Pichurin Pavel, Pichurina Oxana, Chazenbalk Gregorio D, Paras Charmaine, Chen Chun-Rong, Rapoport Basil, McLachlan Sandra M
Autoimmune Disease Unit, Cedars-Sinai Research Institute and University of California School of Medicine, Los Angeles, California 90048, USA.
Endocrinology. 2002 Apr;143(4):1182-9. doi: 10.1210/endo.143.4.8745.
TSH receptor (TSHR) DNA vaccination induces high TSHR antibody levels in BALB/c mice housed in a conventional facility. However, under pathogen-free conditions, we observed a Th1 cellular response to TSHR antigen characterized by interferon-gamma (IFN gamma) production. In the present study we investigated the effect on TSHR DNA vaccination of diverting the cytokine milieu away from Th1 using 1) IFN gamma knockout BALB/c mice, and 2) wild-type mice covaccinated with DNA for the TSHR and for IFN gamma/receptor-Fc protein that prevents IFN gamma from binding to its receptor. Neither approach enhanced TSHR antibody levels, although splenocyte IFN gamma production in response to TSHR antigen was absent (IFN gamma knockouts) or reduced (IFN gamma receptor-Fc). Moreover, production of IL-2, another Th1 cytokine, but not Th2 cytokines, indicated that neither strategy overcame the Th1 bias of im DNA vaccination. Importantly, splenocyte production of IFN gamma and IL-2 provides a sensitive detection system for TSHR-specific T cells. Unexpectedly, higher TSHR antibody levels developed in rare mice. High titer animals had TSHR-specific responses of both Th2 and Th1 types, whereas low titer animals had Th1-restricted TSHR responses. The heterogeneity of responses induced by TSHR DNA vaccination in mice may provide insight into the titers and IgG subclasses of spontaneous autoantibodies in humans.
促甲状腺激素受体（TSHR）DNA疫苗接种可在饲养于传统设施中的BALB/c小鼠体内诱导产生高水平的TSHR抗体。然而，在无病原体条件下，我们观察到对TSHR抗原的Th1细胞应答，其特征为产生干扰素-γ（IFNγ）。在本研究中，我们使用以下两种方法研究了使细胞因子环境偏离Th1对TSHR DNA疫苗接种的影响：1）IFNγ基因敲除的BALB/c小鼠，以及2）与TSHR DNA和IFNγ/受体-Fc蛋白（可阻止IFNγ与其受体结合）共同接种的野生型小鼠。尽管对TSHR抗原的脾细胞IFNγ产生不存在（IFNγ基因敲除小鼠）或减少（IFNγ受体-Fc），但两种方法均未提高TSHR抗体水平。此外，另一种Th1细胞因子IL-2的产生，而非Th2细胞因子的产生，表明两种策略均未克服TSHR DNA疫苗接种的Th1偏向性。重要的是，脾细胞产生的IFNγ和IL-2为TSHR特异性T细胞提供了一个灵敏的检测系统。出乎意料的是，少数小鼠产生了更高水平的TSHR抗体。高滴度动物具有Th2和Th1两种类型的TSHR特异性应答，而低滴度动物具有Th1受限的TSHR应答。TSHR DNA疫苗接种在小鼠中诱导的应答异质性可能有助于深入了解人类自发自身抗体的滴度和IgG亚类。
