TRBC1 Chimeric Antigen Receptor (CAR): A Comprehensive Guide and Our Service & Product Introduction

Our TRBC1 CAR Expression Plasmid Vector Products and Custom Services

Product Features

1. Multiple generations available: We provide 1st to 5th generation TRBC1 CAR expression plasmid vectors, each with unique structural characteristics and functional advantages.
1) 1st generation: Contains only the CD3ζ intracellular signaling domain, suitable for basic research on T-cell activation and TRBC1 recognition.
2) 2nd generation: Adds one co-stimulatory domain (CD28 or 4-1BB) based on the 1st generation, enhancing T-cell proliferation and persistence (e.g., TRBC1 CAR with 41BB-CD3ζ domains, similar to the AUTO4 construct).
3) 3rd generation: Contains two co-stimulatory domains (e.g., CD28+4-1BB or CD28+OX40), further improving the anti-tumor activity and in vivo persistence of CAR-T cells.
4) 4th generation: Modified from the 2nd generation, with inducible or constitutive expression of cytokines, enhancing the anti-tumor effect and reducing adverse reactions.
5) 5th generation: Integrates the intracellular domain of cytokine receptors based on the 2nd generation, further optimizing T-cell function and anti-tumor efficacy.

2. Diverse vector backbones: We offer a variety of vector backbones to meet different application scenarios, including non-viral vectors (plasmid vectors), lentiviral vectors, retroviral vectors, and AAV (Adeno-Associated Virus) vectors. Lentiviral vectors are suitable for efficient transduction of T cells, retroviral vectors are suitable for stable integration and long-term expression, AAV vectors have high safety and low immunogenicity, and non-viral vectors are suitable for transient expression and large-scale production.

3. Flexible promoter options: Our vectors are equipped with a variety of high-efficiency promoters to meet different expression needs, including CMV promoter (strong constitutive expression), EF1α promoter (stable expression in mammalian cells), and T-cell-specific promoters (for targeted expression in T cells), ensuring high and stable expression of TRBC1 CAR in target cells.

4. Multiple fluorescent and antibiotic selection markers: Fluorescent markers include GFP (green fluorescent protein), RFP (red fluorescent protein), which facilitate the observation and sorting of transfected cells. Antibiotic selection markers include Puromycin (Pur), Neomycin (Neo), Hygromycin (Hygro) and Blasticidin (Bla), enabling efficient screening of positive clones. We also provide vectors with dual markers for more flexible experimental design, and can incorporate CD34-based markers for tracking CAR-T cells.

5. High quality and reliability: We implement strict quality control procedures for all TRBC1 CAR expression plasmid vectors to ensure product quality and reliability. Full-length CAR Sanger sequencing is performed to ensure 100% consistency with the theoretical reference sequence.

6. Cost-effectiveness: We provide competitive pricing and bulk purchase discounts, helping to reduce research and development costs. We also offer scalable production options for large-scale needs.

Product Applications

Customized Plasmid Vector Construction Services

Introduction of TRBC1

TRBC1 (T Cell Receptor Beta Constant 1) is a protein encoded by the TRBC1 gene in humans (Gene ID: 28639, Ensembl: ENSG00000211895). The human TRBC1 gene is located on chromosome 7q34, spanning from 142791694 bp to 142793141 bp on the GRCh38.p14 assembly, and is widely conserved in mammals. It is also known by synonyms such as TCRB, TCRBC1, and BV05S1J2.2, with a UniProt ID of P01850. The TRBC1 gene plays a key role in T-cell receptor signaling and adaptive immune response, and its abnormal expression is closely associated with various T-cell malignancies.

TRBC1 is a core component of the alpha-beta T cell receptor (TCR) complex, belonging to the immunoglobulin superfamily. Its structure consists of an extracellular immunoglobulin-like constant domain, a single transmembrane domain, and a short cytoplasmic tail. The extracellular domain is involved in stabilizing the TCR complex and mediating antigen recognition, while the transmembrane domain anchors the protein to the T-cell membrane. The cytoplasmic tail lacks intrinsic kinase activity but interacts with CD3 subunits to mediate downstream signaling pathways, which is crucial for T-cell activation. Notably, TRBC1 can be fused with single-chain variable fragments (scFv) to form TCR-ABR (TCR-fused Antigen Binding Receptor) constructs, which can reprogram the TCR complex to recognize tumor antigens in an HLA-independent manner.

