SALIVARY IGA RESPONSES--REGULATION BY T CELLS

描述（改编自申请人的摘要）：这是竞争性的 更新RO 1补助金，检查粘膜免疫反应， 负责伊加B细胞应答的诱导和调节。 的 工作集中在鼠口腔/鼻腔（例如，下颌下腺， SMG）。 以前的工作表明，Th 2细胞来源的IL-5和IL-6是 对于诱导sIgA阳性B细胞分化特别重要 分泌伊加的浆细胞，以及这些细胞因子的高水平mRNA 以及IFN-γ，研究者报告SMG α β (ab)TCR CD 4阳性T细胞。 目前的申请建议审查 γ δ（gd）T细胞在粘膜免疫应答中的作用。 这 方向是基于这样的事实，即已知gd T细胞定位于 在粘膜部位，它们占IEL的约50%， 研究人员发现，大约20%的 SMG中的T细胞是gd T细胞。 调查人员表示， ELISPOT法检测SMG中优势IG产生细胞为伊加 表明SMG是伊加效应组织，如肠LP。 的 SMG gd T细胞包括IL-4和IL-5产生细胞，但不包括IL-4 生产商 此外，调查人员发现，在最近完成的 gd缺陷（基因敲除）小鼠具有受损的粘膜伊加应答。 除了粘膜免疫系统在产生 sIgA，粘膜诱导的耐受是一种重要的现象，其中口服 施用的抗原可产生粘膜IgA应答，但全身性IgA应答可产生粘膜IgA应答。 低反应性 研究人员已经表明，来自 口服耐受小鼠的肠上皮可以消除 gd T细胞过继转移后的抗原特异性无应答性。 其他人的研究表明，gd T细胞可以下调IgE 口服抗原后的反应。 调查人员建议 gd T细胞可能在粘膜伊加和E 通过细胞因子的产生和 与ab T细胞的相互作用。 在第一个目标中，SMG单核细胞将 通过ELISPOT测定法检测gd缺陷和 一般野生型小鼠和特异性粘膜免疫后， TT. 在ab缺陷小鼠中的类似分析将提供证据， gd T细胞可以直接支持伊加的产生，或者更确切地说，表明它们 主要通过激活ab T细胞发挥作用。 过继转移 实验将证实对ab T细胞的需要，并支持这一观点， gd T细胞的调节作用可以在ab T细胞上介导。 在Aim中 2、gd T细胞作为CD 4 + ab T细胞调节因子在CD 4 + ab T细胞中的作用 将在双室或共培养中直接分析产生伊加 体外实验和T细胞转移实验补充， 体内TCR敲除小鼠。 目标3通过以下方式解决表达和功能 SMG gd T细胞的细胞表面分子B71/2可能介导直接 与ab T细胞的相互作用决定了它们的细胞因子谱。 目标4 检查鼻内免疫产生粘膜伊加应答的模型 沿着系统性（即，血清和脾）低反应性，即， 鼻腔耐受性 然后将gd缺陷小鼠与野生型小鼠进行比较 为了进一步证明gd T细胞在维持粘膜免疫中的作用， 在全身性低反应性和鼻用gd T 来自耐受小鼠的细胞将用于确定它们是否可以逆转 来自类似耐受的小鼠的脾（全身）ab T细胞的低反应性 动物 在目的5中，研究了IL-7在肿瘤发生和增殖中的作用。 将在IL-7缺陷或IL-7 R缺陷小鼠中测定SMG gd T细胞， 由于IL-7最近被证明是GD亚群生长因子 表达其受体的T细胞。

DESCRIPTION (Adapted from the Applicant's abstract): This is the competing renewal of an RO1 grant examining the mucosal immune response that is responsible for the induction and regulation of IgA B-cell responses. The work focuses on the murine oral/nasal cavity (e.g., submandibular gland, SMG). Previous work has shown that Th2 cell derived IL-5 and IL-6 are of particular importance for inducing sIgA positive B cells to differentiate into IgA producing plasma cells, and high levels of mRNA for these cytokines as well as IFN-gamma were reported by the investigator from SMG alpha beta (ab) TCR CD4 positive T cells. The current application proposes to examine the role of gamma delta (gd) T cells in mucosal immune responses. This direction is based on the fact that gd T cells are known to be localized to mucosal sites where they constitute approximately 50 percent of IEL in the intestine, and the investigator has found that approximately 20 percent of the T cells in the SMG are gd T cells. The investigator has shown by ELISPOT assay that the dominant Ig producing cells in SMG were IgA indicating that SMG are an IgA effector tissue, like the intestinal LP. The SMG gd T cells included IL-4 and IL-5 producing cells but not IL-4 producers. Moreover, the investigator has found in very recently completed work that gd deficient (knock out) mice have impaired mucosal IgA responses. Besides the clear role for the mucosal immune system in the production of sIgA, mucosally induced tolerance is an important phenomenon in which orally administered antigens may produce mucosal IgA responses but systemic hyporesponsiveness. The investigator has shown that mucosal gd T cells from the intestinal epithelium of orally tolerized mice can abrogate antigen-specific unresponsiveness upon adoptive transfer of gd T cells. Studies from others have shown that gd T cells can down regulate IgE responses after orally administered antigens. The investigator proposes that gd T cells may play an important regulatory role in mucosal IgA and E responses at mucosal sites through cytokine production and through interactions with ab T cells. In the first aim, SMG mononuclear cells will be examined by ELISPOT assay for IgA producing cells in gd deficient and wild type mice in general and following specific mucosal immunization with TT. Similar analyses in ab deficient mice will provide evidence for whether gd T cells can support IgA production directly, or rather suggest that they act primarily through the activation of ab T cells. Adoptive transfer experiments will confirm the need for ab T cells and support the idea that the regulatory role of gd T cells may be mediated upon ab T cells. In Aim 2, the effects of gd T cells as regulators of CD4 positive ab T cells in producing IgA will be analyzed directly in double chamber or in co-culture experiments in vitro and complemented by T cell transfer experiments using TCR knockout mice in vivo. Aim 3 addresses the expression and function by SMG gd T cells of cell surface molecules B71/2 that may mediate direct interactions with ab T cells that determine their cytokine profiles. Aim 4 examines a model of intranasal immunization to produce mucosal IgA responses along with systemic (i.e., serum and spleen) hyporesponsiveness, that is, nasal tolerance. Then gd deficient versus wild type mice will be compared to further demonstrate the role of gd T cells in maintaining mucosal responses in the setting of systemic hyporesponsiveness, and nasal gd T cells from tolerized mice will be used to determine if they can reverse the hyporesponsiveness of spleen (systemic) ab T cells from similarly tolerized animals. In Aim 5, the role of IL-7 in the development and proliferation of SMG gd T cells will be determined in IL-7 deficient or IL-7R deficient mice, since IL-7 has recently been shown to be a growth factor for a subset of gd T cells that express its receptor.