A NEW SURFACE-ANTIGEN ON HUMAN-LYMPHOCYTES DEFINED BY THE MURINE MONOCLONAL-ANTIBODY IVF7

The murine monoclonal antibody (MoAb) IVF7 was produced against tumour cells from a patient with a CD 3+, CD4+, CD8− T‐cell chronic lymphatic leukaemia (T‐CLL). The MoAb IVF7 showed reactivity with subpopulations of normal peripheral blood lymphocytes (PBL), as well as with a few cell lines of haematopoietic origin. Thirty‐six percent of PBL were stained with IVF7. Analysing subpopulations, we found that 80% of NK cells, 25% of T cells, and 10–20% of B cells were positive. The myelomonocytic cell line KG‐1 was also stained. The molecular weight of the molecule was 40 kDa under reducing conditions. The antigen was found to be trypsinsensitive. MoAb IVF7 could modulate the antigen from the cell surface. The antibody did not stimulate PBL to DNA synthesis, nor did it significantly lnfluence NK cell‐mediaied kilting. Copyright © 1990, Wiley Blackwell. All rights reserved