CN117625545A

CN117625545A - Modified targeted HBV immune cells and medical application thereof

Info

Publication number: CN117625545A
Application number: CN202211040259.XA
Authority: CN
Inventors: 张柯; 金涛; 黄延周; 卡琳·魏斯基兴; 乌尔丽克·普罗策
Original assignee: Singapore Star Hand Biopharmaceutical Co ltd
Current assignee: Singapore Star Hand Biopharmaceutical Co ltd
Priority date: 2022-08-29
Filing date: 2022-08-29
Publication date: 2024-03-01
Also published as: WO2024049348A1

Abstract

The present invention provides a modified immune cell comprising a T Cell Receptor (TCR) capable of specifically targeting HBV surface antigen and a chimeric switching receptor that employs an intracellular activation signal domain of a co-stimulatory molecule in place of an intracellular inhibition signal domain of an immunosuppressive receptor to switch an inhibitory signal induced by binding of the immunosuppressive receptor to a ligand to an activation signal. The invention also provides nucleic acid molecules encoding the TCR and/or encoding the chimeric transition receptor, vectors comprising the nucleic acid molecules, and their use in medicaments for the prophylaxis and/or treatment of HBV infection and diseases associated therewith.

Description

Modified targeted HBV immune cells and medical application thereof

Technical Field

The application relates to the technical field of immunotherapy, in particular to a modified targeted HBV immune cell and medical application thereof.

Background

1.1 Worldwide HBV epidemic

HBV is a non-cytopathic double-stranded DNA virus, transmitted primarily through blood, maternal or sexual transmission. Although HBV has available vaccines and high-potency antiviral agents that act directly, HBV still creates a significant disease burden in the world population. The number of HBV carried worldwide in 2015 is 2.57 hundred million, and the number of deaths caused by chronic HBV infection complications exceeds 88.4 ten thousand, which is equivalent to one death occurring every 36 seconds. Epidemiological study estimates indicate a higher proportion of HBV infection in asian and african countries than in america or europe.

1.2 HBV and HLA genotypes most commonly infected in Asian people

HBV is subject to mutation to produce different genotypes, and it is reported that there are currently 10 different HBV genotypes worldwide. In Asian countries, however, HBV genotypes are mainly subtype B and subtype C. HBV genotype is significantly correlated with prognostic factors such as progression of liver disease, risk of cirrhosis, development of hepatocellular carcinoma (HCC), etc. Researchers have focused on the popularity of different genotypes in different regions. For example, genotypes C and D are more prone to develop cirrhosis and HCC than other genotypes.

Human Leukocyte Antigen (HLA), the most polymorphic gene complex genotyping in the human genome includes HLA-A, HLA-B, HLA-C, HLA-DRB1, HLA-DQB1, and the like. The HLA-A alleles have been found to play a more important role in the Chinese Han population than other HLA genes. The most common subtype HLA-A x 02 in asia is: 01, *02:06 and x 02:07.

1.3 HCC and carcinogenic pathway thereof

Primary liver cancer (HCC, hepatocellular carcinoma) is a fatal long-term complication of chronic hepatitis infection, most commonly in asians. HCC resulted in approximately 47 tens of thousands of deaths in 2017. The molecular pathology of HCC development is a complex process involving various molecular aberrations and genetic mutations, ultimately leading to malignant disease and HCC progression.

HBV-DNA integration is found in 80-90% of HBV-associated hepatocellular carcinoma. HBV-DNA integration plays an important role in the development and progression of HBV-associated HCC. First, HBV-DNA contains genes related to liver cancer occurrence, such as genes encoding telomerase reverse transcriptase, lysine methyltransferase 2B and cyclin A2. Second, HBV integrates into the human genome, increasing genomic instability through the impact on insertion site gene expression, thereby activating certain oncogenic pathways such as phosphoinositide-3-kinase/Akt, myc, wnt/β -catenin, c-Met, hedgehog, and the like. It is thought that activation of Akt signaling inhibits Transforming Growth Factor (TGF) - β -induced apoptosis, promotes neoplasia, and is also associated with β -catenin signaling, thereby triggering hepatocellular carcinoma. In addition, molecular changes due to HBV-DNA integration can also damage DNA checkpoints and lead to tumor formation in the hardened liver. These molecular changes include loss of p53 tumor suppressor function, inactivation of p27 cell cycle regulatory factors, loss of heterozygosity at the insulin-like growth inhibitory 2 receptor site, and loss of p16 cell cycle inhibitor protein expression.

In summary, HBV virus causes changes in liver gene expression, which characterizes cellular tumors. These changes involve alterations in DNA methylation, alterations in mRNA expression profiles, and combined activation of many signal transduction pathways. Among them, the main mechanism of liver cancer induction is mediated by immune response. The virus utilizes an oxidation environment created by immune reaction in the liver to structurally activate a signal pathway, block apoptosis, promote cell survival and support HBV replication, thereby promoting the continuous existence of the virus; at the same time, viruses may also inhibit or block innate immunity, thereby affecting the development of an adaptive immune response. This chronic, persistent immune response, which is characterized in pathological levels by hepatitis and long-term fibrosis, ultimately leads to cirrhosis and liver cancer.

An integrated HBV-DNA comprising an envelope protein of the complete Open Reading Frame (ORF) which can be used as a template for the production of HBs protein. The transcript level of HBV-DNA integrated in the genome of HCC cells and the expression level of HBs protein are positively correlated. Furthermore, HBs protein is expressed in the metastasis of HBV-related HCC. There are studies showing that when the complete open reading frame of HBs protein is chimeric into the host genome, HBs protein can be detected in plasma samples, HCC tumor tissue, while HBs protein is not expressed in adjacent liver tissue. This suggests that these HBs proteins are not caused by infection, but rather are derived from HBV viral genes that are embedded in the host cell genome during the development and progression of liver cancer. I.e. liver cancer cells continuously express HBs protein without HBV infection. Antiviral drugs have no inhibitory or downregulating effect on the protein expressed by this integrated HBV gene. Thus, HCC patients, even under antiviral treatment, are positive for HBs protein expression.

1.4 Current state of treatment for HCC

Currently, surgical resection and liver transplantation are the most effective methods of treating HCC, but HCC patients meeting these surgical criteria are less than 30% and eligible patients have a post-operative recurrence rate of up to 80% within 5 years. In addition, the waiting time of the donor liver is long, and the number of people waiting for transplantation continues to increase, resulting in nearly 25% of patients eventually not receiving transplantation due to tumor progression. The most common conservative treatment is Transcatheter Arterial Chemoembolization (TACE), but this therapy is not applicable to patients with advanced cirrhosis and liver function decompensation; in addition, ischemic injury associated with embolism can lead to increased ascites in the patient and potentially death.

The current FDA approved targeted drugs for the treatment of HCC are sorafenib and regorafenib, both tyrosine kinase inhibitors. Sorafenib had a median total survival (mOS) of 10.7 months in untreated advanced liver cancer and a median to disease progression time of 5.5 months. Two-line advanced HCC in which sorafenib first line treatment failed clinical studies with regorafenib had a mOS of 10.6 months, a median progression-free survival (mPFS) of 3.1 months, and an Objective Remission Rate (ORR) of 11% ]. Furthermore, clinical trial data of patients with advanced HCC suggest that sorafenib and regorafenib are associated with increased bleeding risk and arteriovenous thrombosis, and that their survival advantage in the indicated population is only 2-3 months, with prolonged patient progression. In addition, phase III clinical trials of advanced HCC that failed or was intolerant after past exposure to at least one line of systemic treatment showed that the apatinib group had a mOS of 8.7 months, a mPFS of 4.5 months, and an ORR of 10.7%. The survival data show that the current targeted drugs have limited curative effects.

In recent years, research into immunotherapy of HCC has made a major breakthrough. The status of immunotherapy in HCC first line therapy has been confirmed by relevant clinical studies, and the results of the immune combination therapy first line therapy phase III study (IMbrave 150) show that: the use of the combination of ati Li Zhushan antibody and bevacizumab (t+a) significantly reduced the risk of mortality and disease progression in patients compared to standard therapy sorafenib monotherapy, but the ORR (RECIST v 1.1) reached only 27.3% and its mPFS was only 6.8 months. In chinese patients with worse prognosis of advanced HCC, their mPFS is only 5.7 months. In addition, the basis of PD-1 in HCC two-wire treatment was confirmed in CheckMate-040 that PD-1 single-drug treatment of patients with advanced HCC without HCV or HBV infection, ORR was 15-20%, mOS of subjects not receiving sorafenib treatment was 28.6 months, mOS of subjects receiving sorafenib treatment was 15.6 months. The data show that the immunotherapy of HCC has greatly advanced compared with the prior art, but the curative effect is still poor and needs to be further studied.

Chemotherapy generally does not produce significant survival advantages for HCC patients. Although combination therapies of several chemotherapeutics are currently being developed, such as PIAF (cisplatin, interferon, doxorubicin and 5-fluorouracil), GEMOX (gemcitabine and oxaliplatin) and FOLFOX4 (fluorouracil, calcium folinate and oxaliplatin infusion), the clinical trials associated therewith have not been successful and the results have been incomplete.

HBV-related HCC patients require antiviral treatment to inhibit viral replication, reduce viral load, and improve prognosis of cirrhosis. Meanwhile, since the anti-tumor therapy may activate HBV again, the CSCO primary liver cancer diagnosis and treatment guide 2020 indicates that basic liver diseases must be highly emphasized, and suggests that antiviral therapy be used throughout the course of HCC diagnosis, treatment and clinical study. Antiviral therapy is recommended prophylactic antiviral treatment with entecavir and tenofovir Wei Hang.

Regorafenib and apatinib for class IA evidence and PD-1 mab for class 2A evidence are recommended by class I experts for advanced HCC two-line treatment according to the CSCO2020 guidelines, with no apparent superiority in the existing clinical trials.

In summary, new therapeutic strategies are needed to provide more treatment options for HBV-related HCC patients due to the limitations and risks of currently available therapies and drugs.

