Natural Killer T Cell Modulation of Cutaneous Wound Healing

描述（由申请人提供）：自然杀伤T细胞（NKT）是先天淋巴细胞，可识别mhc - i样分子CD1d中的糖脂抗原。迄今为止，已确定的NKT细胞的生理作用主要局限于自身免疫、癌症、免疫耐受和最近的抗微生物免疫领域的免疫调节。通过导致这种应用的实验，我们发现NKT细胞在皮肤伤口愈合过程中起着核心作用。使用两种不同的小鼠伤口愈合模型（烫伤烧伤和切除伤口），两种不同的NKT细胞缺陷小鼠，以及全身阻断NKT细胞激活，我们观察到NKT细胞似乎调节了早期伤口愈合过程的关键方面。当NKT细胞基因缺失或其激活被系统性阻断时，皮肤伤口在损伤后早期（0-3天）表现出特定亚群细胞因子（TNF1、TGF21）、中性粒细胞和单核巨噬细胞化学引诱剂（MIP-2、KC、MIP-11、MIP-12）的差异表达。最引人注目的是，当NKT细胞缺失或其激活被阻断时，皮肤伤口愈合得更快。由于迄今为止尚未描述NKT细胞在皮肤伤口愈合中的作用，这项为期两年的R21探索性应用的目的是表征/确认NKT细胞在伤口愈合中的作用，并测试NKT细胞通过调节早期炎症信号调节伤口修复的假设。提出了两个目标，以扩大我们的初步调查结果。第一个目的是通过比较NKT细胞缺陷小鼠和用NKT细胞重组的NKT细胞缺陷小鼠的关键伤口愈合参数（伤口闭合、再上皮化、再血管化、炎症细胞浸润）的动力学和大小来证实NKT细胞调节伤口愈合。对NKT细胞活化的要求将通过分析用阻断NKT细胞活化的抗体处理的小鼠的动力学和相同关键参数的大小来确认。第二个目标将使用免疫荧光显微镜和分子生物学技术的结合来1)确认NKT细胞是否以及何时浸润愈合伤口，2)确定NKT细胞是否调节中性粒细胞和单核巨噬细胞的浸润，以及3)确定NKT细胞是否调节对伤口修复启动至关重要的炎症介质的动力学或大小。基于我们的初步发现，我们预计这一探索性应用将为理解NKT细胞调节伤口愈合过程的机制提供基础，并为治疗异常伤口愈合提供潜在的新途径，如烧伤、糖尿病、牛皮癣和瘢痕疙瘩的治疗方法。

DESCRIPTION (provided by applicant): Natural Killer T (NKT) cells are innate lymphocytes that recognize glycolipid antigens in the context of the MHC-I-like molecule, CD1d. To date, the physiologic roles identified for NKT cells have been limited to immunoregulation primarily in the fields of autoimmunity, cancer, immunologic tolerance, and more recently anti-microbial immunity. Through experiments that led to this application, we discovered that NKT cells play a central role in the cutaneous wound healing process. Using two different mouse models of wound healing (scald burns and excisional wounds), two different strains of NKT cell deficient mice, and systemic blockade of NKT cell activation, we observed that NKT cells appear to regulate key aspects of the early wound healing process. When NKT cells were either genetically absent or their activation was blocked systemically, cutaneous wounds exhibited differential expression of a select subset of cytokines (TNF1, TGF21) and neutrophil and monocyte-macrophage chemoattractants (MIP-2, KC, MIP-11, MIP-12) early (0-3 days) after injury. Most strikingly, when NKT cells were absent or their activation was blocked, cutaneous wounds closed more quickly. Since a role for NKT cells in dermal wound healing has not been described to date, the purpose of this two year R21 exploratory application is to characterize / confirm the role of NKT cells in wound healing and to test the hypothesis that NKT cells regulate wound repair via modulation of early inflammatory signals. Two aims are proposed that will expand upon our preliminary findings. The first aim will confirm that NKT cells regulate wound healing by comparing the kinetics and magnitude of key wound healing parameters (wound closure, re-epithelialization, re-vascularization, inflammatory cell infiltrate) in NKT cell deficient mice vs. NKT deficient mice that are re-constituted with NKT cells. The requirement for NKT cell activation will be comfirmed via analysis of the kinetics and magnitude of the same key parameters in mice that are treated with an antibody that blocks NKT cell activation. The second aim will use a combination of immunofluorescence microscopy and molecular biologic techniques to 1) confirm if and when NKT cells infiltrate healing wounds, 2) determine whether NKT cells regulate the infiltration of neutrophils and monocyte-macrophages, and 3) determine whether NKT cells regulate either the kinetics or magnitude of inflammatory mediators critical to the intiation of wound repair. Based on our preliminary findings, we anticipate that this exploratory application will provide the basis for understanding the mechanisms by which NKT cells regulate the wound healing process and provide potential new avenues of investigation for therapeutic approaches to aberrant wound healing, such as what occurs with burns, diabetes, psoriasis, and keloids.