光动力疗法对活化T细胞行为调控及效应机制研究

T cell mediated autoimmune disease is a kind of diseases which has serious hazard to human health. Self reactive T cell is the key factor of these diseases.How to selective removal of activated t cells without damage the resting t cells is still remains unsolved clinical problems.Photodynamic therapy (PDT) has dual selectivity in that the diseased tissue can preferentially take up photosensitizer(PS) and PS activation can be confined to the diseased tissue by restricting the illumination to a specific region.Preliminary study suggests that PDT can selectively kill the activated T cells, suggesting the potential application in autoimmune diseases. But the difference sensitivity of activation t cell and resting t cell to PDT is absolute or only at certain conditoin is still controversial.Furthermore, the causes of the difference sensitivity of these two kinds of t cell to PDT and the destruction mechanism is still not clear. This study is based on specific photosensitizer HMME to clarify the difference sensitivity of activation t cell and resting t cell to PDT is absolute or only at certain conditoin. Then comparison the absorption and subcellular distribution of activation t cell and resting t cell to HMME, and the activation, proliferation and cytokine secretion of resting t cell after PDT, at the sametime, proteomics is apply to study the effect mechanism of PDT on activation t cell and resting t cell. The aim of this study is to reveal the effect of PDT on activation and resting t cell, the differece sensitivity of these two kinds of t cells to PDT, as well as the possible mechanism.

T细胞介导的自身免疫性疾病是一大类严重危害人类身体健康的疾病，异常活化的自身反应性T细胞是导致疾病发生、发展的关键，也是治疗的靶点。上述疾病的治疗非常棘手，突出的难点是治疗的靶向性及选择性（靶向性去除病变的活化T细胞而保留正常静止T细胞及其功能）。光动力疗法（PDT）集高选择性及靶向性等优点于一体，初步研究显示PDT能选择性杀伤活化T细胞，提示其在自身免疫性疾病中的应用潜能。但目前就PDT对两种不同状态T细胞的杀伤差异是绝对存在还是只存于特定范围尚存在争议，且导致杀伤差异的原因及杀伤机制不清，有待于进一步明确。本项目在明确PDT对活化和静止T细胞的杀伤差异绝对存在还是只存于特定范围的基础上，通过比较光敏剂在两种细胞内吸收和亚细胞分布特点，PDT作用静止T细胞活化、增殖等功能的变化，并将蛋白组学引入光动力效应机制的研究，旨在为PDT在T细胞介导的自身免疫性疾病中的应用提供理论依据。

T细胞介导的自身免疫性疾病是一大类严重危害人类身体健康的疾病，异常活化的自身反应性T细胞是导致疾病发生、发展的关键，也是治疗的靶点。上述疾病的治疗非常棘手，突出的难点是治疗的靶向性及选择性（靶向性去除病变的活化T细胞而保留正常静止T细胞及其功能）。光动力疗法（PDT）集高选择性及靶向性等优点于一体，初步研究显示 PDT能选择性杀伤活化T细胞，提示其在自身免疫性疾病中的应用潜能。但目前就PDT对两种不同状态T细胞的杀伤差异是绝对存在还是只存于特定范围尚存在争议，且导致杀伤差异的原因及杀伤机制不清，有待于进一步明确。.本课题主要的研究内容如下：（1）静止T细胞和活化T细胞对光敏剂HMME的吸收动力学研究；（2）HMME在静止T细胞和活化T细胞的亚细胞分布特点；（3）PDT对活化和静止T细胞的杀伤剂量学研究：（4）PDT对活化和静止T细胞效应机制研究。本课题已完成了计划的全部研究内容。获得的重要结果如下：活化和静止T细胞对光敏剂HMME的吸收量的差别取决于其与HMME的孵育浓度和孵育时间，在一定孵育浓度和孵育时间范围内，活化T细胞HMME的吸收量明显高于静止T细胞。在一定的HMME孵育浓度范围内，HMME-PDT对活化和静止T细胞的杀伤具有选择性，两种细胞的存活率存在显著差异，该研究结果的发现有助于形成选择性删除活化T细胞的剂量关联和时间关联的HMME-PDT治疗窗口，在对活化和静止T细胞实现选择性杀伤的PDT治疗参数下，正常静止T细胞能够保留其正常的免疫功能。此外，对HMME-PDT杀伤机制的研究还提示，HMME-PDT对活化T细胞的杀伤可能通过诱导活化T细胞凋亡来实现。而蛋白组学的研究进一步提示：与细胞凋亡、细胞骨架、损伤等相关的多种蛋白质均参与PDT损伤机制。本课题的研究结果对于未来将PDT用于T细胞介导的自身免疫性疾病中的应用提供了初步的理论依据。