Anti-Human CD3 [Clone OKT-3] – APC

Human peripheral blood lymphocytes

This Allophycocyanin (APC) conjugate is formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.4, 1% BSA and 0.09% sodium azide as a preservative.

Liquid

This Allophycocyanin (APC) conjugate is stable when stored at 2-8°C. Do not freeze.

Research Use Only

2 – 8° C Wet Ice

Red Laser (650 nm)

OKT-3 activity is directed against a conformational epitope on human CD3ε.

CD3 is an invariant antigen of the T cell receptor (TCR) belonging to the Ig superfamily¹. The CD3/TCR complex is composed of a ⍺β or γδ TCR heterodimer noncovalently associated with invariant CD3 dimers εγ, εδ, and ζζ in a 1:1:1:1 stoichiometry. The TCR mediates recognition of antigenic peptides bound to major histocompatibility complex (MHC) molecules on antigen- presenting cells, while the CD3 portion of the complex transduces activation signals to the T cell nucleus. Together, TCR and CD3 molecules initiate protective immunity against microbes and cancers.

OKT-3 was generated by immunizing a BALB/c or CAF1 mouse with human peripheral blood lymphocytes². Spleen cells were fused with P3x63Ag8.U1 myeloma cells for hybridoma production.

OKT-3 was initially developed as a pan-T cell antibody to differentiate between cell types³ and later . became the first monoclonal antibody to be approved for therapy in humans⁴. OKT-3 acts as an immunosuppressive drug in transplant patients⁵, type 1 diabetes, and psoriasis⁶. OKT-3 recognizes, binds, and blocks the CD3 complex of the T cell receptor⁴ and thereby blocks the generation and function of cytotoxic T cells⁷. The OKT-3/CD3εγ structure has been resolved⁶.


Application Note: Clone OKT3 can block the binding of clones SK7 and UCHT1

CD3 is expressed on mature T cells and medullary thymocytes.

TCR

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2. Kung PC, Goldstein G, Reinherz EL, et al. Science. 1979. 206: 347-349. J Immunol. 2013 Jun 1;190(11):5351-3. PMID: 23687192.
3. Goldstein G. Nephron. 46 Suppl 1:5-11. 1987.
4. Sgro C. Toxicology. 105(1):23-29. 1995.
5. Smith SL. J Transpl Coord. 6(3):109-119. 1996.
6. Kjer-Nielsen L, Dunstone MA, Kostenko L, et al. Proc Natl Acad Sci U S A. 101(20):7675-7680. 2004.
7. Norman DJ. Ther Drug Monit. 17(6):615-620. 1995.
8. Hoffman RA, Kung PC, Hansen WP, et al. Proc Natl Acad Sci U S A. 77(8):4914-4917. 1980.
9. Burns GF, Boyd AW, Werkmeister JA, et al. Immunology. M55(1):1-6. 1985.
10. Hegewald MG, O'Connell JB, Renlund DG, et al. J Heart Transplant. 8(4):303-309. 1989.
11. Hammond EA, Yowell RL, Greenwood J, et al. Transplantation. 55(5):1061-1063. 1993.
12. Kimball JA, Norman DJ, Shield CF, et al. Transpl Immunol. 3(3):212-221. 1995.