title: The role of antibody in host defense against the agent of mouse pneumonitis.
abstract: Athymic nude (nu/nu) mice, which are more susceptible to the agent of mouse pneumonitis (MoPn) (murine Chlamydia trachomatis) than are their heterozygous littermates (nu/+), do not develop significant IgG or IgA antibody to the MoPn agent. Nu/+ mice develop significant titers of both specific IgG or IgA antibodies after either intranasal or intrauterine challenge. Prior intranasal or intrauterine immunization protects nu/+ but not nu/nu mice against subsequent intranasal challenge with the MoPn agent. Resistance to pneumonia due to the MoPn agent can be transferred to nu/nu mice by nu/+ mouse immune serum (with high titers of IgG and IgA antibodies to the MoPn agent) but not by nu/+ mouse normal serum (with undetectable titers of IgG and IgA antibodies to the MoPn agent). Serum components, probably specific antibodies, are important in host defense against the MoPn agent.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology*; D002690:Chlamydia Infections / Q000276:immunology*; D007070:Immunoglobulin A / Q000276:immunology; D007074:Immunoglobulin G / Q000276:immunology; D051379:Mice; D008819:Mice, Nude / Q000235:genetics*; D011014:Pneumonia / Q000276:immunology*; D013950:Thymus Gland / Q000637:transplantation
chemical_list: D000907:Antibodies, Bacterial; D007070:Immunoglobulin A; D007074:Immunoglobulin G