1.5 Role of T cells in HBV-associated HCC immunotherapy and rationale for using TCR T cells

T cells are immune cells derived from bone marrow, lymph, and differentiated to mature in Thymus (Thymus), whose surface expresses T cell antigen receptor (TCR), and play an important role in clearing infectious and cancerous cells in cell-mediated immunity. TCRs are capable of recognizing and specifically binding to target epitopes presented by Major Histocompatibility Complex (MHC) molecules. Once T cells recognize their target, they can be killed by a number of actions such as proliferation, cytokine release, and cytotoxicity. However, isolation and expansion of virus or tumor specific T cells from the blood of patients is very difficult and time consuming.

The characteristics determine that the target range of the TCR-T cell treatment is wider, including intracellular antigens, cell surface antigens and new antigens generated after tumor cell mutation, can overcome the difference caused by tumor heterogeneity on malignant tumor cell antigen expression, and embody higher therapeutic value.

In addition to this, clinical evidence suggests that adoptive immunotherapy of HBV-specific T cells can play a controlling role in HBV replication or tumor growth. The leukemia patient may even acquire the immunological competence to HBV after bone marrow transplantation, receiving bone marrow from a donor who is specifically immunized against HBV (from a HBV vaccine or who is recovering from HBV infection by means of autoimmunity). Also, the HBV infection of the transplanted liver can be cleared by transplanting HBV-positive liver to a subject having specific immunity to HBV.

Studies have shown that HBV-related HCC cells can be recognized in vivo by gene editing of T cells expressing HBV-specific T Cell Receptors (TCRs) and activated to expand without the observed exacerbation of liver inflammation or other toxicity while reducing HBs protein levels. Thus, HBs protein is a promising potential therapeutic target for HBV-related HCC.

After solving the above problems, T cell depletion is a constant and responsible for the poor efficacy of cell therapy in solid tumors. T cell depletion is common in malignant tumors and is a T cell dysfunction caused by long-term exposure to persistent antigen stimulation, i.e. T cells eventually lose effector function after sustained functioning, which is manifested as defects in (tumor necrosis factor) TNF and (interferon- γ) IFN- γ production. This is also one of the mechanisms by which malignant cells evade immunity. Furthermore, in HBV-associated HCC patients, HBV-specific T cell immunity is often severely suppressed. HBV-specific T cells are functionally defective, rare in number and prone to failure (exhaustion) in these patients. Due to these functional defects, in vitro analysis of patient blood barely detects HBV-specific T cells.

Therefore, the specific TCR of the targeted HBV surface antigen is developed by utilizing biological means such as genetic engineering and the like, T cells of a patient are isolated in vitro by transfection, and the construction of high-affinity TCR-T cells for reinfusion treatment becomes a new choice. However, at present, none of the TCR-T cells has been validated as safe and effective for the treatment of HBV-related diseases, particularly HBV-induced liver cancer; in addition, TCR-T cells are extremely easy to cause TCR-T cell failure due to immunosuppression in tumor microenvironment in solid tumor treatment experiments, so that the anti-tumor effect is poor.

Disclosure of Invention

In view of the technical problems existing at present, the application provides a modified immune cell which targets specific HBV surface antigen and can overcome immune cell exhaustion caused by tumor microenvironment immunosuppression. It can specifically kill liver cancer cells induced by HBV infection, thereby treating liver cancer induced by HBV infection.

A first aspect of the present application provides a modified immune cell comprising a T cell receptor (HBV TCR) that targets HBV surface antigen and a chimeric turnover receptor.

In some embodiments, the HBV TCR comprises a TCR a chain variable region and a TCR β chain variable region; wherein the amino acid sequence of the alpha CDR3 of the TCR alpha chain variable region is shown in SEQ ID NO. 3, or a variant thereof, wherein one or two amino acids are replaced by other amino acids; and the amino acid sequence of the beta CDR3 of the TCR beta chain variable region is shown in SEQ ID NO. 6, or a variant thereof, wherein one or two amino acids are replaced by other amino acids.

In some embodiments, the TCR a chain variable region comprises complementarity determining regions a CDR1, a CDR2, and a CDR3, and the TCR β chain variable region comprises complementarity determining regions β CDR1, β CDR2, and β CDR3, wherein: the alpha CDR1, the alpha CDR2 and the alpha CDR3 are respectively shown as SEQ ID NO 1, SEQ ID NO 2 and SEQ ID NO 3; the beta CDR1, the beta CDR2 and the beta CDR3 are respectively shown as SEQ ID NO 4, SEQ ID NO 5 and SEQ ID NO 6; or CDR variants in which one or two amino acids in one or more CDRs are replaced by other amino acids.

In some embodiments, the TCR a chain variable region comprises an amino acid sequence having at least 90% sequence identity to SEQ ID NO. 7; in some embodiments, the TCR β chain variable region comprises a sequence identical to SEQ ID NO:8, an amino acid sequence having at least 90% sequence identity.

The chimeric transition receptor comprises: an extracellular domain of an immunosuppressive protein (ECD), wherein the ECD is fused to an intracellular domain of a costimulatory molecule (ICD) that mediates an immune cell activation signal; wherein binding of the extracellular domain of the immunosuppressive protein to its ligand generates an immune cell activation signal but not an immune cell deactivation signal in the modified immune cell.

The immunosuppressive protein is selected from any one of PD1, CTLA4, BTLA, TIM3, TIGIT, TGF beta receptor and any other protein with immunosuppressive function or related to immunosuppressive signal path and combination thereof, and ECD of the immunosuppressive protein can have at least one amino acid mutation.

In some embodiments, the ECD of the present application is a PD1 ECD; in some embodiments, at least one amino acid mutation may be present in the PD1 ECD sequence; in some embodiments, there is an amino acid mutation in PD1 ECD, an alanine mutation at position 132 to a leucine, which increases the affinity of PD1 ECD for PDL1, the ECD amino acid sequence being shown in SEQ ID NO. 9.

In some embodiments, the co-stimulatory molecule comprises: CD28, 4-1BB, ICOS, CD27, IL-12R, CD3, OX40 and combinations thereof, the ICD of the co-stimulatory molecule may have at least one amino acid mutation.

In some embodiments, the ICD of the present application is a CD28 ICD; in some embodiments, the ICDs of the present application are 4-1BB ICDs; in some embodiments, the CD28 ICD sequence may have at least one amino acid mutation; in some embodiments, the 4-1BB ICD sequence may have at least one amino acid mutation; in some embodiments, the CD28 ICD amino acid sequence is shown in SEQ ID NO. 12; in some embodiments, the amino acid sequence of 4-1BB ICD is shown in SEQ ID NO. 13.

In some embodiments, the ECD and the ICD are linked by a transmembrane region (TM) sequence; in some embodiments, the transmembrane region comprises a transmembrane domain of a protein selected from the group consisting of: the α, β or δ chain of a T cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD8, CD9, CD16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137 and CD154, and combinations thereof, may have at least one amino acid mutation in the transmembrane domain of the aforementioned proteins.

In some embodiments, the transmembrane region sequence is a CD8 transmembrane region sequence or a CD28 transmembrane region sequence; in some embodiments, the CD8 transmembrane region sequence is set forth in SEQ ID NO. 10; in some embodiments, the CD28 transmembrane region sequence is set forth in SEQ ID NO. 11.

In some embodiments, the chimeric transduction receptor is PD1 (ECD) -CD8 (TM) -4-1BB (ICD) (PD 1-BB); in some embodiments, the PD1-BB amino acid sequence is set forth in SEQ ID NO. 15; in some embodiments, the chimeric transduction receptor is PD1 (ECD) -CD28 (TM) -CD28 (ICD) (PD 1-28); in some embodiments, the PD1-28 amino acid sequence is set forth in SEQ ID NO. 16.

In some embodiments, the immune cells are selected from lymphocytes, dendritic cells, mononucleated, macrophages, granulocytes, mast cells; in some embodiments, the cell is a T cell.

In a second aspect the present application provides a nucleic acid molecule comprising a nucleic acid sequence encoding a TCR molecule as described in the first aspect of the present application; and/or comprises a nucleic acid sequence encoding a chimeric transition receptor described in the first aspect of the application.

In a third aspect the present application provides a vector, wherein the vector comprises a nucleic acid molecule according to the second aspect of the present application.

A fourth aspect of the present application provides a pharmaceutical composition comprising a pharmaceutically acceptable carrier and a modified immune cell as described in the first aspect of the present application, a nucleic acid molecule as described in the second aspect of the present application, a carrier as described in the third aspect of the present application.

In a fourth aspect, the present application provides the use of a modified immune cell according to the first aspect of the present application, a nucleic acid molecule according to the second aspect of the present application, a vector according to the third aspect of the present application or a pharmaceutical composition according to the fourth aspect of the present application in the manufacture of a medicament for the prevention or treatment of a disease associated with HBV infection; the HBV infection related diseases comprise one or more of hepatitis, liver fibrosis, liver cirrhosis and liver cancer.

