Marschang P, Gürtler L, Tötsch M, Thielens N M, Arlaud G J, Hittmair A, Katinger H, Dierich M P
Institut für Hygiene and Ludwig-Boltzmann Institut für AIDS-Forschung, Innsbruck, Austria.
AIDS. 1993 Jul;7(7):903-10. doi: 10.1097/00002030-199307000-00001.
To analyse the ability of different HIV-1 and HIV-2 isolates to activate the complement system.
H9 cells chronically infected with various HIV isolates and the corresponding purified viruses were tested for complement activation. To identify the molecules responsible for complement activation on the surface of infected cells, the expression of complement inhibitors/regulators and viral proteins on the cell surface was analysed.
C3 deposition on the cell surface and the expression of viral and cellular antigens were determined by flow cytometry analysis. Complement activation by purified viruses was measured using a complement consumption assay and a C1 activation assay.
H9 cells infected with different HIV-1 and HIV-2 isolates showed varying degrees of complement activation on the cell surface, ranging from strong activation and deposition of large amounts of C3 to no increased C3 deposition compared to uninfected cells. The C3 deposition was eliminated by EDTA and reduced in the presence of EGTA. In contrast, all purified viral isolates tested activated the complement system in a comparable manner. While the expression of MCP, DAF and CD59 was not modified after infection with different viral isolates, the reaction of the infected cells with a monoclonal antibody (3D6) directed against a gp41 epitope (amino acids 601-620) was found to correlate with the complement activation on the cell surface.
Some HIV-1 as well as HIV-2 isolates activate the complement system on the surface of infected cells independent of anti-HIV antibodies, while other isolates fail to do so. Complement activation on the cell surface is mediated by the alternative and, to a lesser extent, the classical pathway. The differences in complement activation on the cell surface are not caused by a modified expression of membrane-bound complement inhibitors/regulators. C3 deposition on the cell surface correlates with the expression of an epitope lying within the major complement activating domain of gp41 (amino acids 591-620). These results suggest a role of gp41 for complement activation on HIV-infected cells as has been described previously for purified HIV.
分析不同的HIV-1和HIV-2分离株激活补体系统的能力。
对长期感染各种HIV分离株的H9细胞以及相应的纯化病毒进行补体激活检测。为了确定感染细胞表面负责补体激活的分子，分析了补体抑制剂/调节因子和病毒蛋白在细胞表面的表达。
通过流式细胞术分析测定细胞表面的C3沉积以及病毒和细胞抗原的表达。使用补体消耗试验和C1激活试验测量纯化病毒的补体激活情况。
感染不同HIV-1和HIV-2分离株的H9细胞在细胞表面表现出不同程度的补体激活，范围从大量C3的强烈激活和沉积到与未感染细胞相比C3沉积无增加。EDTA可消除C3沉积，EGTA存在时C3沉积减少。相反，所有测试的纯化病毒分离株以类似方式激活补体系统。虽然感染不同病毒分离株后MCP、DAF和CD59的表达未改变，但发现感染细胞与针对gp41表位（氨基酸601 - 620）的单克隆抗体（3D6）的反应与细胞表面的补体激活相关。
一些HIV-1以及HIV-2分离株在感染细胞表面独立于抗HIV抗体激活补体系统，而其他分离株则不能。细胞表面的补体激活由替代途径介导，经典途径介导程度较小。细胞表面补体激活的差异不是由膜结合补体抑制剂/调节因子的表达改变引起的。细胞表面的C3沉积与位于gp41主要补体激活域内的表位（氨基酸591 - 620）的表达相关。这些结果表明gp
