Identification and localization of conserved antigenic epitopes on the G2 proteins of California serogroup Bunyaviruses.
Identification and localization of conserved antigenic epitopes on the G2 proteins of California serogroup Bunyaviruses.
复制标题
加州血清群布尼亚病毒 G2 蛋白上保守抗原表位的鉴定和定位。
DOI：
10.1089/vim.2000.13.201
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Israel,BA
中科院分区：
文献类型：
--
作者：
Cheng,LL;Schultz,KT;Yuill,TM;Israel,BA
加州（CAL）血清群布尼亚病毒是人类虫媒病毒性脑炎的重要病原体。它们在自然界中由蚊子维持并传播给优选的脊椎动物扩增宿主。拉克罗斯病毒（LAC）的G2囊膜糖蛋白是由Ludwig等提出的病毒附着于蚊子中肠细胞的决定因素。G2的单克隆抗体中和链霉蛋白酶处理的病毒对蚊子细胞的感染性。我们确定了LAC G2上抗原位点的位置。我们发现，在加州脑炎和Melao亚组的CAL血清群的病毒之间的LAC G2蛋白存在的抗原区域是保守的，但不是在trivatattus病毒，也不是在BUN血清群。8个CAL和3个BUN病毒的G2胞外区氨基酸序列与单克隆抗体（MAb）结合数据的比较预测了抗原位点的可能位置。我们用体外诱变的LAC G2基因构建了一组G2基因，其编码区中的可疑单克隆抗体结合位点具有替换序列。天然蛋白和突变蛋白在HeLa细胞中表达，并测试了单克隆抗体与表达蛋白结合的能力。四个不连续的氨基酸序列，保守的八个CAL血清群病毒，被确定为有助于两个构象结合域的中和LAC G2单克隆抗体。
California (CAL) serogroup Bunyaviruses are significant agents of arboviral encephalitis in humans. They are maintained and transmitted in nature by mosquitoes to preferred vertebrate amplifying hosts. The G2 envelope glycoprotein of La Crosse virus (LAC) was proposed by Ludwig et al. to be a determinant for virus attachment to mosquito midgut cells. Monoclonal antibodies to G2 neutralize the infectivity of pronase-treated virus for mosquito cells. We determined the location of antigenic sites on the LAC G2. We showed that antigenic areas present on the LAC G2 protein are conserved among viruses in the California encephalitis and Melao subgroups of the CAL serogroup, but not in trivatattus virus, nor within the BUN serogroup. A comparison of the G2 exodomain amino acid sequences of eight CAL and three BUN viruses with monoclonal antibodies (MAb) binding data predicted the possible location of the antigenic sites. We usedin vitromutagenesis of the LAC G2 gene to construct a set of G2 genes with replacement sequences in the coding regions for the suspected MAb binding sites. The native and mutated proteins were expressed in Hela cells and the ability of MAbs to bind to the expressed proteins was tested. Four discontinuous amino acid sequences, conserved among eight CAL serogroup viruses, were identified as contributing to two conformational binding domains for neutralizing LAC G2 MAbs.