The beneficial effects of this application:

in one aspect, the present application isolates T lymphocytes directed against HBV from a donor who has been cleared of HBV infection by means of autoimmunity and further establishes a HBV-specific TCR pool based on these T lymphocytes. The construction of HBs-TCR T cells is based on the results of the selection of TCR molecules in this pool. The modified immune cells we constructed can specifically recognize and lyse HBs positive HCC cells. On the other hand, the modified immune cells express chimeric conversion receptor while expressing targeted HBs TCR-T, highly competitively bind with PD-L1 molecules in tumor cells, convert PD-1/PD-L1 inhibitory signals into immune cell activation signals, effectively block cell depletion induced by natural PD-1 molecules on the surface of T cells, reduce the incapacitation of TCR-T cells in an immunosuppressive microenvironment, and increase the release of cytokines, promote the proliferation capacity and the tumor killing capacity of the cells. Meanwhile, the method is expected to overcome a series of difficult problems of tumor heterogeneity, difficult penetration of tumor barriers, short acting time, local immunosuppressive microenvironment and the like faced by the traditional liver cancer adoptive T cell immunotherapy, and has a huge application prospect in the field of solid tumor cell immunotherapy. In yet another aspect, in vitro and in vivo assays demonstrate that the modified immune cells of the present application, while enhancing the therapeutic utility of TCR-T cells, do not produce non-specific functions on cells negative for antigen and positive for PD-L1, and are superior to the combination of PD1/PD-L1 antibodies and TCR-T cells in terms of side effects and safety.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram showing the principle of action of simultaneous expression of HBV TCR and chimeric transducer receptor;

FIG. 2 shows the simultaneous expression of HBV TCR and chimeric transition receptor structural sequences;

FIG. 3 is HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD1-28 lentiviral titer and T cell MOI;

FIG. 4 shows HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD 1-28T cell expression;

FIG. 5 is a graph showing target cell killing and cytokines by HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD 1-28;

FIG. 6 shows multiple rounds of tumor-stimulating killing experiments with HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD 1-28;

FIG. 7 shows HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD1-28 multiple rounds of tumor stimulating cytokines;

FIG. 8 is HBV TCR-PD1-BB and HBV TCR killing and cytokine function against various target cells;

FIG. 9 shows the multiple rounds of proliferation-stimulating capacity assays of HBV TCR-PD1-BB and HBV TCR target cells;

FIG. 10 shows the in vivo efficacy, body weight and in vivo distribution of HBV TCR-PD1-BB in an immunodeficient mouse HBsAg+PDL1+ transplantation tumor model;

FIG. 11 is a long-term efficacy comparison in vivo of HBV TCR-PD1-BB and HBV TCR-T in immunodeficient mice HBsAg+PDL1+ transplantation tumor models.

Detailed Description

In order that the invention may be more readily understood, certain technical and scientific terms of the invention will be described before describing the embodiments. All other technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, except where explicitly defined otherwise in this application.

The term "hepatitis b surface antigen T Cell Receptor (TCR)" is defined herein as a TCR that binds to HBV surface antigen in the context of a Major Histocompatibility Complex (MHC) molecule to induce a helper or cytotoxic response in cells expressing the recombinant TCR. A TCR of the present application, or a fragment thereof, capable of binding to HBV surface antigen polypeptides presented by HLA-A x 02. In particular, the HBV surface antigen may be HBs20-28, which may be used interchangeably herein as HBs20, HBs20-28, S20-28 and S20, and refers to the S20-28 antigen of genotypes A and D, i.e., FLLTRILTI polypeptide, unless otherwise specified. In some embodiments the HBV surface antigens are HBV genotypes a and D; in some embodiments, the HBV surface antigens are HBV genotypes B and C. In some embodiments, the HBV surface antigen comprises the amino acid sequence of FLLTRILTI (SEQ ID NO: 19); in some embodiments, the HBV surface antigen comprises the amino acid sequence of FLLTKILTI (SEQ ID NO: 20). In some embodiments, the HBV surface antigen is the amino acid sequence of FLLTRILTI (SEQ ID NO: 19); in some embodiments, the HBV surface antigen is the amino acid sequence of FLLTKILTI (SEQ ID NO: 20).

The term "MHC molecule" is a protein of the immunoglobulin superfamily, which may be a class I or class II MHC molecule. Thus, it is specific for antigen presentation, and different individuals have different MHCs, which are capable of presenting different short peptides of a single protein antigen to the respective APC cell surfaces. Human MHC is commonly referred to as an HLA gene or HLA complex.

TCRs are glycoproteins on the surface of cell membranes that exist as heterodimers from either the alpha/beta or gamma/delta chain. TCR heterodimers consist of alpha and beta chains in 95% of T cells, while 5% of T cells have TCRs consisting of gamma and delta chains. The native αβ heterodimeric TCR has an α chain and a β chain, which constitute subunits of the αβ heterodimeric TCR. Each of the α and β chains comprises a variable region and a constant region, each variable region comprising 3 CDRs (complementarity determining regions) chimeric in a framework structure (framework regions), CDR1, CDR2 and CDR3, the CDR regions of the α and β chains of the TCRs herein being defined using IMGT numbering rules. The CDR regions determine the binding of the TCR to the pMHC complex. The sequence of the TCR constant domain can be found in published databases of the international immunogenetic information system (IMGT), for example the constant domain sequence of the α chain of a TCR molecule is "TRAC x 01" and the constant domain sequence of the β chain of a TCR molecule is "TRBC1 x 01" or "TRBC2 x 01".

In this application, the terms "T cell receptor", "TCR molecule" are used interchangeably.

TCR molecules

The TCR or fragment thereof of the present application recognizes HLA-A2 restricted HBV surface antigen. About 50% of the general population expresses MHC class I molecules HLA-A-02, therefore HLA-A-02 restricted TCRs may have general therapeutic uses. In particular, TCRs of the present application can recognize the products of a number of HLA-A x 02 alleles, including HLA-A x 0201, x 0202, x 0203, x 0206, and x 0207, among others. Although, there may be significant differences in HLA gene subtypes for caucasians and asians; however, over 95% of caucasians positive for HLA-A2 are HLA-A0201; whereas chinese positive for HLA-A2 consisted of the following HLA-A2 subtype, 23% HLA-A0201;45% HLA-A0207;8% HLA-A0206;23% HLA-A0203.

In some embodiments, the TCR comprises a TCR a chain variable region and a TCR β chain variable region, and the TCR a and β chains each have 3 Complementarity Determining Regions (CDRs).

In some embodiments, the α CDR3 of the TCR α chain variable region has the amino acid sequence shown in SEQ ID NO. 3, or a variant thereof, wherein one or two amino acids are replaced with other amino acids; and/or the amino acid sequence of the beta CDR3 of the TCR beta chain variable region is shown in SEQ ID NO. 6, or a variant thereof, wherein one or two amino acids are replaced with other amino acids.

In some embodiments, the α CDR1, α CDR2, and α CDR3 are shown in SEQ ID NO. 1, SEQ ID NO. 2, and SEQ ID NO. 3, respectively; and/or the beta CDR1, the beta CDR2 and the beta CDR3 are shown as SEQ ID NO. 4, SEQ ID NO. 5 and SEQ ID NO. 6 respectively.

Chimeric TCRs may be prepared by embedding the CDR region amino acid sequences of the present application described above into any suitable framework structure. As long as the framework structure is compatible with the CDR regions of the TCRs of the present application, one skilled in the art will be able to design or synthesize TCR molecules with corresponding functions based on the CDR regions disclosed herein. Thus, a TCR molecule herein refers to a TCR molecule comprising the above-described alpha and/or beta chain CDR region sequences, and any suitable framework structure. The TCR alpha chain variable region of the present application is an amino acid sequence having at least 90%, preferably 95%, more preferably 98% sequence identity to SEQ ID No. 7; and/or the TCR β chain variable region herein is an amino acid sequence having at least 90%, preferably 95%, more preferably 98% sequence identity to SEQ ID No. 8.

In some embodiments, the TCR is an αβ heterodimer comprising a TCR α chain constant domain and a TCR β chain constant domain. In some embodiments, the constant domain of the TCR molecules of the present application is a human constant domain. The person skilled in the art knows or can obtain the human constant domain amino acid sequence by consulting the public database of related books or IMGT (international immunogenetic information system). For example, the constant region sequence of the α chain of the TCR molecule of the invention may be "TRAC x 01", and the constant region sequence of the β chain of the TCR molecule may be "TRBC1 x 01" or "TRBC2 x 01". In some embodiments, the constant region incorporates an additional disulfide bond to improve stability and reduce mismatch of exogenously transferred TCR molecules with endogenous TCR molecules. The constant region of the TCR molecules of the present application can also be a mouse constant region. The simultaneous replacement of TRAC and TRBC with a mouse-derived constant region can avoid mismatching of an exogenously transferred TCR molecule with an endogenous TCR molecule, resulting in TCR targeting errors. This effect is similar to the purpose of exogenously introducing artificial disulfide bonds.

Chimeric transition receptors

The chimeric transition receptor of the present application comprises:

an extracellular domain of an immunosuppressive protein (ECD), wherein the ECD is fused to an intracellular domain of a costimulatory molecule (ICD) that mediates an immune cell activation signal; wherein binding of the immunosuppressive protein extracellular domain to its ligand generates an immune cell activation signal in the modified immune cell but not an immune cell deactivation signal.

The proteins that the immune cells contain that elicit an immune cell inactivation signal upon binding to their ligands include: immunosuppressive proteins are any one of and combinations of any proteins including PD1, CTLA4, BTLA, TIM3, TIGIT, tgfβ receptors, and any other proteins having immunosuppressive functions or associated with immunosuppressive signaling pathways, where ECD of the foregoing immunosuppressive proteins may have at least one amino acid mutation.

In some embodiments, the ECD of the present application is a PD1 ECD; in some embodiments, at least one amino acid mutation may be present in the PD1 ECD sequence; in some embodiments, there is an amino acid mutation in PD1 ECD, mutation of A to L at position 132 increases the affinity of PD1 ECD for PDL1, and the ECD amino acid sequence is shown in SEQ ID NO. 9.

The costimulatory molecules of the present application comprise: CD28, 4-1BB, ICOS, CD27, IL-12R, CD3, OX40 and combinations thereof, the ICD of the co-stimulatory molecule may have at least one amino acid mutation.

In some embodiments, the ECD and the ICD are connected by a transmembrane region (TM) sequence; the transmembrane region comprises a transmembrane domain of a protein selected from the group consisting of: the α, β or δ chain of a T cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD8, CD9, CD16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137 and CD154, and combinations thereof, may have at least one amino acid mutation in the transmembrane domain of the aforementioned proteins.

Nucleic acid molecules

A nucleic acid molecule of the present application comprising a nucleic acid sequence encoding an HBV TCR molecule; and/or, comprises a nucleic acid sequence encoding a chimeric transduction receptor.

The present application provides nucleic acid molecules encoding the TCR molecules described herein above, or fragments thereof, which may be one or more CDRs, variable regions of the α and/or β chains, and the α and/or β chains.

In some embodiments, the nucleic acid encodes one or more structural features for increasing and/or stabilizing the association between the expressed TCR a and β chains. In some embodiments, the feature may be a particular amino acid or amino acid sequence. In some embodiments, the nucleic acid may encode one or more unnatural cysteine residues for forming one or more disulfide bonds between the TCR a and β chains. In some embodiments, the nucleic acid may encode one or more unnatural cysteine residues in the constant domains of the TCR a and β chains.

