Anti-CD28 [15E8], Rabbit IgG from MyBioSource.com

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