CD1d-restricted invariant Natural Killer T (iNKT) cells represent a unique class of T lymphocytes endowed with potent regulatory and effector immune functions. Although these functions are acquired during thymic ontogeny, the sequence of events that gives rise to discrete effector subsets remains unclear. Using an unbiased single-cell transcriptomic analysis combined with functional assays, we reveal an unappreciated diversity among thymic iNKT cells, especially among iNKT1 cells. Mathematical modeling and biological methods unravel a developmental map whereby iNKT2 cells constitute a transient branching point toward the generation of iNKT1 and iNKT17 cells, which reconciles the two previously proposed models. In addition, we identify the transcription co-factor Four-and-a-half LIM domains protein 2 (FHL2) as a critical cell-intrinsic regulator of iNKT1 specification. Thus, these data illustrate the changing transcriptional network that guides iNKT cell effector fate.

CD1d限制不变的自然杀伤T细胞（iNKT）代表了独特的T淋巴细胞类，具有强大的调节和效应免疫功能。尽管这些功能是在胸腺肿瘤发生期间获得的，但导致离散的效应子集的事件序列仍然不清楚。使用无偏见的单细胞转录组学分析与功能性检测相结​​合，我们揭示了胸腺iNKT细胞之间，尤其是iNKT1细胞之间存在未知的多样性。数学建模和生物学方法揭示了发育图，其中iNKT2细胞构成了向iNKT1和iNKT17细胞生成的瞬时分支点，这与先前提出的两个模型相符。此外，我们确定转录辅因子四个半LIM域蛋白2（FHL2）作为iNKT1规范的关键细胞内在调节剂。因此，这些数据说明了指导iNKT细胞效应子命运的不断变化的转录网络。