HuR-dependent NK cell expansion is required for control of solid tumors and long-term virus infection

Natural Killer (NK) cells are innate lymphocytes capable of controlling tumors and virus infections through direct lysis and cytokine production. NK cells also expand and accumulate in affected tissues, but the role of NK cell expansion in tumor and viral control is not well understood. Here, we describe that post-transcriptional regulation by the RNA-binding protein HuR is essential for NK cell expansion, without overtly affecting NK cell effector functions. HuR-dependent NK cell expansion facilitated control of solid tumors, but it was dispensable for control of tumor metastases. In virus infection, HuR-dependent NK cell expansion contributed to long-term viral control in the absence of adaptive immunity without affecting acute infection. HuR-deficient NK cells displayed defects in expression of and splicing in cell cycle-associated genes, including decreased expression and alternative splicing of Ska2, a component of the spindle and kinetochore complex that is involved in chromosome separation during cell division. Furthermore, we identified an essential role for SKA2 in NK cell expansion. These results show that post-transcriptional regulation by HuR specifically affects NK cell expansion which is required for control of several solid tumors and long-term virus infection. gene expression and alternative splicing analysis between WT and HuR cKO NK cells