The orphan nuclear receptor NR4A3 is dispensable for resident memory CD8+ T cell generation

Different memory CD8+ T cell subsets are generated following acute responses: central, effector and resident (Trm). CD8+ Trm cells established residency at the sites of infection and provide an efficient and rapid frontline defense against re-infection. The NR4A family members (NR4A1, NR4A2 and NR4A3) of orphan nuclear receptor are transiently expressed following TCR signaling and NR4As were shown to influence CD8+ T cell response. Interestingly, Nr4a1, Nr4a2 and Nr4a3 have been reported to be transcribed by CD8+ Trm cells. In absence of NR4A1, less CD8+ Trm cells are present in the liver, lungs, small intestine intra-epithelial lymphocytes (IELs) and Peyers patches. NR4A2 was shown to play a role in the generation of small intestine IEL CD8+ Trm cells. However, evidence is still lacking for the contribution of NR4A3 during CD8+ Tm cell differentiation. In this study, we evaluated the role of NR4A3 in the differentiation and maintenance of CD8+ Trm cells. Our data demonstrate that in contrast to the other family members NR4A1 and NR4A2, NR4A3 is dispensable for the generation of CD8+ Trm cells in both epithelial and non-epithelial sites.