WO2024073710A2 - Systems and methods for controlling and enhancing immune cell signaling - Google Patents

Abstract

Systems and methods for activating immune cells are described. Immune cells can be activated using IgG bound with antigen or via light and light sensitive peptides. An immune cell can be genetically manipulated to express a light sensitive peptide. Light is illuminated on the immune cell to activate it. The light sensitive peptide includes a means for locating to the cellular membrane, an activating domain, and a clustering domain that is responsive to light. Systems and methods for controllably inducing antibody-dependent phagocytosis are also described.

Description

SYSTEMS AND METHODS FOR CONTROLLING AND ENHANCING IMMUNE CELL SIGNALING

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The current application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application Serial No. 63/377,675, entitled “Systems and Methods for Optogenetic Immune Cell Activation”, to Morrissey et al. filed September 29, 2022, the disclosure of which is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with Government support under Grant No. R35 GM1 46935 awarded by the National Institutes of Health (NIH). The Government has certain rights in the invention.

SEQUENCE LISTING

[0003] The instant application contains a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on September 29, 2023, is named “R39-08179.xml” and is 3 KB in size.

TECHNICAL FIELD

[0004] The disclosure is generally directed to systems and methods for activation of immune cells including the use of optogenetic peptides and methods of treating neoplasms and cancer.

BACKGROUND

[0005] The immune system fights off germs and infections with two principal lines of defense: the innate system and the adaptive system. The innate immune system is a more generalized form of defense and is capable of generally recognizing and fighting foreign bodies and pathogens. The adaptive immune system is a more specialized form and learns to specifically recognize certain foreign bodies and pathogens for their specific eradication. The two systems work together to provide a comprehensive immune response.

[0006] When infected with a pathogen, the innate immune response is first on the scene to identify and signal that a pathogen is present and to further fight against the pathogen. The innate system comprises several white blood cells, such as monocytes and macrophages, which scavenge for pathogens. When activated, macrophages engulf and digests pathogens, such as bacteria, or other material such as cancer cells, cellular debris, and foreign substances. This process is referred to as phagocytosis and is important to maintaining immunity against foreign pathogens and preventing development of cancer.

[0007] To select targets for phagocytosis, macrophages measure signals that suggest that the target is to be phagocytosed. One common signal is the presence IgG antibodies, which suggests that the adaptive immune system has recognized the target as a pathogen to be removed from the body. The IgG antibodies activate Fc Receptor (FcR) signaling within the macrophage, stimulating the phagocytic response. Antibodydependent phagocytosis, however, requires the coordinated activation of a sufficient number of FcRs, suggesting that a complex system is required to activate phagocytosis.

SUMMARY

[0008] Various embodiments of the description are directed towards systems and methods for activation of immune cells. In many embodiments, an immune cell is genetically altered to express a light sensitive peptide. In several embodiments, when stimulated with light, the peptide can activate the immune cell signaling without a ligand present. In some embodiments, phagocytic-capable cells are activated via FcR signaling and subsequently display enhanced phagocytosis in an antibody-dependent manner but not in an unspecific manner. In some embodiments, phagocytic-capable cells are activated using light and an expressed light sensitive peptide or antibodies with bound antigen and an expressed Fc receptor. [0009] Several embodiments are directed towards utilizing activated immune cells for the treatment of cancer or pathogenic infection. Generally, immune cells can be activated using light and an expressed light sensitive peptide or antibodies with bound antigen and an expressed Fc receptor. Once activated, macrophages can be utilized as an immunotherapy.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The description and claims will be more fully understood with reference to the following figures and data graphs, which are presented as exemplary embodiments of the invention and should not be construed as a complete recitation of the scope of the invention.

[0011] Fig. 1 provides an example of light sensitive peptide in accordance with various embodiments.

[0012] Figs. 2A to 2F provide a schematic and data showing that an optogenetic Fc receptor (optoFcR) can control phagocytosis. Fig. 2A provides a schematic of optoFcR design, containing a myristoylation signal for membrane localization, an ITAM domain for signaling, a flourophore, and the homo-oligomerizing peptide - cryptochrome 2. Fig. 2B provides representative images of optoFcR in bone marrow derived macrophages (BMDMs) clustering the optoFcR with light exposure and quickly declustering when returned to the dark. Fig. 2C provides representative images of downstream effector protein, SYK, colocalizing at optoFcR clusters. 97% of optoFcR clusters have SYK colocalization (n= 73 cells). Fig. 2D provides a line scan showing colocalization. Yellow arrow (c) shows location of line scan within cell. Fig. 2E provides representative images of internalized beads (stars) following optoFcR activation. Fig. 2F provides quantification of phagocytosis in BMDMs after 15 minutes of optoFcR stimulation at low, medium, and high intensity light compared to control cells that do not express the optoFcR but receive the high intensity light stimulus. Both medium and high intensity light stimulate phagocytosis (n=4 independent replicates). Scale bars are 10 urn. Error bars are SEM.

[0013] Figs. 3A to 3J provide a schematic and data showing prior sub-threshold threshold FcR activation specifically enhances macrophage sensitivity to IgG. Fig. 3A provides a schematic of experimental design. Control (mChcaax) and optoFcR expressing BMDMs were stimulated with light for 15 min then returned to the dark for either 1 or 12 hrs and IgG opsonized targets were introduced. Cells were then imaged and the number of targets per cell was counted. The phagocytic index was calculated based on the fold change from unstimulated control cells. Figs. 3B and 3C provide quantification of 1 nM IgG conjugated bead phagocytosis following a 1 hour and 12 hour delay after light stimulation. Prior low intensity (sub-threshold) stimulation enhances phagocytosis (n=4 independent replicates) while higher intensity stimulation does not. Figs. 3D, 3E, and 3F provide data showing IgG opsonized Raji cell eating at 12 hours post optoFcR stimulation (light) compared to cells that were not stimulated (dark). Figs. 3G and 3H provide data showing optoFcR phagocytosis of IgG opsonized beads at various concentrations compared to control cells that receive the same light stimulation. optoFcR cells have increased sensitivity to IgG. Data are from 4 independent replicates. Fig. 3I provides data showing phagocytosis of bead targets without an ‘eat-me’ signal. Fig. 3J provides data showing phagocytosis of bead targets with the efferocytic ‘eat-me’ signal, phosphatidylserine. Error bars are SEM.

[0014] Figs. 4A to 4C provide data showing that FcR mediated priming occurs via a short- and long-term mechanism. Fig. 4A provides data showing phagocytosis of 1 nM IgG beads at various timepoints following light stimulation. Enhanced phagocytosis occurs in two discrete peaks and lasts for up to 72 hrs. Data are from 4 independent replicates. Fig. 4B provides quantification of priming following Actonomycin D (AD, 10nM, 6 hr treatment) and Cycloheximide (CHX, 10ug/ml, 6 hr treatment) treatment to block transcription and translation respectively. At 1 hr post stimulation, AD and CHX have no effect on priming. At 4 and 6 hrs, AD and CHX completely eliminated the enhanced phagocytosis phenotype (n= 3 independent replicates). Fig. 4C provides quantification of priming following treatment with an ERK inhibitor (PD0325901 0.5uM) or DMSO control for 16 hrs. At 1 hr post stimulation, ERK is not required for priming. At 12 hrs post stimulation ERK is required to enhance phagocytosis (n= 4 independent replicates). Error bars are SEM. [0015] Figs. 5A to 5D provide a schematic and data showing that initiation of phagocytosis is faster and the probability of completing phagocytosis is higher in primed macrophages. Fig. 5A provides data showing a schematic of each step of phagocytosis: binding - target contact with cell, initiation - formation of the phagocytic cup, completion - cup closure and bead internalization. Fig. 5B provides data showing time from binding to initiation in optoFcR primed macrophages is decreased compared with unprimed macrophages (n=2 replicates). Fig. 5C provides time from initiation to completion is unchanged in successful phagocytic events between primed and unprimed macrophages. Fig. 5D provides data showing percent of beads that contact a cell that are completely engulfed is higher in primed macrophages (n=2 independent replicates). Error bars are SEM.

DETAILED DESCRIPTION

[0016] Turning now to the drawings and data, systems and methods for activation of immune cells are provided. In many embodiments, an immunological cell is stimulated via Fc Receptor (FcR) signaling. In some embodiments, an immunological cell is stimulated via IgG with bound antigen. In several embodiments, a light-sensitive peptide is expressed within an immunological cell that is capable of activating the immune cell via light energy. In many embodiments, the light-sensitive peptide stimulates FcR signaling. In some embodiments, an immunological cell expressing a light-sensitive receptor is activated via light and without a specific target ligand. In some embodiments, an immunological cell expressing a light-sensitive peptide is activated via light and ligand to enhance a specific immune response to the ligand. Accordingly, in some instances, immune cells are activated generally and in some instances are activated for an immune response to a particular antigen.

[0017] Several embodiments are directed to peptides with the ability to activate immune cells via light. In many embodiments, a light sensitive peptide comprises a domain that clusters in response to light stimulation, an activating domain, and a means for locating to the cellular membrane. In some embodiments, the activating domain is derived from the Fc receptor, and specifically comprising the internal tyrosine activating motif (ITAM). In some embodiments, the clustering domain activated by light comprises the plant protein cryptochrome 2 (cry2). In some embodiments, the means for locating to the cell membrane comprises a plasma membrane localization sequence and/or a myristoylation domain sequence. In some embodiments, the light sensitive peptide receptor comprises a marker (e.g., fluorescent protein) and/or a tag (e.g., His-tag).

