VTCN1 (B7H4) Chimeric Antigen Receptor (CAR): A Comprehensive Guide and Our Service & Product Introduction

VTCN1, also known as B7H4 (B7 homolog 4), B7S1, or B7X, is a key immune checkpoint molecule belonging to the B7 family of costimulatory proteins. As an emerging target in cancer immunotherapy, VTCN1 (B7H4) is widely overexpressed in various solid tumors and plays a critical role in tumor immune escape.
RGBiotech is dedicated to providing high-quality VTCN1 (B7H4) CAR expression plasmid vectors and customized plasmid construction services, supporting researchers and biotech companies in advancing CAR-T, CAR-NK, and other cellular therapy technologies for solid tumor treatment. We are your reliable partner for VTCN1 (B7H4) CAR plasmid vectors, customized CAR plasmid construction, and solid tumor immunotherapy research support.

Our VTCN1 (B7H4) CAR Expression Plasmid Vector Products and Custom Services

RGBiotech is committed to providing high-quality, comprehensive VTCN1 (B7H4) CAR-related products and services to support global researchers and biotech companies in accelerating VTCN1 (B7H4) CAR research and clinical transformation. RGBiotech offers a full range of VTCN1 (B7H4) CAR expression plasmid vectors and professional customized plasmid construction services, with advantages of high quality, high efficiency, and strong flexibility. As a professional VTCN1 (B7H4) CAR plasmid supplier, we provide one-stop solutions for VTCN1 (B7H4) CAR research, from standard plasmids to customized construction, helping you overcome research challenges and accelerate project progress.

Our VTCN1 (B7H4) CAR expression plasmid vectors cover all generations (1st to 5th) of VTCN1 (B7H4) CAR, with diverse vector backbones and rich functional markers, suitable for different research needs (e.g., CAR-T, CAR-NK, in vitro transcription). All products undergo strict quality control to ensure high purity, high transfection efficiency, and stable expression. Our VTCN1 (B7H4) CAR plasmids are widely used in basic research, preclinical trials, and drug development, trusted by researchers worldwide.

Product Features

Product Applications

Custom Plasmid Vector Construction Services

In addition to standard VTCN1 (B7H4) CAR expression plasmids, we also provide professional customized plasmid construction services to meet the personalized needs of customers. Our R&D team has rich experience in CAR plasmid construction, and can provide one-stop services from sequence design, vector construction, to quality control, with fast delivery and high success rate.
1) Custom VTCN1 (B7H4) CAR Sequence Design: Optimize co-stimulatory domains and signaling domains according to customer research needs. We can also design bispecific/multispecific CAR sequences (e.g., VTCN1 (B7H4)+PD-L1) to address antigen heterogeneity.
2) Vector Backbone Customization: Customize vector backbones (non-viral, lentiviral, retroviral, AAV) according to delivery systems, and modify promoters, and other components to adapt to specific cell types or experimental scenarios.
3) Functional Module Addition: Add functional modules such as cytokine genes (IL-12, IL-15, IL-18), suicide genes (e.g., iCasp9), or reporter genes to the plasmid according to customer needs, enhancing the functionality and safety of VTCN1 (B7H4) CAR.
4) Codon Optimization: Optimize the codon usage of VTCN1 (B7H4) CAR sequences to improve expression efficiency in specific cell types, ensuring high-level CAR expression.

Introduction of VTCN1 (B7H4)

VTCN1 (B7H4) is encoded by the VTCN1 gene (V-set domain containing T cell activation inhibitor 1), which is located on human chromosome 1p13.1-p12. The VTCN1 gene spans a specific genomic region and contains multiple exons, encoding a protein that functions as a negative co-stimulatory ligand in the immune system. The gene has several aliases, including B7H4, B7S1, B7X, and FLJ22418, with NCBI Gene ID: 57207 and UniProt ID: Q7TSP5. Multiple transcript variants encoding different isoforms have been identified for this gene, and genetic polymorphisms (such as rs10754339 A>G) have been associated with susceptibility to certain cancers, including breast cancer. A pseudogene of the VTCN1 gene is located on chromosome 20, further highlighting its evolutionary and functional significance. VTCN1 gene research is essential for understanding tumor immune escape mechanisms and developing targeted immunotherapies such as CAR therapy.

