Generation of Long-Lived Bone Marrow Plasma Cells Secreting Antibodies Specific for the HIV-1 gp41 Membrane-Proximal External Region in the Absence of Polyreactivity.
Generation of Long-Lived Bone Marrow Plasma Cells Secreting Antibodies Specific for the HIV-1 gp41 Membrane-Proximal External Region in the Absence of Polyreactivity.
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DOI：
10.1128/jvi.01089-16
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发表时间：
2016-10-01
影响因子：
5.4
通讯作者：
Kim M
中科院分区：
文献类型：
--
作者：
Donius LR;Cheng Y;Choi J;Sun ZY;Hanson M;Zhang M;Gierahn TM;Marquez S;Uduman M;Kleinstein SH;Irvine D;Love JC;Reinherz EL;Kim M
人们迫切需要有效的预防性疫苗，以遏制目前的HIV-1流行病。跨越HIV-1进化枝的连续gp 41膜近端外部区域（MPER）氨基酸序列的保守性和抗MPER广泛中和抗体（BNAb）阻断病毒半融合/融合的能力两者确立了MPER作为主要疫苗接种靶标。在早期的研究中，我们描述了一种MPER疫苗制剂的开发，该制剂利用脂质体将MPER排列在脂质双层表面上，平行于其在病毒膜上的天然构型，同时还掺入分子佐剂和CD 4 T细胞表位货物。在这里，我们证明了几种免疫与MPER/脂质体诱导高水平的骨髓长寿命浆细胞（LLPC）抗体的生产。单细胞免疫球蛋白基因检索分析表明，这些浆细胞来源于具有不同免疫球蛋白基因表达的生殖系B细胞库，表现出抗原驱动的阳性选择。LLPC重组单克隆抗体（rMAb）的表征表明，抗原识别是通过利用各种互补决定区H3（CDRH 3）长度在共同表位焦点上的收敛来实现的。重要的是，从这些细胞产生的绝大多数rMAb缺乏多反应性，但在脂质的情况下表现出抗原特异性，通过选择压力形成MPR特异性互补位。总之，这些发现表明MPER是疫苗靶标，产生脱靶自身免疫的风险最小。重要性一个有用的疫苗必须产生所需的长期，抗原特异性抗体反应，缺乏多反应性或自身反应性。一些HIV-1 BNAb的常见多反应性特征引起了对引发抗MPER抗体的关注。利用单LLPC库分析和生物物理特性的抗MPER单克隆抗体，我们表明，他们的优良的特异性需要一个结构的健身的抗体结合位点，涉及重链和轻链可变结构域形成的体细胞超突变和亲和力成熟的B细胞在生发中心。也许更重要的是，我们的结果表明，大多数MPR特异性抗体本身不是多特异性和/或自身反应性的，这表明MPR特异性抗体的多反应性与其抗原特异性是可分离的。
An effective preventive vaccine is highly sought after in order to stem the current HIV-1 pandemic. Both conservation of contiguous gp41 membrane-proximal external region (MPER) amino acid sequences across HIV-1 clades and the ability of anti-MPER broadly neutralizing antibodies (BNAbs) to block viral hemifusion/fusion establish the MPER as a prime vaccination target. In earlier studies, we described the development of an MPER vaccine formulation that takes advantage of liposomes to array the MPER on a lipid bilayer surface, paralleling its native configuration on the virus membrane while also incorporating molecular adjuvant and CD4 T cell epitope cargo. Here we demonstrate that several immunizations with MPER/liposomes induce high levels of bone marrow long-lived plasma cell (LLPC) antibody production. Single-cell immunoglobulin gene retrieval analysis shows that these plasma cells are derived from a germ line repertoire of B cells with a diverse representation of immunoglobulin genes, exhibiting antigen-driven positive selection. Characterization of LLPC recombinant monoclonal antibodies (rMAbs) indicates that antigen recognition is achieved through convergence on a common epitopic focus by utilizing various complementarity-determining region H3 (CDRH3) lengths. Importantly, the vast majority of rMAbs produced from these cells lack polyreactivity yet manifest antigen specificity in the context of lipids, shaping MPER-specific paratopes through selective pressure. Taken together, these findings demonstrate that the MPER is a vaccine target with minimal risk of generating off-target autoimmunity. IMPORTANCE A useful vaccine must generate desired long-term, antigen-specific antibody responses devoid of polyreactivity or autoreactivity. The common polyreactive features of some HIV-1 BNAbs have raised concern about elicitation of anti-MPER antibodies. Utilizing single-LLPC repertoire analysis and biophysical characterization of anti-MPER rMAbs, we show that their fine specificities require a structural fitness of the antibody combining site involving heavy and light chain variable domains shaped by somatic hypermutation and affinity maturation of B cells in the germinal center. Perhaps more importantly, our results demonstrate that the majority of MPER-specific antibodies are not inherently polyspecific and/or autoreactive, suggesting that polyreactivity of MPER-specific antibodies is separable from their antigen specificity.