CD4, a single chain transmembrane glycoprotein is found on a T cell subset (helper/inducer) representing 45% of peripheral blood lympocytes. It is also present on 80% of thymocytes and at a lower level on monocytes. It is involved in recognition of antigen presented along with MHC class II by APCs. It serves as receptor for HIV. Antibody to CD4 recognizes T-helper cells required for recognition of class II antigens. It reacts with 60% of peripheral blood E rosette-positive (E+) cells while showing negligible reactivity with E+ cells, monocytes, granulocytes, EBV-transformed B cell lines, and mouse splenocytes. CD4-positive T-cells provide helper funciton in pokeweed mitogen driven B-cell differentiation. Moreover, anti-CD4 selectively blocks the autologus mixed lymphocyte reaction (AMLR) with minimal or no effect on the allogeneic MLR (allo-MLR). Blocking of the autoreactivity occurs when either autologus B-lymphocytes or macrophages are used as stimulators. Specificity closely approximates the binding spectrum of OKT4 and Leu-3 antibodies both of which also recognize 55 to 65% of human peripheral blood T-cells.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.