VTCN1 (B7H4) is a type I transmembrane glycoprotein belonging to the immunoglobulin superfamily, specifically the BTN/MOG family. Its structure consists of three main parts: an extracellular domain, a transmembrane domain, and a very short intracellular tail (only two amino acids in length). The extracellular domain contains two immunoglobulin-like domains: an IgV (immunoglobulin variable) domain and an IgC (immunoglobulin constant) domain, both of which contribute to its co-inhibitory function. The protein is heavily glycosylated, with N-linked glycosylation sites critical for its membrane trafficking, folding, and biological activity. Human VTCN1 (B7H4) encodes a 282-amino acid protein with a molecular weight of approximately 30.9 kDa, while the murine homolog encodes a 283-amino acid protein. Notably, the crystal structure of the human B7H4 IgV-like domain has been resolved, providing insights into its structural basis for immune regulation. This unique structure makes VTCN1 (B7H4) an ideal target for CAR-based immunotherapy, as its extracellular domain can be specifically recognized by engineered CARs.

VTCN1 (B7H4) functions primarily as a negative regulator of T cell-mediated immune responses, playing a key role in maintaining immune homeostasis and preventing autoimmune diseases. Its core functions include inhibiting T cell activation, proliferation, cytokine production (such as IFN-γ), and the development of cytotoxicity. When expressed on the surface of tumor-associated macrophages, VTCN1 (B7H4) works together with regulatory T cells (Tregs) to suppress tumor-associated antigen-specific T cell immunity, thereby promoting tumor immune escape. Additionally, VTCN1 (B7H4) is involved in promoting epithelial cell transformation and regulating trophoblast differentiation and anti-viral responses in the placenta. The expression of VTCN1 (B7H4) on antigen-presenting cells (APCs) is upregulated by interleukin-6 (IL-6) and interleukin-10 (IL-10) and inhibited by granulocyte-macrophage colony-stimulating factor (CSF2/GM-CSF) and interleukin-4 (IL-4), highlighting its dynamic regulation in the immune microenvironment. Importantly, the precise receptor of VTCN1 (B7H4) on T cells has not yet been fully identified, but its co-inhibitory role is well established in tumor immunity.

VTCN1 (B7H4) exhibits a highly restricted expression pattern in normal tissues, with minimal or no expression at the protein level in most healthy organs, making it an attractive target for tumor immunotherapy. In normal tissues, low-level expression can be detected in activated T cells, B cells, monocytes, dendritic cells, and certain organs such as the kidney, liver, lung, ovary, placenta, spleen, and testis, but this expression is typically not functionally significant for immune suppression. In contrast, VTCN1 (B7H4) is frequently overexpressed in a variety of solid tumors, including breast cancer, ovarian cancer, endometrial cancer, renal cell carcinoma (RCC), non-small-cell lung cancer (NSCLC), bladder cancer, glioma, melanoma, and esophageal cancer. In tumor tissues, VTCN1 (B7H4) is expressed on both tumor epithelial cells and tumor-infiltrating macrophages (such as CD68+ macrophages), contributing to the immunosuppressive tumor microenvironment (TME). Notably, its high expression in tumors is often associated with poor prognosis, making it a valuable prognostic biomarker and therapeutic target.

