally wherein binding of the said antibody or antigen-binding portion thereof prevents cleavage of membrane-bound IL1R2.

[0020] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof competes with an enzyme for binding to membrane-bound IL1R2. In certain embodiments, the enzyme comprises at least one of ADAMI 7, a metalloproteinase, aminopeptidase, or an elastase. In certain embodiments, the anti-ILR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane portion of IL1R2.

[0021] In certain embodiments, the cell is a regulatory cell, optionally a regulatory T cell.

[0022] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof causes the depletion or killing of the cell via at least one of: antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP).

[0023] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof comprises a Fc region.

[0024] In certain embodiments, the Fc region comprises human IgGl, human IgG2, human IgG3, or human IgG4 Fc.

[0025] In certain embodiments, the Fc region comprises a wild-type human IgGl. [0026] In certain embodiments, the Fc region comprises a mutated human IgGl.

[0027] In certain embodiments, the Fc region binds a Fc Receptor present on the surface of an effector cell. [0028] In certain embodiments, the Fc Receptor is at least one of FcyRI(CD64), FcyRIIA (CD32A), FcyRIIIA (CD 16 or CD16A), and FcyRIIIB (CD16B).

[0029] In certain embodiments, the effector cell comprises at least one of cytotoxic T-cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes. [0030] In certain embodiments, the Fc region comprises one or more amino acid substitutions relative to wild-type.

[0031] In certain embodiments, the one or more amino acid substitutions in the Fc region improve its ability to mediate at least one effector function.

[0032] In certain embodiments, the effector function comprises at least one of: antibodydependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP).

[0033] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof promotes phagocytosis of one or more IL1R2 expressing cells.

[0034] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof has enhanced effector function.

[0035] In certain embodiments, the enhanced immune response comprises an adaptive immune response.

[0036] In certain embodiments, the enhanced immune response comprises an innate immune response.

[0037] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof increases activity of one or more inflammatory immune cells and/or decreases activity of one or more suppressive immune cells.

[0038] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof increases activity of one or more inflammatory immune cells.

[0039] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof decreases activity of one or more suppressive immune cells.

[0040] In certain embodiments, enhancing the immune response comprises increasing an existing immune response in the subject.

[0041] In certain embodiments, enhancing the immune response comprises initiating an immune response in the subject.

[0042] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof is a depleting antibody or antigen-binding portion thereof.

[0043] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof is a human or humanized antibody or antigen-binding portion thereof. [0044] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof is a monoclonal antibody or antigen-binding portion thereof.

[0045] In certain embodiments, the antibody is a Fab, Fab’, F(ab’)2, Fv, scFv, (scFv)2, single chain antibody, dual variable domain (DVD) antibody, single variable domain antibody, linear antibody, or V domain antibody.

[0046] In certain embodiments, the present disclosure provides an isolated polynucleotide or set of polynucleotides encoding the antibody disclosed herein, a VH thereof, a VL thereof, a light chain thereof, a heavy chain thereof, or an antigen-binding portion thereof; optionally cDNA.

[0047] In certain embodiments, the anti-ILlR2 antibody or antigen-binding portion thereof comprises a second antigen-binding domain that specifically binds to a second molecule on the surface of a second cell. In certain embodiments, the second molecule on the surface of the second cell is CD3. In certain embodiments, the second cell is an effector cell. In certain embodiments, the effector cell comprises at least one of T cells, cytotoxic T-cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes.

[0048] In certain embodiments, the present disclosure provides a vector or set of vectors comprising the polynucleotide or set of polynucleotides disclosed herein.

[0049] In certain embodiments, the present disclosure provides a host cell comprising the polynucleotide or set of polynucleotides or the vector or set of vectors disclosed herein.

[0050] In certain embodiments, the present disclosure provides a method of producing an antibody comprising expressing the antibody with a host cell and isolating the expressed antibody.

[0051] In certain embodiments, the present disclosure provides a kit comprising the isolated antibody of the present disclosure and instructions for use.

[0052] In certain embodiments, the present disclosure provides a pharmaceutical composition comprising a pharmaceutically acceptable carrier and the isolated antibody of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0053] These and other features, aspects, and advantages of the present disclosure will become better understood with regard to the following description, and accompanying drawings, where: [0054] FIG. 1A is a bar graph depicting expression of FOXP3 in purified T cell subsets (CD8⁺, effector T cells (Teff), and regulatory T cells (T_reg)). FIG. IB is a bar graph depicting expression of IL1R2 in purified T cell subsets (CD8⁺, effector T cells (Teff), and regulatory T cells (Treg)). [0055] FIG. 2A is a graph showing expression of IL1R2 transcripts in purified T cell subsets (CD8⁺, effector T cells (Teff), and regulatory T cells (T_reg)) in melanoma patients.

[0056] FIG. 2B is a t-distributed stochastic neighbor embedding (tSNE) plot of IL1R2 transcripts in NSCLC tumor-infiltrating T cells.

[0057] FIG. 2C is a tSNE plot of FOXP3 transcripts in NSCLC tumor-infiltrating T cells. [0058] FIG. 2D is a plot showing IL1R2 expression in different tissue types (normal (N), peripheral blood (P), and tumor-infiltrating (T)) in NSCLC patients.

[0059] FIG. 2E is a tSNE plot of IL1R2 transcripts in HCC tumor-infiltrating T cells.

[0060] FIG. 2F is a tSNE plot of FOXP3 transcripts in HCC tumor-infiltrating T cells.

[0061] FIG. 2G is a plot showing IL1R2 expression in different tissue types (normal (N), peripheral blood (P), and tumor-infiltrating (T)) in HCC patients.

[0062] FIG. 2H is a violin plot showing IL1R2 transcripts in NSCLC tumor-infiltrating neutrophils.

[0063] FIG. 3A is a graph illustrating IL1R2 expression in a distinct subset of NSCLC tumorinfiltrating Treg.

[0064] FIG. 3B is a graph illustrating IL1R2 expression in a distinct subset of HCC tumorinfiltrating Treg.

[0065] FIG. 3C is a dot-plot providing correlation between transcripts for IL1R2 and canonical markers of myeloid-derived suppressor cell (MDSC) or transcripts with known immunosuppressive function in non-small cell lung carcinoma (NSCLC). Each dot presented in the dot-plot corresponds to the magnitude of expression of a single gene in a subset of cells and to its prevalence (i.e., fraction of cells expressing the gene). The median expression scaled across the subsets is represented by black or grey. Black dot indicates low median expression and grey dot indicates high median expression. The size of the dot represents the fraction of cells expressing that transcript.

[0066] FIG. 4A is a histogram showing the results of flow cytometry performed to measure the IL1R2 surface levels on CD4⁺ FOXP3" T cells, CD4⁺ FOXP3⁺ Tregs, and polymorphonuclear myeloid-derived suppressor cells (PMN-MDSC) from a kidney chromophobe renal cell carcinoma tumor from a 68 year old Caucasian male.

[0067] FIG. 4B is a histogram showing the results of flow cytometry performed to measure the IL1R2 surface levels on CD4⁺ FOXP3" T cells, CD4⁺ FOXP3⁺ Tregs, and PMN MDSC a liver cholangiocarcinoma tumor from a 63 year old Caucasian female. [0068] FIGs. 5A-5B are bar graphs showing the results of a reporter bioassay performed to measure the ability of ILlR2-specific antibodies (anti-ILlR2 clone 1 (FIG. 5A; anti-ILlR2 clones 2 and 3 (FIG. 5B)) to activate CD 16 in the presence of ILlR2-expressing SR cells.

DETAILED DESCRIPTION

[0069] The term “ILlR2-positive cells” indicates one or more cells that express IL1R2 as a surface marker. One of skill in the art readily appreciates how to select for or against a specific marker. Thus, by way of example, a population of cells sorted for a particular marker includes identifying cells that are positive for that particular marker and retaining those cells for further use or further selection steps. A population of cells sorted against a specific marker includes identifying cells that are positive for that particular marker and excluding those cells for further use or further selection steps. The terms “IL 1R2 -positive” or “IL1R2+” are used interchangeably in the present disclosure.

[0070] As used herein, “depletion” refers to a partial or complete decrease of one or more cells that express IL1R2 as a surface marker. For example, depletion can refer to the removal of one or more IL1R2+ cells such that the number of IL1R2+ cells present in a subject is less than baseline. Depletion can include killing and/or disabling one or more IL1R2+ cells. For example, depletion of one or more IL1R2+ cells can occur via at least one of antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody- mediated phagocytosis (ADCP).

[0071] The term percent “identity,” in the context of two or more nucleic acid or polypeptide sequences, refer to two or more sequences or subsequences that have a specified percentage of nucleotides or amino acid residues that are the same, when compared and aligned for maximum correspondence, as measured using one of the sequence comparison algorithms described below (e.g., BLASTP and BLASTN or other algorithms available to persons of skill) or by visual inspection. Depending on the application, the percent "identity" can exist over a region of the sequence being compared, e.g., over a functional domain, or, alternatively, exist over the full length of the two sequences to be compared.

[0072] For sequence comparison, typically one sequence acts as a reference sequence to which test sequences are compared. When using a sequence comparison algorithm, test and reference sequences are input into a computer, subsequence coordinates are designated, if necessary, and sequence algorithm program parameters are designated. The sequence comparison algorithm then calculates the percent sequence identity for the test sequence(s) relative to the reference sequence, based on the designated program parameters. [0073] Optimal alignment of sequences for comparison can be conducted, e.g., by the local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482 (1981), by the homology alignment algorithm of Needleman & Wunsch, J. Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson & Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerized implementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA in the Wisconsin Genetics Software Package, Genetics Computer Group, 575 Science Dr., Madison, Wis.), or by visual inspection (see generally Ausubel et al., infra).

[0074] One example of an algorithm that is suitable for determining percent sequence identity and sequence similarity is the BLAST algorithm, which is described in Altschul et al., J. Mol. Biol. 215:403-410 (1990). Software for performing BLAST analyses is publicly available through the National Center for Biotechnology Information (www.ncbi.nlm.nih.gov/).

[0075] The term “optionally” is meant, when used sequentially, to include from one to all of the enumerated combinations and contemplates all sub-combinations.

[0076] The term “sufficient amount” means an amount sufficient to produce a desired effect, e.g., an amount sufficient to modulate protein aggregation in a cell.

[0077] An “effective amount” or “therapeutically effective amount” as used herein refers to an amount of therapeutic compound, such as an anti-ILlR2 antigen binding agent or anti-ILlR2 antibody, administered to an individual, either as a single dose or as part of a series of doses, which is effective to produce or contribute to a desired therapeutic effect, either alone or in combination with another therapeutic modality. Examples of a desired therapeutic effect is enhancing an immune response, slowing or delaying tumor development; stabilization of disease; amelioration of one or more symptoms. An effective amount may be given in one or more dosages.

[0078] The term “treating” as used herein, refers to retarding or reversing the progress of a condition, such as cancer. The term “treatment,” as used herein, refers to the act of treating a condition, such as cancer.

[0079] The term “mammal” as used herein includes both humans and non-humans and include but is not limited to humans, non-human primates, canines, felines, murines, bovines, equines, and porcines.

[0080] An “individual” or “subject” as used herein refers to any animal classified as a mammal, including humans, domestic and farm animals, and zoo, sport, or pet animals, such as dogs, horses, rabbits, cattle, pigs, hamsters, gerbils, mice, ferrets, rats, cats, and the like. In some embodiments, the individual is human. In some embodiments, the individual is mouse. [0081] The terms “modulate” and “modulation” refer to reducing or inhibiting or, alternatively, activating or increasing, a recited variable.

[0082] The terms “increase” and “activate” refer to an increase of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 50-fold, 100-fold, or greater in a recited variable.

[0083] The terms “reduce” and “inhibit” refer to a decrease of 10%, 20%, 30%, 40%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 2-fold, 3-fold, 4-fold, 5-fold, 10-fold, 20-fold, 50-fold, 100-fold, or greater in a recited variable.

[0084] The term “agonize” refers to the activation of receptor signaling to induce a biological response associated with activation of the receptor. An “agonist” is an entity that, e.g., binds to and agonizes a receptor.

[0085] The term “antagonize” refers to the inhibition of receptor signaling to inhibit a biological response associated with activation of the receptor. An “antagonist” is an entity that, e.g., binds to and antagonizes a receptor.

