The Role of Soluble Factors in T-B Cell Collaboration

Abstract

Various theories have been put forward to explain the mechanism of cell collaboration between T and B lymphocytes in antibody production. The antigen focussing hypothesis (1) provides the simplest explanation, but positive evidence for such a concept has been difficult to acquire (2). In contrast several groups of investigators have presented findings suggesting that T-B cell interaction is an active process requiring differentiation and proliferation by T cells (2,3) with elaboration of a factor or factors capable of stimulating B cells (4–6). The two hypotheses are readily amenable to testing in vitro by determining whether a collaborative response can occur when T cells and B cells are separated by a cell impermeable membrane. The present communication describes such a system in which it was possible to define two distinct types of soluble mediator, an antigen specific factor and an allogeneic factor.