VTCN1 (B7H4) dysregulation is closely associated with multiple diseases, primarily solid tumors and autoimmune disorders, due to its role in immune regulation.
1) Solid Tumors: Ovarian cancer is one of the most well-studied malignancies associated with VTCN1 (B7H4) overexpression, where it serves as a potential biomarker for early detection and is linked to tumor progression, drug resistance, and unfavorable prognosis. Breast cancer, especially triple-negative breast cancer (TNBC), shows high VTCN1 (B7H4) expression, which correlates with increased tumor aggressiveness and poor patient outcomes. Other tumors with high VTCN1 (B7H4) expression include renal cell carcinoma, non-small-cell lung cancer, bladder cancer (particularly luminal and luminal-papillary subtypes), glioma, and melanoma, where it contributes to immune escape and tumor progression.
2) Autoimmune Diseases: Defective VTCN1 (B7H4) expression has been associated with type 1 diabetes (T1D), where proteolytic degradation of VTCN1 (B7H4) on pancreatic islet cells leads to impaired negative costimulation and aggressive anti-islet T cell responses. VTCN1 (B7H4) also plays a role in regulating autoimmune responses in other conditions, as its agonistic application can suppress inflammatory responses and prevent autoimmune disease progression.
3) Other Diseases: Abnormal VTCN1 (B7H4) expression has been implicated in pregnancy complications, such as preeclampsia and intrauterine growth retardation, due to its role in trophoblast differentiation and placental immune regulation. Additionally, its overexpression in certain salivary gland cancers (such as adenoid cystic carcinoma) makes it an independent prognostic marker in these diseases.
Given its restricted expression in normal tissues and overexpression in tumors, VTCN1 (B7H4) CAR therapy shows great potential in treating VTCN1 (B7H4)-positive solid tumors while minimizing off-target toxicity.

Introduction of VTCN1 (B7H4) Chimeric Antigen Receptor (CAR)

Chimeric Antigen Receptor (CAR) is a genetically engineered receptor that can redirect immune cells (such as T cells, NK cells) to specifically recognize and kill target cells expressing a specific antigen. VTCN1 (B7H4) CAR is designed to target VTCN1 (B7H4)-positive tumor cells, overcoming the immunosuppressive tumor microenvironment and restoring anti-tumor immune responses. Its development has gone through multiple generations, with continuous optimization in structure and function to improve anti-tumor efficacy and reduce side effects. It has become one of the most promising immunotherapeutic strategies for VTCN1 (B7H4)-positive solid tumors. VTCN1 (B7H4) CAR research and development relies on high-quality expression plasmid vectors, which is where our professional products and services come into play.

VTCN1 (B7H4) CAR consists of three core components: an extracellular antigen-binding domain (usually a single-chain variable fragment, scFv, derived from anti-VTCN1 (B7H4) monoclonal antibodies), a transmembrane domain, and an intracellular signaling domain. The generation of VTCN1 (B7H4) CAR is defined by the number and type of intracellular signaling domains, and our company provides products covering all five generations.
1) 1st Generation VTCN1 (B7H4) CAR: Only contains the CD3ζ signaling domain (with 3 ITAMs), which can trigger basic T cell activation but lacks co-stimulatory signals, resulting in weak proliferation ability, short in vivo persistence, and limited anti-tumor efficacy. Our 1st generation VTCN1 (B7H4) CAR expression plasmids are suitable for basic research on CAR mechanism and VTCN1 (B7H4) recognition.
2) 2nd Generation VTCN1 (B7H4) CAR: Adds one co-stimulatory domain (such as CD28, 4-1BB/CD137) to the CD3ζ domain. CD28 enhances T cell activation and proliferation, while 4-1BB promotes T cell persistence and anti-tumor memory, significantly improving anti-tumor activity compared to the first generation. It is the most widely used generation in current VTCN1 (B7H4) CAR research (e.g., scFv-CD28-CD3ζ, scFv-4-1BB-CD3ζ).
3) 3rd Generation VTCN1 (B7H4) CAR: Contains CD3ζ and two co-stimulatory domains (e.g., CD28+4-1BB, CD28+OX40), further enhancing T cell activation, proliferation, persistence, and cytotoxicity. Preclinical studies have shown that third-generation VTCN1 (B7H4) CAR-T cells have stronger anti-tumor activity in ovarian cancer and breast cancer models, effectively overcoming the immunosuppressive tumor microenvironment. We offer customizable 3rd generation plasmids to meet diverse research needs.
4) 4th Generation VTCN1 (B7H4) CAR (also known as TRUCKs: T cells Redirected for Universal Cytokine Killing): On the basis of the third generation, it integrates cytokine genes (such as IL-12, IL-15, IL-18) or chemokine receptors, which can recruit and activate immune cells in the tumor microenvironment (TME), improve the anti-tumor effect in solid tumors, and reduce tumor escape.
5) 5th Generation VTCN1 (B7H4) CAR: Introduces additional signaling domains (such as STAT3/5, NF-κB) to optimize intracellular signal transduction, further enhancing the proliferation, persistence, and anti-tumor activity of CAR-modified cells, and reducing the risk of exhaustion.

