Potoka D A, Takao S, Owaki T, Bulkley G B, Klein A S
Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, MD 21287-8611, USA.
Free Radic Biol Med. 1998 May;24(7-8):1217-27. doi: 10.1016/s0891-5849(97)00453-x.
Phagocytosis and killing of circulating organisms by Kupffer cells (KCs) are discrete, important components of host defense. However, the killing mechanism(s) are not fully understood, and the potential role of adjacent nonparenchymal cells such as hepatic endothelial cells has not been defined. Rat KCs -/+ an hepatic endothelial cell enriched cellular fraction (HECEF) were incubated with Candida parapsilosis and assayed for phagocytosis and phagocytic killing by validated fluorochromatic vital staining. The role of reactive oxygen metabolites in KC phagocytic functions was examined by inhibition with superoxide dismutase and/or catalase. Diphenyleneiodonium and allopurinol were used to examine the potential roles of NADPH oxidase and xanthine oxidase, respectively, in generating these toxic oxidants. Coculture with HECEF increased KC phagocytic activity (from 75% to 88%) and candidacidal activity (from 20% to 31%). Superoxide dismutase, catalase, diphenyleneiodonium, or allopurinol caused inhibition of candidacidal activity, but did not affect phagocytosis, and did not block the potentiation of phagocytosis or of killing caused by coculture with HECEF. Reactive oxygen intermediates generated by both NADPH oxidase and xanthine oxidase-dependent pathways are important in KC killing of Candida parapsilosis. In vitro, KC phagocytosis and killing are potentiated (via a non-oxidant-mediated mechanism) by coculture with a preparation of hepatic non-parenchymal cells composed primarily of endothelial cells.
库普弗细胞（KCs）对循环中微生物的吞噬和杀伤是宿主防御的重要独立组成部分。然而，其杀伤机制尚未完全明确，相邻的非实质细胞如肝内皮细胞的潜在作用也未得到界定。将大鼠KCs与富含肝内皮细胞的细胞组分（HECEF）一起培养，再与近平滑念珠菌孵育，并通过经过验证的荧光活体染色检测吞噬作用和吞噬杀伤作用。通过用超氧化物歧化酶和/或过氧化氢酶抑制来研究活性氧代谢产物在KC吞噬功能中的作用。分别使用二苯基碘鎓和别嘌呤醇来研究NADPH氧化酶和黄嘌呤氧化酶在产生这些有毒氧化剂中的潜在作用。与HECEF共培养可提高KC的吞噬活性（从75%提高到88%）和杀念珠菌活性（从20%提高到31%）。超氧化物歧化酶、过氧化氢酶、二苯基碘鎓或别嘌呤醇可抑制杀念珠菌活性，但不影响吞噬作用，也不阻断与HECEF共培养所导致的吞噬作用或杀伤作用的增强。由NADPH氧化酶和黄嘌呤氧化酶依赖性途径产生的活性氧中间体在KC杀伤近平滑念珠菌中起重要作用。在体外，与主要由内皮细胞组成的肝非实质细胞制剂共培养可增强KC的吞噬作用和杀伤作用（通过非氧化介导机制）。
