ANALYSIS OF THE REGULATORY FUNCTION OF NK CELLS FROM PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

ABSTRACT

Natural Killer cells (NK cells) participates in the regulation of the immune response. However, the immunomodulatory function of NK cells in systemic lupus erythematosus (SLE) is not well understood. The aim of this study was to evaluate the regulatory function of NK cells in SLE patients and to identify the NK cells involved in the pathogenesis of this complex disease. We analyzed the expression of NK receptors and costimulatory molecules in peripheral NK cells (CD3-CD56+) from SLE patients as well as the numbers of HLA-DR/CD11c+ NK cells. In addition, NK cell regulatory function was assessed by the detection of NK cell-mediated DC lysis. We found that SLE patients showed increased numbers of ILT2+, CD86+ and CD134+ NK cells. Furthermore, NK cells from SLE patients induced higher levels of DC lysis. We were able to identify a new subset of NK cells co-expressing CD11c and HLA-DR. Furthermore, these atypical NK cells were increased in SLE patients when compared with controls.

We have identified an expanded new subset of NK cells in SLE patients. This is the first study, which demonstrates that NK cells in SLE patients have an altered phenotype with a high expression of receptors characteristic of dendritic cells. Our results suggest that the impairment in the regulatory function of NK cells, together with the increased number of DC-like NK cells could play an important role in the development of SLE and highlight the importance of NK cells as a future therapeutic target. This article is protected by copyright. All rights reserved.