T Cell-dependent Mediator in the Immune Response II. PHYSICAL AND BIOLOGICAL PROPERTIES.

Supernatants were obtained from cultures of keyhole limpet haemocyanin (KLH) primed mouse spleen cells, and also from cultures of KLH-educated, thymus-derived lymphocytes (T cells) after re-exposure of cells to the original priming antigen, KLH. These supernatants were able to facilitate the immune response of bone marrow-derived lymphocytes (B cells) to sheep erythrocytes (SRBC). Certain physical and biological properties of such supernatant activities are described. [ABSTRACT FROM AUTHOR]