CD5 Chimeric Antigen Receptor (CAR): A Comprehensive Guide and Our Service & Product Introduction

CD5 Chimeric Antigen Receptor (CAR) technology has become a promising frontier in immunotherapy research and clinical translation, targeting CD5-expressing cells in various hematologic malignancies and immune disorders. RGBiotech is dedicated to providing high-quality CD5 CAR expression plasmid vectors and professional custom construction services, supporting researchers and biopharmaceutical enterprises in accelerating scientific research progress and product development.
If you are interested in our CD5 CAR expression plasmid vectors or custom construction services, or need technical advice for your CD5 CAR research, please contact us at admin@rgbiotech.com. Our professional team will promptly respond to your inquiries, providing personalized solutions to meet your research needs. We look forward to cooperating with you to advance CD5 CAR technology and accelerate the development of innovative immunotherapies for CD5-related diseases.

Our CD5 CAR Expression Plasmid Vector Products and Custom Services

CD5 CAR technology is a rapidly growing field in immunotherapy, with increasing demand for high-quality plasmid vectors and custom construction services. As a professional provider of gene engineering tools, RGBiotech offers a comprehensive range of CD5 CAR expression plasmid vectors and custom construction services, tailored to meet the diverse needs of researchers and biopharmaceutical companies. Our products and services are designed to accelerate CD5 CAR research and translation, with strict quality control and technical support.

Our CD5 CAR expression plasmid vectors cover all generations (1st to 5th) and feature diverse designs to support various research applications. 1) 1st Generation: CD3ζ only (basic activation signal, low persistence); 2) 2nd Generation: CD3ζ + one co-stimulatory domain (CD28 or 4-1BB, enhanced activation and proliferation); 3) 3rd Generation: CD3ζ + two co-stimulatory domains (CD28+4-1BB/OX40, improved in vivo persistence); 4) 4th Generation (ARM CAR): CD3ζ + co-stimulatory domain + cytokine (IL-7/IL-15, enhanced anti-tumor immunity and tumor infiltration); 5) 5th Generation: CD3ζ + co-stimulatory domain + inhibitory checkpoint antagonist (PD-1/CTLA-4 blockade, overcoming T cell exhaustion).

Product Features

Product Applications

Custom CD5 CAR Plasmid Vector Construction Services

Introduction of CD5

The CD5 gene (official symbol: CD5; HGNC ID: 1679; Gene ID: 921) is located on human chromosome 11q12.2, encoding a transmembrane glycoprotein belonging to the scavenger receptor cysteine-rich (SRCR) superfamily. Also known as Lymphocyte antigen T1/Leu-1, this protein-coding gene has multiple alternatively spliced transcript variants that produce different isoforms, playing crucial roles in immune regulation and disease pathogenesis. The human CD5 protein (UniProtKB/Swiss-Prot: P06127.2) consists of 495 amino acids, with conserved sequences across mammalian species, making it a versatile target for cross-species research. The gene’s 5’-flanking region contains evolutionarily conserved transcription regulatory elements that control its tissue-specific expression.

CD5 is a type-I transmembrane glycoprotein characterized by three extracellular SRCR domains, a single transmembrane domain, and a cytoplasmic tail. The extracellular SRCR domains are responsible for ligand binding and immune cell interactions, while the cytoplasmic region lacks intrinsic kinase activity but interacts with downstream signaling molecules (e.g., Lck, Zap-70) to regulate intracellular signaling cascades. As a phosphoprotein with a signal peptide and transmembrane helix, CD5 is localized primarily on the plasma membrane of immune cells, with minor expression in endoplasmic reticulum compartments involved in protein maturation. Its structural features enable it to act as a regulatory receptor in T cell activation and immune homeostasis.

CD5 primarily functions as a negative regulator of the T cell receptor (TCR) signaling pathway, playing a critical role in T cell activation, differentiation, and tolerance. It modulates the threshold of T cell activation to prevent excessive immune responses and autoimmunity, and it suppresses IL-15-induced proliferation of human memory CD8+ T cells by inhibiting mTOR pathways. Additionally, CD5 serves as a co-receptor in T cell-antigen-presenting cell (APC) interactions, regulating the production of cytokines and the maturation of T cell subsets. In B cells, CD5 is expressed on B1a subsets, where it participates in B cell activation and antibody production. Notably, CD5 acts as a key modulator of immune homeostasis, with its dysfunction contributing to the development of autoimmune diseases and malignancies.

