Geng P, Jerrells T R
Department of Pathology, University of Texas Medical Branch, Galveston 77550.
Microbiol Immunol. 1994;38(9):703-11. doi: 10.1111/j.1348-0421.1994.tb01845.x.
Recombinant murine tumor necrosis factor-alpha (TNF-alpha) inhibited intracellular growth of Rickettsia tsutsugamushi, Karp strain, in the mouse embryo cell line C3H/10T1/2 clone 8 at doses of 100 to 10 U/ml. The growth inhibitory effect of TNF-alpha was also evident when peritoneal exudate macrophages or bone marrow-derived macrophages were used as the host cell for rickettsial growth. Interferon-gamma (IFN-gamma), at doses up to 1,000 U/ml, did not affect the growth of this strain of rickettsiae in the mouse embryo cell line but, as expected, profoundly inhibited rickettsial growth in peritoneal exudate macrophages and bone marrow-derived macrophages. The effect of TNF-alpha on rickettsial growth in the mouse embryo cell line was not reproducibly enhanced by IFN-gamma. Treatment of the cell line with TNF-alpha delayed rickettsial cytopathic effects, but the rickettsiae ultimately grew to high numbers in the cells and caused cell death. These findings show that, at least in our system, R. tsutsugamushi is resistant to IFN-gamma-mediated antirickettsial effects in cells other than macrophages. The results of this study support the suggestion that TNF-alpha may inhibit rickettsial growth in cells other than macrophages.
重组鼠肿瘤坏死因子-α(TNF-α)在100至10 U/ml的剂量下可抑制恙虫病东方体Karp株在小鼠胚胎细胞系C3H/10T1/2克隆8中的细胞内生长。当使用腹腔渗出液巨噬细胞或骨髓来源的巨噬细胞作为立克次体生长的宿主细胞时,TNF-α的生长抑制作用也很明显。干扰素-γ(IFN-γ)在高达1000 U/ml的剂量下,不会影响该立克次体菌株在小鼠胚胎细胞系中的生长,但正如预期的那样,会显著抑制其在腹腔渗出液巨噬细胞和骨髓来源的巨噬细胞中的生长。IFN-γ不会使TNF-α对小鼠胚胎细胞系中立克次体生长的影响得到重复性增强。用TNF-α处理该细胞系会延迟立克次体的细胞病变效应,但立克次体最终会在细胞中大量生长并导致细胞死亡。这些发现表明,至少在我们的系统中,恙虫病东方体在巨噬细胞以外的细胞中对IFN-γ介导的抗立克次体效应具有抗性。本研究结果支持TNF-α可能抑制巨噬细胞以外的细胞中立克次体生长的观点。