Anti-Human CD3 [Clone OKT-3] – Purified in vivo GOLD™ Functional Grade

Human peripheral blood lymphocytes

This monoclonal antibody is aseptically packaged and formulated in 0.01 M phosphate buffered saline (150 mM NaCl) PBS pH 7.2 - 7.4 with no carrier protein, potassium, calcium or preservatives added. Due to inherent biochemical properties of antibodies, certain products may be prone to precipitation over time. Precipitation may be removed by aseptic centrifugation and/or filtration.

Liquid

Functional grade preclinical antibodies are manufactured in an animal free facility using only in vitro protein free cell culture techniques and are purified by a multi-step process including the use of protein A or G to assure extremely low levels of endotoxins, leachable protein A or aggregates.

Functional grade preclinical antibodies may be stored sterile as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at ≤ -70°C. Avoid Repeated Freeze Thaw Cycles.

Research Use Only

2 – 8° C Wet Ice

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.

CD3 is expressed on mature T cells and medullary thymocytes.

TCR

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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.