Alteration of circulating innate lymphoid cells in patients with atherosclerotic cerebral infarction

Innate lymphoid cells (ILCs) are associated with innate immunity and tissue remodeling. However, the changes in ILCs and their role in acute cerebral infarction (ACI) remain unexplored. This study aimed to examine the expression of ILCs in patients with ACI and explore the mechanism underlying changes in ILCs induced by the atherosclerotic factor oxidized low-density lipoprotein (ox-LDL). The levels of ILC1, ILC2, and ILC3 in the blood of patients with ACI and controls were examined at the time of admission. The correlation of serum levels of ox-LDL and inflammatory biomarkers with the level of ILCs and the effects of ox-LDL on ILCs in vitro were analyzed. Our results showed that the levels of ILC1 increased while the levels of ILC2 decreased in patients with ACI compared with controls. Serum levels of ox-LDL, LDL-C, and biochemical biomarkers correlated positively with the levels of ILC1 and ILC1/ILC2 ratio but negatively with the levels of ILC2. The in vitro incubation of peripheral blood mononuclear cells (PBMC) with ox-LDL resulted in an elevation of the levels of ILC1s and a marked reduction in the levels of ILC2s in a dose-dependent manner. ILC1s and ILC2s were more susceptible to ox-LDL-mediated alterations in patients with ACI than in controls. Furthermore, the expression of Interleukin 18 (IL-18), IL-33 and IL-23 in PBMCs was detected by real-time PCR, which showed the change trends of related key cytokines were highly consistent with the variation of ILC subsets. These results suggested that the levels of ILC1s and ILC2s appeared to be a novel, sensitive indicator for diagnosing ACI. Ox-LDL directly affected ILC1s and ILC2s, thus contributing to the alternations of ILC1 and ILC2 and occurrence of ACI.