The nucleotide sequence of the nucleic acid molecules of the present application may be single-stranded or double-stranded, the nucleic acid molecules may be RNA or DNA, and may or may not comprise introns. Preferably, the nucleotide sequence of the nucleic acid molecule of the present application does not comprise an intron but is capable of encoding the TCR of the present application, and/or the chimeric transition receptor of the present application.

The nucleotide sequence may be codon optimized. Different cells differ in the use of specific codons, and the amount of expression can be increased by changing codons in the sequence depending on the cell type. Codon usage tables for mammalian cells and a variety of other organisms are well known to those skilled in the art.

In some embodiments, the coding sequences of the present application are single-stranded, the TCR β chain coding sequence and the TCR α chain coding sequence are linked by a P2A coding sequence, and then linked by a T2A coding sequence and a chimeric transduction receptor coding sequence; and the single stranded encoding nucleotides are in the same reading frame.

It will be appreciated that in gene cloning operations, it is often necessary to design suitable cleavage sites, which tend to introduce one or more unrelated residues at the end of the expressed amino acid sequence, without affecting the activity of the sequence of interest. To construct fusion proteins, facilitate expression of recombinant proteins, obtain recombinant proteins that are automatically secreted outside of the host cell, or facilitate purification of recombinant proteins, it is often desirable to add some amino acid to the N-terminus, C-terminus, or other suitable region within the recombinant protein, including, for example, but not limited to, suitable linker peptides, signal peptides, leader peptides, terminal extensions, and the like. Thus, the amino-or carboxy-terminus of the fusion proteins of the invention may also contain one or more polypeptide fragments as protein tags. Any suitable label may be used herein. For example, the tag may be FLAG, HA, HA1, c-Myc, poly-His, poly-Arg, strep-TagII, AU1, EE, T7,4A6, ε, B, gE, and Ty1. These tags can be used to purify proteins.

Carrier body

The invention also relates to vectors comprising the nucleic acid molecule sequences described herein, and one or more regulatory sequences operably linked to these sequences. The nucleic acid molecules of the invention can be manipulated in a variety of ways to ensure expression of the fusion protein. Techniques for altering polynucleotide sequences using recombinant DNA methods are known in the art.

The regulatory sequence may be a suitable promoter sequence. The promoter sequence is typically operably linked to the coding sequence of the protein to be expressed. The promoter may be any nucleotide sequence that exhibits transcriptional activity in the host cell of choice including mutant, truncated, and hybrid promoters, and may be obtained from genes encoding extracellular or intracellular polypeptides either homologous or heterologous to the host cell. The regulatory sequence may also be a suitable transcription terminator sequence, a sequence recognized by a host cell to terminate transcription. The terminator sequence is operably linked to the 3' terminus of the nucleotide sequence encoding the polypeptide. Any terminator which is functional in the host cell of choice may be used in the present invention. The control sequences may also be suitable leader sequences, untranslated regions of mRNA that are important for host cell translation. The leader sequence is operably linked to the 5' terminus of the nucleotide sequence encoding the polypeptide. Any terminator which is functional in the host cell of choice may be used in the present application.

The nucleic acid molecules of the present application can be cloned into many types of vectors. For example, it can be cloned into plasmids, phagemids, phage derivatives, animal viruses and cosmids. Further, the vector is an expression vector. The expression vector may be provided to the cell as a viral vector. Viral vector techniques are well known in the art and are described, for example, in Sambrook et al (2001,Molecular Cloning:A Laboratory Manual,Cold Spring Harbor Laboratory,New York) and other virology and molecular biology manuals. Viruses that may be used as vectors include, but are not limited to, retroviruses, adenoviruses, adeno-associated viruses, herpesviruses, and lentiviruses.

In general, suitable vectors include an origin of replication that functions in at least one organism, a promoter sequence, a convenient restriction enzyme site, and one or more selectable markers (e.g., WO 01/96584 and U.S. Pat. No. 6,326,193).

For example, in certain embodiments, the invention uses a lentiviral vector comprising a replication origin, a 3'LTR, a 5' LTR, a polynucleotide sequence as described herein, and optionally a selectable marker.

One example of a suitable promoter is the immediate early Cytomegalovirus (CMV) promoter sequence. The promoter sequence is a strong constitutive promoter sequence capable of driving high levels of expression of any polynucleotide sequence operably linked thereto. Another example of a suitable promoter is extended growth factor-1α (EF-1α). However, other constitutive promoter sequences may also be used, including but not limited to the simian virus 40 (SV 40) early promoter, the mouse mammary carcinoma virus (MMTV), the Human Immunodeficiency Virus (HIV) Long Terminal Repeat (LTR) promoter, the MoMuLV promoter, the avian leukemia virus promoter, the epstein barr virus immediate early promoter, the ruses sarcoma virus promoter, and human gene promoters such as but not limited to the actin promoter, the myosin promoter, the heme promoter, and the creatine kinase promoter. Further, the use of inducible promoters is also contemplated. The use of an inducible promoter provides a molecular switch that is capable of switching on expression of a polynucleotide sequence operably linked to the inducible promoter when expressed for a period of time and switching off expression when expression is undesirable. Examples of inducible promoters include, but are not limited to, metallothionein promoters, glucocorticoid promoters, progesterone promoters, and tetracycline promoters.

To assess expression of a gene of interest, the expression vector introduced into the cell may also contain either or both a selectable marker gene or a reporter gene to facilitate identification and selection of expression cells from a population of cells sought to be transfected or infected by the viral vector. In other aspects, the selectable marker may be carried on a single piece of DNA and used in a co-transfection procedure. Both the selectable marker and the reporter gene may be flanked by appropriate regulatory sequences to enable expression in the host cell. Useful selectable markers include, for example, antibiotic resistance genes, such as neo and the like.

The reporter gene is used to identify potentially transfected cells and to evaluate the functionality of the regulatory sequences. After the DNA has been introduced into the recipient cell, the expression of the reporter gene is assayed at the appropriate time. Suitable reporter genes may include genes encoding luciferase, beta-galactosidase, chloramphenicol acetyl transferase, secreted alkaline phosphatase, or green fluorescent protein genes. Suitable expression systems are well known and can be prepared using known techniques or commercially available.

Methods for introducing genes into cells and expressing genes into cells are known in the art. The vector may be readily introduced into a host cell, e.g., a mammalian, bacterial, yeast or insect cell, by any method known in the art. For example, the expression vector may be transferred into the host cell by physical, chemical or biological means.

Physical methods for introducing polynucleotides into host cells include calcium phosphate precipitation, lipofection, particle bombardment, microinjection, electroporation, and the like. Biological methods for introducing a polynucleotide of interest into a host cell include the use of DNA and RNA vectors. Chemical means for introducing the polynucleotide into a host cell include colloidal dispersion systems such as macromolecular complexes, nanocapsules, microspheres; and lipid-based systems, including oil-in-water emulsions, micelles, mixed micelles, and liposomes.

Biological methods for introducing polynucleotides into host cells include the use of viral vectors, particularly lentiviral vectors, which have become the most widely used method for inserting genes into mammalian, e.g., human, cells. Other viral vectors may be derived from poxviruses, herpes simplex virus I, adenoviruses, adeno-associated viruses, and the like. Many virus-based systems have been developed for transferring genes into mammalian cells. For example, retroviruses provide a convenient platform for gene delivery systems. The selected gene may be inserted into a vector and packaged into retroviral particles using techniques known in the art. The recombinant virus may then be isolated and delivered to a subject cell in vivo or ex vivo. Many retroviral systems are known in the art. In some embodiments, an adenovirus vector is used. Many adenoviral vectors are known in the art. In one embodiment, lentiviral vectors are used.

Immune cells

The immune cells of the present application are selected from lymphocytes, dendritic cells, monocytes/macrophages, granulocytes, mast cells. In some embodiments, the immune cells are lymphocytes; in some embodiments, the immune cells are NK cells; in some embodiments, the immune cell is a B cell; in some embodiments, the immune cell is a TIL cell. In some embodiments, the immune cells are T cells, which may be derived from T cells isolated from a subject, or may be part of a mixed cell population isolated from a subject, such as a population of Peripheral Blood Lymphocytes (PBLs). For example, the cells may be isolated from Peripheral Blood Mononuclear Cells (PBMCs) and may be cd4+ helper T cells or cd8+ cytotoxic T cells. The cells may be in a mixed population of cd4+ helper T cells/cd8+ cytotoxic T cells. Generally, the cells can be activated with an antibody (e.g., an anti-CD 3 antibody) to render them more receptive to transfection.

The modified immune cell comprises the TCR receptor molecule and the chimeric conversion receptor; in some embodiments, the modified immune cell is constructed by introducing into an isolated immune cell a coding sequence encoding the TCR receptor molecule and the chimeric transition receptor described above or a vector comprising the coding sequence described above; in some embodiments, introducing a coding sequence encoding the TCR receptor molecule and the chimeric transition receptor described above or a vector comprising the coding sequence described above into an immune cell in vivo constructs a modified immune cell; in some embodiments, the coding sequences of the TCR receptor molecule and the chimeric transition receptor are expressed in tandem and in the same reading frame.

Composition and method for producing the same

The present application also provides compositions comprising the modified immune cells, nucleic acids or vectors of the invention. In some embodiments, the composition is a pharmaceutical composition. In some embodiments, the composition is a composition suitable for research, treatment, prevention, and/or diagnosis.

