Dissociation between mitogenicity and immunogenicity of TNP-lipopolysaccharide, a T-independent antigen.

摘要: Two models have been proposed to explain triggering of B cells by so-called T-independent antigen. Feldmann and Basten (1) that the interaction multiple repeating determinants on polymeric antigens with specific Ig receptors B-cell surface is sufficient provide signals for division these differentiation antibody-forming cells. In contrast, coutinho et al. (2, see review, 3) claimed there only one signal, a mitogenic acting merely as passive focusing devices localize antigen where it delivers signal resulting in an antibody-producing cell. This model rests primarily demonstration at high concentration all they tested are (4-6). Compatible this hypothesis observations hydrolysis lipopolysaccharide (LPS) remove ester- linked fatty acids lipid A component abrogates its (7,8) activity well ability, when substituted TNP hapten, induce anti- response (9). However, alkali treatment LPS, although not changing antigenic (8), may also modify molecule physically or chemically which could account loss immunogenic properties (10). We therefore investigated other reagents interact LPS more defined manner effort clarify relationship between molecule. Polymyxin (PB) family cyclic peptide antibiotics bactericidal most gram-negative bacteria. It prevents lethal endotoxic (11, 12) changes physical structure (13). report here low doses PB added cultures mouse spleen inhibit TNP-LPS, T- independent antigen, native but do suppress immune TNP-LPS. interacts TNP-LPS causing change molecule. addition, polymyxin-treated no longer mitogenic. These results suggest dissociation