Abstract

Certain therapies (i.e. daclizumab) that promote expansion of natural killer (NK) cells are associated with clinical amelioration of disease in the context of multiple sclerosis and associated mouse models. The clinical benefits are putatively attributable to an enhanced capacity of NK cells to kill activated pathogenic T cells. Whether a parallel approach will also be effective in systemic lupus erythematosus (lupus), a multi-organ autoimmune disease driven by aberrant responses of self-reactive T and B cells, is unclear. In the present study we assess the therapeutic impact of IL-2 and IL-15-based strategies for expanding NK cells on measures of lupus-like disease in a mouse model. Unexpectedly, cytokine-mediated expansion of cytotoxic lymphocytes aggravated immunological measures of lupus-like disease. Depletion studies reveal that the negative effects of these cytokine-based regimens can largely be attributed to expansion of CD8 T cells rather than NK cells. These results provoke caution in the use of cytokine-based therapeutics to treat co-morbid cancers in patients with lupus and highlight the need for new methods to selectively expand NK cells in order to further assess their clinical value in autoimmune disease.