[0086] The term “about” as used herein refers to the usual error range for the respective value readily known to the skilled person in this technical field. An exemplary error range is plus or minus 5%. Reference to “about” a value or parameter herein includes (and describes) embodiments that are directed to that value or parameter per se.

[0087] For any of the structural and functional characteristics described herein, methods of determining these characteristics are known in the art.

[0088] It must be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.

Interleukin-1 Receptor Type 2 (IL1R2)

[0089] In humans, the IL1R2 gene (IL1R2) is located on the long arm of chromosome 2 at band 2ql2. In mice, IL1R2 is found in the centromere proximal position of chromosome 1 (Copeland et al., Genomics. 1991; 9:44-50). The IL1R2 cDNA and amino acid sequences are similar across species. Examination of bovine IL1R2 cDNA yielded a sequence homology of 79%, 69% and 69% when compared to human, mouse and rat, respectively (Yu et al., Cytokine. 1997; 9:1-8). The amino acid sequence of bovine IL1R2 is 71% identical with human, 58% identical with mouse and 59% identical with rat.

[0090] IL1R2, in humans and non-human primates, is a protein comprised of 398 amino acids. In mice and rats, it is slightly longer at 410 amino acids and 416 amino acids, respectively. As a decoy receptor, IL1R2 cannot generally induce signal transduction. This is due to its lack of an intracellular Toll/interleukin-1 region (TIR) domain, a conserved region shared by IL1R1 and the Toll-like receptors (TLRs) as part of the IL-l/TLR superfamily (Dunne and O’Neill, Sci STKE. 2003:re3, Xu et al., Nature. 2000; 408: 111-115). With three immunoglobulin-like extracellular domains and a single helical transmembrane domain, IL1R2 is structurally similar to IL1R1. IL1R2, however, lacks approximately 200 cytoplasmic amino acids useful to the TIR (Slack et al., J Biol Chem. 2000; 275:4670-4678). Thus, with only a 29 amino acid cytoplasmic region, IL1R2 is a 68 kDa glycoprotein in comparison to IL1R1 which is 80 kDa (Sims et al., Science. 1988; 241 :585-589).

[0091] The IL1R2 receptor exists in both membrane-bound and soluble-forms (SIL1R2).

Generation of SIL1R2 typically occurs via two known mechanisms. First, alternative splicing has been shown to generate SIL1R2 in patients with autoimmune inner ear disease (AIED) (Vambutas et al., PLoS One. 2009; 4:e5293). Second, matrix metalloproteinases can cleave full- length membrane-bound IL1R2, shedding the extracellular domain (Orlando et al., J Biol Chem. 1997; 272:31764-31769). The complete human IL1R2 amino acid sequence is shown as SEQ ID NO: 8. Juxtamembrane domain of human IL1R2 is shown as SEQ ID NO: 1.

Interleukin-1 Receptor Type 2 (IL1R2} Antibodies

[0092] Provided herein are antibodies that can deplete ILlR2-positive cells. In some embodiments, provided herein are means for binding human IL1R2. In some embodiments, provided herein are means for preventing cleavage of human IL1R2. Anti-IL1R2 antibodies of the present disclosure bind human IL1R2. In one aspect, anti-ILlR2 antibodies of the present disclosure binds within the juxtamembrane domain of human IL1R2 (SEQ ID NO: 1).

[0093] In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds within: a region comprising amino acid residues SFQTLRTTVKEASS (SEQ ID NO: 2), a region comprising amino acid residues DLHMDFK (SEQ ID NO: 3), or a combination thereof.

[0094] In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds within a region comprising amino acid residues SFQTL (SEQ ID NO: 4). In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds within a region comprising amino acid residues CVVHNTL (SEQ ID NO: 5). In certain embodiments, an anti-ILlR2 antibody binds at or near an enzyme recognition site, wherein the recognition site comprises the sequence shown in SEQ ID NO: 4. In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds at or near an enzymatic cleavage site, wherein the enzymatic cleavage site is located within the sequence DLHMDFKCVVHNTL (SEQ ID NO: 6).

[0095] In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds human IL1R2 in a manner that prevents cleavage of membrane-bound IL1R2. In certain embodiments, an anti-ILlR2 antibody of the present disclosure sterically hinders an enzyme from cleaving the membrane-bound IL1R2.

[0096] In certain embodiments, an anti-ILlR2 antibody of the present disclosure competes with an enzyme for binding to membrane-bound IL1R2.

[0097] In some embodiments, the anti-ILlR2 antibody comprises MAB2631 (R&D Systems), MAB663 (R&D Systems), abl l868 (8.5; Abeam), ALX-804-461-C100 (MNC2; Enzo Life Sci), TA506802S (OTI3C6; OriGene), 10111-MM11 (Sino Biological), 10111-MM02 (Sino Biological), 10111-R041 (Sino Biological), REA744 (Miltenyi Biotec), or MAB263 (R&D Systems).

[0098] In some embodiments, the anti-ILlR2 antibody is a mouse monoclonal antibody. In some embodiments, the mouse monoclonal antibody comprises MAB2631, MAB663, abl l868, ALX-804-461-C100, TA506802S, 10111-MM11, 10111-MM02, MAB263, combinations, or derivatives thereof. In some the anti-ILlR2 antibody is a rabbit monoclonal antibody. In some embodiments, the rabbit monoclonal antibody comprises 10111-R041 or a derivative thereof. In some embodiments, the anti-ILlR2 antibody is a recombinant antibody. In some embodiments, the recombinant antibody is REA744 or a derivative thereof.

Enzymatic Cleavage of human IL1R2

[0099] Exemplary enzymes that are known to cleave membrane-bound proteins are: metalloproteinase, aminopeptidase, and elastase.

Metalloproteinase

[00100] Metalloproteinases are a superfamily of proteinases (enzymes) whose numbers in recent years have increased dramatically. Based on structural and functional considerations, these enzymes have been classified into families and subfamilies as described in N.M. Hooper (1994) FEBS Letters 354: 1-6. Examples of metalloproteinases include the matrix metalloproteinases (MMPs) such as the collagenases (MMP1, MMP8, MMP 13), the gelatinases (MMP2, MMP9), the stromelysins (MMP3, MMP 10, MMP 11), matrilysin (MMP7), metalloelastase (MMP12), enamelysin (MMP19), the MT -MMPs (MMP 14, MMP 15, MMP 16, MMP 17); the reprolysin or adamalysin or MDC family which includes ADAM family enzymes, for example, ADAMI, ADAM2, ADAM3B, ADAM4, ADAM5, ADAM6, ADAM7, ADAM8, ADAM9, ADAM 10, ADAMI 1, ADAM12, ADAM13, ADAM14, ADAM15, ADAM16, ADAM17 (also known as Tumour necrosis factor alpha activating enzyme), ADAM18, ADAM19, ADAM20, ADAM21, ADAM22, ADAM23, ADAM24, ADAM25, ADAM26, ADAM27, ADAM28, ADAM29, ADAM30, ADAM31, ADAM32, ADAM33, ADAM34, ADAM35, ADAM36, ADAM37, ADAM38, ADAM39, ADAM40, ADAMTS1, ADAMTS2, ADAMTS3, ADAMTS4, ADAMTS5, ADAMTS6, ADAMTS7, ADAMTS8, ADAMTS9, ADAMTS10, ADAMTS11, ADAMTS12, ADAMTS13, ADAMTS14, ADAMTS15, ADAMTS16, ADAMTS17, ADAMTS18, ADAMTS19, ADAMTS20; the astacin family which include enzymes such as procollagen processing proteinase (PCP); and other metalloproteinases such as aggrecanase, the endothelin converting enzyme family, and the angiotensin converting enzyme family.

Aminopeptidase

[00101] An aminopeptidase is an exopeptidase that can act as a catalyst when an amino acid residue is hydrolyzed from the N-terminus of a peptide or protein substrate. This enzyme is widely distributed in various living organisms from bacteria to humans, and plays an important role in protein maturation and in the regulation of metabolism of bioactive peptides (Taylor, A. (1993) Faseb J 7, 290-298 ; Lowther, WT et al (2002) Chem Rev 102, 4581-4608). In addition, some human diseases such as cancer and cardiovascular disorders are based on modulation of the action and regulation of aminopeptidases (Nanus, DM (2003) Clin Cancer Res 9 6307-6309; Sato, Y. (2004) Biol Pharm Bull 27 , 772-776; Mitsui, T. et al., (2004) Biol Pharm Bull 27, 768- 771).

Elastase

[00102] Elastase represents a broad range proteolytic enzymes that preferentially cleave at the C-terminus of alanine, valine, serine, glycine, leucine or isoleucine. Elastase has a unique ability to digest elastin. Its substrates include various extracellular matrix proteins, such as elastin, fibronectin and collagen as well as adhesive molecules like ICAM-1 and junctional cadherins, suggesting a role for elastase in facilitating cell transendothelial migration. In addition, elastase degrades numerous soluble proteins like coagulation factors, immunoglobulins, complement, protease inhibitors, cytokines, growth factor and their receptors (Bank U, et al. J Leukoc Biol. 2001;69: 197-206; Lee WL, et. al. Am J Respir Crit Care Med. 2001; 164:896-904).

[00103] The anti-ILlR2 antibodies of the present disclosure can prevent cleavage of membranebound IL1R2 by any enzyme capable of cleaving one or more membrane-bound proteins. As used herein, the term “prevents cleavage of membrane-bound IL1R2” means an IL1R2 binding agent, such as an anti-ILlR2 antibody, that binds to IL1R2 and interferes with an enzyme’s ability to cleave IL1R2. In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds IL1R2 at or near an enzymatic recognition site. In certain embodiments, an anti- IL1R2 antibody of the present disclosure binds at or near the enzymatic recognition site comprising SEQ ID NO: 4. In certain embodiments, an anti-ILlR2 antibody of the present disclosure binds at or near an enzymatic cleavage site, wherein the enzymatic cleavage site is located within the sequence DLHMDFKCVVHNTL (SEQ ID NO: 6). In certain embodiments, an anti-ILlR2 antibody of the present disclosure competes with an enzyme for binding to membrane-bound IL1R2. In certain embodiments, an anti-ILlR2 antibody sterically hinders binding of an enzyme and prevents cleavage of IL1R2.

Methods of Modulating Immune Response

[00104] Provided herein are methods of modulating an immune response by administering an agent that can deplete or kill an IL1R2+ cell.

[00105] In some embodiments, the agent that can deplete or kill an IL1R2+ cell is an anti-ILlR2 antibody.

[00106] An anti-ILlR2 antibody of the present disclosure can bind to membrane-bound IL1R2 present on the surface of a cell. In certain embodiments, an anti-ILlR2 antibody of the present disclosure prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell. [00107] In some embodiments, an anti-ILlR2 antibody is a depleting antibody. A depleting antibody can be one that would kill a cell upon contact through the antibody’s interaction with other immune cells or molecules. For example, antibodies, when bound to cells bearing IL1R2 proteins, could engage complement proteins and induce complement-dependent cell lysis. Antibodies, when bound to cells bearing IL1R2 proteins, could also trigger neighboring cells bearing Fc receptors to kill them by antibody-dependent cellular cytotoxicity (ADCC).

[00108] In some embodiments, an anti-ILlR2 antibody is at least one of: a monoclonal antibody, a neutral antibody, an antagonistic antibody, an agonist antibody, a polyclonal antibody, an afucosylated antibody, a human antibody, a humanized antibody, a chimeric antibody, a full-length antibody, and an antigen binding fragment thereof.

[00109] In some embodiments, an anti-ILlR2 antibody is a humanized antibody.

[00110] In some embodiments, an anti-ILlR2 antibody is a monoclonal antibody.

[00111] In some embodiments, an anti-ILlR2 antibody is a multispecific antibody comprising a first antigen-binding domain that specifically binds to IL1R2 and a second antigen-binding domain that specifically binds to a second molecule on the surface of a second cell. In certain embodiments, the second molecule on the surface of the second cell is CD3. In certain embodiments, the second cell is an effector cell. In certain embodiments, the effector cell comprises at least one of T cells, cytotoxic T-cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes.

