The ability of the immune system to discriminate self from non-self is essential for eradicating microbial pathogens but is also responsible for allograft rejection. Whether it is possible to selectively suppress alloresponses while maintaining anti-pathogen immunity remains unknown. We found that mice deficient in coronin 1, a regulator of naive T cell homeostasis, fully retained allografts while maintaining T cell-specific responses against microbial pathogens. Mechanistically, coronin 1-deficiency increased cyclic adenosine monophosphate (cAMP) concentrations to suppress allo-specific T cell responses. Costimulation induced on microbe-infected antigen presenting cells was able to overcome cAMP-mediated immunosuppression to maintain anti-pathogen immunity. In vivo pharmacological modulation of this pathway or a prior transfer of coronin 1-deficient T cells actively suppressed allograft rejection. These results define a coronin 1-dependent regulatory axis in T cells important for allograft rejection and suggest that modulation of this pathway may be a promising approach to achieve long-term acceptance of mismatched allografts.

免疫系统将自己与非自己区分开的能力对于根除微生物病原体至关重要，但也对同种异体移植排斥产生影响。能否在维持抗病原体免疫力的同时选择性抑制过敏反应尚不清楚。我们发现缺乏日冕T细胞稳态调节因子coronin 1的小鼠完全保留了同种异体移植物，同时保持了针对微生物病原体的T细胞特异性应答。从机理上讲，冠状蛋白1缺乏症会增加单磷酸环腺苷（cAMP）的浓度，从而抑制同种异体T细胞反应。在微生物感染的抗原呈递细胞上诱导的共刺激能够克服cAMP介导的免疫抑制，从而维持抗病原体的免疫力。体内该途径的药理学调节或冠状蛋白1缺陷型T细胞的先前转移积极抑制同种异体移植排斥。这些结果在同种异体移植排斥中起重要作用的T细胞中定义了冠状蛋白1依赖性调节轴，并表明该途径的调节可能是实现错配同种异体移植长期接受的有希望的方法。