MECHANISMS OF AUTOANTIBODY PRODUCTION IN SLE

该子项目是利用 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 特异性抗核抗体（如抗DNA、抗Sm）与系统性红斑狼疮（SLE）高度相关。 为什么这些特异性在狼疮中产生，而不是其他自身免疫性疾病，尚不清楚。 降植烷可在非自身免疫易感小鼠中诱导类似的自身抗体。 初步研究强烈暗示IL-4和促炎细胞因子IL-6、IL-12和IFN在不同的自身抗体亚群的形成中。 将细胞因子环境从Th 2改变为Th 1可以改变由给定品系的小鼠产生的自身抗体。 因此，细胞因子的过度产生可能是决定自身抗体表型的关键因素。 我们发现SLE患者自身抗体表型也会发生改变。 我们假设，在小鼠中，细胞因子的过度产生可能是决定自身抗体特异性的关键因素，即SLE中的自身抗体表型可能是由不同细胞因子介导的不同形式的SLE的标志物。 将评估该模型的几个预测。 我们将寻找人类“自身抗体表型”，定义为比偶然预测更频繁地一起产生的自身抗体组（目的1）。 例如，抗Sm和抗Ku彼此强烈相关。 我们希望找到更多的例子。 这些表型的频率将在非裔美国人、高加索人和其他SLE队列中确定。 然后我们将确定自身抗体表型是否与某些细胞因子过度产生模式相关（目的2）。 多种细胞因子，其中一些有助于小鼠自身抗体形成，将直接在血液中测量，并通过使用替代标志物间接在受影响的组织中测量。 最后，我们将进行前瞻性研究，以探讨IFN的过度生产，这驱动抗nRNP/Sm自身抗体在小鼠中的生产，增加人类狼疮中自身抗体的子集的发展风险的可能性（目的3）。 我们推测，可能有某些狼疮患者，包括许多非洲裔美国人，谁产生干扰素。 另一组SLE患者，最常见的是高加索人，可能会过度产生一组不同的细胞因子。 这可能有助于解释种族之间的血清学差异。因此，像鼠狼疮，人类SLE可能是几种疾病重叠的临床表现，但不同的发病机制。 如果是这样的话，可能对自身免疫的早期诊断和治疗有重要意义。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Antinuclear antibodies of particular specificities (e.g. anti-DNA, anti-Sm) are highly associated with systemic lupus erythematosus (SLE). Why these specificities are produced in lupus, but not other autoimmune diseases, is unexplained. Similar autoantibodies can be induced in non-autoimmune prone mice by pristane. Preliminary studies strongly implicate IL-4 and the proinflammatory cytokines IL-6, IL-12, and IFN in the formation of different subsets of autoantibodies. Altering the cytokine milieu from Th2 to Th1 can change the autoantibodies produced by a given strain of mouse. Thus, cytokine overproduction may be a key factor determining the autoantibody phenotype. We have found that autoantibody phenotypes in SLE patients also can change. We hypothesize that, as in the mouse, cytokine overproduction may be a critical factor determining autoantibody specificity, i.e. autoantibody phenotypes in SLE may be markers for different forms of SLE mediated by different cytokines. Several predictions of this model will be evaluated. We will look for human "autoantibody phenotypes", defined as groups of autoantibodies produced together more frequently than predicted by chance (Aim 1). For instance, anti-Sm and anti-Ku are strongly associated with one another. We expect to find additional examples. The frequencies of these phenotypes will be determined in African-American, Caucasian, and other SLE cohorts. We will then determine whether the autoantibody phenotypes correlate with certain patterns of cytokine overproduction (Aim 2). A variety of cytokines, some of them contributing to autoantibody formation in mice, will be measured directly in the blood and indirectly in affected tissues through the use of surrogate markers. Finally, we will carry out prospective studies to explore the possibility that the overproduction of IFN , which drives anti-nRNP/Sm autoantibody production in mice, increases the risk of developing a subset of autoantibodies in human lupus (Aim 3). We hypothesize that there may be certain lupus patients, including many African-Americans, who over produce IFN . Another group of SLE patients, most commonly Caucasians, may over produce a different set of cytokines. This may help explain some of the striking serological differences between races. Thus, like murine lupus, human SLE may be several diseases with overlapping clinical manifestations but a different pathogenesis. If so, there could be significant implications for the early diagnosis of autoimmunity and its treatment.