[00112] In some embodiments, the second antigen-binding domain of the multispecific antibody of the present disclosure binds to CD3 on the surface of an effector cell. In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody muromonab-CD3 (also known as Orthoclone OKT3), or antigen-binding fragments thereof. For example, the second antigen-binding domain can include the CDRs, a Fab, or an scFv derived from the parent anti- CD3 antibody. Muromonab-CD3 is disclosed in U.S. Patent No. 4,361,549 and Wilde, et al. Muromonab CD3: a reappraisal of its pharmacology and use as prophylaxis of solid organ transplant rejection, Drugs 51, 865-894 (1996), the entire disclosures of each of which are hereby incorporated by reference.

[00113] In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody otelixizumab, or antigen binding fragments thereof. For example, the second antigenbinding domain can include the CDRs, a Fab, or an scFv derived from the parent anti-CD3 antibody. Otelixizumab is disclosed in U.S. Patent 10,537,638 B2 and Chatenoud et al., Rev Diabet Stud. 2012 Winter; 9(4): 372-381, the entire disclosures of each of which are hereby incorporated by reference. [00114] In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody teplizumab (also known as MGA031 and hOKT3yl (Ala- Ala)), or antigen binding fragments thereof. For example, the second antigen-binding domain can include the CDRs, a Fab, or an scFv derived from the parent anti-CD3 antibody. Teplizumab is disclosed in Chatenoud et al., Rev Diabet Stud. 2012 Winter; 9(4): 372-381, the entire disclosures of each of which is hereby incorporated by reference.

[00115] In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody visilizumab (also known as Nuvion®; HuM291), or antigen binding fragments thereof. For example, the second antigen-binding domain can include the CDRs, a Fab, or an scFv derived from the parent anti-CD3 antibody. Visilizumab is disclosed in U.S. 5,834,597 and W02004052397, and Cole et al., Transplantation (1999) 68:563-571, the entire disclosures of each of which are hereby incorporated by reference.

[00116] In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody foralumab (also known as NI-0401), or antigen binding fragments thereof. For example, the second antigen-binding domain can include the CDRs, a Fab, or an scFv derived from the parent anti-CD3 antibody. In certain embodiments, the anti-CD3 antibody comprises any one of the anti-CD3 antibodies disclosed in U.S. 9,850,304 B2, U.S. 7,728,114, and U.S. 8,551,478 B2, the entire disclosures of each of which are hereby incorporated by reference. [00117] In some embodiments, the second antigen-binding domain comprises the anti-CD3 antibody SP34 (Yang SJ, The Journal of Immunology (1986) 137; 1097-1100) or an antigen binding fragment thereof. For example, the second antigen-binding domain can include the CDRs, a Fab, or an scFv derived from the parent anti-CD3 antibody. The sequence of antibody SP34 is disclosed in WO 2008119565, WO 2008119566, WO 2008119567, WO 2010037836, WO 2010037837, and WO 2010037838, the entire disclosures of each of which are incorporated herein by reference in their entirety.

[00118] In some embodiments, an anti-ILlR2 antibody of the present disclosure is an antigenbinding fragment thereof, a Fab, Fab’, F(ab’)2, Fv, scFv, (scFv)2, single chain antibody molecule, dual variable domain antibody, single variable domain antibody, linear antibody, or V domain antibody.

[00119] In some embodiments, an anti-ILlR2 antibody of the present disclosure has antibodydependent cellular cytotoxicity (ADCC) activity. ADCC can occur when antibodies bind to antigens on the surface of pathogenic or tumorigenic target-cells. Effector cells bearing Fc gamma receptors (FcyR or FCGR) on their cell surface, including cytotoxic T-cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, or monocytes, recognize and bind the Fc region of antibodies bound to the target-cells. Such binding can trigger the activation of intracellular signaling pathways leading to cell death. In particular embodiments, an antibody’s immunoglobulin Fc region subtypes (isotypes) include human IgGl and IgG3. As used herein, ADCC refers to a cell-mediated reaction in which nonspecific cytotoxic cells that express Fc receptors (FcRs) (e.g., Natural Killer (NK) cells, neutrophils, and macrophages) recognize bound antibody on a target cell and subsequently cause lysis of the target cell. The primary cells for mediating ADCC, NK cells, express FcyRIII only, whereas monocytes express FcyRI, FcyRII and FcyRIII. FcR expression on hematopoietic cells in summarized is Table 3 on page 464 of Ravetch and Kinet, Annu. Rev. Immunol 9:457-92 (1991). To assess ADCC activity of a molecule of interest, an in vitro ADCC assay, such as that described in U.S. Patent No. 5,500,362 or 5,821,337 may be performed. Useful effector cells for such assays include peripheral blood mononuclear cells (PBMC) and Natural Killer (NK) cells. Alternatively, or additionally, ADCC activity of the molecule of interest may be assessed in vivo, e.g., in an animal model such as that disclosed in Clynes et al., Proc. Natl. Acad. Sci. (USA) 95:652-656 (1998).

[00120] In some embodiments, an antibody has complement-dependent cytotoxicity (CDC) activity. Antibody-induced CDC is mediated through the proteins of the classical complement cascade and is triggered by binding of the complement protein Clq to the antibody. Antibody Fc region binding to Clq can induce activation of the complement cascade. In particular embodiments, the antibody’s immunoglobulin Fc region subtypes (isotypes) include human IgGl and IgG3. As used herein, CDC refers to the ability of a molecule to lyse a target in the presence of complement. The complement activation pathway is initiated by the binding of the first component of the complement system (Clq) to a molecule (e.g. polypeptide (e.g., an antibody)) complexed with a cognate antigen. To assess complement activation, a CDC assay, e.g. as described in Gazzano- Santoro et al., J. Immunol. Methods 202: 163 (1996), may be performed.

[00121] In some embodiments, an antibody has antibody-dependent cellular phagocytosis (ADCP) activity. ADCP can occur when antibodies bind to antigens on the surface of pathogenic or tumorigenic target-cells. Phagocytic cells bearing Fc receptors on their cell surface, including monocytes and macrophages, recognize and bind the Fc region of antibodies bound to target-cells. Upon binding of the Fc receptor to the antibody-bound target cell, phagocytosis of the target cell can be initiated. ADCP can be considered as a form of ADCC. [00122] The term "Fc domain" or "Fc region" herein is used to define a C-terminal region of an immunoglobulin heavy chain that contains at least a portion of the constant region. The term includes native sequence Fc regions and variant Fc regions. Unless otherwise specified herein, numbering of amino acid residues in the Fc region or constant region is according to the EU numbering system, also called the EU index, as described in Kabat et al, Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, MD, 1991. An "Fc polypeptide" of a dimeric Fc as used herein refers to one of the two polypeptides forming the dimeric Fc domain, i.e. a polypeptide comprising C-terminal constant regions of an immunoglobulin heavy chain, capable of stable self-association. For example, an Fc polypeptide of a dimeric IgG Fc comprises an IgG CH2 and an IgG CH3 constant domain sequence. An Fc can be of the class IgA, IgD, IgE, IgG, and IgM, and several of these may be further divided into subclasses (isotypes), e.g., IgGi, IgG2, IgGs, IgG4, IgAi, and IgA2. In some embodiments, Fc region of the anti-ILlR2 antibody comprises a wild-type human IgGl. In some embodiments, the Fc region comprises a mutated human IgGl.

[00123] The terms “Fc receptor” and “FcR” are used to describe a receptor that binds to the Fc region of an antibody. For example, an FcR can be a native sequence human FcR. Generally, an FcR is one which binds an IgG antibody (a gamma receptor) and includes receptors of the FcyRI, FcyRII, and FcyRIII subclasses, including allelic variants and alternatively spliced forms of these receptors. FcyRII receptors include FcyRIIA (an “activating receptor”) and FcyRIIB (an “inhibiting receptor”), which have similar amino acid sequences that differ primarily in the cytoplasmic domains thereof. Immunoglobulins of other isotypes can also be bound by certain FcRs (see, e.g., Janeway et al., Immuno Biology: the immune system in health and disease, (Elsevier Science Ltd., NY) (4th ed., 1999)). Activating receptor FcyRIIA contains an immunoreceptor tyrosine-based activation motif (IT AM) in its cytoplasmic domain. Inhibiting receptor FcyRIIB contains an immunoreceptor tyrosine-based inhibition motif (ITIM) in its cytoplasmic domain (reviewed in Daeron, Annu. Rev. Immunol. 15:203-234 (1997)). FcRs are reviewed in Ravetch and Kinet, Annu. Rev. Immunol 9:457-92 (1991); Capel et al., Immunomethods 4:25-34 (1994); and de Haas et al., J. Lab. Clin. Med. 126:330-41 (1995). Other FcRs, including those to be identified in the future, are encompassed by the term “FcR” herein. The term also includes the neonatal receptor, FcRn, which is responsible for the transfer of maternal IgGs to the fetus (Guyer et al., J. Immunol. 117:587 (1976); and Kim et al., J. Immunol. 24:249 (1994)).

[00124] In some embodiments, an anti-ILlR2 antibody Fc binds an Fey Receptor selected from the group consisting of: FcyRI (CD64), FcyRIIA (CD32A), FcyRIII A (CD 16 or CD 16 A), and FcyRIIIB (CD16B), including allelic variants and alternatively spliced forms of these receptors. [00125] Modifications in the CH2 domain can affect the binding of FcRs to the Fc. A number of amino acid modifications in the Fc region are known in the art for selectively altering the affinity of the Fc for different Fc-gamma receptors. In some aspects, the Fc comprises one or more modifications to promote selective binding of Fc-gamma receptors.

[00126] In some embodiments, the Fc region binds a Fc Receptor present on the surface of an effector cell. In some embodiments, the effector cell comprises at least one of cytotoxic T-cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes. [00127] In some embodiments, an anti- IL1R2 antibody of the present disclosure includes modifications to improve its ability to mediate effector function. Such modifications are known in the art and include afucosylation, or engineering of the affinity of the Fc towards an activating receptor, mainly FCGR3a for ADCC, and towards Clq for CDC.

[00128] Thus, in one embodiment, an antibody described herein can include a dimeric Fc that comprises one or more amino acid modifications that confer improved effector function. In another embodiment, the antibody can be afucosylated to improve effector function.

[00129] In some embodiments, an anti- IL1R2 antibody comprises a heavy chain constant region of a class selected from IgG, IgA, IgD, IgE, and IgM. In some embodiments, the anti- IL1R2 antibody comprises an IgG heavy chain constant region

[00130] In some embodiments, an anti- IL1R2 antibody comprises a heavy chain constant region of the class IgG and a subclass selected from IgGl, IgG2, IgG3, and IgG4.

[00131] In some embodiments, an anti- IL1R2 antibody comprises a heavy chain constant region of IgGl.

[00132] In some embodiments, an anti-ILlR2 antibody is administered intravenously or subcutaneously. In some embodiments, the IL1R2 antibody is administered intravenously.

