Selective Expansion of HIV-1 Envelope Glycoprotein-Specific B Cell Subsets Recognizing Distinct Structural Elements Following Immunization
Selective Expansion of HIV-1 Envelope Glycoprotein-Specific B Cell Subsets Recognizing Distinct Structural Elements Following Immunization
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DOI：
10.4049/jimmunol.0900407
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发表时间：
2009-09-01
影响因子：
4.4
通讯作者：
Hedestam, Gunilla B. Karlsson
中科院分区：
文献类型：
--
作者：
Dosenovic, Pia;Chakrabarti, Bimal;Hedestam, Gunilla B. Karlsson
HIV - 1包膜糖蛋白（Env）功能性刺突已进化出多种免疫逃避策略，并且在组装好的刺突上只有少数广泛中和决定簇可被抗体（Abs）接近。基于体外抗体结合和中和活性的血清学研究表明，用当前基于Env的免疫原进行疫苗接种主要诱导出结合非中和性或毒株限制性中和表位的抗体。然而，血清中存在的多克隆抗体混合物的部分特异性，尤其是那些针对Env构象表位的特异性，往往难以确定。此外，血清学分析无法提供关于重复抗原接种如何影响Env特异性B细胞亚群的扩增和维持的信息。因此，我们开发了一种高度灵敏的Env特异性B细胞酶联免疫斑点（ELISPOT）系统，该系统能够对来自不同解剖部位、针对Env不同结构决定簇的抗体分泌细胞（ASC）进行计数。在这项研究中，我们利用该系统检测了用佐剂中工程化Env三聚体免疫的小鼠中B细胞应答的演变。我们证明，通过同源加强免疫，针对Env特定结构元件的ASC的相对比例会发生显著改变。这导致了针对Env可变区的ASC的选择性扩增。我们认为，本研究中描述的B细胞特异性和亚群分析是对血清学定位研究的重要补充，可用于检测针对多种免疫原亚特异性的B细胞应答。《免疫学杂志》，2009年，183卷：3373 - 3382页。
The HIV-1 envelope glycoprotein (Env) functional spike has evolved multiple immune evasion strategies, and only a few broadly neutralizing determinants on the assembled spike are accessible to Abs. Serological studies, based upon Ab binding and neutralization activity in vitro, suggest that vaccination with current Env-based immunogens predominantly elicits Abs that bind non-neutralizing or strain-restricted neutralizing epitopes. However, the fractional specificities of the polyclonal mixture of Abs present in serum, especially those directed to conformational Env epitopes, are often difficult to determine. Furthermore, serological analyses do not provide information regarding how repeated Ag inoculation impacts the expansion and maintenance of Env-specific B cell subpopulations. Therefore, we developed a highly sensitive Env-specific B cell ELISPOT system, which allows the enumeration of Ab-secreting cells (ASC) from diverse anatomical compartments directed against different structural determinants of Env. In this study, we use this system to examine the evolution of B cell responses in mice immunized with engineered Env trimers in adjuvant. We demonstrate that the relative proportion of ASC specific for defined structural elements of Env is altered significantly by homologous booster immunizations. This results in the selective expansion of ASC directed against the variable regions of Env. We suggest that the B cell specificity and compartment analysis described in this study are important complements to serological mapping studies for the examination of B cell responses against subspecificities of a variety of immunogens. The Journal of Immunology, 2009, 183: 3373-3382.