Conventional NK cells and ILC1s do not influence pathogenesis of experimental glomerulonephritis

Innate lymphoid cells (ILCs) that express NK cell receptors (NCRs) and the transcription factor T-bet populate non-lymphoid tissues and are crucial in immune responses against viral infections and malignancies. Recent studies highlighted the heterogeneity of this ILC population and extended their functional spectrum to include important roles in tissue homeostasis and autoimmunity. Here, we provide detailed profiling of NCR+T-bet+ ILC populations in the murine kidney, identifying conventional NK (cNK) cells and type 1 ILCs (ILC1s) as the two major subsets. Induction of renal inflammation in a mouse model of glomerulonephritis did not substantially influence abundance or phenotype of cNK cells or ILC1s in the kidney. For functional analyses in this model, widely used depletion strategies for total NCR+ ILCs (αNK1.1 antibody application) and cNK cells (α-asGM1 serum application) were unreliable tools, since they were accompanied by significant off-target depletion of kidney NKT cells and CD8+ T cells, respectively. However, neither depletion of cNK cells and ILC1s in NKT cell-deficient mice, nor specific genetic deletion of cNK cells in Ncr1Cre/wt x Eomesfl/fl mice altered the clinical course of experimental glomerulonephritis. In summary, we show here that cNK cells and ILC1s are dispensable for initiation and progression of immune-mediated glomerular disease and advise caution in the use of standard antibody depletion methods to study NCR+ ILC function in mouse models. Three replicates of cNK cells and ILC1s were FACS sorted from total leukocytes isolated from the kidneys of naive B6 WT animals.