Overview
The CD3 complex is a group of protein subunits (γ, δ, ε, ζ) that associate with the T-cell receptor (TCR) to form the TCR-CD3 complex on T lymphocytes. Discovered in the 1980s, it serves as the primary signal transduction apparatus for antigen recognition. Unlike the variable TCR, CD3 subunits are invariant across all T cells, making them valuable targets for therapeutic and diagnostic applications. In clinical contexts, CD3 is a well-established marker for identifying mature T cells via flow cytometry. Its conserved structure across mammalian species has facilitated cross-species immunological research, though murine and human CD3 show subtle differences in epitope recognition by antibodies.
Physical and Chemical Properties
CD3 consists of four polypeptide chains (γ, δ, ε, and ζ) that form heterodimers (γε and δε) and homodimers (ζζ). Each subunit contains immunoreceptor tyrosine-based activation motifs (ITAMs) that initiate signaling cascades upon TCR engagement. The extracellular domains are relatively small (5-15 kDa), while transmembrane regions feature negatively charged residues critical for TCR association. Biochemically, CD3 is stable in neutral pH buffers but degrades under harsh reducing conditions due to disulfide bonds in its ζ chains. Research-grade CD3 antibodies typically recognize conformational epitopes on the ε subunit, requiring proper folding for binding. Lyophilized formulations maintain stability for years when stored at -20°C.
Main Applications
In research, anti-CD3 antibodies are indispensable for T-cell isolation (positive/negative selection) and activation studies. Clinically, monoclonal antibodies like Teplizumab (targeting CD3ε) are FDA-approved for delaying type 1 diabetes onset by modulating autoreactive T cells. CD3-directed bispecific antibodies (e.g., Blinatumomab) redirect T cells to attack cancer cells in hematologic malignancies. The pharmaceutical industry utilizes CD3 as a scaffold for chimeric antigen receptor (CAR) T-cell therapies. CD3ζ domains are commonly incorporated into CAR constructs to enhance signal transduction. Diagnostic labs employ CD3 staining to quantify T-cell subsets in immunodeficiency disorders or post-transplant monitoring.
Safety and Storage
Recombinant CD3 proteins and antibodies require careful handling to preserve activity. Avoid vortexing concentrated solutions to prevent denaturation. For in vivo applications, verify endotoxin levels (<0.1 EU/μg) to prevent cytokine storms. Therapeutic anti-CD3 antibodies may cause cytokine release syndrome (CRS), requiring clinical monitoring. Storage at -20°C in aliquots prevents repeated freeze-thaw damage. Lyophilized products should be reconstituted with sterile, endotoxin-free water or PBS. Working solutions are stable for 1-2 weeks at 4°C with protease inhibitors. Always centrifuge vial contents before opening to ensure full recovery.
B2B Procurement Guide
When sourcing CD3 reagents, prioritize vendors providing certificates of analysis (CoA) with verified biological activity (e.g., EC50 in T-cell activation assays). For therapeutic development, opt for GMP-grade materials with full traceability. Key selection criteria include: batch-to-batch consistency, species reactivity (human/mouse/cynomolgus), and format (low endotoxin, carrier-free). Bulk purchasers should negotiate volume discounts for research-grade antibodies (typically sold in 0.1-1 mg sizes). Consider custom conjugation services (FITC, PE, biotin) to streamline workflow integration. For clinical trials, partner with manufacturers compliant with ICH Q7 guidelines for biopharmaceutical production.
Related Manufacturers
- 主营：放炮线、爆破线、数码电子雷管线、CD3气体检测仪、雷管箱、雷管柜、潜孔钻头、冲击器、矿用钻头、矿用防水袋、水泡泥袋、水袋封口机、爆破四通直通、气体间隔器、爆破炮被、爆破防护网、水炮泥袋、避炮棚、炮泥机、欧姆表、装药壳、安全背夹、炸药柜、炸药库房、爆破母线
- 主营：马路吹风机、皮带中部取样器、隧道凿毛机、CD3矿用气体检测仪、玻璃安装机械手
- 主营：5CD3、变频器、电子模块、带内置滤波器
- 主营：elisa 试剂盒、Elisa试剂盒、进口试剂盒、小鼠CD3分子elisa试剂盒、国产试剂盒、试剂、细胞、ELISA检测试剂盒、酶联免疫法、酶联免疫试剂盒、酶活性检测、酶标仪检测
- 主营：科研试剂盒、酶免试剂盒、elisa试剂盒、抗人CD3抗体ELISA试剂盒、生化试剂盒、细胞、生物试剂、进口ELISA试剂盒、PCR试剂盒、生化测试盒
- 主营：cbm160808u121、0402b223k500nt、0402b473k500nt、0402b224k160nt、0402b562k500nt、cbw321609u190t、0402b222k500nt、06035c332jat2a、0603x225k160nt、0402b103k500nt、0603b103j500nt、0805b221k500nt、04022r102k500ba、0402cg102j500nt、0402cg4r7c500nt、l9637d013trst19sop
- 主营：放炮线、雷管作业箱、雷管柜、移动库房、气体间隔器、报警器、抗爆容器罐、雷管运输罐、矿用潜孔钻头、防护网炮被、安全背夹、冲击器、水炮泥袋、爆破炮被、水袋封口机、爆破防护网、避炮棚、炮泥机、雷管箱
- 主营：智能wifi开关、遥控开关、电动操作机构、智能均分器、相间隔板、断路器配件
- 主营：CD3试剂盒、elisa试剂盒、试剂盒、抗体
- 主营：ELISA试剂盒、PCR试剂盒、生化试剂盒、CD3价格、科研试剂
- 主营：炸药柜、火工品运输柜、雷管箱、炸药箱、气体间隔器、抗爆容器、手摇警报器、气体检测报警仪、防静电工作服、防冲服、液氧爆破纸、爆破测振仪、矿用放炮塞、爆破线、数码管铜芯线、矿用放炮线
- 主营：烟气流速仪、水质分析仪、超声波明渠流量计、CD3、空气水质采样器
- 主营：CD3便携式气体检测仪、储罐高低液位报警器、HUBA富巴传感器、酒精含量检测仪
- 主营：离心瓶、冻存管、冻存盒、小鼠cd3分选试剂盒、巴氏吸管、细胞过滤器、乳胶手套、丁腈手套、淋洗液发生罐、样品瓶、导电吸头、移液管、采样锥、截取锥、离子色谱柱、离子抑制器、萃取池、氘灯、石墨管、萃取小柱
- 主营：冻存管、淋洗液发生罐、阴离子抑制器、人CD3、样品瓶、试剂槽、色谱柱、离子色谱柱、细胞过滤器