[00133] The methods described herein include administration of an antibody or antibodies, e.g., administration of an anti-ILlR2 antibody. As described above, the term "antibody" includes reference to an immunoglobulin molecule immunologically reactive with a particular antigen and includes both polyclonal and monoclonal antibodies. The term also includes genetically engineered forms such as chimeric antibodies (e.g., humanized murine antibodies) and heteroconjugate antibodies. The term "antibody" also includes antigen binding forms of antibodies, including fragments with antigen-binding capability (e.g., Fab', F(ab')2, Fab, Fv and rlgG. The term also refers to recombinant single chain Fv fragments (scFv). The term antibody also includes bivalent or bispecific molecules, diabodies, triabodies, and tetrabodies. Exemplary antibodies include, but are not limited to, a monoclonal antibody, a polyclonal antibody, a bi- specific antibody, a multispecific antibody, a grafted antibody, a human antibody, a humanized antibody, a synthetic antibody, a chimeric antibody, a camelized antibody, a single-chain Fvs (scFv) (including fragments in which the VL and VH are joined using recombinant methods by a synthetic or natural linker that enables them to be made as a single protein chain in which the VL and VH regions pair to form monovalent molecules, including single chain Fab and scFab), a single chain antibody, a Fab fragment (including monovalent fragments comprising the VL, VH, CL, and CHI domains), a F(ab')2 fragment (including bivalent fragments comprising two Fab fragments linked by a disulfide bridge at the hinge region), a Fd fragment (including fragments comprising the VH and CHI fragment), a Fv fragment (including fragments comprising the VL and VH domains of a single arm of an antibody), a single-domain antibody (dAb or sdAb) (including fragments comprising a VH domain), an isolated complementarity determining region (CDR), a diabody (including fragments comprising bivalent dimers such as two VL and VH domains bound to each other and recognizing two different antigens), a fragment comprised of only a single monomeric variable domain, disulfide-linked Fvs (sdFv), an intrabody, an anti- idiotypic (anti-Id) antibody, or ab antigen-binding fragments thereof. In some instances, the libraries disclosed herein comprise nucleic acids encoding for an antibody, wherein the antibody is a Fv antibody, including Fv antibodies comprised of the minimum antibody fragment which contains a complete antigen-recognition and antigen-binding site. In some embodiments, the Fv antibody consists of a dimer of one heavy chain and one light chain variable domain in tight, non-covalent association, and the three hypervariable regions of each variable domain interact to define an antigen-binding site on the surface of the VH-VL dimer. In some embodiments, the six hypervariable regions confer antigen-binding specificity to the antibody. In some embodiments, a single variable domain (or half of an Fv comprising only three hypervariable regions specific for an antigen, including single domain antibodies isolated from camelid animals comprising one heavy chain variable domain such as VHH antibodies or nanobodies) has the ability to recognize and bind antigen. In some instances, the libraries disclosed herein comprise nucleic acids encoding for an antibody, wherein the antibody is a single-chain Fv or scFv, including antibody fragments comprising a VH, a VL, or both a VH and VL domain, wherein both domains are present in a single polypeptide chain. In some embodiments, the Fv polypeptide further comprises a polypeptide linker between the VH and VL domains allowing the scFv to form the desired structure for antigen binding. In some instances, a scFv is linked to the Fc fragment or a VHH is linked to the Fc fragment (including minibodies). In some instances, the antibody comprises immunoglobulin molecules and immunologically active fragments of immunoglobulin molecules, e.g., molecules that contain an antigen binding site. Immunoglobulin molecules are of any type (e.g., IgG, IgE, IgM, IgD, IgA and IgY), class (e.g., IgG 1, IgG 2, IgG 3, IgG 4, IgA 1 and IgA 2) or subclass.

[00134] In some embodiments, the antibody is a multivalent antibody. In some embodiments, the antibody is a monovalent, bivalent, or multivalent antibody. In some instances, the antibody is monospecific, bispecific, or multispecific. In some embodiments, the antibody is monovalent monospecific, monovalent bispecific, monovalent multispecific, bivalent monospecific, bivalent bispecific, bivalent multispecific, multivalent monospecific, multivalent bispecific, multivalent multispecific. In some instances, the antibody is homodimeric, heterodimeric, or heterotrimeric. [00135] An exemplary immunoglobulin (antibody) structural unit is composed of two pairs of polypeptide chains, each pair having one "light" (about 25 kD) and one "heavy" chain (about 50- 70 kD). The N-terminal domain of each chain defines a variable region of about 100 to 110 or more amino acids primarily responsible for antigen recognition. The terms variable light chain (VL) and variable heavy chain (VH) refer to these light and heavy chain domains respectively. The IgGl heavy chain comprises of the VH, CHI, CH2 and CH3 domains respectively from the N to C-terminus. The light chain comprises of the VL and CL domains from N to C terminus. The IgGl heavy chain comprises a hinge between the CHI and CH2 domains. In certain embodiments, the immunoglobulin constructs comprise at least one immunoglobulin domain from IgG, IgM, IgA, IgD, or IgE connected to a therapeutic polypeptide. In some embodiments, the immunoglobulin domain found in an antibody provided herein, is from or derived from an immunoglobulin based construct such as a diabody, or a nanobody. In certain embodiments, the immunoglobulin constructs described herein comprise at least one immunoglobulin domain from a heavy chain antibody such as a camelid antibody. In certain embodiments, the immunoglobulin constructs provided herein comprise at least one immunoglobulin domain from a mammalian antibody such as a bovine antibody, a human antibody, a camelid antibody, a mouse antibody or any chimeric antibody.

[00136] The term "hypervariable region" or "HVR", as used herein, refers to each of the regions of an antibody variable domain which are hypervariable in sequence and/or form structurally defined loops ("hypervariable loops"). Generally, native four-chain antibodies comprise six HVRs; three in the VH (Hl, H2, H3), and three in the VL (LI, L2, L3). HVRs generally comprise amino acid residues from the hypervariable loops and/or from the complementarity determining regions (CDRs), the latter being of highest sequence variability and/or involved in antigen recognition. With the exception of CDR1 in VH, CDRs generally comprise the amino acid residues that form the hypervariable loops. Hypervariable regions (HVRs) are also referred to as "complementarity determining regions" (CDRs), and these terms are used herein interchangeably in reference to portions of the variable region that form the antigen-binding regions. This particular region has been described by Kabat et al., U.S. Dept, of Health and Human Services, Sequences of Proteins of Immunological Interest (1983) and by Chothia et al., J Mol Biol 196:901-917 (1987), where the definitions include overlapping or subsets of amino acid residues when compared against each other. Nevertheless, application of either definition to refer to a CDR of an antibody or variants thereof is intended to be within the scope of the term as defined and used herein. The exact residue numbers which encompass a particular CDR will vary depending on the sequence and size of the CDR. Those skilled in the art can routinely determine which residues comprise a particular CDR given the variable region amino acid sequence of the antibody. The amino acid sequence boundaries of a CDR can be determined by one of skill in the art using any of a number of known numbering schemes, including those described by Kabat et al., supra ("Kabat" numbering scheme): Al-Lazikani et al., 1997. J. Mol. Biol., 273:927-948 ("Chothia" numbering scheme); MacCallum et al., 1996, J. Mol. Biol.

262:732-745 ("Contact" numbering scheme); Lefranc et al., Dev. Comp. Immunol., 2003, 27:55- 77 ("IMGT" numbering scheme); and Honegge and Pluckthun, J. Mol. Biol., 2001, 309:657-70 ("AHo" numbering scheme); each of which is incorporated by reference in its entirety.

[00137] Selection of antibodies may be based on a variety of criteria, including selectivity, affinity, cytotoxicity, etc. The phrase "specifically (or selectively) binds" to an antibody or "specifically (or selectively) immunoreactive with," when referring to a protein or peptide, refers to a binding reaction that is determinative of the presence of the protein, in a heterogeneous population of proteins and other biologies. Thus, under designated immunoassay conditions, the specified antibodies bind to a particular protein sequences at least two times the background and more typically more than 10 to 100 times the background. In general, antibodies of the present disclosure bind antigens on the surface of target cells in the presence of effector cells (such as natural killer cells or macrophages). Fc receptors on effector cells recognize bound antibodies. [00138] An antibody immunologically reactive with a particular antigen can be generated by recombinant methods such as selection of libraries of recombinant antibodies in phage or similar vectors, or by immunizing an animal with the antigen or with DNA encoding the antigen.

Methods of preparing polyclonal antibodies are known to the skilled artisan. The antibodies may, alternatively, be monoclonal antibodies. Monoclonal antibodies may be prepared using hybridoma methods. In a hybridoma method, an appropriate host animal is typically immunized with an immunizing agent to elicit lymphocytes that produce or are capable of producing antibodies that will specifically bind to the immunizing agent. Alternatively, the lymphocytes may be immunized in vitro. The lymphocytes are then fused with an immortalized cell line using a suitable fusing agent, such as polyethylene glycol, to form a hybridoma cell.

[00139] Human antibodies can be produced using various techniques known in the art, including phage display libraries. Similarly, human antibodies can be made by introducing human immunoglobulin loci into transgenic animals, e.g., mice in which the endogenous immunoglobulin genes have been partially or completely inactivated. Upon challenge, human antibody production is observed, which closely resembles that seen in humans in all respects, including gene rearrangement, assembly, and antibody repertoire.

[00140] Antibodies also exist as a number of well-characterized fragments produced by digestion with various peptidases. Thus pepsin digests an antibody below the disulfide linkages in the hinge region to produce F(ab)'2, a dimer of Fab which itself is a light chain joined to VH- CH1 by a disulfide bond. The F(ab)'2 may be reduced under mild conditions to break the disulfide linkage in the hinge region, thereby converting the F(ab)'2 dimer into an Fab' monomer. The Fab' monomer is essentially Fab with part of the hinge region. While various antibody fragments are defined in terms of the digestion of an intact antibody, one of skill will appreciate that such fragments may be synthesized de novo either chemically or by using recombinant DNA methodology. Thus, the term antibody, as used herein, also includes antibody fragments either produced by the modification of whole antibodies, or those synthesized de novo using recombinant DNA methodologies (e.g., single chain Fv) or those identified using phage display libraries.

[00141] In some embodiments, the antibodies provided herein comprise an antibody fragment. In some embodiments, the antibodies provided herein consist of an antibody fragment. In some embodiments, the antibodies provided herein consist essentially of an antibody fragment. In some aspects, the antibody fragment is an Fv fragment. In some aspects, the antibody fragment is a Fab fragment. In some aspects, the antibody fragment is a F(ab’)2 fragment. In some aspects, the antibody fragment is a Fab’ fragment. In some aspects, the antibody fragment is an scFv fragment. In some aspects, the antibody fragment is an scFv-Fc fragment. In some aspects, the antibody fragment is a fragment of a single domain antibody.

[00142] In some embodiments, an antibody fragment provided herein is derived from an illustrative antibody provided herein. In some embodiments, an antibody fragment provided herein is not derived from an illustrative antibody provided herein and may, for example, be isolated de novo according to the methods provided herein for obtaining antibody fragments. [00143] The term “chimeric antibody” refers to an antibody in which a portion of the heavy and/or light chain is derived from a particular source or species, while the remainder of the heavy and/or light chain is derived from a different source or species.

[00144] A "humanized antibody" is an immunoglobulin molecule which contains minimal sequence derived from non-human immunoglobulin. Humanized antibodies include human immunoglobulins (recipient antibody) in which residues from a complementary determining region (CDR) of the recipient are replaced by residues from a CDR of a non-human species (donor antibody) such as mouse, rat or rabbit having the desired specificity, affinity and capacity. In some instances, Fv framework residues of the human immunoglobulin are replaced by corresponding non-human residues. Humanized antibodies may also comprise residues which are found neither in the recipient antibody nor in the imported CDR or framework sequences. In general, a humanized antibody will comprise substantially all of at least one, and typically two, variable domains, in which all or substantially all of the CDR regions correspond to those of a non-human immunoglobulin and all or substantially all of the framework (FR) regions are those of a human immunoglobulin consensus sequence. The humanized antibody optimally also will comprise at least a portion of an immunoglobulin constant region (Fc), typically that of a human immunoglobulin. The donor antibody can be any suitable non-human antibody, such as a mouse, rat, rabbit, chicken, or non-human primate antibody having a desired specificity, affinity, or biological effect. The humanized antibody is less likely to induce an immune response, and/or induces a less severe immune response, as compared to the non-human species antibody, when it is administered to a human subject. In some instances, selected framework region residues of the recipient antibody are replaced by the corresponding framework region residues from the donor antibody. Humanized antibodies may also comprise residues that are not found in either the recipient antibody or the donor antibody. Such modifications may be made to further refine antibody function. Examples of how to make humanized antibodies can be found in U.S. Pat. Nos. 6,054,297, 5,886,152 and 5,877,293, each of which is incorporated by reference in its entirety. For further details, see Jones et al., Nature, 1986, 321 :522-525; Riechmann et al., Nature, 1988, 332:323-329; and Presta, Curr. Op. Struct. BioL, 1992, 2:593-596, each of which is incorporated by reference in its entirety.

[00145] In one embodiment, the constant domain(s) from a human antibody are fused to the variable domain(s) of a non-human species. In another embodiment, one or more amino acid residues in one or more CDR sequences of a non-human antibody are changed to reduce the likely immunogenicity of the non-human antibody when it is administered to a human subject, wherein the changed amino acid residues either are not utilized for immunospecific binding of the antibody to its antigen, or the changes to the amino acid sequence that are made are conservative changes, such that the binding of the humanized antibody to the antigen is not significantly worse than the binding of the non-human antibody to the antigen.

