Expansion of CD14+HLA-DRneg/low monocytes and CD10neg neutrophils driving proinflammatory responses in patients with acute myocardial infarction
ABSTRACTBackgroundImmature myeloid cells expand in cancer, autoimmune diseases and viral infection, but their appearance and function after acute myocardial infarction (AMI) remain underexplored.Methods and ResultUsing flow cytometry, cell sorting and a mouse model of ischemia/reperfusion we investigated the role of immature granulocytic/monocytic cells in immune responses post-AMI. Seventy-one patients were categorized into unstable angina (n=11), Non-ST-elevation MI (NSTEMI, n=16), and ST-elevation MI (STEMI, n=44). Circulating CD14+HLA-DRneg/low monocytes and normal-density CD16+CD66b+CD10neg neutrophils are expanded in patients with large AMI and strongly correlated with cardiac damage, function and serum levels of S100A9/S100A8, MMP-9 and IL-1ß. Receiver operating characteristic curve analysis highlighted ability of CD14+HLA-DRneg/low and CD16+CD66b+CD10neg cells in discriminating acute coronary syndromes. CD14+HLA-DRneg/low monocytes did not suppress T-cell proliferation but expressed high amounts of IL1R1 and S100A9. Mechanistically, macrophages differentiated from CD14+HLA-DRneg/low monocytes produced more proinflammatory cytokines upon IFNγ stimulation as CD14+HLA-DRhigh monocyte-derived macrophages. CD10neg neutrophils expressed MMP9 and S100A9 at higher levels compared to CD10pos neutrophils. IFNγ production by CD4+ T-cells was increased in presence of CD10neg neutrophils. Remarkably, elevated circulating IFNγ levels were detected in cytomegalovirus-seropositive patients with expanded CD10neg neutrophils and increased frequency of CD4+CD28null T-cells. Lastly, we showed that murine homologs of human CD10neg neutrophils are Ly6GposCXCR2posCD11bdimCD101neg cells. CD101neg neutrophils are rapidly released into the bloodstream after AMI and migrate to ischemic sites, displaying increased expression of MMP-9 at 3 hours and of IL-1ß at 24 hours after reperfusion.ConclusionCD14+HLA-DRneg/low monocytes and normal-density CD10neg neutrophils inducing proinflammatory immune responses expand in patients with AMI.