CD4 Chimeric Antigen Receptor (CAR): A Comprehensive Guide and Our Service & Product Introduction

CD4 Chimeric Antigen Receptor (CAR) technology has emerged as a pivotal tool in immunotherapy research and clinical translation, targeting CD4-expressing cells in various diseases including cancer, HIV infection, and autoimmune disorders. RGBiotech is committed to providing high-quality CD4 CAR expression plasmid vectors and professional custom construction services, supporting researchers and biopharmaceutical enterprises in accelerating scientific research and product development.
If you are interested in our CD4 CAR expression plasmid vectors or custom construction services, or need technical advice for your CD4 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 CD4 CAR technology and accelerate the development of innovative immunotherapies.

Our CD4 CAR Expression Plasmid Vector Products and Custom Services

CD4 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 CD4 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 CD4 CAR research and translation, with strict quality control and technical support.

Our CD4 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-12/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 CD4 CAR Plasmid Vector Construction Services

Introduction of CD4

The CD4 gene (official symbol: CD4; HGNC ID: 1678; Gene ID: 920) is located on human chromosome 12p13.31, spanning from 6,786,858 bp to 6,820,799 bp, and contains 11 exons encoding a 51 kDa glycoprotein. Also known as T4, Leu-3, or IMD79, this protein-coding gene has multiple alternatively spliced transcript variants that produce different isoforms, playing diverse roles in immune regulation and disease pathogenesis. In mice, the CD4 ortholog is located on chromosome 6, with high evolutionary conservation across species.

CD4 is a transmembrane glycoprotein belonging to the immunoglobulin superfamily, consisting of four extracellular immunoglobulin-like domains (D1-D4), a single transmembrane domain, and a cytoplasmic tail. The extracellular D1 domain contains the binding site for major histocompatibility complex (MHC) class II molecules and the HIV envelope glycoprotein gp120, while the cytoplasmic region interacts with src-family kinases (e.g., Lck) to initiate intracellular signaling cascades. The protein is localized in multiple cellular compartments, including the plasma membrane, endoplasmic reticulum, and clathrin-coated endocytic vesicles, reflecting its dynamic role in cellular signaling.

CD4 primarily functions as a co-receptor for the T cell receptor (TCR) complex, facilitating the recognition of antigens presented by MHC class II molecules on antigen-presenting cells (APCs). It plays a crucial role in T cell activation, differentiation, and proliferation, regulating the production of cytokines and the maturation of helper T cell subsets (Th1, Th2, Th17, etc.) that maintain tissue homeostasis and orchestrate adaptive immune responses. Additionally, CD4 serves as a primary receptor for HIV entry into host cells through its interaction with gp120, making it a key target in HIV research. In non-T cells such as macrophages and dendritic cells, CD4 participates in differentiation, activation, and cytokine expression through TCR/Lck-independent pathways.

CD4 is predominantly expressed on the surface of helper T lymphocytes, monocytes, and dendritic cells. It is also broadly expressed in lymphoid tissues such as the spleen (RPKM 82.4) and lymph nodes (RPKM 55.1), as well as in granulocytes, appendix, thymus, and various regions of the brain. In cancer tissues, CD4 is expressed in 65.0% and 78.3% of M4 and M5 subtypes of acute myeloid leukemia (AML), respectively, and in 30-40% of other AML subtypes, while being absent on normal hematopoietic stem cells (HSCs)-a critical feature for targeted therapy.

CD4 is closely associated with a range of diseases due to its central role in immune function.
1) HIV Infection: CD4 is the primary receptor for HIV, and the progressive depletion of CD4+ T cells is a hallmark of AIDS, leading to severe immunodeficiency.
2) Cancer: CD4 is expressed on subsets of AML, lung cancer, and breast cancer cells, and CD4+ T cells can be manipulated by tumor cells to promote tumor development and metastasis, making CD4 a potential therapeutic target.
3) Autoimmune Diseases: Dysregulated CD4+ T cell responses contribute to the pathogenesis of multiple sclerosis, rheumatoid arthritis, and systemic lupus erythematosus (SLE).
4) Infectious Diseases: CD4 participates in the defense response against gram-negative bacteria and viral infections, regulating immune responses to pathogens.

Introduction of CD4 Chimeric Antigen Receptor (CAR)

CD4 Chimeric Antigen Receptor (CD4 CAR) is a genetically engineered receptor designed to redirect immune cells (e.g., T cells, NK cells) to specifically recognize and eliminate CD4-expressing target cells. By fusing the extracellular CD4 domain or anti-CD4 single-chain variable fragment (scFv) with intracellular signaling domains, CD4 CAR-equipped immune cells achieve MHC-independent recognition of CD4+ cells, offering a promising strategy for treating CD4-related diseases.

