A novel method for enhancement of T independent responses.
Bacterial capsular polysaccharides are the major targets for vaccination against encapsulated bacteria but present problems when used for immunisation as they are T cell independent antigens (TI-II). TI-II antigens do not induce a memory response, but induce an antibody response which is of low magnitude and is predominantly IgM, with little or no isotype switching to IgG isotypes. This is because TI-II antigens do not induce T cell help. Such T cell help to B cells is mediated through up regulation of the CD40 ligand (CD154) on the activated T cell, which binds to CD40 inducing B cell activation, proliferation and isotype switching in conjunction with cytokines produced by the T cell. We have successfully mimicked this T cell help and induced very strong, isotype switched antibody responses to TI-II antigens by the simple addition of agonistic anti-CD40 antibodies to pneumococcal polysaccharides before immunisation.
Dullforce
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P
Division of Molecular and Genetic Medicine, University of Sheffield Medical School, U.K.
Sutton
D
D
Heath
A W
AW
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D019013:CD40 Antigens / Q000276:immunology*; D005260:Female; D017578:Immunoglobulin Class Switching; D051379:Mice; D008807:Mice, Inbred BALB C; D008808:Mice, Inbred CBA; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*
D000911:Antibodies, Monoclonal; D019013:CD40 Antigens; D011135:Polysaccharides, Bacterial