期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：1
页码：559-562
DOI：10.1073/pnas.77.1.559
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：When HeLa cells acutely infected with measles virus were incubated in a mixture containing only the six proteins of the alternative pathway of complement activation (C3, factors B and D, beta 1H, C3b inactivator, and native properdin) without antibody, there was activation of the alternative pathway as shown by progressive uptake of 125I-labeled C3b onto the cell surface. This C3b uptake was blocked by EDTA and was not shown by uninfected cells. The rate of 125I-labeled C3 uptake by infected cells was the same in the absence and presence of properdin; however, when antiviral IgG was bound to the cell surface, the rate of C3 uptake was increased in the presence of properdin. Significant 125I-labeled C3 uptake was first detectable when cells were studied at 12 hr after infection, when cells expressed viral polypeptides on their surface. There was also progressive uptake of 125I-labeled C3 onto measles virus-infected cells incubated in human serum depleted of both IgG and C4. Hence, the human alternative pathway of complement activation can be initiated on the surface of measles virus-infected cells independent of IgG antibody. However, lysis of the infected cells only occurs when antiviral antibody is present.