A typical CD4 CAR consists of three core components: 1) Extracellular Antigen-Binding Domain: Usually the CD4 extracellular domain (D1-D4 or D1-D2) or an anti-CD4 scFv, responsible for specific binding to CD4 on target cells. 2) Hinge and Transmembrane Domain: Derived from CD28 or CD8α, facilitating the stability of the CAR on the cell surface and the transmission of intracellular signals. 3) Intracellular Signaling Domain: Varies by CAR generation, including activation domains (CD3ζ) and co-stimulatory domains (CD28, 4-1BB, OX40, etc.), which regulate the activation, proliferation, and persistence of CAR-engineered cells.

Current Research Achievements of CD4 CAR

Approved Drugs of CD4 CAR

To date, there are no FDA or EMA-approved CD4 CAR therapies. However, several CD4 CAR candidates are in preclinical development or early-phase clinical trials, primarily focusing on refractory AML and HIV infection. The development of CD4 CAR therapies is progressing steadily, with ongoing efforts to optimize CAR structure, improve in vivo persistence, and reduce off-target effects. We provide high-quality CD4 CAR plasmid vectors to support CD4 CAR research projects.

CD4 CAR Research Hotspots

CD4 CAR Research Difficulties & Challenges

Frequently Asked Questions (FAQs)

Q: What is the difference between different generations of CD4 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 CD4 recognition but have low in vivo persistence. 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. 4th generation CARs (with cytokines) are suitable for solid tumor research to improve tumor infiltration, while 5th generation CARs (with checkpoint antagonists) are designed to overcome T cell exhaustion. Choose based on your research goals (e.g., AML vs. HIV, in vitro vs. in vivo studies) and cell type.

Q: Which vector backbone is suitable for CD4 CAR-T cell preparation, and why?
A: Lentiviral vectors are the most commonly used backbone for CD4 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. 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 CD4 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), reducing the risk of viral vector-related complications.

Q: How to ensure high CD4 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); 2) Optimize the CD4 CAR gene codons for the target cell type; 3) Use high-purity, low-endotoxin plasmids to avoid cytotoxicity; 4) Select an appropriate delivery method; 5) Ensure the vector has a suitable linker (2A or IRES) for co-expression of CAR and markers.

Q: What are the key considerations for CD4 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); 2) Thaw plasmids on ice and centrifuge briefly before use; 3) Avoid exposure to high temperatures, UV light, and RNase/DNase contamination; 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.

Q: Can your custom service design CD4 CAR vectors with specific modifications (e.g., CRISPR-edited sites, cytokine fusion)?
A: Yes. Our custom service supports various modifications, including inserting CRISPR-edited sites (e.g., CCR5 knockout, PD-1 deletion) to enhance CAR-engineered cell function, fusing cytokines (IL-12, IL-15) to improve in vivo persistence. We can also design dual-CAR vectors (CD4 + other antigens) or TCR-ABR-CD4 CAR vectors for HLA-independent recognition. Simply provide your modification requirements, and our team will design a tailored solution.

Q: How to verify the functionality of CD4 CAR plasmid vectors after purchase?
A: We recommend the following verification steps: 1) Sequence verification to confirm the plasmid sequence is correct; 2) Transfect HEK293T cells with the plasmid, then detect CD4 CAR expression via flow cytometry (using anti-CD4 or anti-CAR antibodies) or fluorescence microscopy (if fluorescent markers are included); 3) Perform in vitro cytotoxicity assays using CD4-expressing target cells (e.g., AML 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 CD4 CAR-T and CD4 CAR-NK cells, and which is better for my research?
A: CD4 CAR-T cells have strong proliferation ability and long-term persistence, making them suitable for long-term disease control (e.g., chronic HIV infection, relapsed AML) but may have higher immunogenicity and risk of cytokine release syndrome (CRS). CD4 CAR-NK cells have lower immunogenicity, no risk of graft-versus-host disease (GVHD), and rapid cytotoxicity, making them suitable for acute diseases (e.g., acute AML) but have shorter in vivo persistence. Choose based on your research focus (long-term control vs. rapid efficacy) and safety requirements.

Q: How to reduce off-target effects of CD4 CAR-engineered cells?
A: Off-target effects can be reduced by: 1) Using highly specific extracellular binding domains (e.g., CD4 D1-D2 domain or high-affinity anti-CD4 scFv) that only recognize CD4 on target cells; 2) Designing tumor-specific CD4 CARs (e.g., targeting CD4 isoforms expressed only on cancer cells); 3) Using tissue-specific promoters to restrict CAR expression to immune cells; 4) Adding a suicide gene (e.g., iCasp9) to the vector to eliminate CAR-engineered cells if off-target toxicity occurs; 5) Optimizing CAR affinity to avoid cross-reactivity with other antigens.

References

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