Pomeroy C, Filice G A, Hitt J A, Jordan M C
Infectious Disease Section, VA Medical Center, Minneapolis, MN 55417.
J Infect Dis. 1992 Sep;166(3):677-81. doi: 10.1093/infdis/166.3.677.
Active cytomegalovirus (CMV) infection is associated with immunosuppression and predisposes to the development of life-threatening superinfections in immunocompromised patients. In a mouse model of virus-induced immunosuppression, acute murine CMV (MCMV) infection induced reactivation of dormant Toxoplasma gondii infection, producing Toxoplasma pneumonia. Changes in lung lymphocyte numbers and phenotypes appeared to be integral to the pathogenesis of MCMV-induced reactivation of T. gondii pneumonia. Numbers of lung CD4+ cells decreased during acute MCMV infection in mice with dormant T. gondii infection as well as in previously uninfected mice. Dually infected mice subsequently developed reactivation of Toxoplasma pneumonia. The pneumonia was characterized by a large influx of T lymphocytes, predominantly CD8+ cells, into the lungs. These lung lymphocytes markedly suppressed the ability of immune splenocytes to proliferate in response to T. gondii antigens and concanavalin A in vitro. These results suggested that the initial fall in the numbers of lung CD4+ cells observed after MCMV infection may have induced reactivation of T. gondii infection in the lungs. The subsequent pneumonia appeared to be a manifestation of a massive influx of T lymphocytes, especially CD8+ cells, into the lungs.
活动性巨细胞病毒（CMV）感染与免疫抑制相关，并使免疫功能低下的患者易发生危及生命的重叠感染。在病毒诱导的免疫抑制小鼠模型中，急性小鼠巨细胞病毒（MCMV）感染导致潜伏的弓形虫感染重新激活，引发弓形虫肺炎。肺淋巴细胞数量和表型的变化似乎是MCMV诱导弓形虫肺炎重新激活发病机制的组成部分。在潜伏感染弓形虫的小鼠以及先前未感染的小鼠中，急性MCMV感染期间肺CD4+细胞数量减少。双重感染的小鼠随后发生弓形虫肺炎重新激活。该肺炎的特征是大量T淋巴细胞，主要是CD8+细胞，涌入肺部。这些肺淋巴细胞显著抑制免疫脾细胞在体外对弓形虫抗原和伴刀豆球蛋白A增殖反应的能力。这些结果表明MCMV感染后观察到的肺CD4+细胞数量最初下降可能诱导了肺部弓形虫感染的重新激活。随后的肺炎似乎是大量T淋巴细胞，尤其是CD8+细胞涌入肺部的表现。