In some embodiments, the modified immune cells, nucleic acids, or vectors of the present application are preferably formulated into medicaments or pharmaceuticals with one or more other pharmaceutically acceptable ingredients known to those skilled in the art, including, but not limited to, pharmaceutically acceptable carriers, adjuvants, excipients, diluents, fillers, buffers, preservatives, antioxidants, lubricants, stabilizers, solubilizers, surfactants, masking agents, colorants, flavorants, and sweeteners. The term "pharmaceutically acceptable" as used herein relates to compounds, ingredients, materials, compositions, dosage forms, and the like, which are, within the scope of sound medical judgment, suitable for use in contact with the tissues of the subject in question (e.g. human) without excessive toxicity, irritation, allergic response, or other problem or complication, commensurate with a reasonable benefit/risk ratio. Each carrier, adjuvant, excipient, etc. must also be "acceptable" in the sense of being compatible with the other ingredients of the formulation. Suitable carriers, adjuvants, excipients, and the like can be found in standard pharmaceutical textbooks, for example, in Remington's Pharmaceutical Sciences; handbook of pharmaceutical excipients (Hand book of Pharmaceutical Excipients).

The pharmaceutical composition of the present invention may be administered in a manner suitable for the disease to be treated (or prevented). The number and frequency of administration will be determined by such factors as the condition of the patient, and the type and severity of the patient's disease.

When referring to an "immunologically effective amount", "antitumor effective amount", "tumor-inhibiting effective amount" or "therapeutic amount", the precise amount of the composition of the present invention to be administered can be determined by a physician, taking into account the age, weight, tumor size, degree of infection or metastasis and individual differences of the condition of the patient (subject). It can be generally stated that: the pharmaceutical composition comprising T cells described herein may be in a dose of E4 to E9 cells/kg body weight, preferably in a dose of E5 to E7 cells/kg body weight. T cell compositions may also be administered multiple times at these doses. Cells can be administered by using injection techniques well known in immunotherapy (see, e.g., rosenberg et al, new Eng. J. Of Med.319:1676, 1988). Optimal dosages and treatment regimens for a particular patient can be readily determined by one skilled in the medical arts by monitoring the patient for signs of disease and adjusting the treatment accordingly.

Administration of the subject compositions may be performed in any convenient manner, including by spraying, injection, swallowing, infusion, implantation, or transplantation. The compositions described herein may be administered to a patient subcutaneously, intradermally, intratumorally, intranodal, intraspinal, intramuscularly, by intravenous injection or intraperitoneally.

Medical application

In another aspect, there is provided the use of a modified immune cell, nucleic acid, vector or pharmaceutical composition of the present application in the manufacture of a medicament for the treatment or prevention of a disease or disorder.

In some embodiments, the modified immune cells, nucleic acids, vectors, or pharmaceutical compositions of the present application are useful for preventing or treating a related disease caused by HBV infection. Related diseases caused by HBV infection include acute hepatitis (including fulminant liver failure), chronic hepatitis, liver fibrosis, cirrhosis, liver cancer such as hepatocellular carcinoma (HCC), or pancreatic cancer.

Therapeutic and prophylactic methods

Treatment may be performed by isolating T cells from a patient or volunteer suffering from HBV-related disease and introducing the nucleic acid molecules or vectors of the present application into the T cells, followed by reinfusion of these genetically modified cells into the patient. Accordingly, the present application provides a method of treating HBV-related disease comprising inputting into a patient isolated T cells expressing a TCR of the present application, preferably, the T cells are derived from the patient itself. Generally, this includes (1) isolating T cells from a patient, (2) transducing T cells in vitro with a nucleic acid molecule or vector of the present application, and (3) introducing genetically modified T cells into a patient. The number of isolated, transfected and reinfused cells can be determined by the physician.

In some embodiments of the invention, the modified immune cells, nucleic acids, vectors or pharmaceutical compositions of the invention may be combined with other therapies known in the art. Such therapies include, but are not limited to, chemotherapy, radiation therapy, immunosuppressives, and viral inhibitors. For example, treatment may be performed in combination with nucleotide analogs or interferons known in the art for treating HBV-induced diseases, including lamivudine, adefovir dipivoxil, telbivudine, entecavir, tenofovir dipivoxil, and clavulanate.

"patient," "subject," "individual," and the like are used interchangeably herein to refer to a living organism, such as a mammal, that can elicit an immune response. Examples include, but are not limited to, humans, dogs, cats, mice, rats, and transgenic species thereof.

The technical solutions of the present application will be clearly and completely described below in conjunction with specific embodiments, and it is apparent that the described embodiments are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application. The following description of the embodiments is not intended to limit the preferred embodiments.

The experimental procedure, which does not address the specific conditions in the examples below, is generally followed by molecular cloning under conventional conditions such as Sambrook et al: conditions in the Laboratory Manual (Molecular cloning-A Laboratory Manual, third edition 2001), or as recommended by the manufacturer. Percentages and parts are by weight unless otherwise indicated. Unless otherwise indicated, all reagents and materials referred to herein are commercially available or may be prepared by one of ordinary skill in the art in accordance with common general knowledge. Any method and material similar or equivalent to those described may be used in the present application. The preferred methods and materials are presented herein for illustrative purposes only and are not limiting upon the disclosure.

Example 1: viral vector constructs expressing HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28

The structural principle of HBV TCR-PD1-BB and HBV TCR-PD1-28 is shown in figure 1, the HBV TCR, HBV TCR-PD1-28 and HBV TCR-PD1-BB sequences are shown in figure 2, the coding sequence of HBV TCR fragment (amino acid sequence is shown as SEQ ID NO: 14), the coding sequence of HBV TCR-PD1-BB fragment (amino acid sequence is shown as SEQ ID NO: 17) and the coding sequence of HBV TCR-PD1-28 fragment (amino acid sequence is shown as SEQ ID NO: 18) are synthesized by total gene synthesis, and the synthetic gene is inserted into a slow vector to construct plasmid after double enzyme digestion, so that the obtained vector is constructed.

Structurally, TCRs consist of two chains, a and β, both of which consist of a variable domain (responsible for binding to the MHC-peptide complex) and a constant domain (responsible for binding to both TCR chains), an increased PD-1 co-stimulatory domain fusion receptor (chimeric switch receptor) as an anti-depleting sequence, the TCR a and β chains being linked via a P2A self-cleaving peptide and then via a T2A self-cleaving peptide to the PD-1 co-stimulatory domain fusion receptor. Wherein the constant region is engineered to reduce endogenous TCR mismatches.

HBV TCR-PD1-BB and HBV TCR-PD1-28 comprise a T cell receptor β chain variable region (TCR β variable region), a T cell receptor β chain constant region (TCR β constant region), a T cell receptor α chain variable region (TCR α variable region), a T cell receptor α chain constant region (TCR α constant region), a PD1 extracellular region, a CD8 or CD28 transmembrane region, a 41BB or CD28 intracellular signaling region (fig. 2).

Cloning the gene of interest into a backbone plasmid:

in order to increase the expression efficiency of the target gene, it is important to select an appropriate backbone plasmid. Based on the original sequence of the disclosed pCDH-EF 1-MCS-T2A-copGGFP plasmid (the information of the enzyme cutting sites of the lentiviral skeleton plasmid is shown in Table 1), the ampicillin resistance gene is replaced by the kanamycin resistance gene, and then the complete gene synthesis of the skeleton plasmid is carried out. And respectively designing primers at two ends of a target gene sequence, introducing EcoRI and SalI enzyme cutting sites, carrying out PCR amplification on the target gene fragment, and selecting a target gene strip according to the electrophoresis result of a PCR product for purification and recovery. Meanwhile, the recovered PCR product and pCDH-EF 1-MCS-T2A-copGGFP framework plasmid are subjected to double digestion and recovery by EcoRI and SalI, 2 fragments are connected by using T4 DNA ligase, the connection product is transformed by using Stbl3 competent cells, monoclonal culture is selected, and the target plasmid is identified by double digestion, electrophoresis and sequencing after the plasmid is extracted. The constructed objective plasmids include main functional elements (key functional elements and positions of lentiviral backbone plasmids are shown in Table 2) such as 5'LTR (long terminal repeat), HIV-1 (package integration signal), RRE (Rev response element), cPPT/CTS (central polypurine tract/central termination sequence), EF-1 alpha core promoter (core promoter of human EF-1 alpha), WPRE (woodchuck hepatitis virus post-transcriptional regulatory element), 3' LTR-SIN (self-inactivating long terminal repeat), and TCR-HBsAg genes.

TABLE 1 information summary of enzyme cleavage sites of lentiviral backbone plasmids

Enzyme cutting position	Restriction enzymes	Recognition sites
			3,090	NheI	GCTAGC
3,096	EcoRI	GAATTC
			4,920	SalI	GTCGAC
	KpnI	GGTACC

TABLE 2 Key functional elements and position Table of lentiviral backbone plasmids

Example 2: lentivirus package

Lentiviral vectors used in the production of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 cell products are third generation "self-activating (SIN)" lentiviral vectors from HIV-1 with VSV-G pseudoenvelope carrying nucleic acid encoding a targeted HBsAg specific T cell receptor (HBsAg TCR). The lentiviral vector has only infectious activity and no replication capacity, has a particle diameter of about 80-120nm, and has a shape of approximately sphere or 20-plane symmetrical structure. The outer membrane of the virus is a lipid envelope and is embedded with the VSV-G envelope protein, inwardly with the globular Matrix (Matrix) formed by protein p17, and the semi-conical Capsid (Capid) formed by protein p24, which contains the RNA nucleic acid information carrying the TCR.

The function of each element of the nucleic acid molecule of the third generation self-inactivating lentiviral vector is described as follows:

at both ends of the TCR gene are truncated/chimeric long terminal repeats, delta 5'LTR and delta 3' LTR, respectively. Wherein the delta 5' LTR is deleted U3, and is replaced by an enhancer and a promoter of the upper respiratory syncytial virus (respiratory syncytial virus pneumonia, RSV) so that the replication of the vector is independent of tat; the delta 3' LTR is deleted U3, which makes it no longer active for initiation/enhancement, making it a self-inactivating vector.

RRE element function: the cis-acting element of Rev promotes transport of non-spliced large mRNA molecules from the nucleus to the cytosol.

cPPT element function: the vector transduction efficiency is improved.

EF-1a promoter function: the start time and the expression degree of gene expression (transcription) are regulated.

WPRE element function: can up-regulate polyadenylation of transcript, promote transcript to go out of core, raise expression efficiency of target gene.

Lentiviral vectors were obtained by transient transfection of 293T cells and purification from a third generation four plasmid system consisting of three packaging plasmids (also known as "helper plasmids") and one plasmid of interest.