Current Research Achievements

In recent years, VTCN1 (B7H4) CAR research has made significant progress, with abundant preclinical data confirming its efficacy in treating VTCN1 (B7H4)-positive solid tumors, and several clinical trials currently underway.
1) Preclinical Research: VTCN1 (B7H4) CAR-T/NK cells have shown potent specific cytotoxicity against VTCN1 (B7H4)-positive tumor cell lines (e.g., ovarian cancer cell lines SKOV3, breast cancer cell lines MDA-MB-231, bladder cancer cell lines T24) and primary patient samples. In xenograft mouse models of ovarian cancer, breast cancer, and bladder cancer, VTCN1 (B7H4) CAR-T cells significantly inhibit tumor growth and prolong mouse survival. Optimized VTCN1 (B7H4) CAR-NK cells (e.g., integrating NKG2D transmembrane domain, DAP10/12 adapter protein) have stronger cytotoxicity and persistence, and almost no risk of GVHD, CRS, or ICANS, showing good safety prospects. Additionally, combining VTCN1 (B7H4) CAR therapy with anti-PD-1 antibodies has been shown to enhance anti-tumor efficacy by reversing T cell exhaustion in the immunosuppressive tumor microenvironment. Our VTCN1 (B7H4) CAR plasmids have been widely used in preclinical research, supporting researchers in achieving reliable experimental results.
2) Clinical Trials: Multiple phase I/II clinical trials of VTCN1 (B7H4) CAR-T cells for relapsed/refractory ovarian cancer, breast cancer, and bladder cancer are underway worldwide (e.g., ClinicalTrials.gov ID: NCT04555551, NCT05184712). Preliminary results show that VTCN1 (B7H4) CAR-T therapy can achieve certain objective remission rates in patients with advanced solid tumors, especially in patients with ovarian cancer who are unresponsive to conventional chemotherapy. Notably, a phase I trial of VTCN1 (B7H4) CAR-T cells for ovarian cancer reported that 3 out of 8 patients achieved partial remission, with manageable side effects. Additionally, VTCN1 (B7H4)-targeted antibodies (such as alsevalimab) combined with CAR therapy are being explored to enhance anti-tumor efficacy.

Approved Drugs

At present, there are no VTCN1 (B7H4) CAR-T drugs approved for marketing globally, but several VTCN1 (B7H4)-targeted drugs have been approved or are in late-stage clinical trials, laying a foundation for the development of VTCN1 (B7H4) CAR therapy.
1) Alsevalimab (FPA150): A human monoclonal antibody targeting VTCN1 (B7H4) with potential antineoplastic and immune checkpoint inhibitory activities, currently in clinical trials for various solid tumors, including ovarian cancer and breast cancer. It works by blocking VTCN1 (B7H4)-mediated immune suppression, restoring T cell function, and has shown promising preliminary efficacy in patients with advanced solid tumors.
2) Felmetatug Vedotin: An anti-VTCN1 (B7H4) antibody-drug conjugate (ADC) composed of a human monoclonal anti-VTCN1 (B7H4) antibody conjugated to vedotin, a cytotoxic agent. It is currently in clinical trials for solid tumors, targeting VTCN1 (B7H4)-positive tumor cells and delivering cytotoxic payloads to kill tumor cells specifically.
3) Other VTCN1 (B7H4)-targeted Drugs: Several other VTCN1 (B7H4)-targeted antibodies, bispecific T cell engagers (BiTEs), and small-molecule inhibitors are in preclinical or early-stage clinical development, further validating the feasibility of VTCN1 (B7H4) as a therapeutic target and creating favorable conditions for the clinical transformation of VTCN1 (B7H4) CAR therapy.

