Immunopotentiation of the humoral response by liposomes: effect of a T cell polyclonal activator.
In this paper, we analyzed the influence of surface-linked Con A on the secondary response to liposome-associated antigen via either encapsulation or covalent linkage at the liposomal surface. The study was carried out on BALB/c mice using bovine serum albumin as antigen. The humoral response was evaluated by measurements of antibody-producing cells (total, IgM, and IgG) and serum antibody titers. The results indicate that Con A at submitogenic concentrations does not potentiate the overall effect of liposomes but drastically changes the isotype distribution pattern obtained in response to encapsulated antigen without however affecting that obtained in response to surface-linked antigen. In all situations where Con A and/or BSA was covalently linked, IgG and IgM isotypes were produced in equal quantity, while in response to encapsulated BSA, IgG was by far the dominant isotype produced as expected for a thymo-dependent antigen. These results suggest that the quality of an immune response and the mechanisms of activation may be profoundly influenced by the nature of antigen association with liposomes as well as by the presence at the liposomal surface of immunomodulators such as Con A.
Thérien
H M
HM
Départment Chimie-Biologie, Université du Québec à Trois-Rivières, Canada.
Shahum
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D000276:Adjuvants, Immunologic; D000818:Animals; D000954:Antigens, Surface / Q000494:pharmacology*; D003208:Concanavalin A / Q000494:pharmacology*; D004797:Enzyme-Linked Immunosorbent Assay; D006384:Hemagglutination; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000096:biosynthesis*; D008081:Liposomes / Q000138:chemical synthesis / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D012710:Serum Albumin, Bovine / Q000494:pharmacology
D000276:Adjuvants, Immunologic; D000954:Antigens, Surface; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D008081:Liposomes; D003208:Concanavalin A; D012710:Serum Albumin, Bovine