Development of specific and cross-reactive lymphocyte proliferative responses during chronic immunizing infections with Rickettsia tsutsugamushi.

AUTOR(ES)

Jerrells, T R

RESUMO

The development of antigen-responsive lymphocytes was followed in mice immunized with the Gilliam, Karp, or Kato strains of Rickettsia tsutsugamushi by utilizing an in vitro lymphocyte proliferation assay. Subcutaneous immunization with viable rickettsiae of all three strains resulted in the appearance of lymphocytes in the spleen responding to irradiated tissue culture-grown rickettsiae used as stimulating antigens. Although all animals demonstrated antigen-induced proliferation elicited by homologous antigen by 14 days after immunization, the time of peak responsiveness varied, depending on the strain of rickettsiae used for immunization. In all cases, peak proliferative responses occurred at a time after immunization that was after the previously reported time after immunization at which resistance to rechallenge was observed. Reactivity to heterologous strains of R tsutsugamushi developed roughly in parallel with homologous reactivity in Karp- and Gilliam-immunized mice, with a marked degree of heterologous reactivity evident. Kato-immunized mice demonstrated greater reactivity to heterologous antigens early in the development of antigen reactivity and demonstrated a somewhat greater degree of cross-reactivity, relative to homologous responses, than the other groups. It was found that nylon wool-nonadherent immune cells, if cultured with antigen and adherent cells obtained from normal spleens or peritoneal exudates, responded in culture. The thymus-derived lymphocyte nature of the responding cell was further suggested when treatment of immune spleen cells with anti-Thy 1.2 serum and complement eliminated antigen response.

Documentos Relacionados

• Cross-reactive lymphocyte responses and protective immunity against other spotted fever group rickettsiae in mice immunized with Rickettsia conorii.
• Identification of type B-specific and cross-reactive cytotoxic T-lymphocyte responses to Epstein-Barr virus.
• Demonstration and partial characterization of antigens of Rickettsia rhipicephali that induce cross-reactive cellular and humoral immune responses to Rickettsia rickettsii.
• Human histocompatibility leukocyte antigen-binding supermotifs predict broadly cross-reactive cytotoxic T lymphocyte responses in patients with acute hepatitis.
• Cross-reactive cytotoxic T-lymphocyte-mediated lysis of Chlamydia trachomatis- and Chlamydia psittaci-infected cells.