[0018] In many embodiments, monocytes or macrophages are genetically altered to express a light sensitive peptide. In several embodiments, when stimulated with light, the peptide can activate a macrophage via FcR signaling without antibody or a ligand present. The activation can be controlled by light such that when the light is removed, the activation is reversed. In many embodiments, the light sensitive peptide is utilized to amplify activation of macrophages with ligand-bound FcRs, amplifying an immune response specific to the ligand. The activated macrophages (unspecific or specific) can be utilized to further activate an immune response by triggering cytokine release and/or activating other immune cells (e.g., T-cells). Several other immune cells are activated by Fc receptor signaling and thus can express a light sensitive peptide and activated via light. Cells that are receptive to FcR signaling include (but are not limited to) macrophages, dendritic cells, B cells, T cells, natural killer cells, neutrophils, eosinophils, basophiles, mast cells, microglia, and astrocytes. Further, FcR signaling can stimulate enhanced phagocytosis, and especially enhanced antibody-dependent phagocytosis. Enhanced phagocytosis can mean phagocytosis is enhanced greater than a baseline level (e.g., prior to stimulation with light or IgG with bound antigen), enhanced greater than a control phagocytic-capable cell (e.g., as compared to phagocytic cells that are not stimulated), or enhanced greater than another stimulated phagocytic-capable cell (e.g., as compared to phagocytic cells provided a different degree of stimulation). Enhanced phagocytosis can be enhanced unspecific phagocytosis and/or enhanced antibody-dependent phagocytosis (i.e., phagocytosis of target opsonized with antibody). Enhanced phagocytosis can mean higher capacity for phagocytosis (e.g. more targets engulfed per phagocytic cell), more quickly able to phagocytose a target (e.g., less time to engulf target), and/or greater success rate at being able to phagocytose a target (e.g., greater success of completing engulfment of a target). Enhanced phagocytosis can also mean more sensitive antibody- dependent phagocytic response to IgG bound to antigen (e.g., increased phagocytosis with lower doses of IgG administered or present). In some embodiments, the cell is a phagocytic-capable immune cell, such as (for example) macrophages, dendritic cells, and neutrophils.

[0019] There are several therapeutic benefits in enhancing immune cell signaling, especially FcR signaling. As stated, FcR signaling can enhance phagocytosis in phagocytic-capable immune cells. When these cells phagocytose pathogens or cancer cells, they can present peptides or other molecules of the pathogen or cancer cell to T cells to increase adaptive immunity towards these pathogens or cancer cells. Accordingly, enhanced phagocytosis can help the adaptive immune system identify pathogenic antigens or neoantigens such that antibody and T cell responses can specifically attack and remove pathogens and cancer cells. FcR signaling also results in increased release of cytokines and chemokines from these cells and other immune cells, which further stimulate the immune system to respond to a pathogenic infection or neoplastic growth. For more information on the benefits of enhancing immune cell signaling, see M. Klichinsky, et al., Nat Biotechnol. 2020, 38(8):947-953 and Y. Chen, et al., J Transl Med. 2023, 21 (1 ):654; the disclosures of which are incorporated herein by reference.

[0020] Several embodiments of the description are also directed towards systems and methods for activating an immune response in an individual. In some embodiments, macrophages are stimulated ex vivo (or in vitro) with ligand bound antibody. The macrophages can be returned (or introduced) along with IgG to an individual. The IgG can target an antigen, which in turn will be phagocytosed by the activated macrophages. [0021] In some embodiments, monocytes or macrophages are extracted from an individual and genetically altered to express a light sensitive peptide. In some embodiments, in vitro cultivated monocytes or macrophages are genetically altered to express a light sensitive peptide. In some embodiments, macrophages expressing light sensitive peptides are expressed are returned (or introduced) to an individual. The genetically altered macrophages can be activated such that they can phagocytose antigens. In some embodiments, the genetically altered macrophages are activated via light stimulation prior to introducing to the individual. In some embodiments, the genetically altered macrophages are activated via light stimulation after introducing to the individual (e.g., using an endoscope).

[0022] Throughout the description, the terms neoplasm and cancer (or neoplastic cell and cancer cell) are utilized interchangeably. A neoplasm, as understood in the field, is a new and abnormal growth of tissue, and thus includes benign growths (e.g., benign tumors) and cancerous growths. Similarly, a cancer is an abnormal growth of cells with the potential to metastasize and to spread to other areas of the body. Accordingly, the various embodiments described herein can be applied to neoplasms and cancers, unless specified to be exclusive to one or the other.

[0023] The term peptide is utilized to describe any amino acid chain comprising two or more amino acids. Accordingly, a peptide can be utilized to describe a protein, polypeptide, or any other biological molecule having an amino acid chain with at least two amino acids.

Peptides for Light Activation of Immune Cells

[0024] Several embodiments are directed towards peptides for activating immune cells via light. A light sensitive peptide can comprise a clustering domain, an activating domain, and a means for localizing to the cellular membrane. The clustering domain is sensitive to light and clusters with other clustering domains when stimulated. The activating domain is itself activated by the clustering with peptides, which then initiates a signaling pathway to activate the immune cell. The means for localizing to the cellular membrane can comprise a sequence motif that directly or indirectly signals for the peptide to be translocated to the cellular membrane.

[0025] Provided in Fig. 1 is an example of a peptide for light activation of immune cells. The peptide 101 comprises three domains, a membrane localizing motif 103, an activating domain 105, and a clustering domain 107. The peptide can further comprise a marker peptide domain 109 and a peptide tag 111 . A linker can be utilized to connect the various domains but is not required.

[0026] The membrane localizing motif 103 can be any peptide domain that localizes the peptide to the cellular membrane yet does not disrupt the activating domain 105 and clustering domain 107 within the intracellular side of the membrane. The membrane localizing motif can be an integral membrane protein sequence, a peripheral membrane protein sequence, or a sequence for covalently linking a fatty acid acyl chain. Generally, integral membrane protein sequences permanently integrate within the lipid bilayer of the cell membrane via hydrophobic amino acids that interact with the lipid bilayer. Peripheral membrane proteins can interact with the lipid bilayer of the cell membrane via hydrophobic amino acid domains that partially integrate within the lipid bilayer or via covalently bound membrane lipids. Lipid anchored proteins incorporate a covalently attached fatty acid acyl chain via palmitoylation, myristoylation, or prenylation. Accordingly, in various embodiments, a light sensitive peptide incorporates a membrane localizing motif comprising one or more of the following: a membrane localization motif sequence, a sequence of amino acids that signals for palmitoylation, a sequence of amino acids that signals for myristoylation, or a sequence of amino acids that signals for prenylation.

[0027] An activating domain 105 is a peptide domain that stimulates activation of a signaling pathway. Herein, in accordance with many embodiments, the activating domain 105 is an amino acid sequence of an immune receptor that activates signaling in an immune cell. One such sequence is the internal tyrosine activating motif (ITAM) of the Fc receptor. Accordingly, in some embodiments, a light sensitive peptide incorporates an ITAM domain for activating an immune cell. Other receptor sequences that can be utilized include (but are not limited to) Megf10, FcRy, Bail , MerTK, TIM4, Stabilin-1 , Stabilin-2, RAGE, CD300f, Integrin subunit av, Integrin subunit [35, CD36, LRP1 , SCARF1 , C1 Qa, and Axl. Alternatively, a synthetic sequence can be utilized having two repeats of the amino acid sequence YxxL/l separated by 6-8 amino acids, wherein each X is independently any amino acid, producing the conserved motif YxxL/lx(6-8)YxxL/l. It should also be understood that multiple activation domains can be utilized; for example, a peptide can comprise 2 or more ITAM domains.

[0028] A clustering domain 107 is a peptide domain that clusters with one or more other peptides having a clustering domain when stimulated with light. Various clustering domains can be utilized, which can be stimulated with various wavelengths of light. In some embodiments, the plant protein cryptochrome 2 (cry2) is utilized as the clustering domain, which when stimulated with blue light, clusters with other peptides having cry2. Other clustering domains that are light sensitive include (but are not limited to) CRY2, CRY2clust, CRY2olig, CRY2PHR, CRY2/CIB1 , Cph1, and DrBpHP. For more details on clustering domains, see H. Park, et al., Nat Commun. 2017, 8(1 ):30; A. Taslimi, et al., Nat Commun. 2014, 5:4925; D. L. Che, et al., ACS Synth Biol. 2015, 4(10):1124-1135; H. Liu, et al., Arabidopsis. Science. 2008, 322(5907): 1535-1539; and M. M. Kramer, et al., Int J Mol Sci. 2021 , 22(10):5300; the disclosures of which are each incorporated by reference. [0029] Peptides can also optionally incorporate a marker peptide domain 109. Examples of marker peptide domains are fluorescent proteins which can help visualize the expression and localization of the light sensitive peptide. Examples of fluorescent proteins include (but are not limited to) GFP, RFP, iRFP, mCherry, and tdTomato. Further, peptides can optionally incorporate a peptide tag which can help identify or utilize the peptide in various biochemical assays. Examples of peptide tags that can be utilized include (but are not limited to) His-tag and c-myc.

[0030] In some embodiments, an expression vector is utilized to express a gene product by incorporating the nucleic acid molecule encoding the gene product or a portion thereof (e.g., a fragment of gene product). In some embodiments, expression vectors are used to encode light sensitive peptides to be expressed within an immune cell. In some embodiments, an expression vector includes regulatory sequences that govern transcription and/or translation. The regulatory sequences can be operably linked to the gene produce sequence.