Research Hotspots

The current research hotspots of VTCN1 (B7H4) CAR mainly focus on the following aspects, aiming to improve efficacy, safety, and clinical applicability in solid tumors.
1) Optimization of CAR Structure: Modification of scFv to adjust binding affinity, enhancing specific recognition of VTCN1 (B7H4)-positive tumor cells while reducing "on-target-off-organ" toxicity (e.g., damage to normal cells with low VTCN1 (B7H4) expression). Additionally, optimization of co-stimulatory domains and signaling pathways to enhance CAR cell persistence and anti-tumor memory, and reduce cell exhaustion in the immunosuppressive tumor microenvironment.
2) CAR-NK Cell Therapy: Due to its advantages of no GVHD, low CRS/ICANS risk, and "off-the-shelf" potential, VTCN1 (B7H4) CAR-NK cells have become a research hotspot. Studies focus on optimizing NK cell sources (peripheral blood, umbilical cord blood, iPSC-derived NK cells) and CAR structure to enhance cytotoxicity and in vivo persistence in solid tumors.
3) Combination Therapy: Combining VTCN1 (B7H4) CAR therapy with immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), chemotherapy, targeted therapy, or radiation therapy to overcome tumor microenvironment immunosuppression and tumor escape. Preclinical studies have shown that combining anti-PD-1 antibodies with VTCN1 (B7H4) CAR-T therapy significantly enhances T cell infiltration and anti-tumor efficacy in bladder cancer models.
4) Overcoming Antigen Heterogeneity: Developing bispecific/multispecific CARs (e.g., VTCN1 (B7H4)+PD-L1, VTCN1 (B7H4)+HER2) to target multiple antigens on solid tumor cells, reducing the risk of tumor escape caused by VTCN1 (B7H4) downregulation. Our customized plasmid construction services can support the design and construction of bispecific/multispecific VTCN1 (B7H4) CAR plasmids.
5) Improving Tumor Penetration: Optimizing CAR-modified cells to enhance their penetration into solid tumor tissues, which is a major challenge for CAR therapy in solid tumors. Strategies include modifying CAR structure to reduce cell aggregation, integrating chemokine receptors to guide CAR cells to tumor sites, and combining with agents that disrupt the tumor extracellular matrix.

Research Difficulties & Challenges

Despite the promising prospects of VTCN1 (B7H4) CAR therapy for solid tumors, there are still many difficulties and challenges in its research and clinical application.
1) Immunosuppressive Tumor Microenvironment (TME): Solid tumors have a complex and immunosuppressive TME, characterized by high levels of Tregs, tumor-associated macrophages (TAMs), and immunosuppressive cytokines (e.g., IL-10, TGF-β), which inhibit the activation and function of VTCN1 (B7H4) CAR-modified cells. This leads to reduced anti-tumor efficacy and CAR cell exhaustion.
2) Tumor Antigen Heterogeneity: Some solid tumor cells may downregulate or lose VTCN1 (B7H4) expression, leading to tumor escape and treatment failure. This is a major challenge for VTCN1 (B7H4) CAR therapy, as single-antigen targeting is prone to resistance.
3) Poor Tumor Penetration: CAR-modified cells have difficulty penetrating solid tumor tissues, limiting their ability to reach and kill all tumor cells, especially in large or advanced tumors. This reduces the overall anti-tumor efficacy of VTCN1 (B7H4) CAR therapy.
4) On-Target-Off-Organ Toxicity: Although VTCN1 (B7H4) is minimally expressed in normal tissues, low-level expression in certain organs (e.g., placenta, kidney) may lead to off-target toxicity by VTCN1 (B7H4) CAR cells, especially in patients with high CAR expression.
5) Low Transduction Efficiency and Poor Persistence: For patients with advanced solid tumors, the quality of autologous T/NK cells may be poor, resulting in low transduction efficiency of VTCN1 (B7H4) CAR and poor in vivo persistence, affecting treatment efficacy. The development of "off-the-shelf" allogeneic CAR cells (e.g., UCB-derived, iPSC-derived) is expected to solve this problem, but there are still challenges in reducing immune rejection and improving safety.

