CD4 mAb (GK 1.5), InVivoPure

The monoclonal antibody GK1.5 reacts with the mouse CD4 molecule, a 55 kDa cell surface receptor expressed by the majority of thymocytes, a subpopulation of mature T cells and dendritic cells. CD4 binds to MHC class II on the surface of antigen-presenting cells and plays an important role both in the development of T cells and in the optimal function of mature T cells. In T cells, CD4 associates with the protein tyrosine kinase p56lck via its cytoplasmic tail. The binding of GK1.5 is blocked by the antibody RM4-5, which competes with GK1.5 for the same binding site on the CD4 molecule. GK1.5 significantly increased the proportion of peripheral CD4+CD25+Foxp3+ Treg cells in CD4+ T cells in mice without altering their immunosuppressive function. The antibody profoundly blocks antigen-specific reactive mouse helper T lymphocyte lines of class II MHC.