Allograft tolerance is the ultimate goal of organ transplantation. Current strategies for tolerance induction mainly focus on inhibiting alloreactive T cells while promoting regulatory immune cells. Pathogenic infections may have direct impact on both effector and regulatory cell populations, therefore can alter host susceptibility to transplantation tolerance induction as well as impair the quality and stability of tolerance once induced. In this review, we will discuss existing data demonstrating the effect of infections on transplantation tolerance, with particular emphasis on the role of the stage of infection (acute, chronic, or latent) and the stage of tolerance (induction or maintenance) in this infection-tolerance interaction. While the deleterious effect of acute infection on tolerance is mainly driven by proinflammatory cytokines induced shortly after the infection, chronic infection may generate exhausted T cells that could in fact facilitate transplantation tolerance. In addition to pathogenic infections, commensal intestinal microbiota also has numerous significant immunomodulatory effects that can shape the host alloimmunity following transplantation. A comprehensive understanding of these mechanisms is crucial for the development of therapeutic strategies for robustly inducing and stably maintaining transplantation tolerance while preserving host anti-pathogen immunity in clinically relevant scenarios.

中文翻译：

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感染对移植耐受的影响。

同种异体移植耐受是器官移植的最终目标。目前诱导耐受的策略主要集中在抑制同种反应性 T 细胞，同时促进调节性免疫细胞。病原体感染可能对效应细胞和调节细胞群产生直接影响，因此可以改变宿主对移植耐受诱导的敏感性，并损害诱导后耐受的质量和稳定性。在这篇综述中，我们将讨论证明感染对移植耐受性影响的现有数据，特别强调感染阶段（急性、慢性或潜伏）和耐受阶段（诱导或维持）在此感染中的作用- 容忍相互作用。虽然急性感染对耐受性的有害影响主要是由感染后不久诱导的促炎细胞因子驱动的，但慢性感染可能会产生耗尽的 T 细胞，这实际上可以促进移植耐受。除了致病性感染外，共生肠道微生物群还具有许多显着的免疫调节作用，可以在移植后塑造宿主的同种免疫。全面了解这些机制对于制定治疗策略至关重要，以强有力地诱导和稳定维持移植耐受，同时在临床相关情况下保留宿主抗病原体免疫力。