Frequently Asked Questions (FAQs)

Q: Which generation of VTCN1 (B7H4) CAR is most suitable for tumor research?
A: The choice of generation depends on your research goals. For basic anti-tumor mechanism research, 1st or 2nd generation plasmids are recommended; for improving CAR cell persistence and cytotoxicity in solid tumors, 3rd generation plasmids are better; for enhancing tumor microenvironment penetration and activating immune cells, 4th generation plasmids (TRUCKs) are suitable; for reducing CAR cell exhaustion in the immunosuppressive TME, 5th generation plasmids are preferred.

Q: What is the difference between VTCN1 (B7H4) CAR-T and CAR-NK cells, and which one is better for solid tumor research?
A: VTCN1 (B7H4) CAR-T cells have strong anti-tumor activity but may have risks of GVHD, CRS, and ICANS; VTCN1 (B7H4) CAR-NK cells have no GVHD risk, low CRS/ICANS risk, and "off-the-shelf" potential, making them more suitable for solid tumor patients with poor autologous T cell quality. If your research focuses on safety and off-the-shelf applications, CAR-NK is recommended; if you focus on strong anti-tumor activity, CAR-T is a better choice.

Q: How to reduce the on-target-off-organ toxicity of VTCN1 (B7H4) CAR?
A: The main methods include optimizing the scFv binding affinity to reduce binding to normal cells with low VTCN1 (B7H4) expression, using tissue-specific promoters to restrict CAR expression in immune cells, and designing inducible CARs to control CAR expression time and level. The optimized scFv plasmids and tissue-specific promoter options can effectively reduce on-target-off-organ toxicity.

Q: Can VTCN1 (B7H4) CAR therapy be combined with other immunotherapies?
A: Yes, combining VTCN1 (B7H4) CAR therapy with immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors) is a promising strategy to overcome the immunosuppressive tumor microenvironment and enhance anti-tumor efficacy. Preclinical studies have shown that this combination significantly improves T cell infiltration and tumor killing in bladder cancer and ovarian cancer models.

Q: Which vector backbone should I choose for VTCN1 (B7H4) CAR-T cell preparation?
A: For stable transfection of T cells, lentiviral vectors (LV) are recommended, as they can integrate into the genome and achieve long-term stable expression; for transient expression or non-integrating needs, non-viral vectors (plasmid, transposon) are suitable; for low immunogenicity and in vivo delivery (e.g., direct injection into tumors), AAV vectors are preferred. We can provide corresponding vector backbones according to your needs.

Q: How to choose the appropriate fluorescent marker and antibiotic selection marker?
A: The choice of fluorescent marker depends on your detection equipment and experimental needs (e.g., GFP for basic fluorescence detection); the choice of antibiotic selection marker depends on the cell type (e.g., puromycin, hygromycin, neomycin, blasticidin, zeocin). We provide multiple options to meet your needs.

Q: What is the storage condition of your VTCN1 (B7H4) CAR plasmids?
A: Plasmids are stored at -20℃ or -80℃, avoiding repeated freeze-thaw cycles. After thawing, the plasmid can be stored at 4℃ for 1-2 weeks.

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