[0031] To express peptides or polypeptides of the disclosure, nucleic acids encoding the peptides are inserted into expression vectors such that the gene product sequence is operably linked to transcriptional and/or translational regulatory sequences. The term “regulatory sequence” refers to nucleic acid sequences that affect the expression of transgene sequences to which they are operably linked. Such regulatory sequences may include a promoter, a splice cassette, translation initiation codon, translation and insertion site for introducing an insert into the vector. The term “operably linked’ refers to a juxtaposition of a regulatory sequence with a transgene permitting them to function in their intended manner. A regulatory sequence operably linked to a transgene sequence is ligated in such a way that expression of the transgene is achieved under conditions compatible with the control sequences. Examples of regulatory sequences permitting expression in eukaryotic host cells include (but are not limited to) the human regulatory sequences CMV-promoter, SV40-promoter, RSV-promoter, CMV-enhancer, SV40- enhancer and a globin intron. Regulatory elements may also include transcription termination signals, such as (for example) the SV40 poly-A site or the tk-poly-A site, typically operably linked downstream of the transgene.

[0032] Typically, expression vectors used in any of the host cells contain sequences for plasmid or virus maintenance and for cloning and expression of exogenous nucleotide sequences. Such sequences, collectively referred to as “flanking sequences” can include one or more of the following operatively linked regulatory sequences: a promoter, one or more enhancer sequences, an origin of replication, a transcriptional termination sequence, a complete intron sequence containing a donor and acceptor splice site, a sequence encoding a leader sequence for polypeptide secretion, a ribosome binding site, a polyadenylation sequence, a polylinker region for inserting the nucleic acid encoding the polypeptide to be expressed, and a selectable marker element.

[0033] Numerous expression systems exist that include at least a part or all of the expression vectors discussed above. Prokaryote- and/or eukaryote-based systems can be employed for use with an embodiment to produce nucleic acid sequences, or their cognate polypeptides, proteins and peptides. Commercially and widely available systems include in but are not limited to bacterial, mammalian, yeast, and insect cell systems. Different host cells have characteristic and specific mechanisms for the post-translational processing and modification of proteins. Appropriate cell lines or host systems can be chosen to ensure the correct modification and processing of the foreign protein expressed. Those skilled in the art are able to express a vector to produce a nucleic acid sequence or its cognate polypeptide, protein, or peptide using an appropriate expression system.

[0034] In several embodiments, an expression cassette is provided within a viral vector cassette, which can be nucleic acid capable of packaging within a viral vector. Generally, a viral vector cassette includes sequences for encoding virus components for viral vector generation and expression cassette encapsulation. Viral vectors that may be utilized include (but are not limited to) lentivirus, retrovirus, adenovirus, herpes simplex virus, and adeno-associated virus.

Systems and Methods for Immune Cell Activation

[0035] Several embodiments are directed toward activating an immune cell, which can be done utilizing IgG with bound antigen. When IgG with bound antigen comes in contact with an immune cell expressing an FcR, the clustering domain will cluster the FcRs together. The clustering of FcR will result in oligomerization and stimulation of the activating domain. When the activating domain is turned on, the immune cell will activate, resulting in immune function.

[0036] Several immune cells are known to be activated by FcRs, including (but not limited to) macrophages, dendritic cells, B cells, T cells, natural killer cells, neutrophils, eosinophils, basophiles, mast cells, microglia, and astrocytes. Further, FcR signaling can stimulate phagocytosis, and especially antibody-dependent phagocytosis. In some embodiments, the cell is a phagocytic-capable immune cell, such as (for example) macrophages, dendritic cells, and neutrophils. Accordingly, these cells can be activated these cells by contacting the cells with an IgG bound with antigen.

[0037] Some embodiments are directed to controllably stimulate a phagocytic-capable cell into antibody-dependent phagocytosis. In some embodiments, the phagocytic- capable cell into antibody-dependent phagocytosis but not into nonspecific phagocytosis. It has been found that low-level stimulation of the FcR of phagocytic-capable cells results in stimulation of enhanced antibody-dependent phagocytosis but not unspecific phagocytosis. Accordingly, in some embodiments, one or more phagocytic-capable cells are contacted with IgG with bound antigen to stimulate the cells into enhanced antibodydependent phagocytosis but not into nonspecific phagocytosis.

[0038] Interestingly, it was also found that stimulation of antibody-dependent phagocytosis was not antibody-specific or antigen-specific, meaning the stimulated phagocytic cell was capable of phagocytosing any target opsonized with an antibody and not just the antibody/antigen combination used for stimulation. An assessment can be performed to determine if the stimulated phagocytic cells is capable of antibodydependent phagocytosis and/or nonspecific phagocytosis using a number of assays known in the art, such as (for example) assessing whether the stimulated cell is capable of engulfing opsonized beads and/or naked beads. Engulfment of opsonized beads but not naked beads suggests that the phagocytic cells is activated for antibody-dependent phagocytosis but not unspecific phagocytosis.

[0039] In some embodiments, controllably activating an immune cell is done via light and expression of a light sensitive peptide. As described in the previous section, a light sensitive peptide can comprise a clustering domain, an activating domain, and a means for localizing to the cellular membrane. Thus, when expressed within a cell the light sensitive peptide will localize to the cellular membrane. When light is illuminated onto the cell, the clustering domain will cluster the light sensitive peptides together. The clustering of the peptides will result in oligomerization and stimulation of the activating domain. When the activating domain is turned on, the immune cell will activate, resulting in immune function.

[0040] Provided in Fig. 2A is an exemplary schematic for activating an immune cell via light. On the left side of the figure are dispersed light sensitive peptides that are inactive. Each light sensitive peptide comprises a clustering domain, an activating domain, and a means for localizing to the cellular membrane. The clustering domain is cry2, the activating domain is ITAM, and the means for localizing to the cellular membrane is the myristoyl lipid. The light sensitive peptide further includes a fluorescent protein to provide a fluorophore for visualization of the peptide. When activating light is illuminated onto the immune cell, the cry2 domains cluster together, bringing the light sensitive peptides within proximity. This allows the ITAM domains to be phosphorylated and recruit downstream effector proteins, resulting in activation of the peptide. The active peptide initiates a signaling cascade that results in activation of the immune cell.

[0041] As previously stated, several immune cells are known to be activated by FcRs, including (but not limited to) macrophages, dendritic cells, B cells, T cells, natural killer cells, neutrophils, eosinophils, basophiles, mast cells, microglia, and astrocytes. Further, FcR signaling can stimulate phagocytosis, and especially antibody-dependent phagocytosis. In some embodiments, the cell is a phagocytic-capable immune cell, such as (for example) macrophages, dendritic cells, and neutrophils. Accordingly, light sensitive peptides incorporating a FcR signaling domain (e.g., an ITAM domain) can be utilized within these cells to provide a means for controllably activating these cells by illuminating light thereupon.

[0042] Activation of immune cells via light sensitive peptides can occur without any ligand. As shown in Fig. 2A, the activation of the cell occurs without any ligand present. Accordingly, in some embodiments, an immune cell is generally activated via light. However, it is also possible to enhance activation of immune cells having a particular ligand. Immune cells expressing native or heterologous FcRs can have an antigen associated with the Fc Receptor for specific activation of the immune cells to that antigen. For instance, antibody-dependent phagocytosis of a macrophage via antibody binding to FcRs can be enhanced by co-expressing a light sensitive peptide and illuminating that macrophage with light. This enhancement persists for at least several days after light stimulation. In addition, engineered immune cells designed to activate an immune response against a particular antigen can be enhanced via activation of light sensitive peptides. Types of engineered immune cells that could benefit via activation of light sensitive peptides include (but are not limited to) T cells expressing a chimeric antigen receptor (CAR-T cells) and macrophages expressing a chimeric antigen receptor. By coexpressing the CAR and the light sensitive peptide within an immune cell, illumination of light onto the immune cell will increase the immune response to the antigen recognized by the chimeric antigen receptor.

[0043] Some embodiments are directed to controllably stimulate an engineered phagocytic-capable cell into antibody-dependent phagocytosis via light stimulation and light sensitive peptides. In some embodiments, the phagocytic-capable cell into antibodydependent phagocytosis but not into nonspecific phagocytosis. It has been found that low-level stimulation of the FcR of phagocytic-capable cells results in stimulation of antibody-dependent phagocytosis but not unspecific phagocytosis. Accordingly, in some embodiments, one or more phagocytic-capable cells are engineered to express light sensitive peptides incorporating a FcR signaling domain (e.g, an ITAM domain). These cells can be stimulated with light to stimulate the cells into antibody-dependent phagocytosis but not into nonspecific phagocytosis.

[0044] As stated previously, it was also found that stimulation of enhanced antibodydependent phagocytosis was not antibody-specific or antigen-specific, meaning the stimulated phagocytic cell was capable of phagocytosing any target opsonized with an antibody and not just the antibody/antigen combination used for stimulation. An assessment can be performed to determine if the stimulated phagocytic cells is capable of enhanced antibody-dependent phagocytosis and/or nonspecific phagocytosis using a number of assays known in the art, such as (for example) assessing whether the stimulated cell is capable of engulfing opsonized beads and/or naked beads. Engulfment of opsonized beads but not naked beads suggests that the phagocytic cells is activated for antibody-dependent phagocytosis but not unspecific phagocytosis.

