Isolation and partial characterization of an antibody enhancing factor from leukaemic owl monkey cell cultures

Herpesvirus saimiri inoculated into owl monkeys (Aotus trivirgatus) causes leukaemia and lymphoma. Peripheral lymphocytes from leukaemic monkeys grown in culture are predominantly T lymphocytes. The supernatants from these cultures contain a factor which enhances the antibody response of murine B cells to sheep red blood cells (SRBC). The factor has been partially characterized by ammonium sulphate precipitation, DEAE-chromatography, gel filtration over Sephadex G-150 and disc-gel electrophoresis. The enhancing factor is a protein with a molecular weight of approximately 40,000.