Mitogenic activity of water-soluble adjuvant (Bu-WSA) obtained from Bacterionema matruchotii. V Requirement of three stimulatory signals for proliferation of human peripheral blood T lymphocytes.:V. Requirement of three stimulatory signals for proliferation of human peripheral blood T lymphocytes

Butanol-extracted water-soluble adjuvant (Bu-WSA) is a carbohydrate-rich substance extracted from Bacterionema matruchotii , oral gram-positive bacterium . The substance is a potent adjuvant for antibody response in mice1), and also a powerful mitogen for murine splenic B cells2). Its effects are not due to peptidoglycan in the cell walls2). The mode of action of Bu-WSA on proliferative response of murine spleen cells clearly differed in several points from that of bacterial lipopolysaccharide (LPS) which is a well-known B cell mitogen obtained from gram-negative bacteria2,3). Bu-WSA, itself, as well as LPS lacks the ability to induce proliferative response of the human peripheral B lymphocytes. However, a combination of concanavalin A (Con A), which activates human peripheral T lymphocytes selectively5), and Bu-WSA or LPS results in a synergistic effect on the proliferative response of human peripheral blood T lymphocytes as measured by [3H]-thymidine uptake in vitro4,6,7). Although T cells are the proliferative cells in consequence of the synergistic activation by these stimulants4,6), the mode of action of the mixture of Con A and Bu-WSA are very different from that of Con A and LPS because of the requirement of different bystander cells irrelevant to mitogenic stimulation4,6). In the synergistic effect of Bu-WSA on Con A-induced T cell proliferation , wed emonstrated4) that both mitogens work on the identical T cells. Nevertheless the bystander cells, either B cells or macrophages , are necessary to obtain synergy . Thus, these