The packaging plasmid pGagpol-KanR encodes the viral structural protein Gag, which forms the viral core structure, and the reverse transcriptase Pol, which is necessary for RNA reverse transcription and integration.

The packaging plasmid pRev-KanR codes for Rev protein, and the Rev protein is combined with RNA to promote mRNA transport and protein expression.

The packaging plasmid pVSV-G-KanR codes vesicular stomatitis virus envelope protein VSV-G, replaces HIV virus envelope protein, enables lentiviral vectors to infect almost all cells from tissue sources, and improves the stability of lentiviral particles.

D10 cell complete culture preparation: DMEM (Gibco, 11965092-092), 10% fbs (Gibco, 10099141), 1%Sodium Pyruvate (Gibco, 11360070) were placed in a 4 ℃ refrigerator for use.

Day 0:293T cells were less than 20 passages and overgrown; at 2X 10 ⁷ 150mm dishes (Corning, 430599), 20mL of D10 medium were spread, the cells were thoroughly mixed, and incubated overnight at 37 ℃.

Day 1: transfection was performed when 293T cells reached 60-80% confluency, and the time from plating to transfection was no more than 24h.

Lentiviral packaging plasmid complexes were prepared as in table 3.

TABLE 3 materials required for plasmid complexes

Main plasmid	RRE	REV	VSVG	PEIpro	OptiMEM
						18ug	10ug	7ug	7ug	70uL	1mL+1mL

While gently swirling the plasmid, adding the PEIpro dropwise, fully and uniformly mixing and standing at room temperature for 15min to form a plasmid-PEI complex; slowly adding the compound into 293T cells of a 150mm dish, fully and uniformly mixing, and culturing for 6 hours at 37 ℃ in a carbon dioxide incubator.

Day 1:293T cells transfected for 6h were gently changed to 20mL fresh D10 medium.

Day 3: the virus supernatant from the transfection for 48h was collected and buffered in a refrigerator at 4℃and 20mL of D10 medium was added.

Day 4: collecting virus supernatant transfected for 72h, and mixing with virus supernatant transfected for 48 h; 4 degrees, 3000g centrifugal 10min, through the 0.45um filter to remove fragment retention supernatant, using 100K ultrafiltration cup for virus concentration.

Centrifuging at 4deg.C and 3000g to the volume of virus concentration, taking out the centrifuging device, separating the filter cup from the lower filtrate collecting cup, and back-fastening the filter cup on the sample collecting cup; and (3) centrifuging at 4 ℃ for 2min at 1000g, wherein the virus concentrated solution is obtained in a sample collection cup, and the concentrated solution is collected, split-packed and stored below-70 ℃.

Virus droplet size detection: 24 well plates were prepared, jurkat was 1 x 10 ⁵ And (3) adding a certain amount of virus concentrated solution into the well of 500ul, carrying out gradient dilution, and carrying out flow detection on the virus titer after 72H culture.

Virus titer detection:

preparing a streaming buffer solution: DPBS (Gibco, 14190250), 2% FBS (Gibco, 10099141), and placing in a refrigerator at 4deg.C for use

Jurkat cells were taken, 1X 10 in each group ⁶ Cells were centrifuged at 400g for 5min and the supernatant was discarded and washed 2 times with streaming buffer;

PE Dextramer HBV-S20 was diluted with streaming buffer at a ratio of 1:100, 100ul antibody dilution was added to each sample, incubated at 4deg.C in the dark for 30 min, cells were washed with streaming buffer, supernatant was discarded by centrifugation at 400g for 5min, and repeated 2 times;

resuspension of cells with 100ul of flow buffer, flow-on detection;

vector infection titer (TU/mL) =number of cell plates per well x positive rate (%) x dilution fold/titration volume (mL)

As shown in FIG. 3a, the titers of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 lentiviral vectors were all above 1E7 TU/ml, indicating that 3 HBV TCRs could successfully package the virus and were high in titers.

Example 3: preparation of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28

Preparing a T cell culture medium: PRIME-XV-T cell CDM (Irvine, 91154), 400IU/ml IL-2.

Preparing T cell cryopreservation liquid: 75% CS10 (ThermoFisher, A2596101) +25% HSA (FLEXBUMIN, S20181007).

Day0: isolation of purer CD3+ T cells from apheresis and adjustment of cell concentration to 1X 10 with T cell culture medium ⁶ Per mL, per transaction (CD 3/CD28 microspheres) (Macs, 6201000014): adding an activator into the cell suspension=1:30, lightly and fully mixing, adding interleukin 2 with the final concentration of 400IU/mL, and stimulating virus infection after 24 hours of culture;

day1: count cells, adjust the density of T cells to 5×10 ⁵ Adding virus liquid into the solution;

day2-11: after cell infection, observing the state of cells every day, and timely supplementing T cell culture solution containing IL-2 400IU/mL to maintain the density of T cells at 5×10 ⁵ Expanding the cells;

day12:300g is centrifuged for 5 minutes to harvest cells, the cells are washed by physiological saline solution containing 5% human serum albumin, frozen by a T cell special frozen stock solution according to proper density, and the cells are stored in liquid nitrogen after being frozen by a program temperature reducing instrument.

Example 4: MOI detection and TCR specific expression of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 by flow cytometry

HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 MOI assays

Preparing a streaming buffer solution: DPBS (Gibco, 14190250), 2% FBS (Gibco, 10099141) was placed in a refrigerator at 4deg.C for use.

Taking HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD1-28 cells and UT cells (control group), washing the supernatant for 1 time by using PBS, adding PE Dextramer HBV-S20 (Immulex, WB 3290-PE), washing the supernatant by using PBS after light shielding for 30 minutes at 4 ℃, re-suspending the supernatant, and finally detecting by using a flow cytometer (Beckman CytoFLEX).

As shown in FIG. 3b, HBV TCR expression was higher than that of HBV TCR-PD1-BB and HBV TCR-PD1-28, and the TCR positive rate was 30% or more and the HBV TCR positive rate was 60% or more when each group MOI=1.0, indicating that the gradient detection of HBV S20 TCR-T MOI of three monoclonal numbers was stably expressed.

HBV TCR-T specific expression and mismatch rate detection

Preparing a streaming buffer solution: DPBS and 2% FBS are placed in a refrigerator at 4 ℃ for standby.

Taking the prepared cells and UT cells of each of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 (control group), washing for 1 time by PBS, discarding the supernatant, dividing each group into 2 parts, respectively adding PE Dextramer HBV-S20/BV421 PD-1 and PE Dextramer HBV-S20/APC TCR vβ 5.1,4 ℃ for 30 minutes in dark place, washing for 3 times by using a flow buffer solution, re-suspending, and finally detecting by using a flow cytometer.

As shown in FIG. 4, the mismatch rates of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 expression are low, and the specific expression is over 30%, which indicates that each group of HBV TCR-T can be specifically expressed, and the mismatch rate is low.

Example 5: killing and cytokine detection of liver cancer cells by HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28

Preparation of M10 cells by complete culture: DMEM, 10% fbs (Gibco, 10099141), 1%Sodium Pyruvate (Gibco, 11360070), 1% hepes (Gibco, 15630080), 1% neaa (Gibco, 11140-050) were placed in a refrigerator at 4 ℃ for use.

Killing of liver cancer cells by HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 (RTCA)

D0: taking HepG2-LMS-LG cells and HepG2 cells (negative control) with good growth state, and adjusting cell density to 4×10 after digestion ⁵ For use/ml, a piece of Collagen coated RTCA was taken and used in 96-well plates, 50 ul/well M10 medium was added for instrument baseline measurement, and then 4X 10 density was added per well ⁵ 50ul of corresponding cells per ml, standing for about 5min, and then loading the cells for about 16 hours to continuously detect a growth curve;

d1: preparing effector cells according to the positive rate by taking TCR-T, UT with the measured TCR% and cell activity rate, adding 50 ul/hole of the effector cells according to the effective target ratio of 1:1 and 15, and continuously detecting a killing curve by an on-machine.

D3: copying the growth and killing curve of RTCA, stopping, and collecting the co-culture supernatant for cytokine detection.

Cytokine detection:

the CBA kit (Human Th1/Th2 Cytokine Cytometric Bead Array Kit II, BD, 551809) was equilibrated to room temperature.

2ml of Assay reagent reconstituted standard was pipetted to a concentration of 5000pg/ml and equilibrated at room temperature for 30min.

Preparing a standard substance: taking standard substances, marking the standard substances as S1, diluting the standard substances S2-S9 and S10 in sequence by 2 times, and taking the standard substances as blanks.

Preparing a Human Th1/Th2 Cytokine Capture Beads mixed solution: taking microsphere solutions A1-A6, shaking and mixing uniformly, and mixing according to the same volume.

A96-well U-shaped bottom plate was taken, 50ul of a mixture of Human Th1/Th2 Cytokine Capture Beads was added, and 50ul of Human Th1/Th2 PE Detection Reagent was added.

Cytokine test samples 400g were centrifuged in 5min, and 50ul of each sample was added to the sample test well, and Kong Jiaru ul of standard curve was prepared as S10-S1.

Incubate 180min at room temperature in the dark, add 100ul Wash buffer,300g 5min centrifuge, discard supernatant.

And (5) re-suspending by using a 100ul stream Wash buffer, loading the sample for flow detection, and carrying out flow result analysis.

The results show that: after 48H co-incubation, the killing ratio of HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28 with the effective target ratio of 1:5 to HepG2-LMS-LG target cells is over 90%, and UT has no obvious killing to the target cells (figure 5). At an effective target ratio of 1:1, HBV TCR-PD1-BB and HBV TCR-PD1-28 and UT co-incubated with negative target cells (HepG 2) barely secrete cytokines; when incubated with positive target cells, IFN-. Gamma.cytokine secretion by HBV TCR-PD1-BB was about 10-fold that of HBV TCR-PD1-28, 20-fold that of HBV TCR group, and UT was not apparent cytokine secretion (FIG. 5).

