Anti-CD28 mAbs [15E 8](MABL-851)

MABL-851

ELISA, FC

Engineer antibody

Human

15E 8

Recombinant Antibody

This antibody binds human CD28, which is found on a sub-population of T cells and activated B cells. The antibody does not react with B cells, granulocytes or monocytes. CD28 is involved in T-cell activation, the induction of cell proliferation and cytokine production and promotion of T-cell survival.

T-cell-specific surface glycoprotein CD28; TP44

P10747

The original mouse antibody was generated by immunizing mice with human T lymphocytes.

This antibody works independently of TcR/CD3 and activation of protein kinase C (PKC) for activation of T cells and nehances cytokine secretion (PMID: 1647959). This antibody is capable of stimulating T cells in combination with either murine OKT3 antibody or CDR-mutated OKT3 Fab variants. It was found that cross-linking of specific tumor antigens with the T-cell-associated CD3 and CD28 antigens can increase IL-2 secretion, proliferation and antigen-specific cytotoxicity in resting T cells. This cross- linking can be achieved effectively by bispecific monoclonal antibodies (BiMAb) with specificity for both the tumor antigen and CD3 or CD28 antigen. A combination of bispecific antibodies BiMAb OKT3/HRS-3 with reactivity against both CD3 and Hodgkin's-lymphoma-associated CD30 antigen and BiMAb 15E8/HRS-3 with reactivity to both CD28 and CD30 antigen was able to activate resting T cells, represented by Jurkat cells (CD3+/CD28+) to produce IL-2 (PMID: 7686889). This antibody was also used in another study wherein the combined use of two CD3 x CD19 plus CD28 x CD22 bispecific antibodies induced optimal interleukin 2 secretion by Jurkat T-cell acute lymphocytic leukemia cells in the presence of target B-cells (PMID: 7689932). This antibody also provides a co-stimulatory signal to T cells. The scFv fragment of this antibody induced proliferation of peripheral blood mononuclear cells in the presence of anti-CD3 or anti-CD2 mAb and enhanced anti-tumor activity of anti-MUC1×anti-CD3 bispecific antibody when tested with lymphokine- activated killer cells with T cell phenotype (PMID: 10913626). The humanzied version of this antibody is available on request.

Van Lier et al. T cell receptor/CD3 and CD28 use distinct intracellular signaling pathways/ Eur J Immunol. 1991 Jul;21(7):1775-8. PMID:1647959

This paper investigates whether stimulation of T cells by CD28 is dependent on the activation of protein kinase C (PKC).

100 μg Purified antibody.

1 mg/ml.

Protein A affinity purified

PBS with 0.02% Proclin 300.

Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at - 20⁰C.