TRBC1 is primarily involved in T-cell receptor signaling pathways, adaptive immune responses, and alpha-beta T-cell activation. It forms a functional TCR complex with TCR alpha chains, CD3 subunits, and other components, enabling T cells to recognize specific antigens presented by HLA molecules and initiate immune responses. TRBC1 is also predicted to participate in immune response activation, defense responses against external organisms, and phagocytosis. Its expression is critical for normal T-cell maturation and function, and its dysregulation can lead to abnormal T-cell activation and the development of hematological malignancies.

TRBC1 is specifically expressed in subsets of normal T cells, with a partial expression pattern in healthy individuals—for example, a positive rate of 23.83% ± 2.74% in normal bone marrow samples. It is mainly expressed on the surface of mature alpha-beta T cells, thymocytes, and subsets of peripheral T cells, but not on non-T cells such as B cells, NK cells, or hematopoietic stem cells. Importantly, TRBC1 expression is monotypic in normal T cells, while malignant T-cell populations often show abnormal polytypic expression, which can be detected by flow cytometry to aid in the diagnosis of T-cell malignancies. It is not expressed in non-hematopoietic tissues, making it an ideal target for immunotherapy of T-cell-related diseases.

TRBC1 is closely associated with a variety of T-cell malignancies, as its abnormal expression is a hallmark of clonal T-cell proliferation. It is frequently expressed in T-cell acute lymphoblastic leukemia (T-ALL), peripheral T-cell lymphoma (PTCL), anaplastic large cell lymphoma (ALCL), angioimmunoblastic T-cell lymphoma, and other mature T-cell neoplasms. Approximately 12.8% of T-ALL patients show positive TRBC1 expression, while subsets of PTCL patients also exhibit abnormal TRBC1 expression. Flow cytometric evaluation of surface and cytoplasmic TRBC1 expression can aid in the differential diagnosis of T-ALL and normal thymocyte expansions, as neoplastic T-lymphoblast populations often lack the characteristic polytypic expression pattern of normal thymocytes. TRBC1’s mutually exclusive expression with TRBC2 (T Cell Receptor Beta Constant 2) makes it a unique target for selective targeting of malignant T cells while sparing normal TRBC2-positive T cells.

Introduction of TRBC1 Chimeric Antigen Receptor (CAR)

TRBC1 Chimeric Antigen Receptor (TRBC1 CAR) is a genetically engineered receptor designed to specifically recognize the TRBC1 antigen on the surface of malignant T cells. Its structure typically includes four main components: an extracellular antigen-recognition domain (scFv) that binds to TRBC1, an extracellular hinge region that provides flexibility and stability, a transmembrane domain that anchors the receptor to the T-cell membrane, and an intracellular signaling domain that mediates T-cell activation. TRBC1 CAR-modified T cells (TRBC1 CAR-T cells) can specifically recognize and kill TRBC1-positive tumor cells.

In recent years, TRBC1 CAR research has made significant progress, with multiple preclinical and clinical studies confirming its efficacy in the treatment of relapsed/refractory T-cell malignancies. The LIBRA-T1 study, an ongoing multicenter phase 1/2 trial of autologous TRBC1 CAR-T cells (AUTO4) in relapsed/refractory TRBC1-positive PTCL, reported promising interim results: among the first 10 patients, 4 achieved complete metabolic response, with two patients maintaining durable remissions beyond 1 year. AUTO4 was well-tolerated, with only one patient developing grade 3 cytokine release syndrome (CRS), demonstrating a favorable safety profile. Notably, TRBC1 CAR-T cells were detected in lymph node biopsy samples from tumor sites, indicating effective homing to malignant lesions.
Preclinical studies have also shown that TRBC1-targeted CAR-T cells and antibody-drug conjugates (ADCs) exhibit potent anti-tumor activity against TRBC1-positive T-cell cancers. TRBC1 TCR-ABR constructs, which fuse scFv to TCR α subunits, can effectively reprogram the TCR complex to recognize TRBC1 in an HLA-independent manner, enhancing the anti-tumor efficacy of engineered T cells. Additionally, flow cytometric evaluation of TRBC1 expression has been validated as a reliable method to detect T-cell clonality, aiding in the diagnosis and monitoring of TRBC1-positive malignancies.

