Impact of smoking on immune response and arthritis in humanized mice

描述(由申请人提供)： HLA-DQ8和DRB1*0401分子使人类和转基因小鼠易患关节炎，而DRB1*0402则提供保护。胶原诱导性关节炎(CIA)易感的HLA转基因小鼠产生与患者相似的类风湿因子和抗环瓜氨酸肽抗体(ACPA)。然而，并不是100%遗传DR4的人类和小鼠会患上关节炎，这表明其他遗传和环境因素可能与疾病的沉淀有关。在人类中的流行病学研究表明，吸烟是血清阳性类风湿性关节炎的主要环境危险因素。吸烟被认为会增加存在*0401分子时类风湿关节炎的严重性和关节外特征。然而，吸烟调节免疫反应导致ACPA严重程度增加和产生更多ACPA的机制尚不清楚。临床研究表明，ACPA先于RA的临床症状出现，这表明自身免疫开始的时间比临床疾病的实际发病时间要早得多。已有研究表明，吸烟会增加肺部中的肽基精氨酸脱亚胺酶(PAD)。瓜氨酸化过程需要垫子。这些观察表明，在关节炎中导致自身蛋白瓜氨酸化的免疫反应可能不一定始于滑膜。然而，并没有在所有研究中观察到吸烟的这种影响，这表明吸烟可以通过另一种机制影响免疫反应。吸烟者表现为表达HLA-DR的活化T细胞数量增加，DC功能受到抑制。该模型中提出的转基因小鼠在CD3+T细胞亚群中表达HLAII类分子，这与小鼠不同，但与人类相似。我们使用转基因小鼠进行的初步研究表明，与对照组相比，暴露于香烟烟雾中的DQ8小鼠患关节炎的时间更早，严重程度也更高，尽管这种影响在DR4小鼠中没有观察到。这些研究可能会使在欧洲和美国的人类研究队列中观察到的差异合理化。我们假设，吸烟可能通过调节肺部的免疫反应而增加疾病的严重性，从而导致自身蛋白的呈递，如Vimentin，从而导致自身反应。在这项建议中，我们有两个目标。在目的1中，我们将利用转基因小鼠DRB1*0401、DQ8和DR4/DQ研究吸烟对关节炎发病的影响，以确定MHC基因与环境因素的相互作用。我们将研究T细胞对自身蛋白的反应，Vimentin是类风湿关节炎的自身抗原，以了解吸烟是否会导致对自身蛋白的耐受性下降。在AIM2中，我们将在RA易感和抵抗等位基因与关节炎的背景下，研究吸烟对免疫反应的调节机制。这里描述的模型在性别偏见、自身抗体谱和病理上与人类疾病相似。目前还没有关于人类白细胞抗原基因和环境因素在关节炎中相互作用的动物研究文献。人类研究表明吸烟和关节炎有一定作用，但存在争议，而且由于人类DR和DQ等位基因的连锁，缺乏环境因素与遗传相关的机制。在某些遗传因素的背景下定义环境因素可能会导致更早的干预和教育患者，从而产生更好的生活质量。 公共卫生相关性： 类风湿性关节炎是一种导致关节破坏的致残性疾病。家庭研究表明，遗传因素在患关节炎的易感性中起到了作用。人类研究表明，它是一种多因素疾病，需要遗传和环境因素之间的相互作用。到目前为止，还没有特定的环境因素与关节炎有关。最近的研究表明，吸烟是关节炎的一个危险因素。在这项研究中，我们将使用表达人类关节炎相关基因的小鼠来描述吸烟在关节炎中的作用。这些人源化的小鼠在病理学和自身抗体上模仿类风湿性关节炎。关节炎小鼠产生自身抗体，如类风湿因子和抗环瓜氨酸肽抗体，用于诊断类风湿性关节炎。这些研究将确定某些基因是否会使个人更容易受到吸烟的影响，以便及早进行干预，以避免关节畸形。

DESCRIPTION (provided by applicant): HLA-DQ8 and DRB1*0401 molecules render humans and transgenic mice susceptible to develop arthritis while DRB1*0402 provide protection. Collagen-induced arthritis (CIA) susceptible HLA transgenic mice produce rheumatoid factor and anti-cyclic citrullinated peptide antibodies (ACPA) similar to that in patients.. However, not 100% of humans and mice inheriting DR4 develop arthritis suggesting other genetic and environmental factors that may be involved in precipitation of disease. Epidemiological studies in humans have suggested smoking as a major environmental risk factor for seropositive RA. Smoking has been suggested to increase severity and extra-articular features of RA in the presence of *0401 molecules. However, the mechanism by which smoking modulates immune response leading to increased severity and higher production of ACPA is unknown. Clinical studies have suggested that ACPA precede onset of clinical symptoms of RA suggesting autoimmunity starts much earlier that the actual onset of clinical disease. Smoking has been shown to increase peptidylarginine deiminase (PAD) enzymes in lungs. PADs are required for citrullination process. These observations suggest that immune response that leads to citrullination of self- proteins in arthritis may not necessarily start in synovium. However, this effect of smoking has not been observed in all studies suggesting another mechanism by which smoking can impact immune response. Smokers show an increased number of activated T cells expressing HLA-DR with suppressed function of DCs. The transgenic mice proposed in this model express HLA class II molecules in a subset of CD3+T cells unlike mice but similar to that of humans. Our pilot studies using transgenic mice showed that DQ8 mice develop arthritis with earlier onset and increased severity in mice exposed to cigarette smoke compared to controls, although this effect was not observed in DR4 mice. These studies may rationalize the differences observed in human study cohorts from Europe and USA. We hypothesize that smoking may increase disease severity by modulating immune response in lungs leading to presentation of a self protein like Vimentin ensuing autoreactive response. In this proposal, we have 2 aims. In aim 1 we will study the Impact of smoking on pathogenesis of arthritis using transgenic mice, DRB1*0401, DQ8 and DR4/DQ, to determine interaction between MHC genes and environmental factors. We will study T cell response to self protein, Vimentin an autoantigen in RA, to understand if smoking leads to break in tolerance to self-protein. In aim2,we will study the mechanism of modulation of immune response after exposure to smoking in context of RA susceptible and resistant HLA allele and arthritis. The model described here develops arthritis with similarities to human disease in sex-bias, autoantibody profile and pathology. There are no animal studies in literature on the interaction of HLA genes and environmental factors in arthritis. The human studies suggest a role of smoking and arthritis but are controversial and lack mechanism by which environmental factors associate with genetics due to linkage of DR and DQ alleles in humans. Definition of environmental factors in context of certain genetic factors may lead to earlier intervention and educating patients resulting in a better quality of life. PUBLIC HEALTH RELEVANCE: Rheumatoid arthritis is a disabling disease that leads to joint destruction. Family studies have suggested role of genetic factors in predisposition to develop arthritis. Human studies suggest that it is a multifactorial disease requiring interaction between both genetic and environmental factors. To date there is no specific environmental factor that has been associated with arthritis. Recent studies suggest smoking as a risk factor for arthritis. In this study we will use mice that express human arthritis associated genes to delineate the role of smoking in arthritis. These humanized mice mimic rheumatoid arthritis in pathology and autoantibodies. Arthritic mice produce autoantibodies like rheumatoid factor and anti-cyclic citrullinated peptide antibodies that are used for diagnosis of rheumatoid arthritis. These studies will identify if certain genes make individuals more susceptible to the effects of smoking so that an earlier intervention can be done to avoid joint deformities.