Example 6: multiple rounds of stimulation assays of target cells for tumor depletion with HBV TCR, HBV TCR-PD1-BB and HBV TCR-PD1-28

For the practical difficulty of escape of solid tumors by PD-L1, we simulated in vivo T cells depleted by tumor cell surface PD-L1 signaling through multiple rounds of tumor cell stimulation experiments, comparing HBV TCR-PD1-BB and HBV TCR-PD1-28 (anti-depleting TCR-T cells) with HBV TCR (TCR-only expressing T cells) for their ability to kill tumor cells to verify the role of PD-1 helper sequences.

Target cells were stimulated in multiple rounds:

D1: counting HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD1-28 and UT with measured cell activity rate, and regulating cell density to 5×10 ⁵ Per ml,4ml was added to a 6-well plate, and an equivalent amount of target cells HepAD38-PDL1 was added;

d5: counting and adjusting finenessCell amount is 5×10 ⁵ Per ml,4ml, adding the same amount of target cells for 2 nd round stimulation;

d10: harvesting the cells, counting, and performing subsequent experiments;

cell killing function detection

Preparation of M10 cells by complete culture: DMEM, 10% fbs (Gibco, 10099141), 1%Sodium Pyruvate (Gibco, 11360070), 1% hepes (Gibco, 15630080), 1% neaa (Gibco, 11140-050) were placed in a refrigerator at 4 ℃ for use. D0: target cells HepAD38-PDL1 were taken and digested to adjust the cell density to 4X 10 ⁵ For use/ml, a piece of Collagen coated RTCA was taken and used in 96-well plates, 50 ul/well M10 medium was added for instrument baseline measurement, and then 4X 10 density was added per well ⁵ 50ul of corresponding cells per ml, standing for about 5min, and then loading the cells for about 24 hours to continuously detect a growth curve;

d1: taking HBV TCR, HBV TCR-PD1-BB, HBV TCR-PD1-28 and UT with TCR% and cell activity, and counting 4×10 positive viable cells ⁵ Preparing effector cells per ml, adding 50ul of effector cells per hole according to the effective target ratio of 1:1, and continuously detecting a killing curve by an on-machine;

Cytokine detection was performed according to the cytokine detection procedure of example 5.

The results show that: after two rounds of tumor cell stimulation, only HBV TCR-PD1-BB and HBV TCR-PD1-28 still had significant killing effect on target cells HepAD38-PDL1, while HBV TCR had substantially no function, indicating that HBV TCR-PD1-BB and HBV TCR-PD1-28 were still able to retain anti-tumor effect after two rounds of tumor cell stimulation and still kill approximately 80% of tumor cells at 48 hours, indicating that their killing ability was not affected and diminished (fig. 6). Meanwhile, no cytokine secretion was detected by each group of negative target cells (HepG 2), almost no cytokine was secreted by HBV TCR and UT when incubated with positive target cells (HepAD 38-PDL 1), cytokines IFN-. Gamma.and TNF-. Alpha.were detected by HBV TCR-PD1-BB and HBV TCR-PD1-28, and HBV TCR-PD1-BB group was significantly higher than HBV TCR-PD1-28 group (FIG. 7).

In summary, HBV TCR-PD1-BB and HBV TCR-PD1-28 can maintain their anti-tumor effect and killing ability after multiple rounds of tumor stimulation, because the anti-depletion sequence (PD-1 auxiliary sequence) can convert the brake signal (PD-L1) on the surface of tumor cell line into a stimulation signal to prevent cells from entering the depletion state in advance, thereby having anti-depletion ability and continuous killing effect.

Example 7: detection of killing and cytokine release of HBV TCR and HBV TCR-PD1-BB on various target cell functions

We next analyzed the anti-tumor effect of HBV TCR-PD 1-BB. Because the activating signal carried by HBV TCR-PD1-BB contains two types of HBsAg and PD-L1, in order to verify whether HBV TCR-PD1-BB has different killing capacities on the difference of tumor cell expression of HBsAg and PD-L1, we constructed HBsAg+/PD-L1+, HBsAg+/PD-L1-, HBsAg-/PD-L1+ and HBsAg-/PD-L1-four liver cancer cell lines for functional evaluation. Preparing a T cell culture medium: PRIME-XV-T cell CDM (Irvine, 91154), 400IU/ml IL-2.

Preparation of M10 cells by complete culture: DMEM, 10% fbs (Gibco, 10099141), 1%Sodium Pyruvate (Gibco, 11360070), 1% hepes (Gibco, 15630080), 1% neaa (Gibco, 11140-050) were placed in a refrigerator at 4 ℃ for use. D0: the 4 target cells are taken and digested, and then the cell density is regulated to 4 multiplied by 10 ⁵ For use/ml, a piece of Collagen coated RTCA was taken and used in 96-well plates, 50 ul/well M10 medium was added for instrument baseline measurement, and then 4X 10 density was added per well ⁵ 50ul of corresponding cells per ml, standing for about 5min, and then loading the cells for about 16 hours to continuously detect a growth curve;

d1: HBV TCR, HBV TCR-PD1-BB and UT with TCR% and cell viability were taken and the number of positive viable cells was 4X 10 ⁵ /ml、0.8×10 ⁵ Preparing effector cells per ml, adding 50ul per hole of effector cells according to the effective target ratio of 1:1 and 1:5, and continuously detecting a killing curve by an on-machine;

The results show (FIG. 8) that untransfected T cells did not exert a significant killing effect on both target cells, and that HBV TCR-PD1-BB and HBV TCR did not exert a significant killing effect on HBsAg-/PD-L1+ and HBsAg-/PD-L1-target cells. At an effective target ratio of 1:5, the killing of HBV TCR-PD1-BB and HBV TCR to HBsAg+ target cells for 24h is more than 60%, and the killing of HBV TCR-PD1-BB to HBsAg+/PD-L1+ and HBsAg+/PD-L1-is stronger than that of HBV TCR; HBV TCR-PD1-BB kills HBsAg+/PD-L1+ target cells more strongly than HBsAg+/PD-L1-and HBV TCR is the opposite.

In addition, the cytokine detection results show that the HBV TCR-PD1-BB can hardly secrete cytokines when being co-cultured with HBsAg-/PD-L1+ or HBsAg-/PD-L1-target cells, the IFN-gamma secreted by the HBV TCR when being co-cultured with HBsAg+/PD-L1-target cells is equivalent to the secretion amount of HBV TCR, and the IFN-gamma secreted by the HBV TCR when being co-cultured with HBsAg+/PD-L1+ target cells is obviously higher than HBV TCR.

The experiment shows that HBV TCR-PD1-BB can target and kill liver cancer cells of HBsAg+, and as HBV TCR-PD1-BB can convert the inhibiting signal of PD-1 into active stimulating signal, the anti-tumor effect of HBV TCR-PD1-BB is more prominent for the liver cancer cells of HBsAg+ with high expression of PD-L1, the secreted cytokines are obviously increased, and the tumor killing capacity is stronger. In addition, HBV TCR-PD1-BB only targets and kills liver cancer cells expressing HBsAg, and has no nonspecific killing on tumor cells only expressing PD-L1 and not expressing HBsAg.

Example 8: proliferation potency assay of HBV TCR-PD1-BB and HBV TCR target cells after multiple rounds of stimulation

The ability of T cells to proliferate again after multiple rounds of stimulation is also an important indicator of antitumor activity. CPDF450 (Cell Proliferation Dye eFluor) ^TM 450 A purple fluorescent dye that can be used to monitor single cell division. The fluorescent dye can be combined with any cell protein containing primary amine, the dye can be uniformly distributed among daughter cells along with cell division, and the cell division times can be detected by continuously halving the fluorescent intensity of the dye.

Target cells were stimulated in multiple rounds:

D1: counting HBV TCR, HBV TCR-PD1-BB and UT with measured cell activity rate, and regulating cell amount to 5×10 ⁵ Per ml,4ml was added to a 6-well plate, and an equivalent amount of target cells HepAD38-PDL1 was added;

d2: counting, observing the state of cells, and timely replenishing liquid;

d5: counting, adjusting cell quantity to 5×10 ⁵ Per ml,4ml, adding the same amount of target cells for 2 nd round stimulation;

and by analogy, 4 rounds of stimulation are performed, and proliferation times are calculated according to the total cell amount and the count and the culture volume; the results showed that HBV TCR-PD1-BB remained highly proliferative after 3 and 4 rounds of stimulation, with a 200-fold breakthrough in total proliferation fold, significantly higher than HBV TCR and UT groups (fig. 9).

Cell proliferation potency assay:

preparing a streaming buffer solution: DPBS and 2% FBS are placed in a refrigerator at 4 ℃ for standby;

taking HBV TCR, HBV TCR-PD1-BB and UT cells after 2 rounds of stimulation, centrifuging 400g for 5min, and discarding the supernatant; adding CPDF450, and placing in an incubator to dye for 30min in a dark place;

washing the cells with streaming buffer, centrifuging 400g for 5min, discarding the supernatant, repeating 2 times;

washing the cells 2 times with T cell medium;

Day1: counting, adjusting cell quantity to 5×10 ⁵ Per ml,4ml was added to a 6-well plate, and an equivalent amount of target cells HepAD38-PDL1 was added;

day5: taking cells, centrifuging 400g for 5min, discarding supernatant, and adding an streaming buffer solution to wash the cells;

resuspension of cells with 100ul of flow buffer, flow-on detection;

the results showed that only about 15% of the cells in the negative control cell group and HBV TCR added to the positive target cells had proliferative activity after 2 rounds of stimulation, while more than 70% of the cells in the HBV TCR-PD1-BB group added to the positive target cells had proliferative activity (FIG. 9)

Example 9: immunodeficient mouse HBsAg ⁺ Human HCC transplantation tumor model HBV TCR-PD1-BBIn vivo efficacy and amplification assays

In order to understand the killing effect of HBV TCR-PD1-BB on tumor cells in an in-vivo environment, an immunodeficiency mouse and HBsAg+hepatoma cells are used for modeling, and a CDX model (tumor cell line transplantation model) of the mouse is constructed so as to simulate the killing and clearing effects of clinical hepatoma patients on in-vivo hepatoma cells after receiving HBV TCR-PD1-BB cells with different doses under a stranguria clearing and chemotherapy state.