[0045] To express light sensitive peptides within an immune cell, mRNA or expression cassettes having an encoding sequence for the peptide can be delivered into the immune cell. In some embodiments, an mRNA encoding the light sensitive peptide is contacted with host cells to induce transgene expression. In some embodiments, a vector having the expression cassette is contacted with host cells to induce transgene expression. An expression construct encoding a transgene can be transfected or transduced or infected into cells according to a variety of methods known in the art. Vector DNA or mRNA can be introduced into immune cells via conventional transfection or viral transduction techniques. One of skill in the art would understand the conditions under which to incubate host cells to maintain them and to permit expression of the peptide and/or replication of a vector. Also understood and known are techniques and conditions that would allow large-scale production of expression vectors.

[0046] For stable transfection of mammalian cells, depending upon the expression vector and transfection technique used, typically only a fraction of cells (i.e., not 100%) will integrate the foreign DNA into their genome. In order to identify stably expressing cells within a population, a selectable marker (e.g., gene product inducing resistance to antibiotics or a fluorescent protein) is generally introduced into the host cells along with the gene of interest. Cells stably transfected with the introduced nucleic acid can be identified by drug selection (e.g., cells that have incorporated the selectable marker gene will survive, while the other cells die) or identifying and isolating fluorescent cells (e.g., via flow cytometry) or identifying and isolating cells with ectopic expression of a transgene product (e.g., via flow cytometry and tagging cells with fluorescent antibodies capable of detecting the transgene product), among other methods known in the arts.

[0047] Several embodiments are directed towards design and preparation of viral vectors. In various embodiments, viral vectors incorporate genetic information via RNA or DNA, as appropriate for the particular virus or vector. In some embodiments, the genetic polynucleotide is modified to achieve desired biological features that may be advantageous in a treatment. For example, in various embodiments, viral vectors may be attenuated, rendered replication incompetent, and/or express one or more transgenes. Viral vectors that may be utilized include (but are not limited to) lentivirus, retrovirus, adenovirus, herpes simplex virus, and adeno-associated virus.

[0048] In various embodiments, a viral vector incorporates an expression cassette that is a nucleic acid sequence encoding one or more regulatory sequences operably linked to one or more transgenes. Accordingly, a viral vector can contact an immune cell and induce expression of the transgene therein. In some embodiments, a viral vector induces expression of a light sensitive peptide within the immune cell.

[0049] Immune cells can be genetically engineered by any appropriate technique that can stably introduce one or more expression cassettes. In some embodiments, an expression cassette is integrated into the immune cell’s genome or maintained extrachromosomally. In some embodiments, immune cells that successfully integrate and/or stably extrachromosomally maintain the expression cassette is selected, which can be done by identifying and purifying cells expression the transgene product and/or utilizing a co-expressed selectable marker (e.g., fluorescent protein, puromycin, hygromycin, etc.)

[0050] In some embodiments, a viral vector is utilized to introduce an expression cassette. Accordingly, a viral vector is incorporating the expression cassette developed and propagated, and then transduced into immune cells at an appropriate multiplicity of infection (MOI), which may ensure robust transgene expression but mitigate harmful side effects of vector integration. A viral vector comprising the expression can then be contacted with a cell such that the cassette is introduced therein and expressed.

[0051] In some embodiments, an expression cassette or mRNA encoding the light enveloped is incorporated into a liposome or other lipid nanoparticle, which can be utilized to introduce the cassette or mRNA into an immune cell. Accordingly, expression cassette nucleic acids or mRNA are synthesized and then encapsulated within the liposome or lipid nanoparticle. A complex comprising the expression cassette or mRNA and liposome or lipid nanoparticle can then be contacted with a cell such that the cassette or mRNA is introduced therein and expressed.

[0052] In some embodiments, site-directed insertion and/or mutagenesis (e.g., CRISPR) is utilized to introduce an expression cassette. Accordingly, in various embodiments utilizing a CRISPR technique, an expression cassette utilizes Cas9 enzymes (or similar) and guide RNAs to nick and/or break DNA at a genomic location such that a donor expression cassette is integrated at the site, which can be integrated at a specific site if desired. The expression cassette and CRISPR system can then be contacted with a cell such that the cassette and CRISPR system is introduced therein and expressed.

Immunological Treatments and Immunotherapy

[0053] Various embodiments are directed to treatments based on activating immune cells via FcR signaling. In some embodiments, immune cells are activated using IgG antibody with bound antigen. In some embodiments, immune cells are activated using a light sensitive peptide with an activating domain and membrane localization motif. Activating domains include (but are not limited to) ITAM, Megf10, FcRy, Bail , MerTK, TIM4, Stabilin-1 , Stabilin-2, RAGE, CD300f, Integrin subunit av, Integrin subunit [35, CD36, LRP1 , SCARF1 , C1 Qa, and Axl.

[0054] As described herein, an immune cell can be genetically manipulated to express a light sensitive peptide for activating an immune cell. In various embodiments, activated immune cells are administered to an individual having a neoplasm. In various embodiments, the activated immune cells to be administered are one or more of: an activated macrophage, an activated dendritic cell, a CAR-T cell, or a CAR macrophage. [0055] In accordance with this disclosure, the term “pharmaceutical composition” relates to a composition for administration to an individual. In some embodiments, a pharmaceutical composition comprises an activated immune cell for enteral or a parenteral administration, or for direct injection into a neoplasm. In some embodiments, a pharmaceutical composition comprising the activated immune cell is administered to the individual via infusion or injection.

[0056] In some embodiments, activated immune cells are administered in a therapeutically effective amount as part of a course of treatment. As used in this context, to "treat" means to ameliorate at least one symptom of the disorder to be treated or to provide a beneficial physiological effect. For example, one such amelioration of a symptom could be reduction of tumor size.

[0057] A therapeutically effective amount can be an amount sufficient to prevent reduce, ameliorate or eliminate the symptoms of cancer. In some embodiments, a therapeutically effective amount is an amount sufficient to reduce the growth of neoplasm and/or metastasis of a cancer.

Cancer treatments

[0058] A number of embodiments are directed towards treating an individual for a neoplasm and/or cancer.

[0059] Based on a discovery that macrophages can be activated with low levels of IgG antibody, an individual can be treated with FcR activated, phagocytic-capable immune cells in conjunction with IgG antibodies. In some embodiments, an individual is treated is as follows:

(i) extract immune cells from the individual and/or expand immune cells in vitro

(ii) contact immune cells with IgG antibody having bound antigen to activate FcR signaling

(iii) administer the immune cells to the individual

(iv) administer IgG that targets an antigen involved in a treatment. [0060] The IgG and bound antigen can be any IgG capable of stimulating human Fc receptors and any antigen. It is not necessary for the antigen to be related to treatment. In some embodiments, the step of contacting phagocytic-capable immune cells with IgG antibody to activate FcR signaling does not initiate unspecific phagocytosis but does initiate enhanced antibody-dependent phagocytosis. In some embodiments, the amount light energy impinged to stimulate phagocytic-capable immune cells is below a threshold to induce unspecific phagocytosis but is above a threshold to induce enhanced antibodydependent phagocytosis. In some embodiments, an assessment is performed to determine whether the stimulated phagocytic-capable immune cells have initiated unspecific phagocytosis and/or antibody-dependent phagocytosis. In some embodiments, the immune cells comprise macrophages. In some embodiments, the immune cells comprise dendritic cells. In some embodiments, the immune cells comprise CAR T-cells. In some embodiments, the immune cells comprise CAR macrophages. In some embodiments, the IgG that is administered comprises convalescent antibodies. In some embodiments, the IgG that is administered comprises an IgG that targets a cancer antigen. In some embodiments, the IgG that is administered comprises an IgG that targets a pathogenic antigen.

[0061] Based on a discovery that engineered macrophages can be activated using light sensitive peptide with an activation domain, an individual can be treated with activated immune cells. In some embodiments, an individual is treated is as follows:

(i) extract immune cells from the individual and/or expand immune cells in vitro

(ii) engineer the individual’s immune cells to express a light sensitive peptide

(iii) impinge light energy on the immune cells to activate signaling

(iv)administer the engineered immune cells to the individual.

[0062] In some embodiments, the immune cells comprise phagocytic-capable immune cells. In some embodiments, the step of impinging light energy on phagocytic-capable immune cells to activate FcR signaling does not initiate unspecific phagocytosis but does initiate antibody-dependent phagocytosis. In some embodiments, the amount light energy impinged to stimulate phagocytic-capable immune cells is below a threshold to induce unspecific phagocytosis but is above a threshold to induce enhanced antibody-dependent phagocytosis. In some embodiments, an assessment is performed to determine whether the stimulated phagocytic-capable immune cells have initiated unspecific phagocytosis and/or antibody-dependent phagocytosis. In some embodiments, the immune cells comprise macrophages. In some embodiments, the immune cells comprise dendritic cells. In some embodiments, the immune cells comprise CAR T-cells. In some embodiments, the immune cells comprise CAR macrophages. In some embodiments, the individual is further treated as follows: (v) administer IgG with Fc domain that targets an antigen involved in a treatment. In some embodiments, the IgG that is administered comprises convalescent antibodies. In some embodiments, the IgG that is administered comprises an IgG that targets a cancer antigen. In some embodiments, the IgG that is administered comprises an IgG that targets a pathogenic antigen.

[0063] In some embodiments, an individual is treated is as follows:

(i) extract immune cells from the individual and/or expand immune cells in vitro

(ii) engineer the individual’s immune cells to express a light sensitive peptide

(iii) administer the engineered immune cells to the individual

(iv) impinge light energy on the immune cells to activate FcR signaling.

