title: Host defence mechanisms.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D001402:B-Lymphocytes / Q000276:immunology; D005796:Genes; D006168:Guinea Pigs; D006801:Humans; D007109:Immunity; D007111:Immunity, Cellular; D051379:Mice; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology