Normal And Pathologic Mechanisms Of Inflammation, Innate

该计划的研究重点是宿主动员和调节细胞炎症反应以防御外来抗原和感染性病原体的基本机制。在多学科的方法中，整合素粘附，趋化性，信号传导，介体合成和凋亡的机制在体外进行了探索，并扩展到实验动物模型（基因敲除和转基因小鼠）进行体内分析。此外，在细胞、分子和生物化学水平上探讨了人类慢性炎症性疾病对创伤、肿瘤、感染性病原体或未知病因的反应。了解控制正常免疫细胞募集、激活和/或缺失以及向发病机制转变的机制，是我们长期开发调节慢性致病性炎症性疾病策略的基础。在实验动物模型中，除了DNA微阵列和蛋白质组学分析之外，我们还通过表型、功能和形态学参数表征了免疫病理学，以确定治疗干预的靶点。对涉及CD 4 + CD 25+调节性T细胞、TGF-β、IL-17和SLPI的免疫功能调节的新认识提高了控制免疫耐受、哮喘、自身免疫和肿瘤免疫的新方法的前景。 分泌性白细胞蛋白酶抑制剂-一种天然免疫调节分子： 宿主对细胞内病原体的有效防御依赖于先天性和适应性免疫应答的激活，以遏制或消除感染性微生物。同样重要的是终止旺盛反应以恢复免疫系统内稳态的调节机制。SLPI是一种有效的丝氨酸蛋白酶抑制剂，具有抗微生物和抗炎功能，存在于与口腔、鼻腔、呼吸道和生殖道粘膜表面相关的液体中。此外，SLPI由小鼠巨噬细胞产生，但也通过抑制NF κ B依赖性信号传导途径抑制巨噬细胞活化。SLPI的组合？的杀微生物活性和对病原体介导的免疫应答的抑制活性暗示了该分子在先天宿主防御中的作用，并且SLPI敲除小鼠提供了探索SLPI在炎症应答和宿主防御中的体内作用的模型。使用屋尘螨诱导的粘膜哮喘模型，发现SLPI对过敏原诱导的气道高反应性的发展具有保护作用，并且SLPI消融后疾病加重。为了确定SLPI如何参与防御感染性病原体，在皮肤利什曼病模型中用细菌（肺炎链球菌、金黄色葡萄球菌）或细胞内寄生虫主要利什曼原虫感染SLPI无效和野生型小鼠。与C57 B1/6 SLPI野生型同窝出生的小鼠相反，其在L.主要接种后，SLPI无效小鼠的慢性感染加重，病变大小和寄生虫数量增加，导致寄生虫的全身传播。尽管SLPI野生型小鼠中病变的自发愈合涉及Th 1-显性细胞因子应答，但SLPI缺失小鼠中升高的抑制性Th 2细胞因子IL-4、IL-10和TGF-β可能导致宿主应答失败，尽管IFN-γ水平持续升高。类似地，在细菌感染中，SLPI的消融与夸大但无效的免疫应答相关。这些研究强调了SLPI在感染性疾病中的保护作用，并揭示了其作为治疗炎症和感染性疾病的治疗剂的潜力。 TGF-β和调节性T细胞在控制感染性、免疫性和肿瘤性疾病中的作用： 除了可诱导/适应性Tr 1和Th 3细胞之外，天然存在的和可诱导的调节性T细胞（Treg）在控制对自身和非自身抗原的免疫应答中是基本的。Treg以CD 4、CD 25、GITR、CTLA-4、TGF-β和TGF-β受体II型的膜表达为特征，所有这些都有助于其独特的功能库，Treg特异性表达转录因子Foxp 3。我们以前已经表明，这些细胞在体外产生和过继转移到实验动物与免疫介导的粘膜病理减轻疾病的症状。最近的证据也暗示Treg控制先天免疫应答，包括抑制自然杀伤（NK）细胞。同样明显的是，虽然Treg的增加在自身免疫和抗原驱动的病理中是有益的，其中数量不足是贡献的，但是这些细胞的过度表达也可能是有害的，特别是在感染性和肿瘤性疾病中。在这方面，我们已经确定了TGF-β在浸润肿瘤组织的细胞中的高水平表达，以及与这些肿瘤相关的Foxp 3+细胞的丰度。这些Treg可能导致免疫监视无法检测和/或消除此类肿瘤，并可能成为促进免疫介导的肿瘤治疗的潜在靶点。新的证据表明，TGF-β为辅助性T淋巴细胞17（Th 17）谱系定型提供了独特和必要的触发因素。产生Th 17的细胞在修饰先天途径和自身免疫性疾病的演变中起作用，将TGF-β与免疫应答的诱导和抑制联系起来。

Research in this program is focused on the basic mechanisms by which the host mobilizes and modulates cellular inflammatory reactions in defense against foreign antigens and infectious pathogens. In a multi-disciplinary approach, mechanisms of integrin adhesion, chemotaxis, signaling, mediator synthesis and apoptosis are explored in vitro and extended into experimental animal models (knockout and transgenic mice) for in vivo analysis. In addition, human conditions of chronic inflammatory disease in response to trauma, tumors, infectious pathogens, or of unknown etiology are explored at the cellular, molecular and biochemical levels. Understanding the mechanisms, which control normal immune cell recruitment, activation and/or deletion and the switch to pathogenesis, underlies our longterm development of strategies for modulating chronic pathogenic inflammatory diseases. In experimental animal models, we have characterized immunopathology through phenotypic, functional and morphologic parameters, in addition to DNA microarrays and proteomic analyses, to identify targets for therapeutic intervention. New insights into the regulation of immune function involving CD4+CD25+ regulatory T cells, TGF-beta, IL-17 and SLPI raise the prospect of novel approaches to controlling immunological tolerance, asthma, autoimmunity, and tumor immunity. Secretory Leukocyte Protease Inhibitor - an Innate Immunomodulatory Molecule: Effective host defense against intracellular pathogens relies upon activation of both innate and adaptive immune responses to contain or eliminate the infectious microbe. Equally important are regulatory mechanisms to terminate exuberant responses to restore homeostasis in the immune system. SLPI is a potent serine protease inhibitor with both anti-microbial and anti-inflammatory functions and is found in fluids associated with mucosal surfaces of the