Toogood C I, Crompton J, Hay R T
Department of Biochemistry and Microbiology, University of St Andrews, Fife, U.K.
J Gen Virol. 1992 Jun;73 ( Pt 6):1429-35. doi: 10.1099/0022-1317-73-6-1429.
The adenovirus (Ad) hexon contains both group-and type-specific antigenic determinants. To identify the latter, peptides were synthesized corresponding to residues 281 to 292 from loop 1 and 441 to 455 from loop 2 of the Ad2 hexon. These sequences display type-specific variation and have been shown by X-ray crystallography to be present on the surface of the virion. Antisera raised against the peptides bound both peptide and the native hexon in ELISA, and blocked virus infectivity, as determined by immunofluorescence or neutralization assays. The loop 1 peptide was shown to inhibit binding of the corresponding antiserum to the native hexon in ELISA and to abolish its neutralizing activity. Neither the loop 1- nor loop 2-specific antiserum neutralized the infectivity of Ad4 or Ad40. Neutralization did not appear to result from aggregation of virus particles and thus their inability to attach to the cell, because virions treated with immune serum were internalized to the same extent as those treated with preimmune serum. Examination of the immune response elicited by Ad2 infection revealed that antibodies directed against the L1 and L2 epitopes were also present in human serum. Thus, the variable regions exposed on the surface of the Ad2 hexon represent type-specific neutralizing antigenic determinants.
腺病毒（Ad）六邻体包含组特异性和型特异性抗原决定簇。为了鉴定后者，合成了与Ad2六邻体环1的281至292位残基以及环2的441至455位残基相对应的肽段。这些序列表现出型特异性变异，并且X射线晶体学显示它们存在于病毒粒子表面。在酶联免疫吸附测定（ELISA）中，针对这些肽段产生的抗血清既能结合肽段也能结合天然六邻体，并且通过免疫荧光或中和试验确定其能阻断病毒感染性。在ELISA中，环1肽段可抑制相应抗血清与天然六邻体的结合，并消除其中和活性。环1特异性抗血清和环2特异性抗血清均不能中和Ad4或Ad40的感染性。中和作用似乎不是由病毒颗粒聚集以及由此导致的无法附着于细胞引起的，因为用免疫血清处理的病毒粒子与用免疫前血清处理的病毒粒子内化程度相同。对Ad2感染引发的免疫反应进行检测发现，人血清中也存在针对L1和L2表位的抗体。因此，Ad2六邻体表面暴露的可变区代表型特异性中和抗原决定簇。
