著者

小山 孝

出版者

一般社団法人 日本感染症学会

雑誌

感染症学雑誌 (ISSN:03875911)

巻号頁・発行日

vol.53, no.5, pp.243-257, 1979-05-20 (Released:2011-09-07)

参考文献数

23

---

Time course studies were carried out on splenic lymphoid cell subpopulations, serum antibody titer and weight of the spleens in mice infected with Rickettsia sennetsu and Rickettsia tsutsugamushi of high and low virulent strains.1. All of the mice infected with R. sennetsu Miyayama strain died in two weeks. In this case, weight of the spleens and the number of lymphoid cells, both T and B cells, increased trasiently at the time of manifestation of symptoms, and decreased later at the late stage.When the mice infected with R. sennetsu Miyayama strain were treated with tetracycline, the spleens enlarged till the convalescence and then constricted to near normal range. They enlarged with the recrudescence and constricted again when symptoms of the mice became severe, and the mice died finally in spite of the treatment. In lymphoid cell subpopulations of the spleens, T cells began to increase first at a start of the treatment. Increase of B cells, on the other hand, ocurred later at the convalescence. Lymphoid cell subpopulations of the spleens returned to normal range temporarily when the mice were recovered by the treatment. However, the number of lymphoid cells of the spleens, both T and B cells, decreased again when the mice had a relapse of the disease and became in a critical condition after discontinuance of tetracycline therapy.High titers of serum antibodies were observed at the 4th week after infection and were maintained even when the mice relapsed into the disease and were in a critical condition.2. Most of the mice infected with Gilliam strain of high virulent R. tsutsugamushi died in two weeks. In this case, weight of the spleens and lymphoid cell subpopulations of the spleens showed changes similar to those observed in mice infected with R. sennetsu. But occasionally some of the mice were long-survived. In these mice, the spleens enlarged till the convalescence and then constricted to near normal range. In lymphoid cell subpopulations, T cells increased first prior to the convalescent stage, whereas, increase of B cells ocurred when the mice recovered.High titers of serum antibodies were observed at the 4th week after infection and were maintained for a long time.3. The mice infected with Irie strain of low virulent R. tsutsugamushi progressed subclinically. In this case, the spleens began to enlarge from the 2nd week to the 3rd or the 4th week after infection and c/a then constri ted to near normal r nge. T cells in the spleens began to increase at the 2nd week. On the other hand, B cells continued to decrease till the 3rd week and then increased. Finally, the number of lymphoid cells of the spleens and their subpopulations recovered to normal range.Serum antibodies were detected at the 2nd week after infection. They reached to high titers at the 4th week and were maintained in high titer for a long time.These findings suggested that increase of T cells had a very important role on recovering from rickettsial infections and that humoral immunity could not prevent the development of the rickettsial infections but cellular immunity could prevent it.