Holmes K V, Welsh R M, Haspel M V
J Immunol. 1986 Feb 15;136(4):1446-53.
Spleen cells from uninfected control mice selectively lysed BALB/c 3T3 fibroblasts infected with mouse hepatitis virus (MHV), a murine coronavirus. Lysis of infected cells occurred within 3 hr, and histocompatibility between effector and target cells was not required. This natural, cell-mediated, virus-associated cytotoxicity differed from NK cell- and T cell-mediated lysis. Spleen cells from animals infected with MHV were enriched in NK activity and were more cytotoxic to YAC-1 target cells, but did not show enhanced cytotoxicity for MHV-infected target cells. Spleen cells from beige mice, which are deficient in NK cell activity, were able to lyse MHV-infected target cells, as were spleen cells from nude mice, which are deficient in T cell activity. Lysis of MHV-infected target cells could be mediated by cells from the spleen and, to a lesser extent, by cells from the bone marrow, but not by resident peritoneal cells or thymocytes. We suggest the term "virus killer (VK) activity" for this phenomenon. VK activity of splenocytes from different mouse strains correlated with the ability of the splenocytes to bind purified radiolabeled MHV virions. MHV virions caused agglutination of spleen leukocytes from susceptible mouse strains, indicating that leukocyte agglutination or adsorption may provide a useful assay for coronaviruses such as MHV which lack hemagglutinating activity. SJL mouse splenocytes did not bind MHV and did not lyse infected targets. MHV bound relatively well to splenocytes of other mouse strains, but poorly to thymocytes and erythrocytes. Binding of MHV to leukocytes was not influenced by 6 mM EDTA or EGTA, indicating a lack of requirement for Mg++ or Ca++. VK activity was also resistant to EDTA and EGTA, in contrast to NK activity, which was sensitive to those chelating agents. VK activity was also unaffected by actinomycin D, cycloheximide, or puromycin, indicating that new protein synthesis was not required for lysis. Antibody to interferon-alpha/beta did not block lysis, nor was there substantially enhanced lysis mediated by leukocytes from mice infected with virus and thus exposed to high levels of interferon. VK activity was blocked by antibody directed against the peplomeric glycoprotein E2 of MHV. VK activity required infected target cells, because cells with adsorbed MHV virions were not lysed by splenocytes.(ABSTRACT TRUNCATED AT 400 WORDS)
来自未感染对照小鼠的脾细胞选择性地裂解感染了鼠肝炎病毒（MHV，一种鼠冠状病毒）的BALB/c 3T3成纤维细胞。感染细胞的裂解在3小时内发生，效应细胞和靶细胞之间不需要组织相容性。这种天然的、细胞介导的、与病毒相关的细胞毒性不同于自然杀伤（NK）细胞和T细胞介导的裂解。感染MHV的动物的脾细胞富含NK活性，对YAC-1靶细胞的细胞毒性更强，但对感染MHV的靶细胞没有增强的细胞毒性。NK细胞活性缺陷的米色小鼠的脾细胞能够裂解感染MHV的靶细胞，T细胞活性缺陷的裸鼠的脾细胞也能如此。感染MHV的靶细胞的裂解可由脾细胞介导，骨髓细胞介导的程度较小，但不能由驻留的腹腔细胞或胸腺细胞介导。我们建议用“病毒杀手（VK）活性”来描述这种现象。来自不同小鼠品系的脾细胞的VK活性与脾细胞结合纯化的放射性标记MHV病毒粒子的能力相关。MHV病毒粒子导致易感小鼠品系的脾白细胞凝集，这表明白细胞凝集或吸附可能为缺乏血凝活性的冠状病毒（如MHV）提供一种有用的检测方法。SJL小鼠脾细胞不结合MHV，也不裂解感染的靶细胞。MHV与其他小鼠品系的脾细胞结合相对较好，但与胸腺细胞和红细胞结合较差。MHV与白细胞的结合不受6 mM乙二胺四乙酸（EDTA）或乙二醇双四乙酸（EGTA）的影响，这表明不需要Mg++或Ca++。与对这些螯合剂敏感的NK活性相反，VK活性也对EDTA和EGTA有抗性。VK活性也不受放线菌素D、环己酰亚胺或嘌呤霉素的影响，这表明裂解不需要新的蛋白质合成。抗α/β干扰素抗体不阻断裂解，感染病毒并因此暴露于高水平干扰素的小鼠的白细胞介导的裂解也没有显著增强。针对MHV的包膜糖蛋白E2的抗体阻断VK活性。VK活性需要感染的靶细胞，因为吸附了MHV病毒粒子的细胞不会被脾细胞裂解。（摘要截短至400字）