[0064] In some embodiments, the light energy is provided by an endoscope. In some embodiments, the light energy is directed at a tumor, which can activate immune cells in and around the tumor. In some embodiments, the immune cells comprise phagocytic- capable immune cells. In some embodiments, the step of impinging light energy on phagocytic-capable immune cells to activate FcR signaling does not initiate unspecific phagocytosis but does initiate enhanced antibody-dependent phagocytosis. In some embodiments, the amount light energy impinged to stimulate phagocytic-capable immune cells is below a threshold to induce unspecific phagocytosis but is above a threshold to induce antibody-dependent threshold. In some embodiments, when light is impinged directly on a tumor, the locality of unspecific phagocytosis can be controlled by stimulating the phagocytosis only in and around the tumor. In some embodiments, an assessment is performed to determine whether the stimulated phagocytic-capable immune cells have initiated unspecific phagocytosis and/or antibody-dependent phagocytosis. In some embodiments, the immune cells comprise macrophages. In some embodiments, the immune cells comprise dendritic cells. In some embodiments, the immune cells comprise CAR T-cells. In some embodiments, the immune cells comprise CAR macrophages. In some embodiments, the individual is further treated as follows: (v) administer IgG with Fc domain that targets an antigen involved in a treatment. In some embodiments, the IgG that is administered comprises convalescent antibodies. In some embodiments, the IgG that is administered comprises an IgG that targets a cancer antigen. In some embodiments, the IgG that is administered comprises an IgG that targets a pathogenic antigen.

[0065] In some embodiments, an individual is treated is as follows:

(i) envelope mRNA that encodes a light sensitive peptide within liposome or other lipid nanoparticle

(ii) administer liposome-mRNA complex to the individual to express the light sensitive peptide within immune cells

(iii) impinge light energy on the immune cells to activate signaling.

[0066] In some embodiments, the light is provided by an endoscope. In some embodiments, the light energy is directed at a tumor, which can activate immune cells in and around the tumor. In some embodiments, the immune cells comprise phagocytic- capable immune cells. In some embodiments, the step of impinging light energy on phagocytic-capable immune cells to activate FcR signaling does not initiate unspecific phagocytosis but does initiate antibody-dependent phagocytosis. In some embodiments, the amount light energy impinged to stimulate phagocytic-capable immune cells is below a threshold to induce unspecific phagocytosis but is above a threshold to induce enhanced antibody-dependent threshold. In some embodiments, the amount light energy impinged to stimulate phagocytic-capable immune cells induces unspecific phagocytosis. In some embodiments, when light is impinged directly on a tumor, the locality of unspecific phagocytosis can be controlled by stimulating the phagocytosis only in and around the tumor. In some embodiments, an assessment is performed to determine whether the stimulated phagocytic-capable immune cells have initiated unspecific phagocytosis and/or antibody-dependent phagocytosis. In some embodiments, the immune cells comprise macrophages. In some embodiments, the immune cells comprise dendritic cells. In some embodiments, the immune cells comprise CAR T-cells. In some embodiments, the immune cells comprise CAR macrophages. In some embodiments, the individual is further treated as follows: (iv) administer IgG with Fc domain that targets an antigen involved in a treatment. In some embodiments, the IgG that is administered comprises convalescent antibodies. In some embodiments, the IgG that is administered comprises an IgG that targets a cancer antigen. In some embodiments, the IgG that is administered comprises an IgG that targets a pathogenic antigen.

[0067] In some embodiments, the treatment is an adjuvant treatment. In some embodiments, the treatment is a neoadjuvant treatment.

[0068] In accordance with various embodiments, numerous types of neoplasms can be treated. Neoplasms that can be treated include (but not limited to) anal cancer, astrocytomas, basal cell carcinoma, bile duct cancer, bladder cancer, breast cancer, breast adenocarcinoma (BRCA), cervical cancer, chronic myeloproliferative neoplasms, colorectal cancer, endometrial cancer, ependymoma, esophageal cancer, diffuse large B-cell lymphoma (DLBCL), esthesioneuroblastoma, Ewing sarcoma, fallopian tube cancer, gallbladder cancer, gastric cancer, gastrointestinal carcinoid tumor, hepatocellular cancer, hypopharyngeal cancer, Kaposi sarcoma, Kidney cancer, Langerhans cell histiocytosis, laryngeal cancer, liver cancer, lung cancer, melanoma, Merkel cell cancer, mesothelioma, mouth cancer, neuroblastoma, non-small cell lung cancer, osteosarcoma, ovarian cancer, pancreatic cancer, pancreatic neuroendocrine tumors, pharyngeal cancer, pituitary tumor, prostate cancer, rectal cancer, renal cell cancer, retinoblastoma, skin cancer, small cell lung cancer, small intestine cancer, squamous neck cancer, testicular cancer, thymoma, thyroid cancer, uterine cancer, vaginal cancer, and vascular tumors.

[0069] In accordance with many embodiments, treatments involving administration of activated immune cells can be combined with other therapies, including (but not limited to) surgery, immunotherapy, chemotherapy, radiation therapy, targeted therapy, hormone therapy, stem cell therapies, and blood transfusions. In some embodiments, an anticancer and/or chemotherapeutic agent is administered, including (but not limited to) alkylating agents, platinum agents, taxanes, vinca agents, anti-estrogen drugs, aromatase inhibitors, ovarian suppression agents, endocrine/hormonal agents, bisphophonate therapy agents and targeted biological therapy agents. Medications include (but are not limited to) cyclophosphamide, fluorouracil (or 5-fluorouracil or 5-Fll), methotrexate, thiotepa, carboplatin, cisplatin, taxanes, paclitaxel, protein-bound paclitaxel, docetaxel, vinorelbine, tamoxifen, raloxifene, toremifene, fulvestrant, gemcitabine, irinotecan, ixabepilone, temozolomide, topotecan, vincristine, vinblastine, eribulin, mitomycin, capecitabine, capecitabine, anastrozole, exemestane, letrozole, leuprolide, abarelix, buserlin, goserelin, megestrol acetate, risedronate, pamidronate, ibandronate, alendronate, zoledronate, tykerb, daunorubicin, doxorubicin, epirubicin, idarubicin, valrubicin mitoxantrone, bevacizumab, cetuximab, ipilimumab, ado- trastuzumab emtansine, afatinib, aldesleukin, alectinib, alemtuzumab, atezolizumab, avelumab, axtinib, belimumab, belinostat, bevacizumab, blinatumomab, bortezomib, bosutinib, brentuximab vedoitn, briatinib, cabozantinib, canakinumab, carfilzomib, certinib, cetuximab, cobimetnib, crizotinib, dabrafenib, daratumumab, dasatinib, denosumab, dinutuximab, durvalumab, elotuzumab, enasidenib, erlotinib, everolimus, gefitinib, ibritumomab tiuxetan, ibrutnib, idelalisib, imatinib, ipilimumab, ixazomib, lapatinib, lenvatinib, midostaurin, nectiumumab, neratinib, nilotinib, niraparib, nivolumab, obinutuzumab, ofatumumab, olaparib, loaratumab, osimertinib, palbocicilib, panitumumab, panobinostat, pembrolizumab, pertuzumab, ponatinib, ramucirumab, reorafenib, ribociclib, rituximab, romidepsin, rucaparib, ruxolitinib, siltuximab, sipuleucel- T, sonidebib, sorafenib, temsirolimus, tocilizumab, tofacitinib, tositumomab, trametinib, trastuzumab, vandetanib, vemurafenib, venetoclax, vismodegib, vorinostat, and ziv- aflibercept. In accordance with various embodiments, an individual may be treated, by a single medication or a combination of medications described herein. A common treatment combination is cyclophosphamide, methotrexate, and 5-fluorouracil (CMF).

[0070] Dosing and therapeutic regimes can be administered appropriate to the neoplasm to be treated, as understood by those skilled in the art. For example, 5-FU can be administered intravenously at dosages between 25 mg/m² and 1000 mg/m².

[0071] In some embodiments, medications are administered in a therapeutically effective amount as part of a course of treatment. As used in this context, to "treat" means to ameliorate at least one symptom of the disorder to be treated or to provide a beneficial physiological effect. For example, one such amelioration of a symptom could be reduction of tumor size and/or risk of relapse.

[0072] A therapeutically effective amount can be an amount sufficient to prevent, reduce, ameliorate or eliminate the symptoms of cancer. In some embodiments, a therapeutically effective amount is an amount sufficient to reduce the growth and/or metastasis of a cancer.

[0073] Various embodiments are also directed to diagnostic scans performed after treatment of an individual to detect residual disease and/or recurrence of neoplastic growth. If a diagnostic scan indicates residual and/or recurrence of neoplastic growth, further treatments may be performed as described herein. If the neoplastic growth and/or individual is susceptible to recurrence, diagnostic scans can be performed frequently to monitor any potential relapse.

EXAMPLES

[0074] The embodiments described will be better understood with the several examples provided within. It has been discovered that Fc receptor activation enhances antibody dependent phagocytosis in macrophages. The results provide support for treatments using macrophages that have been activated via FcR signaling. The results also provide that a light responsive peptide can be utilized to activate macrophages without the presence of a specific antigen with bound antibody.

