Role of TCRy& T cells in the mucosal response to intestinal infection

描述(由申请人提供)：尽管临床上相关的感染源，如人类免疫缺陷病毒通过肠道粘膜进入，但肠道T细胞对感染的反应仍未得到充分研究。单核细胞增多性李斯特菌(Lm)已被用作研究T细胞反应的模式生物，它的正常感染途径和作为疫苗的一种潜在途径是通过摄入。然而，绝大多数的LM免疫学研究使用口服以外的接种途径。此外，在所使用的细菌菌株中，内源性A蛋白与人E-钙粘附素结合亲和力高，但与小鼠E-钙粘附素结合较差。这种受体-配体配对是LM进入肠上皮细胞所必需的。本文提出的口腔感染研究利用了一种表达与小鼠E-钙粘蛋白具有高亲和力的内源性A蛋白的重组LM。因此，在我们的研究中，我们概括了LM的生理路线和切入点。我们的初步研究显示，粘膜TCRgd T细胞对口服LM感染有显著的反应，其动力学模拟适应性T细胞反应。最重要的是，这种表型和功能不同的粘膜TCRgd T细胞亚群可以长期保留，并在受到挑战时进行召回反应。在这项建议中要检验的假设是，这种假定的记忆TCRgd T细胞的特殊亚群对于防止LM感染是重要的，并调节长期保护性CDB TCRA反应。这一假设将在以下具体目标中得到验证：目的1.测试TCRgd的一个子集是否代表真正的粘膜记忆细胞。将对原发和继发的TCRgd细胞对口腔LM感染的反应进行详细的动力学、表型和功能分析。目的2.确定肺炎衣原体感染对粘膜TCRgd激活的要求。在这里，我们将测试树突状细胞、共刺激和细胞因子在提高原发和继发TCRgd细胞反应中的作用。目的3.观察口腔粘膜TCRgd细胞对Lm感染的反应。口腔感染系统提供了一个特殊的机会来检查粘膜TCRgd细胞反应的解剖。

DESCRIPTION (provided by applicant): Despite the fact that clinically relevant infectious agents such as human immunodeficiency virus enter through the intestinal mucosa, the intestinal T cell response to infection remains understudied. Listeria monocytogenes (LM) has been used as a model organism for studying T cell responses and the normal route of infection for LM and a potential route for use of LM as a vaccine is through ingestion. Nevertheless, the vast majority of LM immunological studies utilize inoculation routes other than oral. Moreover in the bacterial strains used, the internalin A protein binds human E-cadherin with high affinity but poorly binds mouse E-cadherin. This receptor-ligand pairing is required for entry of LM into intestinal epithelial cells. The oral infection studies proposed here utilize a recombinant LM that expresses an internalin A protein with high affinity for mouse E-cadherin. Thus, the physiologic route and entry point of LM is recapitulated in our studies. Our preliminary studies revealed a remarkable mucosal TCRgd T cell response to oral LM infection, whose kinetics mimic an adaptive T cell response. Most importantly, this phenotypically and functionally distinct subset of mucosal TCRgd T cells are retained long-term and undergo a recall response upon challenge. The hypothesis to be tested in this proposal is that this specialized subset of putative memory TCRgd T cells is important for protection against LM infection and also regulates the long-term protective CDB TCRa¿ response. This hypothesis will be tested in the following specific aims: Aim 1. To test whether a subset of TCRgd represent bona fide mucosal memory cells. A detailed kinetic, phenotypic and functional analysis of the primary and secondary TCRgd cell response to oral LM infection will be undertaken. Aim 2. To determine the requirements for mucosal TCRgd activation in response to LM infection. Here we will test the role of dendritic cells, costimulation and cytokines in mounting primary and secondary TCRgd cell responses. Aim 3. To visualize the mucosal TCRgd cell response to oral LM infection. The oral infection system provides an exceptional opportunity to examine the anatomy of the mucosal TCRgd cell response.