The emerging role of the TIM molecules in transplantation.

Since their discovery in 2001, the T cell immunoglobulin mucin (TIM) family members have been shown to play important roles in the regulation of immune responses. The TIM family comprises of eight genes in the mouse, three of which are conserved in humans (TIM-1, TIM-3 and TIM-4). Initially, TIM-1 and TIM-3 were thought to be expressed solely on T cells. However, emerging data suggest a much broader expression pattern where their presence on APCs confers differing functions, including the ability to mediate phagocytosis. In contrast, TIM-4 is exclusively expressed on APCs. Together, the TIM molecules provide a functional repertoire for determining the fate of T cell activation and differentiation. To date, much of the knowledge about the TIM family members has been garnered from models of asthma, allergy and autoimmunity. More recently, data from experimental models of transplantation demonstrate that TIM family members are also key in alloimmunity. This review will serve to highlight the emerging data regarding this unique family of molecules, and to identify their potential in transplantation tolerance.

自2001年被发现以来，T细胞免疫球蛋白黏蛋白（TIM）家族成员已被证明在免疫应答的调节中发挥重要作用。在小鼠中，TIM家族包含8个基因，其中3个在人类中是保守的（TIM - 1、TIM - 3和TIM - 4）。最初，人们认为TIM - 1和TIM - 3仅在T细胞上表达。然而，新出现的数据表明其表达模式更为广泛，它们在抗原呈递细胞（APCs）上的存在具有不同的功能，包括介导吞噬作用的能力。相比之下，TIM - 4仅在抗原呈递细胞上表达。总之，TIM分子为决定T细胞活化和分化的命运提供了一个功能库。到目前为止，关于TIM家族成员的大部分知识是从哮喘、过敏和自身免疫模型中获得的。最近，来自移植实验模型的数据表明，TIM家族成员在同种免疫中也很关键。本综述将着重介绍有关这一独特分子家族的新数据，并确定它们在移植耐受中的潜力。