Example 1 : Prior Fc Receptor Activation Enhances Antibody Dependent Phagocytosis in Macrophages

[0075] Macrophages phagocytose foreign pathogens and native cells that infected, cancerous or dying. To select targets for phagocytosis, macrophages measure ‘Eat Me’ signals, like IgG antibodies. IgG is recognized by the Fc Receptor (FcR), which is phosphorylated and recruits the kinase Syk, triggering downstream signaling (see., e.g., S. A. Freeman, Immunological Reviews 2014, 262:193-215; and Y. Zhang Proceedings of the National Academy of Sciences 2010, 107:19332-19337; the disclosures of which are each incorporated herein by reference). Therapeutic IgGs like Rituximab trigger Antibody-dependent Cellular Phagocytosis (ADCP) or Antibody-dependent Cellular Cytotoxicity (ADCC) to reduce cancer growth. Many antibodies originally designed to block the function of their target actually activate the FcR for full efficacy. Given the therapeutic importance, there is substantial interest in understanding how to boost macrophage phagocytosis.

[0076] What affects macrophage appetite? One important parameter is how sensitive a macrophage is to ‘Eat me’ signals. Antibody-dependent phagocytosis requires the coordinated activation of a sufficient number of Fc Receptors. Targets with a subthreshold amount of IgG are not phagocytosed, despite triggering the initial steps in the phagocytosis signaling pathway. In other macrophage signaling pathways, low levels of activating signal do not elicit any response on their own, but prime macrophages for rapid and intense response to future stimuli. Whether sub threshold FcR signaling has any effect on macrophage appetite is not clear.

[0077] During an immune response macrophages encounter multiple potential targets for phagocytosis sequentially. Some encounters with antibody-opsonized cells result in phagocytosis of the entire cell, but many do not. Instead macrophages may trogocytose, or nibble, a target cell or simply ignore it. In some circumstances, prior phagocytosis increases macrophage appetite, while in others it decreases macrophage appetite. There is no clear, unifying model explaining these differences, which could be explained by the specific eat me signal, the time since phagocytosis, the intensity of the eat me signal, or any number of other factors.

[0078] To unravel how prior IgG exposure affects macrophage appetite, an assay can be performed to precisely control the timing and intensity of activating specific phagocytic receptors. Delivering a temporally controlled, homogenous antibody stimuli to a population of cells was very difficult with the current tools. Because soluble IgG does not activate the Fc Receptor, IgG must be presented on antibody bound targets. Due to the size of these targets relative to cells, they are not distributed equally across the macrophage population with some cells encountering multiple targets while others encounter none. Further, it is difficult to precisely and rapidly remove these targets to end Fc Receptor activation.

[0079] To quantitatively control the duration and strength of FcR activation, an optogenetic Fc receptor (optoFcR) we developed. It was found that prior FcR activation primes macrophages for greater responses to subsequent stimuli. Counterintuitively, low levels of optoFcR activation induced stronger priming than high levels of optoFcR activation. Macrophage priming is controlled by two independent mechanisms, one shortterm (<1 hour) and one long-term response (starting at 4 hours, and lasting up to 3 days). The short-term response is associated with an increase in Fc Receptor mobility that accelerates initiation of phagocytosis and decreases the chance of phagocytic cup retraction and failure. The long-term response requires activation of Erk to drive changes in transcription. These data suggest that macrophages can integrate signaling from previous encounters with IgG to modify the response to the next target.

Results

Optogenetic Fc Receptor recapitulates native Fc Receptor signaling for precise temporal control over signaling.

[0080] To determine if macrophages integrate information across multiple encounters with antibody bound targets, an optogenetic Fc Receptor was designed and fabricated that could be turned on and off with light. This would allow control of the temporal pattern of FcR activation across an entire field of cells. Prior work has shown that the Fc Receptor clusters upon IgG binding, and that FcR clustering promotes phagocytosis. It was hypothesized that clustering may be sufficient to induce Fc Receptor activation. To test this, an optoFcR construct was designed that consists of a myristoylation sequence for membrane localization, the functional ITAM domain for the native Fc Receptor and a light activatable peptide CRY2. Upon blue light (450nm) stimulation the optoFcR clusters (Figs. 2A and 2B). This clustering is reversed when the cells are returned to the dark. These clusters recruited the downstream effector protein Syk, suggesting that clustering was sufficient to induce Fc Receptor phosphorylation (Figs. 2C and 2D). [0081] It was next sought to determine if clustering of the optoFcR is sufficient to trigger phagocytosis. ICAM-1 conjugated beads were incubated with macrophages expressing either the optoFcR or membrane tethered GFP (GFP-CAAX) and stimulated with 15 min of light using the 488nm laser line on the confocal microscope. ICAM-1 allows for binding to the macrophage, but does not trigger phagocytosis of otherwise unopsonized beads. Macrophages expressing the optoFcR engulfed three times as many beads as control macrophages when stimulated with the highest intensity light and twice as many beads when stimulated with medium intensity light (Figs. 2E and 2F). Low intensity light did not activate phagocytosis, suggesting that a sub-threshold dose of light can be delivered to macrophages. Together, these data demonstrate that clustering of the FcR ITAM domain is sufficient to initiate phagocytosis in macrophages without a specific ligand.

Prior optoFcR activation generates a molecular memory that enhances phagocytosis of IgG coated beads and opsonized cancer cells.

[0082] With the ability to temporally control FcR activation in bone marrow derived macrophages, we next sought to determine if prior FcR activation influences phagocytic ability. Using low, medium, and high intensity light, macrophages were stimulated with blue light to activate the optoFcR for 15 minutes. IgG opsonized bead targets were added following either a 1 or 12 hr delay from light stimulation, and the number of beads engulfed per cell after 15 min were counted. The fold chance in phagocytosis from unstimulated optoFcR or mChCAAX expressing macrophages was calculated. It was found that prior activation increased the amount of eating roughly 2-fold in macrophages that previously received a low dose of optoFcR activation (Figs. 3A, 3B, and 3C). This suggests that prior FcR activation primes macrophages to respond to future IgG stimuli by integrating subthreshold stimuli to increase responses to future targets.

[0083] It was next sought to determine if primed macrophages are capable of increasing whole cell eating of opsonized cancer cell targets. In addition to phagocytosis, macrophages often trogocytose target cells, stripping the cancer cells of target antigen without killing them. To measure both the amount of whole cell phagocytosis and trogocytosis, IgG opsonized Raji cell targets were coincubated with primed or unprimed optoFcR expressing bone-marrow derived macrophages (BMDMs) and imaged every 2 minutes for 10 hours. The number of trogocytosis and phagocytosis events were counted in each condition. The results show that following the initial stimulation the percentage of macrophages that phagocytosed increased, but not the percentage that trogocytosed, (Figs. 3D and 3E). The total number of cancer cells phagocytosed was almost 3 times higher in macrophages that received a priming dose of light compared to macrophages that did not have prior stimulation (Fig. 3F).

Priming specifically enhances macrophage sensitivity to IgG.

[0084] It was next investigated if prior FcR stimulation changed macrophage sensitivity for IgG, lowering the threshold amount of IgG required for initiating phagocytosis, or if capacity - the maximum number of targets each macrophage can engulf - was increased. (Figs. 3G and 3H). IgG Beads were added at various concentrations to BMDMs and assessed for phagocytic index. Primed macrophages show enhanced eating of beads with low concentration of IgG. While capacity is reached with a lower concentration of IgG, the total capacity for phagocytosis is not significantly changed. This indicated that priming primarily alters how a macrophage sets a threshold for what to eat, integrating previous low-level encounters with potential targets.

[0085] It was next assessed whether prior FcR activation specifically primed macrophages to phagocytose IgG coated targets or if it broadly enhanced phagocytosis unspecific to IgG. it was first determined whether prior FcR activation increased nonspecific phagocytosis of unopsonized targets. Primed macrophages did not phagocytose more unopsonized beads than control macrophages (Fig. 3I). It was then determined if prior FcR activation increased efferocytosis, the engulfment of apoptotic cells. Efferocytosis is similar to antibody-dependent phagocytosis but is mediated by separate receptors and follows a divergent cellular signaling pathway. By integrating the efferocytic signal phosphatidylserine (PS) into the lipid mixture of the silica bead targets, the apoptotic corpse engulfment is recapitulated in vitro. PS coated beads were incubated with macrophages at 1 and 12 hours post light stimulation and measured the amount of eating. There was no change in the amount of eating at either timepoint (Fig. 3J). These data suggest that prior FcR activation primes macrophages to specifically react to IgG.

Macrophage priming occurs through a short term and long-term mechanism.

[0086] It was next sought to determine the molecular mechanism for enhanced phagocytosis after FcR activation. While 12 hours post-stimulation is likely enough time for changes in transcription or translation to affect macrophage phenotypes, 1 hour is likely too short for this mechanism. It was decided to carefully assess when macrophage priming occurred. To do this length of time after activating optoFcR was varied before presenting a IgG coated beads and measuring phagocytosis. Robust priming occurred in two discrete waves: a short-term response that peaks around 1 hour after FcR activation, and a long-term response that begins at 4 hours after FcR activation and persists for at least 24 hours (Fig. 4A).

[0087] As the long-term priming following optoFcR activation persists for up to 72 hours, it was speculated that this response requires de novo protein production rather than a more transient post-translational modification mechanism. To assess this hypothesis, primed macrophages were treated with cycloheximide and actinomycin D to inhibit translation and transcription respectively. Treatment with either cycloheximde or actinomycin D significantly reduced phagocytosis compared to control macrophages at 4 and 6 hours, but not at 1 hour, post light stimulation (Fig. 4B). This suggests that de novo mRNA and protein synthesis is required for a long-term memory response but not 1-hour post stimulation, suggesting that short-term memory may utilize post-translation modification or other rapid mechanisms. These results suggest that there are two distinct mechanisms for macrophage priming - one that operates on a short timescale and does not require protein synthesis, and one that operates on a long time scale and requires gene transcription and translation. ERK activation is required for long term priming.