CD5 is predominantly expressed on the surface of thymocytes, mature T lymphocytes (both CD4+ and CD8+ subsets, including naive, central memory, and effector memory cells), and a subset of B lymphocytes (B1a cells). It is also expressed on CD5+ dendritic cells and is broadly distributed in lymphoid tissues, with biased expression in lymph nodes (RPKM 19.1) and appendix (RPKM 11.9), as well as in the thymus, spleen, and tonsils. Importantly, CD5 is widely expressed in hematologic malignancies but absent in most non-hematopoietic tissues, providing a "tissue-level" specificity that makes it an attractive target for immunotherapy. In cancer tissues, CD5 is expressed in approximately 85% of T-cell tumors and subsets of B-cell malignancies, further supporting its therapeutic potential.

CD5 is closely associated with a range of immune-related diseases and malignancies due to its central role in immune regulation.
1) Hematologic Malignancies: CD5 is a key marker for T-cell malignancies, including T-cell acute lymphoblastic leukemia (T-ALL), peripheral T-cell lymphoma (PTCL), and cutaneous T-cell lymphoma (CTCL). It is also expressed in subsets of B-cell malignancies, such as chronic lymphocytic leukemia (CLL), mantle cell lymphoma (MCL), and splenic marginal zone lymphomas with TP53 abnormalities.
2) Autoimmune Diseases: Dysregulated CD5 expression or function contributes to the pathogenesis of rheumatoid arthritis, systemic lupus erythematosus (SLE), and multiple sclerosis, as it impairs T cell tolerance and promotes excessive immune responses.
3) Infectious Diseases: CD5 participates in the immune response against viral and bacterial infections, regulating T cell activation and cytokine production to control pathogen dissemination.
4) Solid Tumors: CD5 is expressed in some solid tumors, including carcinoma showing thymus-like differentiation (CASTLE) of the major salivary gland, where it serves as an ancillary diagnostic marker.

Introduction of CD5 Chimeric Antigen Receptor (CAR)

CD5 Chimeric Antigen Receptor (CD5 CAR) is a genetically engineered receptor designed to redirect immune cells (e.g., T cells, NK cells) to specifically recognize and eliminate CD5-expressing target cells. By fusing the extracellular CD5-binding domain (e.g., anti-CD5 single-chain variable fragment (scFv) or CD5 ligand) with intracellular signaling domains, CD5 CAR-equipped immune cells achieve MHC-independent recognition of CD5+ cells, offering a promising strategy for treating CD5-related malignancies and immune disorders.

Current Research Achievements of CD5 CAR

Approved Drugs of CD5 CAR

CD5 CAR Research Hotspots

Frequently Asked Questions (FAQs)

Q: What is the difference between different generations of CD5 CARs, and how to choose the right one?
A: The main difference lies in the intracellular signaling domains. 1st generation CARs (CD3ζ only) are suitable for preliminary studies of CD5 recognition but have low in vivo persistence and are prone to exhaustion. 2nd (CD3ζ + single co-stimulatory domain) and 3rd (CD3ζ + two co-stimulatory domains) generations are ideal for preclinical studies requiring enhanced cell activation and persistence, especially for in vivo models. 4th generation CARs (with cytokines) are suitable for solid tumor or advanced hematologic malignancy research to improve tumor infiltration and persistence. 5th generation CARs (with checkpoint antagonists) are designed to overcome T cell exhaustion, making them ideal for long-term disease control. Choose based on your research goals (e.g., T-ALL vs. CLL, in vitro vs. in vivo studies) and cell type (T cells vs. NK cells).

Q: Which vector backbone is suitable for CD5 CAR-T cell preparation, and why?
A: Lentiviral vectors are the most commonly used backbone for CD5 CAR-T cell preparation, as they can transduce both dividing and non-dividing cells, integrate into the host genome for stable long-term CAR expression, and have low immunogenicity-critical for avoiding HAMA responses. Retroviral vectors are suitable for dividing cells (e.g., activated T cells) and are cost-effective for large-scale production. AAV vectors are ideal for transient or tissue-specific CD5 CAR expression, with high safety and low integration risk. Non-viral plasmid vectors are suitable for in vitro studies or non-viral delivery systems (e.g., electroporation, LNP), reducing the risk of viral vector-related complications and lowering manufacturing costs.

