Clouse K A, Cosentino L M, Weih K A, Pyle S W, Robbins P B, Hochstein H D, Natarajan V, Farrar W L
Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892.
J Immunol. 1991 Nov 1;147(9):2892-901.
Results and conclusions concerning the ability of HIV glycoprotein (gp) 120 to stimulate monokine secretion have been equivocal, based on observations using natural gp120 derived from infected human cells and a Chinese hamster ovary (CHO) cell-derived recombinant fusion protein. Current studies were designed to determine whether differences in recombinant gp120 proteins could result in failure to trigger monokine production. We found that natural gp120 could stimulate monocytes to release TNF-alpha, IL-1 beta, IL-6, and granulocyte-macrophage-CSF, and this effect could be blocked with soluble CD4. Full-length rgp120 either expressed from an adenovirus vector and purified from infected human cells, or derived from CHO cells, could function similarly. In contrast, full-length recombinant envelope protein expressed in a baculovirus system and a CHO cell-derived recombinant fusion protein tested previously, consistently failed to stimulate monokine production. The stimulatory capacity of both natural and full-length CHO cell-derived gp120 was eliminated by heating at 100 degrees C, and could be blocked with excess CHO cell-derived gp120 fusion protein. Inasmuch as the baculovirus-expressed gp120 and the CHO cell-derived recombinant fusion protein can bind to CD4, these results suggest that HIV gp120 binding to CD4 on the monocyte surface may of itself be insufficient for stimulation of monokine secretion. Therefore, primary protein structure, as well as posttranslational protein modifications, may determine this activity.
基于使用从受感染人类细胞中提取的天然gp120以及一种中国仓鼠卵巢（CHO）细胞衍生的重组融合蛋白所做的观察，关于HIV糖蛋白（gp）120刺激单核因子分泌能力的结果和结论一直存在争议。当前的研究旨在确定重组gp120蛋白的差异是否会导致无法触发单核因子的产生。我们发现天然gp120能够刺激单核细胞释放肿瘤坏死因子-α、白细胞介素-1β、白细胞介素-6以及粒细胞-巨噬细胞集落刺激因子，并且这种效应能够被可溶性CD4阻断。从腺病毒载体表达并从受感染人类细胞中纯化得到的全长rgp120，或者源自CHO细胞的rgp120，其功能相似。相比之下，在杆状病毒系统中表达的全长重组包膜蛋白以及之前测试过的一种CHO细胞衍生的重组融合蛋白，始终无法刺激单核因子的产生。天然的以及全长CHO细胞衍生的gp120的刺激能力在100℃加热后消失，并且能够被过量的CHO细胞衍生的gp120融合蛋白阻断。鉴于杆状病毒表达的gp120和CHO细胞衍生的重组融合蛋白能够与CD4结合，这些结果表明HIV gp120与单核细胞表面的CD4结合本身可能不足以刺激单核因子的分泌。因此，蛋白质一级结构以及翻译后蛋白质修饰可能决定这种活性。