oral, nasal, respiratory, and reproductive tracts. Furthermore, SLPI is produced by mouse macrophages but also inhibits macrophage activation by suppressing NFkB-dependent signaling pathways. The combination of SLPI?s microbicidal activity and suppressive activity on pathogen-mediated immune responses implicate this molecule in innate host defense and the SLPI null mouse provides a model to explore the in vivo role for SLPI in inflammatory responses and host defense. Using a model of house dust mite-induced mucosal asthma, SLPI was found to be protective from development of allergen-induced airway hyperreactivity and disease was exacerbated following ablation of SLPI. To determine how SLPI participates in defense against infectious pathogens, SLPI null and wildtype mice were infected with bacteria (Streptococcus pneumoniae, Staphylococcus aureus) or an intracellular parasite Leishmania major in a model of cutaneous leishmaniasis. In contrast to C57Bl/6 SLPI wildtype littermates which develop self-healing skin lesions at the site of L. major inoculation, SLPI null mice an exacerbated chronic infection with increased lesion size and parasite numbers that result in systemic spread of parasites. Whereas spontaneous healing of lesions in SLPI wildtype mice involves a Th1-dominant cytokine response, elevated suppressive Th2 cytokines IL-4, IL-10 and TGF-beta in SLPI null mice likely contribute to the failed host response, despite persistently elevated levels of IFN-g. Similarly, in bacterial infections, ablation of SLPI is associated with exaggerated, but ineffective immune responses. These studies highlight a protective role for SLPI in infectious diseases and reveal its potential as a therapeutic agent for the treatment of inflammatory and infectious disease. TGF-beta and regulatory T cells in the control of infectious, immune and neoplastic diseases: Naturally occurring and inducible regulatory T cells (Treg), in addition to inducible/adaptive Tr1 and Th3 cells, are fundamental in the control of immune responsiveness to self and nonself antigens. Characterized by membrane expression of CD4, CD25, GITR, CTLA-4, TGF-beta and TGF-beta receptor type II, all of which contribute to their unique functional repertoire, Treg specifically express the transcription factor Foxp3. We have previously shown that generation of these cells in vitro and adoptive transfer into experimental animals with immune-mediated mucosal pathology alleviates the symptoms of disease. Recent evidence also implicates Treg in control of innate immune responses, including suppression of natural killer (NK) cells. It is also evident that whereas an increase in Treg is beneficial in autoimmune and antigen-driven pathologies where insufficient numbers are contributory, an over-representation of these cells can also be detrimental, especially evident in infectious and neoplastic diseases. In this regard, we have identified a high level of expression of TGF-beta in cells infiltrating tumor tissues, in addition to an abundance of Foxp3+ cells in association with these tumors. These Treg may contribute to the failure of immune surveillance to detect and/or eliminate such tumors and be a potential target in promoting immune-mediated tumor therapy. New evidence reveals that TGF-beta provides a unique and essential trigger for T helper lymphocyte 17 (Th17) lineage commitment. Th17 generating cells are instrumental in embellishing innate pathways and in the evolution of autoimmune disease, linking TGF-beta with both induction and suppression of an immune response.