Background
Identification of CD4 on human helper/inducer T cells expressing the 60,000 M.W. surface antigen (HLA class II reactive). CD4 is present in low density on monocytes. 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% of 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.

Synonyms: CD4 FITC - CD28 PE

Source

Immunogen: CD4=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.

Product

Product Form: Bi-Test (FITC/RPE) Reagent

Formulation: Provided as solution in phosphate buffered saline with 0.08% sodium azide and 0.2% carrier protein

Purification Method: Protein A/G Chromatography

Concentration: Titered for flow cytometry

Applications
PBMC: Add10 µl of MAB/10^6 PBMC in 100 µl PBS. Mix gently and incubate for 15 minutes at 2º to 8ºC. Wash twice with PBS and analyze or fix with 0.5% v/v of paraformaldehyde in PBS and analyze. WHOLE BLOOD: Add10 µl of MAB/100 µl of whole blood. Mix gently and incubate for 15 minutes at room temperature 20ºC. Lyse the whole blood. Wash once with PBS and analyze or fix with 0.5% v/v of paraformaldehyde in PBS and analyze. See instrument manufacturer’s instructions for Lysed Whole Blood and Immunofluorescence analysis with a flow cytometer or microscope.

Functional Analysis: Flow Cytometry Staining

Storage
Product should be stored at 4-8ºC. DO NOT FREEZE

Product Stability: See expiration date on vial

Shipping Conditions: Room Temperature

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. It may contain hazardous ingredients. Please refer to the Safety Data Sheets (SDS) for additional information and proper handling procedures. Dispose product remainders according to local regulations.This datasheet is as accurate as reasonably achievable, but Exalpha Biologicals accepts no liability for any inaccuracies or omissions in this information.

References
1. Thymus Dependent Membrane Antigens in Man: Inhibition of Cell-Mediated Lympholysis by Monoclonal Antibodies to the TH-2 Antigen. Evans, R.L., Wall, D.W., Platsoucas, C.D., Siegal, F.P., Fikrig, S.M., Testa, C.M, and Good, R.A. Proc. Nat. Acad. Sci. 78,544,1981. 2. Novel Immunoregulatory Functions of Phenotypically Distinct Subpopulations of CD4+ cells in the Human Neonate. Clement, L.T., Vink, P.E., Bradley, G.E. J. Immunology 145(1):102-8,1990 . 3. Antigen Presentation by the CD4 Positive Monocyte Subset. Szabo, G., Miller, C.L., Kodys, K., J. Leukoc. Biol. 47(2): 111-20,1990. 4. Human Immunodeficiency Virus Infection is Efficiently Mediated by a Glycolipid-Anchored form of CD4. Diamond, D.C., Finberg, R., Chaudhuri, S., Sleckman, B.P., Burakoff, S.J., Proc. Natl. Acad. Sci. 87(13):5001-5,1990. 5. Development Regulation of the Intrathymic T cell Precursor Population. Adkins, B., J. Immunol. 146(5):1387-93,1991. 6. Induction of CD4 and Susceptibility to HIV-1 Infection in Human CD8+ T Lymphocytes by Human Herpesvirus 6. Lusso, P., De Maria, A., Malnati, M., Lori, F., DeRocco, S.E., Baseler, M., Gallo, R.C., Nat. 349(6309):533-5,1991. 7. 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. 8. 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. 9. 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. 10. 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. 11. 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 12. 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 13. 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 14. 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 15. 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 16. 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 17. 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

Protein Reference(s)

Database Name: UniProt

Accession Number: P01730, P10747

Safety Datasheet(s) for this product: