Role of T-lymphocytes in production of antibody to antigens of Rickettsia tsutsugamushi and other Rickettsia species.
The requirement of thymus-dependent lymphocytes for antibody production to Rickettsia tsutsugamushi, Rickettsia akari, Rickettsia conorii, and Rickettsia typhi was investigated by comparing antibody production in athymic (nu/nu) or thymus-bearing BALB/c mice. Athymic BALB/c mice produced antibody after infection with R. akari, R. conorii, and R. typhi as measured by indirect fluorescent antibody titration or radioimmunoassay. Antibody production in these mice was a great or greater than in the thymus-bearing mice and demonstrated similar kinetics. In contrast, athymic BALB/c mice infected either intraperitoneally or subcutaneously with the Gilliam strain of R. tsutsugamushi failed to produce demonstrable antibody. The requirement of thymus-dependent lymphocytes for antibody production to R. tsutsugamushi was further suggested by the demonstration of antibody production after transfer of immune thymus-dependent lymphocytes to athymic mice and the demonstration of R. tsutsugamushi-specific T helper cells in immune thymus-bearing mice. The antibody produced in athymic mice after infection with R. akari, R. conorii, and R. typhi was predominantly immunoglobulin M, based on isotype-specific radioimmunoassays and sucrose gradient fractionation. Furthermore, the antibody produced by athymic mice in response to R. akari infection reacted with a carbohydrate-containing outer membrane component.
D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000096:biosynthesis*; D000942:Antigens, Bacterial / Q000276:immunology*; D005260:Female; D007116:Immunization, Passive; D007075:Immunoglobulin M / Q000032:analysis; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008819:Mice, Nude; D012285:Orientia tsutsugamushi / Q000276:immunology*; D012281:Rickettsia / Q000276:immunology*; D012612:Scrub Typhus / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology
D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D007075:Immunoglobulin M