We used NSG immunodeficient mice vaccinated 1X 10 on Day-12 days on the right of the mice body ⁷ HBsAg + tumor cells. Day 0, tumor size reached about 120mm ³ We divided mice into five groups, three of which received different doses of HBV TCR-PD1-BB cell injection, respectively high dose group (1×10 ⁷ Individual cells/individual), medium dose group (3X 10) ⁶ Individual cells/individual) and low dose group (1X 10) ⁶ Individual cells/single) and the remaining two groups served as Control groups, which received cell cryopreservation (Control) and untransfected T cells (UT), respectively, for testing. Tumor size was measured every 3 to 4 days thereafter and data was collected.

Test results show that HBV TCR-PD1-BB cells with different doses have obvious inhibition effect on tumor growth and accept 1X 10 ⁷ Tumor volumes in mice with individual cells were significantly smaller than in the other two dose groups (fig. 10 a). In addition, 1×10 is returned ⁷ In individual-cell mice, the tumor almost completely disappeared within a period of three weeks, while HBV TCR-PD1-BB mice did not develop significant weight loss within 6 days (fig. 10 b). This represents that HBV TCR-PD1-BB can retain its anticancer effect in mice, and that HBV TCR-PD1-BB cells at a certain concentration have a remarkable effect on tumor cell clearance.

HBV TCR-PD1-BB mouse in vivo survival:

to examine the persistence of HBV TCR-PD1-BB in mice, qPCR was performed on mouse blood samples at day 20 post cell injection and WPRE was used as a signature fragment to determine the gene copy number of transfection positive HBV TCR-PD1-BB T cells in mouse peripheral blood. Wherein, in the feedback process, 1×10 ⁶ HBV TCR-PD1-BB group, 3X 10 ⁶ HBV TCR-PD1-BB group and 1×10 ⁷ Obvious cell survival can be detected in the blood of mice in HBV TCR-PD1-BB group, and the copy number of VCN in the peripheral blood of the mice is 91.56+ -37.34 copies/. Mu.g, 1256.35 + -661.43 copies/. Mu.g, 6330.33 + -4662.88 copies/. Mu.g (P)<0.01 The presence of HBV TCR-PD 1-BB-active cells was demonstrated after 20 days of reinfusion (FIG. 10 c). In addition, the degree of amplification (VCN copy number) of HBV TCR-PD1-BB in mice exhibited a clear negative correlation with tumor size, with tumor volumes significantly smaller in the higher VCN copy number mice experimental group than in the other groups. The result shows that the more obvious the HBV TCR-PD1-BB is amplified in mice, the stronger the killing and inhibiting effects on tumors are.

Example 10: long-term efficacy of HBV TCR-PD1-BB in vivo for immunodeficient mice HBsAg+PDL1+ transplantation tumor model

The purpose of the experiment is as follows: pharmacodynamics evaluation of the tested TCR-T cells in a human liver cancer HepAD38-PDL1-LG-G5 cell strain subcutaneous xenograft NCG female mouse model.

Experimental animals: NCG mice, females, 6-8 weeks old, weigh 18-22 grams.

Tumor cell inoculation: the target cell strain was inoculated subcutaneously into the armpit of the right foreleg of NCG mice at an inoculum size of 1X10 ⁷ Individual cells (PBS with Matrigel,1:1,0.2 ml). The average tumor volume reaches 100-150 mm ³ The start of the group dosing regimen is as follows:

group of

Mouse strain

Treatment

Dosage of

Administration volume

Route of administration

Quantity of

1

NCG Female

Cryoprotectant

N/A

400μl

IV once

6

2

NCG Female

UT

2*10 ⁷

400μl

IV once

6

3

NCG Female

HBV TCR

0.2*10 ⁷

400μl

IV once

6

4

NCG Female

HBV TCR

2*10 ⁷

400μl

IV once

6

5

NCG Female

HBV TCR-PD1-BB

0.2*10 ⁷

400μl

IV once

6

NCG Female

HBV TCR-PD1-BB

2*10 ⁷

400μl

IV once

6

The results showed that HBV TCR-PD1-BB high dose group (2 x 10 ⁷ ) Mice had been completely cleared of tumors in vivo and had not relapsed for 42 days, low dose group (0.2 x 10 ⁷ ) Also has certain tumor inhibiting effect; HBV TCR high dose group (2 x 10 ⁷ ) The tumor inhibition was shown to be strong, but after one month the tumor had obvious recurrence, whereas none of HBV TCR low dose group (UT), negative control group (UT) and blank control group (Cryoprotectant) was seen with tumor inhibition (fig. 11).

Compared with HBV TCR-T, HBV TCR-PD1-BB has better in-vivo efficacy in HBsAg+PDL1+ transplantation tumor model, can overcome in-vivo immunosuppression, and can inhibit tumor for a long time without recurrence.

The foregoing has outlined rather broadly the more detailed description of the present application, wherein specific examples have been provided to illustrate the principles and embodiments of the present application, the description of the examples being provided solely to assist in the understanding of the method of the present application and the core concepts thereof; meanwhile, as those skilled in the art will vary in the specific embodiments and application scope according to the ideas of the present application, the contents of the present specification should not be construed as limiting the present application in summary.

Claims

1. A modified immune cell comprising a T Cell Receptor (TCR) that targets HBV surface antigen and a chimeric turnover receptor.

2. The modified immune cell of claim 1, wherein the TCR comprises a TCR a chain variable region and a TCR β chain variable region; wherein,

the amino acid sequence of the alpha CDR3 of the TCR alpha chain variable region is shown in SEQ ID NO. 3, or a variant thereof, wherein one or two amino acids are replaced by other amino acids; and;

the amino acid sequence of the beta CDR3 of the TCR beta chain variable region is shown in SEQ ID NO. 6, or a variant thereof, wherein one or two amino acids are replaced by other amino acids.

3. A modified immune cell as in claim 2, wherein the TCR α chain variable region comprises complementarity determining regions α CDR1, α CDR2, and α CDR3, and the TCR β chain variable region comprises complementarity determining regions β CDR1, β CDR2, and β CDR3, wherein:

the alpha CDR1, the alpha CDR2 and the alpha CDR3 are respectively shown in SEQ ID NO. 1, SEQ ID NO. 2 and SEQ ID NO. 3, and the beta CDR1, the beta CDR2 and the beta CDR3 are respectively shown in SEQ ID NO. 4, SEQ ID NO. 5 and SEQ ID NO. 6; or a CDR variant as described above, wherein one or both amino acids in one or more CDRs are replaced by other amino acids.

4. A modified immune cell as in claim 2, wherein the tcra chain variable region comprises an amino acid sequence having at least 90% sequence identity to SEQ ID No. 7; and/or

The TCR β chain variable region comprises a sequence identical to SEQ ID NO:8, an amino acid sequence having at least 90% sequence identity.

5. The modified immune cell of claim 1, wherein the chimeric switch receptor comprises:

an extracellular domain of an immunosuppressive protein (ECD), wherein the ECD is fused to an intracellular domain of a costimulatory molecule (ICD) that mediates an immune cell activation signal; wherein binding of the extracellular domain of the immunosuppressive protein to its ligand generates an immune cell activation signal but not an immune cell deactivation signal in the modified immune cell.

6. The modified immune cell of claim 5, wherein the immunosuppressive protein is any one of or a combination of proteins including PD1, CTLA4, BTLA, TIM3, TIGIT, tgfβ receptor, and any other protein having immunosuppressive function or associated with immunosuppressive signaling pathway, and the ECD sequence of the immunosuppressive protein may have at least one amino acid mutation;

And/or

The co-stimulatory molecule comprises: CD28, 4-1BB, ICOS, CD27, IL-12R, CD3, OX40 and combinations thereof, and the costimulatory molecule ICD sequence may have at least one amino acid mutation;

preferably, the ECD is a PD1 ECD; more preferably, the PD1 ECD sequence has an amino acid mutation, wherein the alanine at position 132 is mutated to leucine, and the mutated PD1 ECD amino acid sequence is shown in SEQ ID NO. 9;

preferably, the ICD is a CD28 ICD or a 4-1BB ICD; more preferably, the amino acid sequence of the CD28 ICD is shown as SEQ ID NO. 12, or the amino acid sequence of the 4-1BB ICD is shown as SEQ ID NO. 13.

7. The modified immune cell of claim 5, wherein the ECD and the ICD are linked by a transmembrane region sequence; preferably, the transmembrane region comprises a transmembrane domain of a protein selected from the group consisting of: the α, β or δ chain of a T cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD8, CD9, CD16, CD22, CD33, CD37, CD64, CD80, CD86, CD134, CD137 and CD154, and combinations thereof, and the transmembrane region sequence may have at least one amino acid mutation; more preferably, the transmembrane region sequence is a CD8 transmembrane region sequence or a CD28 transmembrane region sequence; more preferably, the CD8 transmembrane region sequence is shown in SEQ ID NO. 10 and the CD28 transmembrane region sequence is shown in SEQ ID NO. 11.

8. The modified immune cell of claim 1, wherein the immune cell is selected from the group consisting of lymphocytes, dendritic cells, macrophages, granulocytes, mast cells; preferably, the immune cells are T cells.

9. A nucleic acid molecule comprising a nucleic acid sequence encoding the TCR molecule of any one of claims 1-8; and/or

A nucleic acid sequence comprising a sequence encoding the chimeric transduction receptor of any one of claims 1-8.

10. A vector comprising the nucleic acid molecule of claim 9.

11. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and a modified immune cell according to any one of claims 1 to 8, a nucleic acid molecule according to claim 9, and a carrier according to claim 10.

12. Use of a modified immune cell according to any one of claims 1 to 8, a nucleic acid molecule according to claim 9, a vector according to claim 10 or a pharmaceutical composition according to claim 11 for the manufacture of a medicament for the prevention or treatment of a disease associated with HBV infection.

13. The use according to claim 12, wherein said HBV infection-related disease comprises one or more of hepatitis, liver fibrosis, cirrhosis, liver cancer.