Zurbrick B G, Follett D M, Czuprynski C J
Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706.
Infect Immun. 1988 Jul;56(7):1692-7. doi: 10.1128/iai.56.7.1692-1697.1988.
In this study we examined the influence of various crude and recombinant cytokines on the ingestion and intracellular survival of Mycobacterium paratuberculosis within bovine monocytes and monocyte-derived macrophages. Cytokine pretreatment had little effect on the ingestion of M. paratuberculosis by bovine monocytes and macrophages. Monocytes that were continuously incubated with virus-induced crude bovine interferon (100 U) or recombinant bovine alpha interferon (100 U) significantly restricted the subsequent intracellular growth of M. paratuberculosis, as determined by microscopic counts of acid-fast bacilli and by recovery of CFU from lysed monocyte monolayers. In contrast to their effects on freshly adherent monocytes, these cytokines had little effect on the growth of M. paratuberculosis within monocyte-derived macrophages. In two separate experiments, we also observed inhibition of bacillary growth in monocytes treated with unpurified recombinant human granulocyte-macrophage colony-stimulating factor. Conversely, intracellular growth of M. paratuberculosis was enhanced in monocytes that were pretreated with culture supernatants from M. paratuberculosis-stimulated peripheral blood mononuclear cells obtained from an immunized calf. The growth-enhancing activity of these supernatants was labile at pH 2.0, suggesting a role for gamma interferon; however, subsequent experiments indicated that recombinant gamma interferon alone neither enhanced nor restricted intracellular bacillary growth. To determine the possible contributions of monocyte oxidative activity to cytokine-induced bacteriostasis, we compared the release of superoxide anion from cytokine-treated and control monocytes. No obvious relationship was observed between the release of superoxide anion and the subsequent intracellular fate of the bacilli.
在本研究中，我们检测了多种粗制和重组细胞因子对副结核分枝杆菌在牛单核细胞和单核细胞衍生巨噬细胞内摄取及细胞内存活的影响。细胞因子预处理对牛单核细胞和巨噬细胞摄取副结核分枝杆菌的影响很小。通过抗酸杆菌的显微镜计数以及从裂解的单核细胞单层中回收菌落形成单位（CFU）来确定，持续用病毒诱导的粗制牛干扰素（100 U）或重组牛α干扰素（100 U）孵育的单核细胞显著限制了随后副结核分枝杆菌在细胞内的生长。与它们对新鲜贴壁单核细胞的作用相反，这些细胞因子对单核细胞衍生巨噬细胞内副结核分枝杆菌的生长影响很小。在两项独立实验中，我们还观察到用未纯化的重组人粒细胞 - 巨噬细胞集落刺激因子处理的单核细胞中杆菌生长受到抑制。相反，用来自免疫小牛的副结核分枝杆菌刺激的外周血单核细胞的培养上清液预处理的单核细胞中，副结核分枝杆菌的细胞内生长增强。这些上清液的生长增强活性在pH 2.0时不稳定，提示γ干扰素发挥了作用；然而，随后的实验表明单独的重组γ干扰素既不增强也不限制细胞内杆菌的生长。为了确定单核细胞氧化活性对细胞因子诱导的抑菌作用的可能贡献，我们比较了细胞因子处理的单核细胞和对照单核细胞中超氧阴离子的释放。未观察到超氧阴离子的释放与杆菌随后的细胞内命运之间存在明显关系。
