Background: Identification of human cytotoxic/suppressor T cells expressing the 32 and 43,000 M.W. surface antigen. CD38 antigen is an integral membrane glycoprotein, M.W. 45 kD. Anti-human CD28 binds the 44kDa MW cell surface protein on the surface of most T cells. CD28 acts as the ligand for the B7/BB-1 molecule on the surface of activated B cells. B7/BB-1 co-stimulates T cells through CD28, along with CD2 and CD3. CD28 antigen is a disulfide-linked homodimeric glycoprotein. The CD28 antigen is present on approximately 60%-80% T lymphocytes (95% of CD4 and 50% of CD8 lymphocytes). CD28 regulates the expression of cytokines by T cells, not only IL-2, but also IL-1 alpha and CSF-1, usually synthesized by accessory cells. CD28 functions as a cell adhesion molecule (CAM) for certain T cell subsets.
Immunogen: CD8=Derived from the hybridization of mouse NS-1 myeloma cells with spleen cells from BALB/c mice immunized with human perherial blood T lymphocytes.CD28=Derived from the hybridization of mouse Sp2/O-Ag14 myeloma cells with spleen cells of BALB/c mice immunized with the HPB-ALL T-cell line.
Purification Method: Protein A/G Chromatography
Concentration: Titered for flow cytometry
Formulation: Provided as solution in phosphate buffered saline with 0.08% sodium azide and 0.2% carrier protein
References: 1. Evolutionary Conservation of Surface Molecules that Distinguish T Lymphocyte Helper/Inducer and T Cytotoxic/Suppressor Subpopulations in Mouse and Man. Ledbetter,J.A., Evans,R.L., Lipinski,M., Cunningham-Rundles,C., Good,R.A. and Herzenberg,L.A., J. Exp. Med. 153,310, 1981. 2. Circulating Antigen-Specific Suppressor T Cells in a Healthy Woman: Mechanism of Action and Isolation with a Monoclonal Antibody. Engleman,E.G.,Benike,C.J.,and Evans,R.L., Clin. Res. 29, 365a 1981. 3. Induction of Immunoglobulin Secreting Cells in the Allogeneic Mixed Leukocyte Reaction: Regulation by Helper and Suppressor Lymphocyte Subsets in Man. Kotzin,B.L., Benike,C.J. and Engleman,E.G., J. Imm. 127,931,1981. 4. CD4 and CD8 molecules can physically associate with the same T-cell receptor. Gallagher,P.F., Fazekas de St. Groth,B., Miller, J.F.A.P., Proc. Nat. Acad. Sci. 1989,86:10044. 5. Immunofluorescence Measurement in a Flow Cytometer using Low-Power Helium Neon Laser Excitation. Shapiro, H.M, Glazer, A.N., Christenson, L., Williams, J.M., and Strom, T. B. Cytometry 4,276, 1983. 6. Comparison of Helium Neon and Dye lasers for Excitation of Allophycocyanin. Loken, M.R., Kiej, J.F. and Kelly, K.,A. Cytometry 8, 96, 1987. 7. CD28 is an inducible T cell surface antigen that transduces a proliferative signal in CD3+ mature thymocytes. Turka LA; Ledbetter JA; Lee K; June CH; Thompson CB J Immunol 1990 Mar ;144(5):1646-53 8. CD28 ligation in T-cell activation: evidence for two signal transduction pathways. Ledbetter JA; Imboden JB; Schieven GL; Grosmaire LS; Rabinovitch PS; Lindsten T; Thompson CB; June CH Blood 1990 Apr ;75(7):1531-9 9. T-cell antigen CD28 mediates adhesion with B cells by interacting with activation antigen B7/BB-1. Linsley PS; Clark EA; Ledbetter JA Proc Natl Acad Sci U S A 1990 Ju;87(13):5031-5 10. Role of the CD28 receptor in T-cell activation. June CH; Ledbetter JA; Linsley PS; Thompson CB Immunol Today 1990 Ju;11(6):211-6 11. Differences in surface phenotype and mechanism of action between alloantigen-specific CD8+ cytotoxic and suppressor T cell clones. Koide J; Engleman EG J Immunol 1990 Jan ;144(1):32-40 12. Binding of the B cell activation antigen B7 to CD28 costimulates T cell proliferation and interleukin 2 mRNA accumulation. Linsley PS; Brady W; Grosmaire L; Aruffo A; Damle NK; Ledbetter JA J Exp Med 1991 Mar ;173(3):721-30 13 13. The CD28 ligand B7/BB1 provides costimulatory signal for alloactivation of CD4+ T cells. Koulova L; Clark EA; Shu G; Dupont B J Exp Med 1991 Mar ;173(3):759-62
UniProt: P01732, P10747
Caution: This product is intended FOR RESEARCH USE ONLY, and FOR TESTS IN VITRO, not for use in diagnostic or therapeutic procedures involving humans or animals.