Currently, there are no TRBC1 CAR-T cell drugs officially approved by the U.S. Food and Drug Administration (FDA), European Medicines Agency (EMA), or National Medical Products Administration (NMPA) globally. However, multiple TRBC1 CAR-T products are in advanced clinical trial stages (phase 1/2), with AUTO4 (Autolus Therapeutics) being one of the most promising candidates, focusing on the treatment of relapsed/refractory PTCL. Other ongoing clinical trials include TRBC1 CAR-T therapy for T-ALL and ALCL, with preliminary data showing encouraging efficacy and safety. With the continuous advancement of clinical research, it is expected that the first TRBC1 CAR-T drug will be approved for marketing in the future, bringing new treatment options for patients with TRBC1-positive T-cell malignancies.

TRBC1 CAR Research Hotspots

TRBC1 CAR Research Difficulties & Challenges

Frequently Asked Questions (FAQs)

Q: What is the difference between different generations of TRBC1 CAR expression plasmid vectors?
A: The main difference lies in the composition of the intracellular signaling domain. The 1st generation only contains CD3ζ; the 2nd generation adds one co-stimulatory domain (CD28 or 4-1BB), which enhances T-cell persistence (e.g., the 41BB-CD3ζ domain used in AUTO4); the 3rd generation contains two co-stimulatory domains; the 4th generation can express cytokines; the 5th generation integrates the intracellular domain of cytokine receptors. With the increase of generations, the anti-tumor activity, proliferation ability, and in vivo persistence of TRBC1 CAR-T cells are gradually improved.

Q: Which vector backbone should I choose for TRBC1 CAR-T cell preparation?
A: It depends on your experimental needs. Lentiviral vectors are suitable for efficient transduction of T cells and stable long-term expression; retroviral vectors (e.g., γ-retroviral) are suitable for dividing cells and stable integration, as used in clinical TRBC1 CAR-T products; AAV vectors have high safety and low immunogenicity, suitable for in vivo delivery; non-viral plasmid vectors are suitable for transient expression, large-scale production, and low-cost experiments.

Q: How to choose the appropriate promoter for TRBC1 CAR expression plasmid vectors?
A: CMV promoter is suitable for strong constitutive expression in most mammalian cells; EF1α promoter has stable expression and is not easily silenced, suitable for long-term cell culture; T-cell-specific promoters are suitable for targeted expression in T cells. If you are not sure, we recommend choosing CMV or EF1α promoter for general research.

Q: What are the advantages of fluorescent markers in TRBC1 CAR expression plasmid vectors?
A: Fluorescent markers (such as GFP, RFP) can help you quickly observe the transfection efficiency of the vector, sort transfected positive cells by flow cytometry, and track the expression and distribution of TRBC1 CAR in cells and animal models. We can also incorporate CD34-based markers for convenient CAR-T cell tracking, similar to the RQR8 safety switch system.

Q: How to ensure the purity and safety of plasmid vectors?
A: We implement strict quality control procedures, including sequence verification and endotoxin testing (upon request), to ensure that the plasmid vector has high purity, low endotoxin, and no harmful impurities. All products meet international standards and can be safely used in in vitro experiments and preclinical research.

Q: How to solve the problem of CAR-T fratricide when using TRBC1 CAR expression plasmid vectors?
A: You can choose vectors designed for depletion of TRBC1-positive T cells before transduction, as used in the AUTO4 CAR-T product, to avoid fratricide during manufacturing. You can also use vectors compatible with CRISPR-Cas9-mediated TRBC1 gene knockout in CAR-T cells, further reducing fratricide risk.

Q: What is the delivery time for customized plasmid vector construction services?
A: The delivery time depends on the complexity of the customized project. Generally, the standard customized project can be delivered within 2-4 weeks, and the complex project (such as multi-functional element addition, TCR-ABR construct design, large-scale preparation) can be delivered within 4-8 weeks. We will evaluate the delivery time with you before starting the project and do our best for on-time delivery.

References

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