The role for Notch signaling in inflammatory responses in infectious disease

描述(申请人提供)：巴西利什曼原虫感染可导致炎症性临床形式的疾病，皮肤(CL)和粘膜利什曼病(ML)。这些人的外周血单核细胞(PBMC)分泌高水平的干扰素-γ和肿瘤坏死因子-α，以及低水平的IL-10，以响应可溶的利什曼原虫。这些患者的皮损以单核细胞浸润为主，几乎未见寄生虫。尽管寄生虫的增殖得到了控制，但免疫病理仍在继续，并试图在体外使用重组IL-10或抗IL-12和抗IL-15的单抗来调节炎症，但未能下调这些患者PBMC产生的干扰素-γ，提示另一种免疫反应调节机制可能参与了CL和ML的发病。Notch信号在淋巴细胞分化、增殖和细胞因子产生中的作用已有报道。Notch配体Delta4在树突状细胞(DCs)中的表达可以协调Th1细胞的分化，最近的研究表明，Toll样受体配体诱导的DC和单核细胞的激活也依赖于Notch信号。我们的初步数据显示，用伽马分泌酶抑制剂阻断Notch信号可以减少利什曼原虫抗原诱导的CL患者干扰素-伽马的产生。此外，我们的数据显示，人单核细胞分化为CD16+(促炎单核细胞)依赖于伽马分泌酶的活性。在目前的提案中，我们试图确定参与Notch信号转导的分子(Delta和锯齿状)，这些分子参与CL和ML患者炎症反应的产生和维持。患者和对照组将从巴西东北部佩德拉岛的巴西乳杆菌传播流行区招募。在这个流行地区，每年平均发生1000例CL和40例ML，我们小组在这个地点进行临床和免疫学研究近30年。在佩德拉角的地方性疫区，我们还发现15%的人群皮肤试验利什曼原阳性，没有症状或病史。这些人已知患有亚临床巴西乳杆菌感染，并将与未感染的人一起组成我们将为研究招募的对照人员。在这些研究结束后，我们应该已经从Notch信号中确定了在CL和ML的炎症反应中起作用的分子。

DESCRIPTION (provided by applicant): Leishmania braziliensis infection can lead to the inflammatory clinical forms of disease, cutaneous (CL) and mucosal leishmaniasis (ML). Peripheral blood mononuclear cells (PBMC) from these individuals secrete high levels of IFN-gamma and TNF-alpha and low levels of IL-10 in response to soluble Leishmania antigen. Lesions of these patients are composed by mononuclear cells infiltrate and very few parasites are observed. Despite the control of parasite multiplication, the immunopathology persists and attempt to modulate inflammatory in-vitro using recombinant IL-10 or monoclonal antibodies anti- IL-12 and anti-IL-15 failed to down-regulate IFN-gamma production in PBMC from these patients, suggesting that another mechanism of regulation of immune response might contribute to pathogenesis of CL and ML. A role of Notch signaling in lymphocyte differentiation, proliferation and cytokine production has been reported. Expression of the Notch ligand, Delta4 in dendritic cells (DCs) was shown to orchestrate differentiation of Th1 cells and, recently, it has been shown that toll like receptor ligand-induced DC and monocytes activation is also dependent upon Notch signaling. Our preliminary data shows that disruption of Notch signaling using gamma secretase inhibitor can decrease Leishmania antigen- induced IFN-gamma production in patients with CL. Also, our data shows that differentiation of human monocytes into CD16+ (pro-inflammatory monocytes) is dependent on gamma secretase activity. In the present proposal we seek to identify the molecules that participate in the Notch signaling (Delta and Jagged) that are involved in the generation and maintenance of inflammatory responses in CL and ML individuals. The patients and controls will be recruited from the L. braziliensis transmission endemic area of Corte de Pedra, Northeastern Brazil. In this endemic area an average of 1000 CL cases and 40 ML cases occurs per year, and our group has been performing clinical and immunological studies in this site for almost three decades. In the endemic are of Corte de Pedra we also found that 15% of the population has positive skin test for Leishmania antigen without symptoms or history of disease. These individuals are known to have sub-clinical L. braziliensis infection and, together with uninfected individuals, will compose the controls we will recruit for our studies. After the conclusion of these studies we should have identified the molecules from Notch signaling that contributes from inflammatory response in CL and ML.