[00146] A “human antibody” is one which possesses an amino acid sequence corresponding to that of an antibody produced by a human or a human cell, or derived from a non-human source that utilizes a human antibody repertoire or human antibody-encoding sequences (e.g., obtained from human sources or designed de novo). Human antibodies specifically exclude humanized antibodies. In one embodiment, all of the variable and constant domains are derived from human immunoglobulin sequences (a fully human antibody). These antibodies may be prepared in a variety of ways including through the immunization with an antigen of interest of a mouse that is genetically modified to express antibodies derived from human heavy and/or light chainencoding genes.

[00147] In some embodiments, the antibodies provided herein comprise an antibody fragment. In some embodiments, the antibodies provided herein consist of an antibody fragment. In some embodiments, the antibodies provided herein consist essentially of an antibody fragment. In some embodiments, the antibody fragment is an Fv fragment. In some embodiments, the antibody fragment is a Fab fragment. In some embodiments, the antibody fragment is a F(ab’)2 fragment. In some embodiments, the antibody fragment is a Fab’ fragment. In some embodiments, the antibody fragment is an scFv fragment. In some embodiments, the antibody fragment is an scFv-Fc fragment. In some embodiments, the antibody fragment is a fragment of a single domain antibody.

[00148] In some embodiments, the antibodies provided herein comprise a light chain. In some aspects, the light chain is a kappa light chain. In some aspects, the light chain is a lambda light chain.

[00149] In some embodiments, the antibodies provided herein comprise a heavy chain. In some aspects, the heavy chain is an IgA. In some aspects, the heavy chain is an IgD. In some aspects, the heavy chain is an IgE. In some aspects, the heavy chain is an IgG. In some aspects, the heavy chain is an IgM. In some aspects, the heavy chain is an IgGl. In some aspects, the heavy chain is an IgG2. In some aspects, the heavy chain is an IgG3. In some aspects, the heavy chain is an IgG4. In some aspects, the heavy chain is an IgAl. In some aspects, the heavy chain is an IgA2. [00150] In some embodiments, the antibodies provided herein are monoclonal antibodies. In some embodiments, the antibodies provided herein are polyclonal antibodies.

[00151] In some embodiments, the antibodies provided herein comprise a chimeric antibody. In some embodiments, the antibodies provided herein consist of a chimeric antibody. In some embodiments, the antibodies provided herein consist essentially of a chimeric antibody. In some embodiments, the antibodies provided herein comprise a humanized antibody. In some embodiments, the antibodies provided herein consist of a humanized antibody. In some embodiments, the antibodies provided herein consist essentially of a humanized antibody. In some embodiments, the antibodies provided herein comprise a human antibody. In some embodiments, the antibodies provided herein consist of a human antibody. In some embodiments, the antibodies provided herein consist essentially of a human antibody.

[00152] In some embodiments, the antibodies provided herein comprise an alternative scaffold. In some embodiments, the antibodies provided herein consist of an alternative scaffold. In some embodiments, the antibodies provided herein consist essentially of an alternative scaffold. Any suitable alternative scaffold may be used. In some aspects, the alternative scaffold is selected from an Adnectin™, an iMab, an Anticalin®, an EETI-II/AGRP, a Kunitz domain, a thioredoxin peptide aptamer, an Affibody®, a DARPin, an Affilin, a Tetranectin, a Fynomer, and an Avimer. [00153] In some embodiments, the methods described herein include administration of antibodies with sequences described herein; e.g., the heavy chain, light chain, and/or CDR sequences described herein. The sequences of the administered antibodies can be, e.g., at least 95, at least 96, at least 97, at least 98, at least 99, or 100% identical to the sequences described herein.

[00154] It is known that when an antibody is expressed in cells, the antibody is modified after translation. Examples of the posttranslational modification include cleavage of lysine at the C terminal of the heavy chain by a carboxypeptidase; modification of glutamine or glutamic acid at the N terminal of the heavy chain and the light chain to pyroglutamic acid by pyroglutamylation; glycosylation; oxidation; deamidation; and glycation, and it is known that such posttranslational modifications occur in various antibodies (See Journal of Pharmaceutical Sciences, 2008, Vol. 97, p. 2426-2447, incorporated by reference in its entirety). In some embodiments, an antibody is an antibody or antigen-binding fragment thereof which has undergone posttranslational modification. Examples of an antibody or antigen-binding fragment thereof which have undergone posttranslational modification include an antibody or antigen-binding fragments thereof which have undergone pyroglutamylation at the N terminal of the heavy chain variable region and/or deletion of lysine at the C terminal of the heavy chain. It is known in the art that such posttranslational modification due to pyroglutamylation at the N terminal and deletion of lysine at the C terminal does not have any influence on the activity of the antibody or fragment thereof (Analytical Biochemistry, 2006, Vol. 348, p. 24-39, incorporated by reference in its entirety). [00155] In some embodiments, the antibodies are monoclonal antibodies.

[00156] In some embodiments, the antibodies are polyclonal antibodies.

[00157] In some embodiments, the antibodies are produced by hybridomas. In other embodiments, the antibodies are produced by recombinant cells engineered to express the desired variable and constant domains.

[00158] In some embodiments, the antibodies may be single chain antibodies or other antibody derivatives retaining the antigen specificity and the lower hinge region or a variant thereof.

[00159] In some embodiments, the antibodies may be polyfunctional antibodies, recombinant antibodies, human antibodies, humanized antibodies, fragments or variants thereof. In particular embodiments, the antibody fragment or a derivative thereof is selected from a Fab fragment, a Fab '2 fragment, a CDR and ScFv.

[00160] In some embodiments, antibodies are specific for surface antigens, such as IL1R2 protein. In some embodiments, therapeutic antibodies are specific for tumor antigens (e.g., molecules specifically expressed by tumor cells). In particular embodiments, the therapeutic antibodies may have human or non-human primate IgGl or IgG3 Fc portions.

[00161] An antibody can compete with an enzyme for binding to IL1R2. In some embodiments, the enzyme is a metalloproteinase (e.g., ADAMI 7)

[00162] An antibody can prevent binding between IL1R2 and an enzyme capable of cleaving IL1R2.

[00163] An antibody can displace IL1R2 from a pre-existing complex comprising IL1R2 and IL1.

[00164] An antibody can bind to IL1R2 located on a cell surface.

[00165] An antibody can be an antagonistic antibody. An antibody can be a human antibody. An antibody can be a monoclonal antibody.

[00166] An antibody can be an antigen-binding fragment thereof, a Fab, Fab’, F(ab’)2, Fv, scFv, (scFv)2, single chain antibody molecule, dual variable domain antibody, single variable domain antibody, linear antibody, or V domain antibody. An antibody can include a scaffold, optionally wherein the scaffold is Fc, optionally a human Fc. An antibody can include a heavy chain constant region having an isotype of IgG, IgA, IgD, IgE, or IgM. An antibody can include a heavy chain constant region having a human isotype of class IgG and a subclass of IgGl, IgG2, IgG3, or IgG4.

[00167] In some embodiments, an antibody is an antagonistic antibody. An antagonistic antibody can block (e.g. decrease) one or more activities or functions of a cell after the antibody binds an IL1R2 protein expressed on the cell. For example, the antagonist antibody may bind to and block ligand binding to one or more proteins, preventing differentiation and proliferation of the cell or modifying antigen presentation capabilities.

Methods of Using IL1R2 Antibodies

[00168] Provided herein are methods of using an IL1R2 inhibitor (e.g., an antibody) to modulate an immune response in a subject. Also provided herein are methods of treating cancer in a subject, comprising administering an IL1R2 antibody to the subject. In some embodiments, the subject is a human subject.

[00169] Disclosed herein is a method of enhancing an immune response in a subject, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody to the subject, wherein the anti- IL1R2 antibody binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell, prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell.

[00170] The immune response can include an adaptive immune response. The immune response can include an innate immune response.

[00171] An antibody can increase activity of one or more inflammatory immune cells and/or decrease activity of one or more suppressive immune cells by increasing the amount of free IL1 in a subject relative to baseline. An antibody can increase activity of one or more inflammatory immune cells. An antibody can decrease activity of one or more suppressive immune cells.

[00172] In some aspects, enhancing an immune response comprises increasing an existing immune response in the subject

[00173] In some aspects, enhancing an immune response comprises initiating an immune response in the subject.

[00174] Also disclosed herein is a method of depleting or killing an IL1R2+ cell, comprising contacting the cell with an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of the cell and causes the depletion or killing of the cell.

[00175] Also disclosed herein is a method of treating cancer in a subject, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell, prevents enzymatic cleavage of membrane-bound IL1R2, and causes the depletion or killing of the cell. [00176] The term “tumor” or “cancer” refers to all neoplastic cell growth and proliferation, whether malignant or benign, and all pre-cancerous and cancerous cells and tissues. The terms “cancer,” “cancerous,” “cell proliferative disorder,” “proliferative disorder” and “tumor” are not mutually exclusive as referred to herein. The terms “cell proliferative disorder” and “proliferative disorder” refer to disorders that are associated with some degree of abnormal cell proliferation. In some embodiments, the cell proliferative disorder is a cancer.

[00177] In some embodiments, the antibody is administered intravenously or subcutaneously. In some embodiments, the antibody is administered intravenously.

[00178] In the methods described herein, compositions, e.g., an anti-ILlR2 antibody is administered to a subject. The composition can be administered by parenteral, topical, intravenous, intra-abdominal, intra-tumoral, oral, subcutaneous, intra-arterial, intracranial, intraperitoneal, intranasal or intramuscular means. A typical route of administration is intravenous or intra-tumoral, although other routes can be equally effective.

[00179] In some embodiments, the anti-ILlR2 antibody is administered intra-abdominally. In some embodiments, the anti-ILlR2 antibody is administered intravenously. In some embodiments, the anti-ILlR2 antibody is administered subcutaneously. In some embodiments, the anti-ILlR2 antibody is administered intra-tum orally. Administration may be repeated as necessary for depletion of the IL 1R2 -positive cell population.

[00180] One or more antibodies disclosed herein can be administered by a medical professional, optionally a physician.

[00181] One or more antibodies disclosed herein can be administered by the subject.

Pharmaceutical compositions

[00182] An antibody can be formulated in pharmaceutical compositions. These compositions can comprise, in addition to one or more of the antibody, a pharmaceutically acceptable excipient, carrier, buffer, stabilizer or other materials well known to those skilled in the art. Such materials should typically be non-toxic and should not interfere with the efficacy of the active ingredient. The precise nature of the carrier or other material can depend on the route of administration, e.g. oral, intravenous, cutaneous or subcutaneous, nasal, intramuscular, intraperitoneal routes.

[00183] Whether it is a polypeptide, antibody, or other pharmaceutically useful compound that is to be given to an individual, administration is preferably in a “therapeutically effective amount” or “prophylactically effective amount” (as the case can be, although prophylaxis can be considered therapy), this being sufficient to show benefit to the individual. The actual amount administered, and rate and time-course of administration, will depend on the nature and severity of protein aggregation disease being treated. Prescription of treatment, e.g. decisions on dosage etc, is within the responsibility of general practitioners and other medical doctors, and typically takes account of the disorder to be treated, the condition of the individual patient, the site of delivery, the method of administration and other factors known to practitioners. Examples of the techniques and protocols mentioned above can be found in Remington's Pharmaceutical Sciences, 16th edition, Osol, A. (ed), 1980.

[00184] A composition can be administered alone or in combination with other treatments, either simultaneously or sequentially dependent upon the condition to be treated.

Kits and Articles of Manufacture

[00185] The present application provides kits comprising any one or more of the antibody compositions described herein. In some embodiments, the kits further contain a component selected from any of secondary antibodies, reagents for immunohistochemistry analysis, pharmaceutically acceptable excipient and instruction manual and any combination thereof. In one specific embodiment, the kit comprises a pharmaceutical composition comprising any one or more of the antibody compositions described herein, with one or more pharmaceutically acceptable excipients.

