Jerrells T R, Palmer B A, Osterman J V
Infect Immun. 1983 Jan;39(1):262-9. doi: 10.1128/iai.39.1.262-269.1983.
Mice immunized with three injections of gamma-irradiated Karp strain of Rickettsia tsutsugamushi were evaluated for the presence of cell-mediated immunity by using delayed-type hypersensitivity, antigen-induced lymphocyte proliferation, and antigen-induced lymphokine production. These animals also were evaluated for levels of circulating antibody after immunization as well as for the presence of rickettsemia after intraperitoneal challenge with viable Karp rickettsiae. After immunization with irradiated Karp rickettsiae, a demonstrable cell-mediated immunity was present as evidenced by delayed-type hypersensitivity responsiveness, lymphocyte proliferation, and production of migration inhibition factor and interferon by immune spleen lymphocytes. Also, a reduction in circulating rickettsiae was seen in mice immunized with irradiated rickettsiae after challenge with 1,000 50% mouse lethal doses of viable, homologous rickettsiae. All responses except antibody titer and reduction of rickettsemia were similar to the responses noted in mice immunized with viable organisms. Antibody levels were lower in mice immunized with irradiated rickettsiae than in mice immunized with viable rickettsiae. Furthermore, mice that were immunized with viable rickettsiae demonstrated markedly lower levels of rickettsemia after intraperitoneal challenge compared with either mice immunized with irradiated rickettsiae or nonimmunized mice.
用三次γ射线照射的恙虫病立克次体卡尔普株免疫小鼠，通过迟发型超敏反应、抗原诱导的淋巴细胞增殖和抗原诱导的淋巴因子产生来评估细胞介导免疫的存在情况。还评估了这些动物免疫后的循环抗体水平以及用活的卡尔普立克次体进行腹腔攻击后的立克次体血症情况。用照射过的卡尔普立克次体免疫后，出现了可证实的细胞介导免疫，表现为迟发型超敏反应性、淋巴细胞增殖以及免疫脾淋巴细胞产生迁移抑制因子和干扰素。此外，在用1000个50%小鼠致死剂量的活的同源立克次体攻击后，用照射过的立克次体免疫的小鼠体内循环立克次体数量减少。除抗体滴度和立克次体血症减少外，所有反应均与用活生物体免疫的小鼠中观察到的反应相似。用照射过的立克次体免疫的小鼠的抗体水平低于用活立克次体免疫的小鼠。此外，与用照射过立克次体免疫的小鼠或未免疫的小鼠相比，用活立克次体免疫的小鼠在腹腔攻击后立克次体血症水平明显较低。
