Anti-CD34+ Fabs generated against hematopoietic stem cells in HIV-derived combinatorial immunoglobulin library suggest antigen-selected autoantibodies.
Anti-CD34+ Fabs generated against hematopoietic stem cells in HIV-derived combinatorial immunoglobulin library suggest antigen-selected autoantibodies.
复制标题
针对 HIV 衍生的组合免疫球蛋白库中的造血干细胞生成的抗 CD34 Fab 表明存在抗原选择的自身抗体。
DOI：
10.1016/s0161-5890(98)00075-3
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发表时间：
1998
影响因子：
3.6
通讯作者：
Boosalis,M
中科院分区：
文献类型：
--
作者：
Rubinstein,DB;Leblanc,P;Wright,DG;Guillaume,T;Strotchevoi,A;Boosalis,M
与HIV感染相关的骨髓抑制似乎不仅仅是由于直接的病毒致细胞病变作用。自身抗体可能在骨髓抑制中发挥作用，但目前尚不清楚HIV感染中产生的自身抗体是否代表主要致病过程或仅反映多克隆B细胞活化。为了解决这些问题，我们使用来自具有循环自身抗体证据的HIV+个体的pComb 3噬菌粒产生组合免疫球蛋白文库。从一个文库中，通过噬菌体消减法，使用新鲜的CD 34+细胞作为抗原靶标鉴定了三个抗CD 34 Fab。抗CD 34 Fab通过免疫印迹和Elisa具有特异性，并且具有高亲和力，计算的Kd在10−7-10− 8 M的范围内。核酸测序显示所有三个是VH 3家族，并具有λ轻链，其中一些基因片段表达很少的体细胞突变，而其他片段以提示抗原选择的模式体细胞突变。这些发现表明：（1）HIV相关抗CD 34自身抗体的一个亚群是单特异性的和抗原选择性的，并且不仅仅是HIV中多克隆B细胞活化和升高的IG水平的结果。因此，HIV中的自身反应性包括多特异性低亲和力抗体以及单特异性抗原选择的高亲和力抗体。(2)虽然HIV骨髓抑制可能是多因素的，但针对造血干细胞的自身抗体可能有助于其发病机制。(3)VH基因家族重排的文库取样显示没有证据表明VH 3家族在HIV感染的免疫失调中代表性不足。噬菌体消减被证实是一种有效的手段，识别，克隆和表征造血分化抗原的抗体。
Bone marrow suppression associated with HIV infection does not appear to be solely due to direct viral cytopathic effects. Autoantibodies may play a role in myelosuppression, however it is unclear whether autoantibodies produced in HIV infection represent a primary pathogenic process or merely reflect polyclonal B cell activation. To address these questions, we generated combinatorial immunoglobulin libraries using the pComb3 phagemid from an HIV+individual with evidence of circulating autoantibodies. From one library, three anti-CD34 Fabs were identified using fresh CD34+cells as antigenic targets by a method of phage subtraction. The anti-CD34 Fabs are specific by immunoblotting and Elisa and are of high affinity, with calculated Kds in the range of 10−7–10−8M. Nucleic acid sequencing revealed all three to be of the VH3 family and to have lambda light chains with some gene segments expressing little somatic mutation, while other segments were somatically mutated in patterns suggestive of antigen selection. These findings indicate that (1) A subset of HIV-associated anti-CD34 autoantibodies are monospecific and antigen-selected and are not merely a consequence of polyclonal B cell activation and elevated Ig levels in HIV. Autoreactivity in HIV therefore includes both polyspecific, low affinity antibodies as well as monospecific antigen-selected high affinity antibodies. (2) Although bone marrow suppression in HIV is likely to be multifactorial, autoantibodies to hematopoietic stem cells may contribute to its pathogenesis. (3) Library sampling of VH gene family rearrangements shows no evidence for under-representation of the VH3 family in the immune dysregulation of HIV infection. Phage subtraction is corroborated to be an effective means of identifying, cloning, and characterizing antibodies to hematopoietic differentiation antigens.