[00186] In some embodiments, the kit comprises a container and a label or package insert on or associated with the container. Suitable containers include, for example, bottles, vials, syringes, and IV solution bags. The containers may be formed from a variety of materials, such as glass or plastic. The container holds a composition that is by itself, or when combined with another composition, effective for treating, preventing and/or diagnosing a disease or disorder. The container may have a sterile access port. For example, if the container is an intravenous solution bag or a vial, it may have a port that can be pierced by a needle. At least one active agent in the composition is an antibody provided herein. The label or package insert indicates that the composition is used for treating the selected condition.

[00187] In some embodiments, the kit comprises (a) a first container with a first composition contained therein, wherein the first composition comprises an antibody provided herein; and (b) a second container with a second composition contained therein, wherein the second composition comprises a further therapeutic agent. The kit in this embodiment can further comprise a package insert indicating that the compositions can be used to treat a particular condition.

[00188] Alternatively, or additionally, the kit may further comprise a second (or third) container comprising a pharmaceutically-acceptable excipient. In some aspects, the excipient is a buffer. The kit may further include other materials desirable from a commercial and user standpoint, including filters, needles, and syringes. [00189] The present application also provides articles of manufacture comprising any one of the antibody compositions or kits described herein. Examples of an article of manufacture include vials (including sealed vials).

EXAMPLES

[00190] Below are examples of specific embodiments for carrying out the present disclosure. The examples are offered for illustrative purposes only and are not intended to limit the scope in any way. Efforts have been made to ensure accuracy with respect to numbers used (e.g., amounts, temperatures, etc.), but some experimental error and deviation should, of course, be allowed for.

[00191] The practice will employ, unless otherwise indicated, conventional methods of protein chemistry, biochemistry, recombinant DNA techniques and pharmacology, within the skill of the art. Such techniques are explained fully in the literature. See, e.g., T.E. Creighton, Proteins: Structures and Molecular Properties (W.H. Freeman and Company, 1993); A.L. Lehninger, Biochemistry (Worth Publishers, Inc., current addition); Sambrook, et al. , Molecular Cloning: A Laboratory Manual (2nd Edition, 1989); Methods In Enzymology (S. Colowick and N. Kaplan eds., Academic Press, Inc.); Remington's Pharmaceutical Sciences, 18th Edition (Easton, Pennsylvania: Mack Publishing Company, 1990); Carey and Sundberg Advanced Organic Chemistry 3^rd Ed. (Plenum Press) Vols A and B (1992).

Example 1: IL1R2 is expressed in tumors and its over expression correlates with poor prognosis

Expression of IL1R2 in tumors versus adjacent normal tissue

[00192] To better understand which tumor types have up-regulated IL1R2 expression in tumors relative to adjacent normal tissues, normalized IL1R2 isoform expression levels (fragments per kilobase of transcript per million, FPKM) were extracted from a data set downloaded from UC Santa Cruz’s Xena browser

(xenabrowser.net, ^/datapages/?cohort=TCGA%20TARGET%20GTEx) that merges the cancer genome atlas (TCGA), therapeutically applicable research to generate effective treatments (TARGET), and genotype-tissue expression (GTEx) RNA-Seq data sets using Toil RNA-seq Recompute methods (ncbi.nlm.nih.gov/pmc/articles/PMC5546205/). The log2 -transformed data provided were exponentiated and the sum of expression levels for all ligand-binding isoforms (ENST00000332549, ENST00000393414, ENST00000441002, and ENST00000457817) in each sample was computed. For each tumor type from TCGA in which at least 5 adjacent normal samples were available for analysis, the ratio of median IL 1R2 -Binding expression in tumors versus adjacent normal tissues was computed. The significance of the difference in IL1R2- binding expression in tumors versus adjacent normal tissues was assessed using a two-sided Wilcoxon rank sum test. TABLE 1 summarizes the tumor types for which the median expression of IL1R2 (ligand-binding isoforms only) was greater in tumors than in adjacent normal tissues. Statistically significant results are represented by an asterisk.

[00193] TABLE 1 : Tumor types for which the median expression of IL1R2 is greater in tumors than in adjacent normal tissues.

Association of high IL1R2 transcript levels with prognosis

[00194] Overall survival (OS) and Progression Free (PFI) survival univariate analysis was performed across all TCGA tumor types. TCGA tumor-type study abbreviations follow the National Cancer Institute GDC nomenclature (gdc.cancer.gov/resources-tcga-users/tcga-code- tables/tcga-study-abbreviations). For each tumor type, subjects were split into two groups based upon mRNA expression greater than or equal to (>=) the median expression level. The p-value from a Kaplan-Meier (KM) estimator survival analysis (survminer R package version 0.4.8, R version 3.6.3) is shown in Table 2. Values marked as ¥ indicate that higher expression is associated with worse outcome and p-value < 0.05. ND: not done. Input data was obtained from the UCSC Xena data portal (TCGA PANCAN).

[00195] Multivariate analysis was performed on a set of tumor types for which univariate analysis demonstrated association of shorter OS with high IL1R2 expression with p < 0.05 (Lung Adenocarcinoma (LU AD), Kidney renal clear cell carcinoma (KIRC), Brain Lower Grade Glioma (LGG), Acute Myeloid Leukemia (LAML), Thymoma (THYM), Uveal Melanoma (UVM)) and on tumor sets as specificity controls (Lung squamous cell carcinoma (LUSC), Uterine Corpus Endometrial Carcinoma (UCEC)). Multivariate analysis was performed using a COX proportional hazards (COX-PH) model (survivalAnalysis R package version 0.1.2, R version 3.6.3). Any covariate was included in the multivariate model if p < 0.05 in a single variable analysis. COX-PH was performed with the following covariates for individual cancer types: LUAD OS ~ IL1R2 + stage; KIRC OS ~ IL1R2 + stage + age; LGG OS ~ IL1R2 + histo + grade + age; THYM OS ~ IL1R2 + age; UVM OS ~ IL1R2 + stage + age; LUSC OS ~ IL1R2 + stage + age; UCEC OS ~ IL1R2 + stage. IL1R2 transcript and age were modeled as continuous variables, while stage and histology were modeled as categorical variables. The data points marked with ¥ indicate higher IL1R2 transcript expression was associated with worse outcome. Input data was obtained from the UCSC Xena data portal (TCGA PANCAN).

[00196] TABLE 2 Multivariate analysis of correlation between IL1R2 expression and overall or progression-free survival. Abbreviation used in the table: TCGA: the cancer genome atlas; OS: overall survival; PFI: progression free survival; Kaplan-Meier (KM); COX-PH: COX proportional hazards; KIRC: kidney renal clear cell carcinoma; KIRP: kidney renal papillary cell carcinoma; LAML: acute myeloid leukemia; LGG: brain lower grade glioma; LUAD: lung adenocarcinoma; LUSC: lung squamous cell carcinoma; THYM: thymoma; UCEC: uterine corpus endometrial carcinoma; UVM: uveal melanoma; ND- Analysis not done.

Example 2: IL1R2 expression correlates with inferred frequencies of regulatory T cells and PMN-MDSC

Cell type correlation analysis across tumor types in TCGA

[00197] Correlation of IL1R2 transcript and T-regulatory (Treg) cells or neutrophils in human cancers was performed using TIMER2.0 (timer.cistrome.org/; Li et al, Nucleic Acids Res. 2020 Jul 2;48(W1): W509-W514). The correlation between the expression of IL1R2 and the abundance of immune cell subsets was tested across all cancer types in the TCGA dataset.

TIMER2.0 extracts raw counts and Transcripts Per Million (TPM). Estimates of immune infiltration (including Tregs and neutrophils) were done using an R package which integrates six state-of-the-art user-provided expression profile algorithms including TIMER, xCell, MCP- counter, CIBERSORT, EPIC, and quanTIseq. [00198] The Spearman’s correlations between the expression of IL1R2 and the abundance of Tregs across all cancer types is depicted in TABLE 3. The Spearman’s correlations between the expression of IL1R2 and the abundance of neutrophils across all cancer types is depicted in TABLE 4. The purity-adjusted Spearman's rho value is indicated, with a statistically-significant positive correlation represented by “a” (p < 0.05, rho value >0), negative correlations represented by “b” (p < 0.05, rho value <0), and non-significant correlations (p > 0.05). The positive Spearman’s correlations that are observed suggests that the expression of IL1R2 is consistently associated with Treg and neutrophils across different cancer types using different estimation algorithms. Abbreviations used in the Tables 3 and 4: ACC: adrenocortical carcinoma; BLCA: bladder urothelial carcinoma; BRCA: breast invasive carcinoma; HER2: human epidermal growth factor receptor 2; LumA: luminal A; LumB: luminal B; CESC: cervical squamous cell carcinoma and endocervical adenocarcinoma; CHOL: cholangiocarcinoma; COAD: colon adenocarcinoma; DLBC: lymphoid neoplasm diffuse large B-cell lymphoma;

ESC A: esophageal carcinoma; GBM: glioblastoma multiforme; HNSC: head and neck squamous cell carcinoma; HPV-: human papillomavirus negative; HPV+: human papillomavirus positive; KICH: kidney chromophobe; KIRC: kidney renal clear cell carcinoma; KIRP: kidney renal papillary cell carcinoma; LGG: brain lower grade glioma; LIHC: liver hepatocellular carcinoma; LU AD: lung adenocarcinoma; LUSC: lung squamous cell carcinoma; MESO: mesothelioma; OV: ovarian serous cystadenocarcinoma; PAAD: pancreatic adenocarcinoma; PCPG: pheochromocytoma and paraganglioma; PRAD: prostate adenocarcinoma; READ: rectum adenocarcinoma; SARC: sarcoma; SKCM: skin cutaneous melanoma; STAD: stomach adenocarcinoma; TGCT: testicular germ cell tumors; THCA: thyroid carcinoma; THYM: thymoma; UCEC: uterine corpus endometrial carcinoma; UCS: uterine carcinosarcoma; UVM: uveal melanoma; NA: Not applicable.

[00199] TABLE 3 : Correlation of IL1R2 expression with abundance of Treg across all cancer types in TCGA.

[00200] TABLE 4 : Correlation of IL1R2 expression with abundance of neutrophils across all cancer types in TCGA.

Example 3: IL1R2 expression is unregulated in tissue-resident and tumor-infiltrating regulatory T cells

RNAseq analysis of IL1R2 expression in purified T cells

[00201] IL1R2 transcripts were found to be upregulated in Treg relative to other CD4⁺ (Teff) and CD8⁺ T cells and were found to be specifically highly expressed within tumor tissue. IL1R2 was found to be preferentially expressed within tissue-resident Tregs at levels comparable to the expression of Treg marker FOXP3. FIG. 1A is a bar graph depicting expression of FOXP3 in purified T cell subsets (CD8+, effector T cells (Teff), and regulatory T cells (Treg)). FIG. IB is a bar graph depicting expression of IL1R2 in purified T cell subsets (CD8+, effector T cells (Teff), and regulatory T cells (Treg)). As shown in FIG. 1A, expression of IL1R2 is upregulated in Treg cells in comparison to other T cell subsets. The expression levels of IL1R2 were comparable to expression levels of Treg marker FOXP3 shown in FIG. IB.

[00202] IL1R2 expression is further upregulated in tumor tissue (non-muscle invasive bladder cancer, NMIBC). CD4⁺ and CD8⁺ T cells were isolated using fluorescence-activated cell sorting (FACS) from dissociated patient tissue samples from healthy blood (n = 7), healthy skin (n = 8), and low-grade non-invasive muscle bladder cancer tumors (n = 5). Patient samples were not matched. Samples were digested and tissue-resident immune populations were isolated by FACS. Tregs were identified as CD45⁺CD3⁺CD4⁺CD25^high cells, and Teff were all other CD45⁺CD3⁺CD4⁺ cells. mRNA was isolated from sorted populations and prepared for mRNA- Seq using SMARTer Ultra Low Kits (Takara Biosciences) following manufacturer’s instructions. Genes were normalized using size factor normalization as implemented by the R package DESeq2. Batch effects due to RNA Integrity Number (RIN) and patient sex were corrected using linear regression, and the resulting expression values plotted. FIGs. 1A and IB are bar graphs depicting expression of FOXP3 and IL1R2, respectively in NMIBC tumor tissue. As shown in FIG. 1A, expression of IL1R2 is upregulated in Treg cells in NMIBC tumor tissue in comparison to other T cell subsets. The expression levels of IL1R2 in NMIBC were comparable to expression levels of Treg marker FOXP3 shown in FIG. IB.

