Immune Response of Mice Transgenic for Human Histocompatibility Leukocyte Antigen-DR to Human Thyrotropin Receptor-Extracellular Domain
Immune Response of Mice Transgenic for Human Histocompatibility Leukocyte Antigen-DR to Human Thyrotropin Receptor-Extracellular Domain
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DOI：
10.1089/thy.2008.0349
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发表时间：
2009-11-01
期刊：
影响因子：
6.6
通讯作者：
De Groot, Leslie J.
中科院分区：
文献类型：
--
作者：
Inaba, Hidefumi;Pan, Deshun;De Groot, Leslie J.
背景：Graves病甲亢是由抗促甲状腺激素受体（hTSH-R）自身抗体引起的。方法：采用组织相容性白细胞抗原DR 3或DR 2转基因小鼠，分别以hTSH R胞外区cDNA（hTSH R ECD）、hTSH R ECD蛋白或hTSH R肽表位免疫小鼠。免疫小鼠脾细胞对hTSH-ECD序列表位的增殖反应、抗TSH-R抗体反应、血清甲状腺素和TSH水平以及甲状腺组织学均被记录下来。结果：DR 3小鼠在6周的免疫程序中对几个表位产生增殖反应，其强度增加并扩散到包括更多表位。DR 2转基因小鼠产生弱的增殖反应。通过酶联免疫吸附试验或TSH结合抑制试验，两种类型的小鼠均在16-60%的动物中产生抗TSH-R抗体。有证据表明，一组动物的甲状腺刺激较弱。DR 3转基因小鼠对hTSH-R-ECD蛋白的免疫诱导了对具有序列ISRIYVSIDVTLQQLES（aa 78 -94）的表位的显著应答。对源自TSH-R-ECD序列（包括aa 78 -94）的肽的免疫引起对表位的强烈应答，并产生对hTSH序列内几个其他非重叠表位的免疫应答（表位扩散）和与hTSH-R反应的抗体。结论：DR 3和DR 2转基因小鼠对基因免疫的T细胞和B细胞反应不同，抗体的遗传控制比T细胞反应少。在基因组和肽表位免疫期间，存在免疫期间表位扩散的证据。几个功能上重要的表位是明显的，尤其是aa 78 -94。然而，如果在人类疾病中发生类似的进行性表位募集，则基于表位的治疗将难以实现。
Background: Hyperthyroidism of Graves' disease is caused by auto-antibodies to human thyrotropin receptor (hTSH-R). To elucidate important T-cell epitopes in TSH-R, we studied three models of immunity to TSH-R in mice.Methods: Mice transgenic for histocompatibility leukocyte antigen DR3 or DR2 were immunized with cDNA for hTSH-R-extracellular domain (hTSH-R-ECD), or hTSH-R-ECD protein, or hTSH-R peptide epitopes. Proliferative responses of immunized splenocytes to epitopes derived from the hTSH-ECD sequence, anti-TSH-R antibody responses, serum thyroxine and TSH, and thyroid histology were recorded.Results: DR3 mice responded to genomic immunization with proliferative responses to several epitopes, which increased in intensity and spread to include more epitopes, during a 6-week immunization program. DR2 transgenic mice developed weak proliferative responses. Both types of mice developed anti-TSH-R antibodies measured by enzyme-linked immunosorbent assay or TSH-binding inhibition assay in 16-60% of animals. There was evidence of weak thyroid stimulation in one group of animals. Immunization of DR3 transgenic mice to hTSH-R-ECD protein induced a striking response to an epitope with sequence ISRIYVSIDVTLQQLES (aa78-94). Immunization to peptides derived from the TSH-R-ECD sequence (including aa78-94) caused strong responses to the epitopes, and development of immune responses to several other nonoverlapping epitopes within the hTSH sequence (epitope spreading) and antibodies reacting with hTSH-R. This implies that immunization with hTSH-R epitopes produced immunity to mouse TSH-R.Conclusion: T-cell and B-cell responses to genetic immunization differ in DR3 and DR2 transgenic mice, and there is less genetic control of antibody than of T-cell responses. During both genomic and peptide epitope immunization there was evidence of epitope spreading during the immunization. Several functionally important epitopes are evident, especially aa78-94. However, if similar progressive epitope recruitment occurs in human disease, epitope-based therapy will be difficult to achieve.