title: Cellular immunity to the mouse pneumonitis agent.
abstract: During infection with the mouse pneumonitis biovar of Chlamydia trachomatis, heterozygous (nu/+) mice with relatively intact T cell function develop both delayed hypersensitivity to C trachomatis antigen and antigen-specific lymphocyte transformation, whereas athymic nude (nu/nu) mice do not. Nu/nu mice are protected against death from mouse pneumonitis by transfer of immune T cells from nu/+ mice, which are more resistant to C trachomatis. While this enables athymic mice to make antibody to C trachomatis (which does not occur without reconstitution), resistance correlates best with development of antigen-specific lymphocyte transformation in the recipient animals. During infection nu/+ mice develop activated alveolar macrophages (by both morphological and functional criteria) while nu/nu mice do not. Nu/+ mice that have been preinfected with Histoplasma capsulatum to activate cellular immunity become more resistant to C trachomatis than do nu/+ controls. Cell-mediated immunity to C trachomatis pneumonia is T cell dependent and is important in host defense.
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology; D002690:Chlamydia Infections / Q000276:immunology*; D002692:Chlamydia trachomatis / Q000276:immunology; D005260:Female; D006046:Gold / Q000494:pharmacology; D012971:Gold Sodium Thiosulfate / Q000494:pharmacology; D006660:Histoplasmosis / Q000276:immunology; D007111:Immunity, Cellular; D007116:Immunization, Passive; D008213:Lymphocyte Activation; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D010950:Plasma Cells / Q000276:immunology; D011014:Pneumonia / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000942:Antigens, Bacterial; D006046:Gold; D012971:Gold Sodium Thiosulfate