Lymphocyte Transformation in Rickettsioses

Lymphocyte transformation was studied with leukocytes from persons who had received rickettsial vaccines or had been infected with rickettsiae. The antigens were prepared from normal yolk sacs or yolk sacs infected with Rickettsia prowazeki (ET), Rickettsia mooseri (MT), Rickettsia akari (RP), or Rickettsia rickettsii (SF). When the antigens were diluted 1:100 and the cultures incubated 5 days, the reactions to normal yolk sac were minimal and the reactions to rickettsial antigens were satisfactory. With persons infected with MT and with those vaccinated with ET vaccine, the reactions to ET and MT antigens were about the same. With persons infected with SF or vaccinated with SF vaccine, the reactions to RP and SF were also about the same. There was some cross-reaction between antigens of the typhus and spotted fever group. Five normal persons were followed during primary immunization with ET vaccine; two gained responsiveness to ET and MT antigens. Incubation in immune serum did not cause normal cells to gain responsiveness. For all donors, there was a rough correlation between complement-fixing antibody titer and lymphocyte transformation. Several persons with antibody titers less than 1:8 had elevated lymphocyte transformation.