An Antigen Expressed by Murine CD8+ T Cells and Activated B Cells

Abstract A monoclonal antibody, H1F5, is described that reacts with a subset of Lyt-2 (CD8) mouseT cells and LPS-activated B cells. In both lymph nodes and spleen of BALB/c mice, the H1F5 antigen is coexpressed approximately on 20%-30% of the CD8+ T cells and approximately on 91% of LPS-activated B cells. In the thymus, few cells (less than 1%) are positive for the marker, but no correlation could be demonstrated with markers for mature T cells such as MEL-14 and PNA expression. Elimination of H1F5+ cells by complement lysis led to a 30 %-50 % reduction of specific lysis as measured in a primary allo CTL, indicating that the ytotoxic effector cells are injured. The relationship of this marker and other antigenic determinants on lymphocytes is discussed.