The humoral response to xenografts is controlled by a restricted repertoire of immunoglobulin VH genes
The humoral response to xenografts is controlled by a restricted repertoire of immunoglobulin VH genes
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DOI：
10.1097/00007890-199811270-00019
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发表时间：
1998-11-27
期刊：
影响因子：
6.2
通讯作者：
Borie, D
中科院分区：
文献类型：
--
作者：
Cramer, DV;Wu, GD;Borie, D
背景。宿主的早期阶段；对异种移植物的免疫反应主要是抗供体抗体。介导宿主对异种移植物的体液反应的免疫途径在很大程度上是未知的，本报告阐述了控制宿主对异种移植物抗体反应的免疫球蛋白基因的性质。利用大鼠抗仓鼠单克隆抗体和LEW大鼠抗仓鼠心脏异种移植脾淋巴细胞建立的cDNA文库，克隆、测序和鉴定编码大鼠抗仓鼠心脏异种移植抗体的免疫球蛋白基因。通过基因组DNA克隆建立了鼠种系可变区重链（V-H）基因文库，并进行了核苷酸测序分析。采用集落滤点杂交法检测Ig V-H基因用于控制仓鼠异种移植物抗体反应的频率。然后将这些基因的核酸结构与其基因组祖基因进行比较，以鉴定用于介导应答的Ig V-H基因表达的数量和结构多样性。大鼠单克隆抗体的选择是因为它们有能力沉淀仓鼠异种移植的排斥反应，它们只使用一组密切相关的V-H基因。这些抗体使用的V-H基因仅限于一个生殖系基因家族（V(H)HAR），其中已鉴定出15个家族成员。V(H)HAR基因在LEW大鼠脾脏产生igm的B细胞中的使用频率从初始动物的0.8%迅速增加到异种移植后4天受体的13%。在移植后第4天和第21天，从初次或异种移植受体的脾淋巴细胞中建立表达V(H)HAR基因的cDNA文库。对20个cDNA克隆的检测表明，大多数（75%）克隆表达V(H)HAR基因，并表现出有限的体细胞突变。在种系结构中使用一组密切相关的Ig VH基因来控制对异种移植物的早期体液反应，这表明这种反应可能代表了移植物受体利用原始的、不依赖T细胞的抗体产生途径。
Background. The early phases of the host; immune response to xenografts are dominated by anti-donor antibodies. The immunological pathways responsible for mediating the host humoral responses to xenografts are largely unknown, and this report addresses the nature of the immunoglobulin genes controlling the host antibody response to xenografts.Methods. cDNA libraries established from rat anti-hamster monoclonal antibodies and splenic lymphocytes from LEW rats rejecting hamster heart xenografts were used to clone, sequence, and identify the immunoglobulin genes responsible for encoding rat xenoantibodies to hamster heart grafts. Libraries for germline variable region heavy chain (V-H) genes encoding the anti-hamster xenograft antibodies were established by genomic DNA cloning and analyzed by nucleotide sequencing. The frequency of Ig V-H gene usage for controlling the antibody responses to hamster xenografts was examined by colony-filter dot hybridization. The nucleic acid structure of these genes was then compared to their genomic progenitors to identify the number and structural diversity expressed by the Ig V-H genes used to mediate the response.Results. Rat monoclonal antibodies selected for their ability to precipitate the rejection off hamster xenografts exclusively use a closely related group of V-H genes. The V-H genes used by these antibodies are restricted to a single family of germline genes (V(H)HAR) for which 15 family members have been identified. The frequency of V(H)HAR gene usage in splenic IgM-producing B cells from LEW rats rapidly expands from 0.8% in naive animals to 13% in recipients 4 days after xenotransplantation. cDNA libraries expressing V(H)HAR genes were established from splenic lymphocytes derived from naive or xenograft recipients at 4 and 21 days after transplantation. Examination of 20 cDNA clones revealed that the majority (75%) of these clones express V(H)HAR genes displaying limited somatic mutation.Conclusions. The use of a closely related group of Ig VH genes in a germline configuration to control the early humoral response to xenografts suggests that this response may represent the utilization of a primitive, T cell-independent pathway of antibody production by the graft recipients.