Unconventional T cells are a diverse and underappreciated group of relatively rare lymphocytes that are distinct from conventional CD4⁺ and CD8⁺ T cells, and that mainly recognize antigens in the absence of classical restriction through the major histocompatibility complex (MHC). These non-MHC-restricted T cells include mucosal-associated invariant T (MAIT) cells, natural killer T (NKT) cells, γδ T cells and other, often poorly defined, subsets. Depending on the physiological context, unconventional T cells may assume either protective or pathogenic roles in a range of inflammatory and autoimmune responses in the kidney. Accordingly, experimental models and clinical studies have revealed that certain unconventional T cells are potential therapeutic targets, as well as prognostic and diagnostic biomarkers. The responsiveness of human Vγ9Vδ2 T cells and MAIT cells to many microbial pathogens, for example, has implications for early diagnosis, risk stratification and targeted treatment of peritoneal dialysis-related peritonitis. The expansion of non-Vγ9Vδ2 γδ T cells during cytomegalovirus infection and their contribution to viral clearance suggest that these cells can be harnessed for immune monitoring and adoptive immunotherapy in kidney transplant recipients. In addition, populations of NKT, MAIT or γδ T cells are involved in the immunopathology of IgA nephropathy and in models of glomerulonephritis, ischaemia–reperfusion injury and kidney transplantation.

非常规 T 细胞是一组多样化且被低估的相对罕见的淋巴细胞，与传统的 CD4 ⁺和 CD8 ^+不同T 细胞，主要通过主要组织相容性复合体 (MHC) 在没有经典限制的情况下识别抗原。这些非 MHC 限制性 T 细胞包括黏膜相关不变 T (MAIT) 细胞、自然杀伤 T (NKT) 细胞、γδ T 细胞和其他通常定义不明确的亚群。根据生理环境，非常规 T 细胞可能在肾脏的一系列炎症和自身免疫反应中发挥保护或致病作用。因此，实验模型和临床研究表明，某些非常规 T 细胞是潜在的治疗靶点，以及预后和诊断生物标志物。例如，人类 Vγ9Vδ2 T 细胞和 MAIT 细胞对许多微生物病原体的反应对早期诊断具有重要意义，腹膜透析相关性腹膜炎的风险分层和靶向治疗。巨细胞病毒感染期间非 Vγ9Vδ2 γδ T 细胞的扩增及其对病毒清除的贡献表明，这些细胞可用于肾移植受者的免疫监测和过继免疫治疗。此外，NKT、MAIT 或 γδ T 细胞群参与 IgA 肾病的免疫病理学以及肾小球肾炎、缺血再灌注损伤和肾移植模型。