Gamma Interferon Production in Response to Homologous and Heterologous Strain Antigens in Mice Chronically Infected with Rickettsia tsutsugamushi

摘要

The ability of antigen-responsive thymus-derived lymphocytes to produce immune (gamma) interferon was investigated during the development and expression of cellular immunity to Rickettsia tstsugamushi. C3H/HeDub mice infected subcutaneously with the Gilliam strain developed the ability to produce serum interfereon in response to intravenously inoculated antigen, this response correlated with the development of resistance to interperitoneal rechallange. Antigen-responsive lymphocytes, measured by interferon production and proliferation, were first apparent in draining lymph node cells, but spleen cell responses were detectable relatively soon after the appearance of reactive lymph node cells. The peak spleen cell response was of a greater magnitude and was found to be relatively long--lived. Reactivity to heterologous strains of R. tstsugamushi also developed after immunization and paralled the homologous responses, although reactivity was greatest to homologous antigens, Responses to hetorologous strains differed in magnitude and time of appearances, however immune mice resisted challange with all strains of R. tsutsugamushi tested.