[0088] Because long term priming requires new protein production, it was sought to dissect which transcriptional programs were being executed by the macrophages. ERK, a nuclear kinase, and NFkB, a transcription factor, are downstream of the FcR and regulate the macrophage's dose dependent response to LPS as well as many other immune signaling pathways. To determine if these proteins contribute to long term macrophage priming, ERK and NFkB inhibitors were used to block their activation and optoFcR was simulated in macrophages before adding IgG coated beads. Inhibiting ERK signaling blocked long-term memory with no effect on short-term memory (Fig. 4C). These results indicate that long-term priming requires a transcriptional response mediated by ERK activation.

Initiation of engulfment proceeds faster and the probability of completing phagocytosis is higher in primed macrophages.

[0089] Because short-term priming is controlled by a separate mechanism from longterm priming, it was next sought to determine the mechanism for short term priming. It was first sought to determine which step in the phagocytic process was enhanced by prior sub-threshold activation of the FcR. The kinetics of engulfment was quantified using live cell imaging, breaking the process of phagocytosis into three steps: binding, initiation, and completion (Figs. 5A and 5B) (for more on assay details, see N. Kern, Elife. 2021 , 10:e68311 , the disclosure of which is incorporated herein by reference). The time between each step and the percent of macrophages that successfully progressed from one step to the next without retracting their membrane and releasing the target was quantified, comparing primed and unprimed macrophages. Initiation of engulfment proceeded faster in stimulated macrophages (Fig. 5C), while there was no change in the time between initiation and completion (Fig. 5D). This indicates that prior sub-threshold FcR activation primes macrophages for faster target recognition - implicating early phagocytic machinery. Further, the percent of bead contacts that turn into successful phagocytic events is significantly increased in primed macrophages. This suggests that the increase in phagocytosis between primed and unprimed macrophages is due to a reduction in the percent of failed phagocytosis attempts.

Methods

Bone-marrow derived macrophage cell culture.

[0090] Six- to ten-week-old C57BL/6 mice were sacrificed by CO2 inhalation. Hips and femurs were dissected and bone marrow was harvested as described in Weischenfeldt and Porse (Bone Marrow-Derived Macrophages (BMM): Isolation and Applications. CSH Protoc. 2008, 2008:pdb.prot5080, the disclosure of which is incorporated herein by reference). Macrophage progenitors were differentiated for seven days in lymphocyte media (RPMI-1640, 10% FBS, 1 % PSG) supplemented with 20% L929- conditioned media. Macrophage differentiation was confirmed by flow cytometry identifying cd11 b and f4/80 double positive cells.

Lentivirus production and infection.

[0091] All constructs were expresses in BMDMs using lentiviral infection. Lentivirus was produced in HEK293T cells transfected with pMD2.G (Addgene plasmid # 12259 containing the VSV-G envelope protein), pCMV-dR8.2 (Addgene plasmid #8455), and a lentiviral backbone vector containing the construct of interest using lipofectamine LTX (Invitrogen, Catalog # 15338-100). The media was harvested 72 h post-transfection, filtered through a 0.45 pm filter and concentrated using LentiX (Takara Biosciences). Concentrated lentivirus was added to cells. Cells were analyzed a minimum of 60 h later, and maintained for a maximum of one week.

ICAM-1 protein purification.

[0092] ICAM-tagBFP-Hisw was expressed in SF9 or HiFive cells using the Bac-to-Bac baculovirus system as described previously (See G. P. O’Donoghue, et al., Elife. 2013, 2:e00778; and E Hui and R. D. Vale, Nat Struct Mol Biol. 2014, 21 (2): 133-142, the disclosure of which is incorporated herein by reference). Insect cell media containing secreted proteins was harvested 72 h after infection with baculovirus. His10 proteins were purified by using Ni-NTA agarose (QIAGEN, Catalog # 30230), followed by size exclusion chromatography using a Superdex 200 10/300 GL column (GE Healthcare, Catalog # 17517501 ). The purification buffer was 150 mM NaCI, 50 mM HEPES pH 7.4, 5% glycerol, 2 mM TCEP.

Supported lipid bilayer coated beads.

[0093] SUV preparation: For IgG conjugated beads the following chloroformsuspended lipids were mixed and desiccated overnight to remove chloroform: 98.8% POPC (Avanti, Catalog # 850457), 1 % biotinyl cap PE (Avanti, Catalog # 870273), 0.1% PEG5000-PE (Avanti, Catalog # 880230, and 0.1 % atto390-DOPE (ATTO-TEC GmbH, Catalog # AD 390-161 ). The lipid sheets were resuspended in PBS, pH7.2 (GIBCO, Catalog # 20012050) and stored under inert gas.

[0094] For ICAM-1 conjugated beads following chloroform-suspended lipids were mixed and desiccated overnight to remove chloroform: 97.8% POPC (Avanti, Catalog # 850457), 2% DGS-NTA (Avanti, Catalog # 790404), 0.1 % PEG5000-PE (Avanti, Catalog # 880230, and 0.1% atto390-DOPE (ATTO-TEC GmbH, Catalog # AD 390-161 ). The lipid sheets were resuspended in PBS, pH7.2 (GIBCO, Catalog # 20012050) and stored under inert gas.

[0095] For PS beads the following chloroform-suspended lipids were mixed and desiccated overnight to remove chloroform: 89.8% POPC (Avanti, Catalog # 850457), 10% DOPS (Avanti, Catalog # 840035), 0.1 % PEG5000-PE (Avanti, Catalog # 880230, and 0.1 % atto390-DOPE (ATTO-TEC GmbH, Catalog # AD 390-161). The lipid sheets were resuspended in PBS, pH7.2 (GIBCO, Catalog # 20012050) and stored under inert gas.

[0096] The lipids were broken into small unilamellar vesicles via several rounds of freeze-thaws. The lipids were then stored at -80°C under argon for up to six months.

[0097] Bead preparation: Silica beads with a 4.98 pm diameter (10% solids, Bangs Labs, Catalog # SS05N) were washed with PBS, mixed with 1 mM SUVs in PBS and incubated at room temperature for 30 min with end-over-end mixing to allow for bilayer formation. Beads were then washed with PBS to remove excess SUVs and incubated in 0.2% casein (Sigma, catalog # C5890) in PBS for 15 min before protein coupling (IgG and ICAM-1 beads). For IgG conjugated beads, anti-biotin AlexaFluor647-lgG (Jackson ImmunoResearch Laboratories Catalog # 200-602-211 , Lot # 137445) was added at 1 nM, unless otherwise indicated. For ICAM-1 conjugated beads, ICAM-1 was added at 10nM. Proteins were coupled to the bilayer for 30 min at room temperature with end-over- end mixing.

[0098] Bead enqulfment assay: 50,000 BMDMs were plated in one well of a 96-well glass bottom MatriPlate (Brooks, Catalog # MGB096-1 -2-LG-L) between 12 and 24 h prior to the experiment. ~8 x 10⁵ beads were added to well and engulfment was allowed to proceed for 15 min.

[0099] Microscopy and analysis: Images were acquired on a spinning disc confocal microscope (Nikon Ti2-E inverted microscope with a Yokogawa CSU-W1 spinning disk unit and an Orca Fusion BT scMos camera) equipped with a 40 x 0.95 NA Plan Apo air and a 100 x 1.49 NA oil immersion objective. The microscope was controlled using Nikon Elements. Data was analyzed in Imaged by a blinded analyzer.

Optogenetics stimulation.

[0100] Cells receiving low intensity (12 uM/cm²) and medium intensity (442 uW/cm²) were stimulated using a LITOS LED illumination plate (T. C. Hohener, et al., ci Rep. 2022, 12(1 ): 13139, the disclosure of which is incorporated herein by reference). Cells receiving high intensity were stimulated using the 488 laser on a spinning disc confocal microscope for 1 s at 20 s for a total of 15 m.

Raji eating assay.

[0101] 40,000 BMDMs were plated in 1 well of a 96-well glass bottom plate 24 hrs prior to the experiment and stimulated with low intensity LITOS illumination 12 hrs prior to the experiment. Raji cells were dyed with CellTrace Far Red (Thermo, C34572), incubated with a human-mouse hybrid aCD20 (InvivoGen hcd20-mab10, 5ng/ml), added to wells at 40,000 cells per well, and imaged immediately. 25 positions per well were automatically selected and imaged every 3 min for 10 hrs. Phagocytic macrophages were characterized as BMDMs that engulfed whole raji cell targets. Trogocytic macrophages were characterized as BMDMs that engulfed portions of raji targets.

Kinetics of engulfment.

[0102] BMDMs were plated as described in bead engulfment assay 12-24 hrs prior to the experiment and stimulated with low intensity LITOS illumination 1 hr prior to the experiment. Using ND acquisition in Elements, 2-3 positions per well were manually selected and imaged at 20 s intervals through 7 z planes for 15 min. Approximately 4 x 10⁵ beads were added and imaged immediately.

