A requirement for helper T cells in the production of IgG antibody by B cells

A requirement for helper T cells in the production of IgG antibody by B cells has been known for a long time and has been extensively studied (1-3). More recently, evidence has accumulated that there may be two classes of helper T cells for antibody production (4-6) and that T cell-T cell collaboration may be involved in the in vitro generation ofcytotoxic T lymphocytes (CTL) 1 against alloantigens (7-10). Moreover, Pilarski and her colleagues (1 I, 12) have shown that there is an absolute requirement for antigen-specific helper T cells in the generation of C T L from thymocyte precursors, as well as for C T L responses to metabolically inactivated stimulator cells (13). The possible participation of helper T cells in anti-viral C T L responses is suggested from recent work both in vivo (14) and in vitro (15-17). A similar requirement for helper cells in the generation of H-Y-specific C T L has also been suggested by yon Boehmer and Haas (18). On the other hand, Finberg et al. (19) have shown that radioresistant helper T cells generated in vivo can augment trinitrophenyl (TNP)-specific C T L activity generated in vitro, and Fujiwara et al. (20) have found a similar situation with respect to cell-mediated immunity (CMI) against syngeneic tumors in vitro. Another major arm of the CMI response is the delayed-type hypersensitivity (DTH) response, and there are now three reports that such activity can be generated in vitro from normal spleen cells against heterologous erythrocytes (21, 22), or to a soluble protein and a synthetic antigen (23). A recent paper has suggested that there is a requirement for T T cooperation for the manifestation of a D T H response to the synthetic polypeptide poly(LTyr,LGlu)-poly(DLAla)--poly(LLys) [(T,G)-A--L] (24). Earlier work from this laboratory has studied the D T H response to influenza virus as an antigen, both in vivo (25-27) and in vitro (28), and on the possible role of the D T H effector cells in the pathogenesis of viral infection (27). We have recently demonstrated that a weak pr imary D T H response to influenza virus can be obtained in vitro 2. In this report, we show that this response can be greatly augmented by radioresistant helper T cells and describe the antigenic specificity, as well as H-2 requirement of the helper cells.