Q: How to ensure high CD5 CAR expression efficiency in target cells?
A: Several factors affect expression efficiency: 1) Choose a suitable promoter (EF-1α for stable long-term expression, CMV for strong transient expression, or T cell-specific promoters for targeted expression); 2) Optimize the CD5 CAR gene codons for the target cell type to enhance translation efficiency; 3) Use high-purity, low-endotoxin plasmids to avoid cytotoxicity that impairs cell viability and expression; 4) Select an appropriate delivery method; 5) Ensure the vector has a suitable linker (2A or IRES) for co-expression of CAR and markers, avoiding interference between components.

Q: What are the key considerations for CD5 CAR plasmid vector storage and handling?
A: To maintain plasmid integrity and activity: 1) Store plasmids at -20°C or -80°C, avoiding repeated freeze-thaw cycles (aliquot into single-use portions to prevent degradation); 2) Thaw plasmids on ice and centrifuge briefly before use to ensure uniform concentration; 3) Avoid exposure to high temperatures, UV light, and RNase/DNase contamination, which can damage plasmid DNA; 4) For lentiviral/retroviral backbones, store the packaged virus at -80°C with cryoprotectants to maintain transduction efficiency; 5) Follow sterile procedures when handling plasmids for cell culture applications to prevent contamination that could invalidate experiments.

Q: Can your custom service design CD5 CAR vectors with specific modifications (e.g., CD5 knockout sites, bispecific design, cytokine fusion)?
A: Yes. Our custom service supports various modifications, including inserting CRISPR-edited sites (e.g., CD5 knockout, PD-1 deletion) to prevent fratricide and enhance CAR-T cell persistence, fusing cytokines (IL-7, IL-15) to improve in vivo expansion, and designing bispecific CARs (e.g., CD5/CD7) to mitigate tumor escape. We can also incorporate tissue-specific promoters to restrict CAR expression. Simply provide your modification requirements, and our team will design a tailored solution.

Q: How to verify the functionality of CD5 CAR plasmid vectors after purchase?
A: We recommend the following verification steps: 1) Sequence verification to confirm the plasmid sequence is correct, including the CD5 CAR gene, promoter, and markers; 2) Transfect HEK293T cells with the plasmid, then detect CD5 CAR expression via flow cytometry (using anti-CD5 or anti-CAR antibodies) or fluorescence microscopy (if fluorescent markers are included); 3) Perform in vitro cytotoxicity assays using CD5-expressing target cells (e.g., T-ALL cell lines, CLL cell lines) to verify the killing ability of CAR-transduced T/NK cells; 4) Detect cytokine production (e.g., IFN-γ, IL-2) via ELISA to confirm CAR activation.

Q: What is the difference between CD5 CAR-T and CD5 CAR-NK cells, and which is better for my research?
A: CD5 CAR-T cells have strong proliferation ability and long-term persistence, making them suitable for long-term disease control (e.g., relapsed T-ALL, chronic CLL) but may have higher risk of fratricide, CRS, and GVHD. CD5 CAR-NK cells have lower immunogenicity, no risk of GVHD, and rapid cytotoxicity, making them suitable for acute diseases (e.g., acute T-ALL) or patients with compromised T cell function. However, CAR-NK cells have shorter in vivo persistence and may require repeated infusions. Choose based on your research focus (long-term control vs. rapid efficacy) and safety requirements (e.g., allogeneic vs. autologous therapy).

Q: How to reduce off-target effects and fratricide of CD5 CAR-engineered cells?
A: Off-target effects and fratricide can be reduced by: 1) Using highly specific extracellular binding domains (e.g., fully human anti-CD5 scFv or CD5 ligand) that only recognize CD5 on target cells; 2) Knocking out CD5 in CAR-T cells via CRISPR/Cas9 to prevent self-attack (fratricide); 3) Using tissue-specific promoters to restrict CAR expression to immune cells, avoiding expression in non-target cells; 4) Adding a suicide gene (e.g., iCasp9) to the vector to eliminate CAR-engineered cells if off-target toxicity occurs; 5) Designing bispecific CARs that target CD5 and a tumor-specific antigen, enhancing specificity for malignant cells; 6) Optimizing CAR affinity to avoid cross-reactivity with other antigens.

References

Contact Us