Example 2: OptoFcR peptide

[0103] The optogenetic FcR (optoFcR) is a light sensitive peptide for activation of macrophages. The peptide can be specifically manipulated for controllable inputs into the macrophage inducing phagocytosis, inflammation, and antigen cross presentation. This modular tool consists of: a myristoylation sequence for plasma membrane localization; the internal tyrosine activation motif (ITAM) of the Fc Receptor common gamma chain (aa 45-86 Uniprot P20491 (FCERG_MOUSE)) for cellular signaling; the fluorophore mScarlet (mSc) for visualization (aa 1 -232 Sequence ID APD76535.1 ); the photoreceptor protein cryptochrome 2 for light induced activation (aa 1-498 Uniprot Q96524 (CRY2_ARATH)). The optoFcR peptide used in various experimentation has the following amino acid sequence:

MGSSKSKPKDPSQRRLKIQVRKAAIASREKADAVYTGLNTRSQETYETLKHEKPPQST SGMVS

KGEAVIKEFMRFKVHMEGSMNGHEFEIEGEGEGRPYEGTQTAKLKVTKGGPLPFSWD ILSPQF

MYGSRAFTKHPADIPDYYKQSFPEGFKWERVMNFEDGGAVTVTQDTSLEDGTLIYKV KLRGTN

FPPDGPVMQKKTMGWEASTERLYPEDGVLKGDIKMALRLKDGGRYLADFKTTYKAKK PVQMP

GAYNVDRKLDITSHNEDYTVVEQYERSEGRHSTGGMDELYKSDPGSGSMKMDKKTIV WFRRD

LRIEDNPALAAAAHEGSVFPVFIWCPEEEGQFYPGRASRWWMKQSLAHLSQSLKALG

SDLTLIK

THNTISAILDCIRVTGATKWFNHLYDPVSLVRDHTVKEKLVERGISVQSYNGDLLYEPW

EIYCEK

GKPFTSFNSYWKKCLDMSIESVMLPPPWRLMPITAAAEAIWACSIEELGLENEAEKPSN

ALLTRA

WSPGWSNADKLLNEFIEKQLIDYAKNSKKVVGNSTSLLSPYLHFGEISVRHVFQCARM

KQIIWA

RDKNSEGEESADLFLRGIGLREYSRYICFNFPFTHEQSLLSHLRFFPWDADVDKFKAW

RQGRT

GYPLVDAGMRELWATGWMHNRIRVIVSSFAVKFLLLPWKWGMKYFWDTLLDADLEC

DILGWQ

YISGSIPDGHELDRLDNPALQGAKYDPEGEYIRQWLPELARLPTEWIHHPWDAPLTVLK

ASGVE LGTNYAKPIVDIDTARELLAKAISRTRGAQIMIGAAARDPP*

(SEQ. ID No: 1 )

Claims

WHAT IS CLAIMED IS:

1 . A method of activating an immune cell, comprising: expressing a light sensitive peptide within an immune cell, wherein the light sensitive peptide comprises a means for locating to the cellular membrane, an activating domain, and a clustering domain that is responsive to light; and impinging light energy onto the immune cell.

2. The method of claim 1 , wherein the means for locating to the cellular membrane is one of: a membrane localization motif sequence, a sequence of amino acids that signals for palmitoylation, a sequence of amino acids that signals for myristoylation, or a sequence of amino acids that signals for prenylation.

3. The method of claim 1 or 2, wherein the activating domain is an amino acid sequence of an immune receptor that activates signaling in an immune cell.

4. The method of claim 1 , 2 or 3, wherein the activating domain is one of: ITAM, Megfl O, FcRy, Bail , MerTK, TIM4, Stabilin-1 , Stabilin-2, RAGE, CD300f, Integrin subunit av, Integrin subunit |35, CD36, LRP1 , SCARF1 , C1 Qa, Axl, or YxxL/lx(6-8)YxxL/l.

5. The method of any one of claims 1-4, wherein the clustering domain that is responsive to light is one of: CRY2, CRY2clust, CRY2olig, CRY2PHR, CRY2/CIB1 , Cph1 , or DrBpHP.

6. The method of any one of claims 1 -5, wherein the light sensitive peptide further comprises a marker peptide domain or a peptide tag.

7. The method of any one of claims 1 -6, wherein the immune cell is transfected or transduced with an expression cassette comprising a nucleic acid sequence for expressing the light sensitive peptide.

8. The method of any one of claims 1-7, wherein the immune cell is one of: a macrophage, a dendritic cell, a B cell, a T cell, a natural killer cell, a neutrophil, an eosinophil, a basophil, a mast cell, a microglial cell, or an astrocyte.

9. The method of any one of claims 1-8, wherein the immune cell is a CAR T cell or a CAR macrophage.

10. The method of any one of claims 1 -9, wherein the immune cell is a phagocytic- capable immune cell.

11. The method of claim 10, wherein the phagocytic-capable immune cell is: a macrophage, a dendritic cell, or a neutrophil.

12. The method of claim 10 or 11 further comprising: activating the phagocytic-capable immune cell to enhance phagocytosis in an antibody-dependent manner but not in an unspecific manner.

13. The method of claim 12, wherein the activating of the phagocytic-capable immune cell is controlled by an amount of light sensitive peptide expressed in the cell.

14. The method of claim 12 or 13, wherein the activating of the phagocytic-capable immune cell is controlled by an amount of light energy impinged on the cell.

15. The method of claim 12, 13 or 14 further comprising: performing an assessment to determine whether the phagocytic-capable immune cell is activated to enhance phagocytosis in an antibody-dependent manner but not in an unspecific manner.

16. The method of any one of claims 12-15, further comprising: upon activating the phagocytic-capable immune cell, contacting the phagocytic- capable cell with an opsonized target, wherein the opsonized target is opsonized with an antibody.

17. The method of claim 16, wherein the antibody is IgG.

18. The method of any one of claims 12-15, further comprising: upon activating the phagocytic-capable immune cell, administering the phagocytic- capable cell to an individual.

19. The method of claim 18, further comprising: administering antibodies to the individual.

20. The method of claim 19, wherein the antibodies target a neoplastic antigen or a pathogenic antigen.

21 . A method of activating enhanced antibody dependent phagocytosis in an immune cell, comprising: providing a phagocytic-capable immune cell that expresses an Fc Receptor; and contacting the phagocytic-capable immune cell with an IgG antibody bound with an antigen.

22. The method of claim 21 , wherein the phagocytic-capable immune cell is: a macrophage, a dendritic cell, or a neutrophil.

23. The method of claim 21 or 22 further comprising: activating the phagocytic-capable immune cell to enhance phagocytosis in an antibody-dependent manner but not in an unspecific manner.

24. The method of claim 23, wherein the activating of the phagocytic-capable immune cell is controlled by an amount of the IgG antibody bound with an antigen used for contacting the phagocytic-capable immune cell relative to an amount of phagocytic- capable immune cells provided.

25. The method of claim 23 or 24, wherein the activating of the phagocytic-capable immune cell is controlled by an amount of time the IgG antibody bound with an antigen is allowed to contact the phagocytic-capable immune cell.

26. The method of claim 23, 24, or 25 further comprising: performing an assessment to determine whether the phagocytic-capable immune cell is activated to phagocytose in an antibody-dependent manner but not in an unspecific manner.

27. The method of any one of claims 23-26 further comprising: upon activating the phagocytic-capable immune cell, contacting the phagocytic- capable cell with an opsonized target, wherein the opsonized target is opsonized with an antibody.

28. The method of any one of claims 23-26 further comprising: upon activating the phagocytic-capable immune cell, administering the phagocytic- capable cell to an individual.

29. The method of claim 28, further comprising: administering antibodies to the individual.

30. The method of claim 29, wherein the antibodies administered to the individual targets a different antigen than the IgG antibody bound with an antigen used to contact the phagocytic-capable immune cell.

31 . A method of treatment, comprising: extracting immune cells from an individual, wherein the in immune cells comprise phagocytic-capable immune cells that express an Fc receptor; contacting the immune cells with IgG antibody having bound antigen to activate FcR signaling in the phagocytic-capable immune cells; administering the activated immune cells back to the individual; and administering IgG that targets a neoplastic antigen or a pathogenic antigen.

32. A method of treatment, comprising: extracting immune cells from an individual; engineering the immune cells to express a light sensitive peptide comprising a means for locating to the cellular membrane, an activating domain, and a clustering domain that is responsive to light; impinging light energy on the immune cells to activate signaling via the light sensitive peptide; and administering the engineered immune cells back to the individual.

33. The method of claim 32, wherein the in immune cells comprise phagocytic-capable immune cells.

34. The method of claim 33 further comprising: activating the phagocytic-capable immune cell to enhance phagocytosis in an antibody-dependent manner but not in an unspecific manner.

35. The method of claim 34 further comprising: performing an assessment to determine whether the phagocytic-capable immune cell is activated to phagocytose in an antibody-dependent manner but not in an unspecific manner.

36. The method of claim 34 or 35, further comprising: administering antibodies to the individual, wherein the antibodies target a neoplastic antigen or a pathogenic antigen.

37. The method of any one of claims 32-36, wherein the step of impinging light energy on the immune cells is performed after administering the engineered immune cells back to the individual.

38. The method of claim 37, wherein the step of impinging light energy on the immune cells is performed utilizing an endoscope and is directed at a tumor.

39. A method of treatment, comprising: enveloping mRNA that encodes a light sensitive peptide within liposome; administering liposome-mRNA complex to an individual to express the light sensitive peptide within immune cells, wherein the light sensitive peptide comprises a means for locating to the cellular membrane, an activating domain, and a clustering domain that is responsive to light; and impinging light energy on a tumor to activate signaling via the light sensitive peptide.

40. A peptide comprising: a means for locating to the cellular membrane, an activating domain, and a clustering domain that is responsive to light.