Bautista A P
Department of Physiology and NIAAA-Sponsored Alcohol Research Center, Louisiana State University Health Sciences Center, New Orleans 70112, USA.
Life Sci. 2001 Mar 16;68(17):1939-49. doi: 10.1016/s0024-3205(01)00986-9.
Chemokines are involved in the inhibition of HIV-1 infection and in the pathogenesis of tissue injury in a number of conditions, including endotoxemia and alcoholic liver disease. CC chemotactic peptides (MIP-1alpha, MCP-1 and RANTES) are produced by a wide variety of cell types in response to immunological stimuli, bacterial endotoxin and gp120 from HIV-1 and HIV-2. This work tests the hypothesis that prior exposure to endotoxin and/or ethanol in vivo inhibits the production of CC-chemokines following a secondary challenge with HIV-1 gp120 in vitro. Male Sprague-Dawley rats received in intravenous infusion of ethanol to maintain blood ethanol level at 170 mg/dl for 3 hr. Escherichia coli LPS (1 mg/Kg) was given intravenously 5 min after the ethanol bolus was injected. Control groups received similar volumes of saline. Three hr after LPS treatment, Kupffer cells were obtained and treated with HIV-1 gp120 (5 microg/10(6) cells/24 hr). At the end of the incubation period, cells were obtained for RT-PCR analysis of CC-chemokine mRNA expression. Chemokine release in culture supernatants was measured by ELISA. Results show that in vivo ethanol was associated with downregulation of MIP-1alpha and MCP-1 mRNA expression and protein release in primary cultures of Kupffer cells. However, ethanol alone primed isolated Kupffer cells for enhanced RANTES mRNA and protein release in the presence or absence of HIV-1 gp120. These results demonstrate that acute ethanol intoxication and endotoxemia may selectively act as a desensitizing agent in response to a secondary challenge with bacterial or viral products.
趋化因子参与了对HIV-1感染的抑制以及在多种病症(包括内毒素血症和酒精性肝病)中组织损伤的发病机制。CC趋化肽(MIP-1α、MCP-1和RANTES)由多种细胞类型在免疫刺激、细菌内毒素以及HIV-1和HIV-2的gp120作用下产生。本研究检验了这样一个假设:体内预先接触内毒素和/或乙醇会抑制体外再次用HIV-1 gp120刺激后CC趋化因子的产生。雄性Sprague-Dawley大鼠静脉输注乙醇以维持血液乙醇水平在170mg/dl达3小时。在注射乙醇推注后5分钟静脉给予大肠杆菌LPS(1mg/Kg)。对照组给予相似体积的生理盐水。LPS处理3小时后,获取库普弗细胞并用HIV-1 gp120(5μg/10⁶细胞/24小时)处理。在孵育期结束时,获取细胞用于CC趋化因子mRNA表达的RT-PCR分析。通过ELISA测量培养上清液中的趋化因子释放。结果表明,体内乙醇与库普弗细胞原代培养物中MIP-1α和MCP-1 mRNA表达及蛋白释放的下调相关。然而,单独乙醇预处理分离的库普弗细胞,无论有无HIV-1 gp120,都会增强RANTES mRNA和蛋白释放。这些结果表明,急性乙醇中毒和内毒素血症可能作为一种脱敏剂,选择性地应对细菌或病毒产物的再次刺激。