Example 4: IL1R2 expression is upregulated in tumor-infiltrating regulatory T cells and PMN-MDSC

Single-cell RNAseq analysis of T cell subsets in Melanoma

[00203] A tumor-specific pattern of IL1R2 expression was observed in a single cell RNA-Seq (scRNA-Seq) dataset drawn from melanoma patients. In this dataset, elevated Treg -specific expression of IL1R2 was observed in tumor-draining lymph nodes as well as the tumor itself. Using the same protocol as in Example 3, cells were isolated from N=4 melanoma patients (matched blood and tumor-draining, tumor-bearing lymph node; tumor samples present for N=2 patients) and prepared for single cell RNA sequencing (scRNA-Seq). scRNA-Seq data were collected and aligned using 10X Chromium and the CellRanger pipeline. The resulting data were cleaned of low-quality and outlier cells, normalized, scaled, and clustered with the Seurat 3 pipeline. The IntegrateData() function was used to correct for patient-to-patient batch effects. Canonical marker expression was used in conjunction with sample-specific flow cytometry- purified information to bin cells into CD4+ Treg, CD4+ Teff, and CD8+ cells. Mean IL1R2 expression in the normalized, scaled counts were plotted. FIG. 2A is a graph showing expression of IL1R2 transcripts in purified T cell subsets (CD8+, effector T cells (Teff), and regulatory T cells (Treg)) in melanoma patients. As shown in FIG. 2A, expression of IL1R2 is upregulated in tumor-infiltrating Tregs in tumor samples from melanoma patients.

Single-cell RNAseq analysis of T cell subsets in Non-Small Cell Luns Cancer

[00204] To determine whether IL1R2 is expressed in tumor-infiltrating Treg, IL1R2 transcripts were analyzed in a single-cell RNA (scRNA) database representing T cell subsets from human non-small cell lung carcinoma (NSCLC) as described in Guo, X. et al. Nat. Med. 24, 978-985 (2018). Single cells were analyzed by scRNA-Seq after human lung tumor tissue dissociation. FIG. 2B is a t-distributed stochastic neighbor embedding (tSNE) plot of IL1R2 transcripts in NSCLC tumor-infiltrating T cells. FIG. 2B depicts the expression level of IL1R2 across 9,055 single tumor-infiltrating T cells. FIG. 2C is a tSNE box plot of FOXP3 transcripts in NSCLC tumor-infiltrating T cells. As shown in FIGs. 2B and 2C, expression of IL1R2 resembles that of FOXP3, indicating that these cells are Tregs. A comparison of IL1R2 transcript levels in Tregs isolated from normal lung tissue (at least 2 cm adjacent to matched tumor), peripheral blood, and from NSCLC tumors indicated a greater abundance and higher median level of IL1R2 transcript in tumor-infiltrating Tregs compared with normal or peripheral blood Tregs. FIG. 2D is a plot showing IL1R2 expression in different tissue types (normal (N), peripheral blood (P), and tumorinfiltrating (T)) in NSCLC patients. In FIG. 2D, the boxplot shows the expression of IL1R2 in Treg from each compartment [log2 (TPM +1)]. The thick horizontal line represents the median value. As shown in FIG. 2D, the expression level of IL1R2 is upregulated in tumor-infiltrating Tregs in NSCLC tumors.

Single-cell RNAseq analysis of T cell subsets in Hepatocellular Carcinoma

[00205] scRNA-Seq was performed on flow-sorted CD3⁺CD4⁺ and CD3⁺CD8⁺ T cells from single cell suspension isolated from hepatocellular carcinoma (HCC) tumors (see Zheng, C. et al. Cell 169, 1342-1356. el6 (2017)). Unsupervised clustering identified a total of 11 clusters, including 5 clusters for CD8⁺ and 6 clusters for CD4⁺ cells, depicted in t-SNE plots in FIGs. 2E and 2F. FIG. 2E is a tSNE plot of IL1R2 transcripts in HCC tumor-infiltrating T cells. FIG. 2F is a tSNE plot of FOXP3 transcripts in HCC tumor-infiltrating T cells. As shown in FIGs. 2E and 2F, expression of IL1R2 resembles that of FOXP3, indicating that these cells are Tregs. A comparison of IL1R2 transcript levels in Tregs isolated from normal liver tissue (at least 2 cm adjacent to matched tumor), peripheral blood, and from HCC tumors indicates a greater abundance of IL1R2 transcripts in tumor-infiltrating Tregs compared with normal or peripheral blood Tregs, depicted in FIG. 2G. FIG. 2G is a plot showing IL1R2 expression in different tissue types (normal (N), peripheral blood (P), and tumor-infiltrating (T)) in HCC patients. The boxplot shows the expression of selected genes in different populations. The thick horizontal line represents the median and median values. As shown in FIG. 2G, the expression level of IL1R2 is upregulated in tumor-infiltrating Tregs in HCC tumors.

Single-cell RNAseq analysis of tumor-infiltrating neutrophils

[00206] To determine whether IL1R2 is expressed in tumor-infiltrating neutrophils, IL1R2 transcripts were analyzed in a scRNA database representing a variety of major and minor immune subsets from human non-small cell lung carcinoma (NSCLC), including various myeloid cells (mast cells, neutrophils, classical DCs, plasmacytoid DCs (pDCs), monocytes, and macrophages) and lymphoid cells (T cells, natural killer (NK) cells, B cells, and plasma cells) as described in Zilionis et al, Immunity. 2019 May 21 ;50(5): 1317-1334. elO. Single cells were analyzed by scRNA-Seq after human lung tumor tissue dissociation. FIG. 2H is a violin plot showing IL1R2 transcripts in NSCLC tumor-infiltrating neutrophils. Depicted in FIG. 2H is IL1R2 transcript abundance (portrayed as violin plots) across the 42 different immune cell subtypes, demonstrating that IL1R2 was expressed at greater levels in tumor-infiltrating neutrophils, including TNI, TN2, TN3, TN4, TN5, with the TNI representing the neutrophil subset with the greatest fraction of cells expressing IL1R2 transcripts (transcript values = counts/10,000 or cplOK).

Example 5: IL1R2 expression in highly-immunosuppressive subsets of tumor-infiltrating Treg and PMN-MDSCs

Single-cell RNAseq analysis of tumor-infiltrating Treg

[00207] Analysis of tumor-infiltrating T-cells using scRNAseq has revealed substantial transcript heterogeneity between different T-cell subtypes, representing naive CD4 and CD8⁺ cells, CD8⁺ exhausted T cells, Tregs, CD4 and CD8⁺ Teff cells. To determine whether IL1R2 is expressed in discrete subsets of tumor-infiltrating Tregs, IL1R2 transcripts were analyzed in scRNA databases representing T cell subsets from non-small cell lung carcinoma (NSCLC) and from hepatocellular carcinoma (HCC) (see Guo, X. et al. Nat. Med. 24, 978-985 (2018); Zheng, C. et al. Cell 169, 1342-1356. el6 (2017)). FIG. 3A is a graph illustrating IL1R2 expression in a distinct subset of NSCLC tumor-infiltrating Treg. As shown in FIG. 3A, a highly selective enrichment of IL1R2 transcripts [log2 (TPM +1)] in the CD4-C9-CTLA4 Treg cluster in NSCLC was observed. This set represents a more suppressive subset of Tregs based on enrichment of genes associated with immunosuppression. Two FOXP3⁺ Treg clusters were identified in HCC, with higher CTLA4 expression in the C8 CD4-CTLA4 cluster compared to C7 CD4-FOXP3. FIG. 3B is a graph illustrating IL1R2 expression in a distinct subset of HCC tumor-infiltrating Treg. As shown in FIG. 3B, a highly selective enrichment of IL1R2 transcripts [log2 (TPM +1)] in the C8 CD4-CTLA4 cluster of CD4-CTLA4 Tregs, which express higher amounts of Treg-related genes such as TNFRSF9 and TIGIT, was observed.

Single-cell RNAseg analysis of infiltrating immune cells in Non-Small Cell Luns Cancer

[00208] A publicly available data mining platform was used to examine IL1R2 expression at single-cell resolution. BioTuring Browser (BioTuring.com) was used to examine single cell RNA seq (scRNA-seq) data compiled from a list of indications including, but not limited to, NSCLC. The software’s internal features address the concerns of quality control, batch effect, imputation, dimensionality reduction, and cell clustering across independent data sets. This enables unique features to be examined within and across disease areas.

[00209] The ILlR2-expressing Tregs were compared to ILlR2-negative Tregs within the data set disclosed in Laughney et al., Nat Med. 2020 26, 259-269, and a number of genes were found to be differentially expressed, with false discovery rates (FDR) below 0.05 indicating statistical significance. Among the top 12 genes enriched in ILlR2-positive Tregs are 0X40 (TNFRSF4), GITR (TNFRSF18), TIGIT, CD25 (IL2RA), and FOXP3 (See TABLE 5). This pattern is suggestive that IL1R2 expression is enriched in more highly-suppressive Tregs. This analysis independently supports a finding within the same indication put forth in Guo, X. et al. Nat. Med. 24, 978-985 (2018), where IL1R2 is enriched on Tregs co-expressing TNF superfamily member receptors.

[00210] TABLE 5: Transcripts significantly enriched in ILlR2-expressing Treg in NSCLC

Single-cell RNAseq analysis of NSCLC tumor-infiltrating neutrophils

[00211] Tumor-infiltrating neutrophils have been ascribed both anti- and pro-tumor properties, as well as diverse molecular phenotypes (Engblom et al., Nature Reviews Cancer. 2016 July; 16(7):447-462). In order to address whether IL1R2 expression within tumor-infiltrating neutrophils or myeloid-derived suppressor cells (MDSC) was associated with an immunosuppressive phenotype, co-expression of IL1R2 with a number of canonical MDSC transcripts or transcripts with known immunosuppressive function was evaluated in a scRNAseq database representing immune cell subsets from NLCLC. Transcripts included the core MDSC markers CD1 lb (ITGAM), CD33, CD66b (CEACAM8), and CD15 (FUT4 and FUT9) as well as arginase 1 (ARG1), which is associated with immunosuppressive function (see Zilionis et al., Immunity. 2019 May 21;50(5): 1317-1334. elO). Depicted in FIG. 3C is a dot-plot of IL1R2 and these canonical markers across the tumor-infiltrating neutrophil and T-cell subsets. Each dot corresponds to the magnitude of expression of a single gene in a subset of cells and to its prevalence (i.e., fraction of cells expressing the gene). The median expression scaled across the subsets is represented by black or grey, (black indicates low expression and grey indicates high median expression) and the size representing the fraction of cells expressing that transcript. As shown in FIG. 3C, IL1R2 transcripts are expressed at greater levels in tumor-infiltrating neutrophils and T-cell subsets with the TNI representing the neutrophil subset with the greatest fraction of cells expressing IL1R2 transcripts. IL1R2 transcript levels are greater in comparison to transcripts with known immunosuppressive function.

[00212] TABLE 6 describes the total number of cells (Ntotai) in each of the neutrophil subsets [tumor-infiltrating neutrophils(tNl-5)]; the number of cells with measured mRNA expression greater than 0 cplOk for IL1R2 (NIL1R2 > 0), ARG1 (NARG1 > 0), or both genes (NIL1R2 & ARG1 > 0); and the fractions of those cells with measured mRNA expression greater than 0 cplOk for IL1R2, ARG1, or both genes. Transcript values = counts/10,000 or cplOK.

[00213] TABLE 6: Expression of IL1R2 and ARG1 in NSCLC-infiltrating neutrophils

[00214] Data depicted in TABLE 6 indicate that IL1R2 is co-expressed with ARG1 in tNl cells and that IL1R2 is expressed in the majority of ARG1 -expressing tNl tumor-infiltrating neutrophils.

Example 6: IL1R2 protein can be detected on the cell surface of tumor-infiltrating Tree and PMN-MDSC with an antibody

Flow Cytometry

[00215] Expression of IL1R2 protein by intratumoral human immune cells was determined by flow cytometry. Fresh human tumors were minced and dissociated using a Human Tumor Digestion Kit (Miltenyi Biotec) and gentleMACS Octo Dissociator. The dissociated tumor cells were filtered through a 70 micron cell strainer and stained using a panel of antibodies to label tumor infiltrating immune cell populations, including CD4⁺ T cells, Tregs, and PMN-MDSC. Surface IL1R2 was measured using an APC-conjugated anti-ILlR2 antibody (Monoclonal Mouse IgGl Clone # 34141 from R&D Systems). The stained cells were analyzed using a BD LSRFortessa flow cytometer.

