Hanson B
Department of Microbiology and Immunology, University of Maryland, Baltimore 21201.
Infect Immun. 1991 Nov;59(11):4134-41. doi: 10.1128/iai.59.11.4134-4141.1991.
Three strains of Rickettsia tsutsugamushi (Karp, Gilliam, and TA716, representing three virulence types in mice) were examined for their sensitivity to the inhibitory effects of recombinant gamma interferon (IFN-gamma) and purified IFN-alpha/beta in two cultured mouse fibroblast cell lines. The susceptibilities of another species, Rickettsia rickettsii, and of encephalomyocarditis virus (EMCV) were also tested for comparative purposes. IFN-gamma inhibited rickettsial replication in only one of the six combinations of R. tsutsugamushi strains and mouse cells (strain Gilliam and the BALB/c mouse-derived cell line). In contrast, R. rickettsii and EMCV replication were markedly inhibited in both cell types, but to a greater extent in the BALB/c line than in the C3H cells. IFN-alpha/beta (300 to 450 U/ml) was uniformly ineffective in three of the combinations of R. tsutsugamushi strains and mouse cells (Gilliam in C3H cells and Karp in both C3H and BALB/c cells); in the remaining sets, IFN-alpha/beta-mediated inhibition of rickettsial replication was variable and in no case was it very pronounced. The tests with R. rickettsii in both cell types also indicated slight, variable sensitivity to IFN-alpha/beta. EMCV, on the other hand, was very susceptible to IFN-alpha/beta, confirming the potency of the preparation used; as with IFN-gamma, virus replication was inhibited to a greater degree in the BALB/c cell line than in the C3H cultures. These results are discussed in terms of their relationship to the virulence properties of the R. tsutsugamushi strains in BALB/c and C3H mice and to the known IFN-sensitivities of the more widely studied Rickettsia prowazekii.
研究了三株恙虫病东方体（Karp、Gilliam和TA716，代表小鼠中的三种毒力类型）在两种培养的小鼠成纤维细胞系中对重组γ干扰素（IFN-γ）和纯化的IFN-α/β抑制作用的敏感性。为作比较，还测试了另一物种立氏立克次体以及脑心肌炎病毒（EMCV）的敏感性。IFN-γ仅在恙虫病东方体菌株与小鼠细胞的六种组合中的一种（Gilliam菌株和源自BALB/c小鼠的细胞系）中抑制立克次体复制。相比之下，立氏立克次体和EMCV的复制在两种细胞类型中均受到显著抑制，但在BALB/c细胞系中的抑制程度大于C3H细胞。IFN-α/β（300至450 U/ml）在恙虫病东方体菌株与小鼠细胞的三种组合（C3H细胞中的Gilliam以及C3H和BALB/c细胞中的Karp）中均无作用；在其余组合中，IFN-α/β介导的立克次体复制抑制作用各不相同，且在任何情况下都不十分显著。在两种细胞类型中对立氏立克次体的测试也表明其对IFN-α/β的敏感性轻微且各不相同。另一方面，EMCV对IFN-α/β非常敏感，证实了所用制剂的效力；与IFN-γ一样，病毒复制在BALB/c细胞系中的抑制程度大于C3H培养物。根据这些结果与恙虫病东方体菌株在BALB/c和C3H小鼠中的毒力特性以及更广泛研究的普氏立克次体已知的IFN敏感性之间的关系进行了讨论。