[00216] FIG. 4A is a histogram showing the results of flow cytometry performed to measure the IL1R2 surface levels on CD4⁺ FOXP3" T cells, CD4⁺ FOXP3⁺ Tregs, and polymorphonucler myeloid-derived suppressor cells (PMN-MDSC) from a kidney chromophobe renal cell carcinoma tumor from a 68 year old Caucasian male. FIG. 4B is a histogram showing the results of flow cytometry performed to measure the IL1R2 surface levels on CD4⁺ FOXP3" T cells, CD4⁺ FOXP3⁺ Tregs, and PMN-MDSC a liver cholangiocarcinoma tumor from a 63 year old Caucasian female. As seen in FIG. 4A and 4B, higher IL1R2 levels were observed on Tregs and PMN-MDSC compared to CD4⁺ FOXP3" T cells in both samples.

Example 7: Antibodies directed against IL1R2 deplete ILlR2-positive cells in vitro

Mechanisms of antibody-induced cell lysis

[00217] The Fc portion of IL1R2 depleting antibodies can function to recruit immune cells that kill cells coated with the IL1R2 depleting antibodies. One such mechanism is antibodydependent cell-mediated cytotoxicity (ADCC), e.g., by Natural Killer (NK) cells. ADCC is mediated by activation of CD 16 (Fc gamma receptor Illa). ILlR2-directed antibodies

[00218] ILlR2-directed antibodies were generated via different methods including but not limited to the following:

Antibodies were generated with recombinant protein comprised of the complete extracellular domain of IL1R2 [amino acid residues 14-343 of SEQ ID NO: 8] and that prevent engagement of IL lb;

Antibodies were generated against the complete extracellular domain of IL1R2 and selected for binding to the D3 domain and/or juxtamembrane sequence;

Antibodies were generated against a recombinant protein comprised only of the IL1R2 D3 domain and juxtamembrane sequences [SEQ ID NO: 9]

SEQ ID NO: 9

KEETIPVIISPLKTISASLGSRLTIPCKVFLGTGTPLTTMLWWTANDTHIESAYPGG RVTEGPRQEYSENNENYIEVPLIFDPVTREDLHMDFKCVVHNTLSFQTLRTTVKE ASSTFS;

Antibodies were generated against cells that express IL1R2. D3 and juxtamembrane- specific antibodies may preferentially bind to cell-surface IL1R2 rather than soluble IL1R2 and may include antibodies that prevent the shedding of IL1R2 from the cell surface by ADAM17 or other matrix metalloproteases. Antibodies are also examined in which ADCC function is enhanced by afucosylation or the introduction of Fc mutations that enhance affinity for CD 16.

[00219] Exemplary IL1R2 antibodies comprising an antigen-binding domain that specifically binds IL1R2 may comprise or be derived from (e.g., Fab or scFv) the VH and/or VL sequence from the exemplary IL1R2 antibodies, including but not limited to, goat polyclonal antibody (AF263; R&D), MAB663 (R&D), MAB263 (R&D).

CD! 6 reporter bioassay

[00220] Expression of CD16-dependent reporter genes induced by antibodies in the presence of target cells has been well-established to reflect ADCC activity (Cheng et al., Journal of Immunological Methods. 2014 December; 414:69-81). One such reporter cell line is a Jurkat cell line that stably expresses a variant of CD 16 with a polymorphism that confers higher affinity for Fc (Valine at position 158); the Luciferase reporter gene is controlled by Nuclear factor of activated T cells (NF AT) (Promega # G7010).

[00221] ILlR2-directed antibodies described above were tested in a CD16 reporter assay using ILlR2-expressing cell lines as the target cells: including SR cells which endogenously express IL1R2. CD16 reporter bioassay using cell lines as target cells

[00222] CD 16 reporter cells were co-incubated with antibody (isotype control or test) and SR cells at optimal effector-to-target ratios at 37 °C for up to 24 hours. At the end of the incubation time, plates were allowed to equilibrate to room temperature, and an equal volume of Bio-Gio™ Luciferase Assay Reagent (Promega) was added. Luminescence was measured using a luminometer (Synergy Neo 2, BioTek/ Agilent, VT).

[00223] FIGs. 5A-5B are bar graphs showing the results of a CD 16 reporter bioassay performed with exemplary IL1R2 antibodies. All IL1R2 antibodies were able to activate CD16 in the presence of SR cells at all 3 concentrations tested.

[00224] While the disclosure has been particularly shown and described with reference to a preferred embodiment and various alternate embodiments, it will be understood by persons skilled in the relevant art that various changes in form and details can be made therein without departing from the spirit and scope of the disclosure.

[00225] All references, issued patents and patent applications cited within the body of the instant specification are hereby incorporated by reference in their entirety, for all purposes.

Claims

CLAIMS A method of enhancing an immune response in a subject in need thereof, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti-ILlR2 antibody or antigen-binding portion thereof: binds within a region comprising amino acid residues VHNTLSFQTLRTTVKEASS (SEQ ID NO: 7); and binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell. The method of claim 1, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of IL1R2. The method of claim 2, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The method of claim 3, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. A method of enhancing an immune response in a subject in need thereof, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell. The method of claim 5, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of. The method of claim 6, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The method of claim 7, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. A method of depleting or killing a IL1R2+ cell, comprising contacting the cell with an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of the cell and causes the depletion or killing of the cell. The method of claim 9, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of IL1R2.

44 The method of claim 9, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues VHNTLSFQTLRTTVKEASS (SEQ ID NO: 7). The method of claim 11, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The method of claim 8, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. A method of treating cancer in a subject, comprising administering an anti-interleukin 1 receptor 2 (IL1R2) antibody or antigen-binding portion thereof to the subject, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell. The method of claim 14, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of IL1R2. The method of claim 14, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues VHNTLSFQTLRTTVKEASS (SEQ ID NO: 7). The method of claim 16, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The method of claim 17, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. The method of any of the above claims, wherein the cell is a regulatory cell, optionally a regulatory T cell. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof causes the depletion or killing of the cell via at least one of: antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP). The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof comprises a Fc region. The method of claim 21, wherein the Fc region comprises human IgGl, IgG2, IgG3, or IgG4 Fc. The method of claim 22, wherein the Fc region comprises a wild-type human IgGl. The method of claim 22, wherein the Fc region comprises a mutated human IgGl.

45 The method of any of claims 21-24, wherein the Fc region binds a Fc Receptor present on the surface of an effector cell. The method of claim 25, wherein the Fc Receptor is at least one of FcyRI(CD64), FcyRIIA (CD32A), FcyRIIIA (CD 16 or CD16A), and FcyRIIIB (CD16B). The method of claim 25, wherein the effector cell comprises at least one of cytotoxic T- cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes. The method of any one of claims 21-27, wherein the Fc region comprises one or more amino acid substitutions relative to wild-type. The method of claim 28, wherein the one or more amino acid substitutions in the Fc region improve its ability to mediate at least one effector function. The method of claim 29, wherein the effector function comprises at least one of: antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP). The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof promotes phagocytosis of one or more IL1R2 expressing cells. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof has enhanced effector function. The method of any of the above claims, wherein the enhanced immune response comprises an adaptive immune response. The method of any of the above claims, wherein the enhanced immune response comprises an innate immune response. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof increases activity of one or more inflammatory immune cells and/or decreases activity of one or more suppressive immune cells. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof increases activity of one or more inflammatory immune cells. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof decreases activity of one or more suppressive immune cells. The method of any of the above claims, wherein enhancing the immune response comprises increasing an existing immune response in the subject. The method of any of the above claims, wherein enhancing the immune response comprises initiating an immune response in the subject.

46 The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof is a depleting antibody or antigen-binding portion thereof. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof is a human or humanized antibody or antigen-binding portion thereof. The method of any of the above claims, wherein the anti-ILlR2 antibody or antigenbinding portion thereof is a monoclonal antibody or antigen-binding portion thereof. The method of any of the above claims, wherein the antibody is a Fab, Fab’, F(ab’)2, Fv, scFv, (scFv)2, single chain antibody, dual variable domain (DVD) antibody, single variable domain antibody, linear antibody, or V domain antibody. An isolated antibody or antigen-binding portion thereof that binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds within a region comprising amino acid residues VHNTLSFQTLRTTVKEASS (SEQ ID NO: 7). The antibody of claim 44, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of IL1R2. The antibody of claim 45, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The antibody of claim 46, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. An isolated antibody or antigen-binding portion thereof that binds to the extracellular domain of membrane-bound IL1R2 present on the surface of a cell and causes the depletion or killing of the cell. The antibody of claim 48, wherein the anti-ILlR2 antibody or antigen-binding portion thereof binds the enzymatically cleaved, membrane-bound portion of IL1R2. The antibody of claim 49, wherein the enzymatically cleaved, membrane-bound portion of IL1R2 has been cleaved by an enzyme. The antibody of claim 50, wherein the enzyme comprises at least one of ADAM17, a metalloproteinase, aminopeptidase, and an elastase. The antibody of any of claims 44-51, wherein the cell is a regulatory cell, optionally a regulatory T cell. The antibody of any of claims 44-52, wherein the antibody causes the depletion or killing of the cell via at least one of: antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP). The antibody of any of claims 44-53, wherein the antibody comprises a Fc region. The antibody of claim 54, wherein the Fc region comprises human IgGl, IgG2, IgG3, or IgG4 Fc. The antibody of claim 55, wherein the Fc region comprises a wild-type human IgGl. The antibody of claim 55, wherein the Fc region comprises a mutated human IgGl. The antibody of any of claims 54-57, wherein the Fc region binds a Fc Receptor present on the surface of an effector cell. The antibody of claim 58, wherein the Fc Receptor is at least one of FcyRI(CD64), FcyRIIA (CD32A), FcyRIIIA (CD 16 or CD16A), and FcyRIIIB (CD16B). The antibody of claim 58, wherein the effector cell comprises at least one of cytotoxic T- cells, natural killer (NK) cells, macrophages, neutrophils, eosinophils, dendritic cells, and monocytes. The antibody of any of claims 54-60, wherein the Fc region comprises one or more amino acid substitutions relative to wild-type. The antibody of claim 61, wherein the one or more amino acid substitutions in the Fc region improve its ability to mediate at least one effector function. The antibody of claim 62, wherein the effector function comprises at least one of: antibody-dependent cell- mediated cytotoxicity (ADCC), complement-dependent cytotoxicity (CDC), and antibody-mediated phagocytosis (ADCP). The antibody of any of claims 44-63, wherein the antibody promotes phagocytosis of one or more IL1R2 expressing cells. The antibody of any of claims 44-63, wherein the antibody has enhanced effector function. The antibody of any of claims 44-63, wherein the antibody is a depleting antibody or antigen-binding portion thereof. The antibody of any of claims 44-63, wherein the antibody is a human or humanized antibody or antigen-binding portion thereof. The antibody of any of claims 44-63, wherein the antibody is a monoclonal antibody or antigen-binding portion thereof. The antibody of any of claims 44-63, wherein the antibody is a Fab, Fab’, F(ab’)2, Fv, scFv, (scFv)2, single chain antibody, dual variable domain (DVD) antibody, single variable domain antibody, linear antibody, or V domain antibody. An isolated polynucleotide or set of polynucleotides encoding the antibody of any of the above claims, a VH thereof, a VL thereof, a light chain thereof, a heavy chain thereof, or an antigen-binding portion thereof; optionally cDNA. A vector or set of vectors comprising the polynucleotide or set of polynucleotides of claim 70. A host cell comprising the polynucleotide or set of polynucleotides of claim 64 or the vector or set of vectors of claim 71. A method of producing an antibody comprising expressing the antibody with the host cell of claim 72 and isolating the expressed antibody. A kit comprising the isolated antibody of any one of the preceding antibody claims and instructions for use. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and the isolated antibody of any one of the preceding claims.

49