Measles virus infection of rhesus macaques affects neutrophil expression of IL-12 and IL-10

Cytokine production by phagocytic cells is an important component of the immune response to infection with a variety of pathogens. Neutrophils are phagocytic cells capable of expressing interleukin (IL)-12 and IL-10 in response to infection with parasites, fungi, and bacteria. These cytokines are postulated to play important roles in the immune response during measles. Neutrophils isolated from naive or measles virus (MV)-infected rhesus macaques expressed IL-12 and IL-10 following in vitro stimulation with lipopolysaccharide (LPS) and interferon-gamma (IFN-γ). Stimulated neutrophils secreted proportionally more of the biologically active IL-12 heterodimer p70 and more IL-10 than similarly stimulated peripheral blood mononuclear cells (PBMCs). During MV infection, the number of IL-12 and IL-10-producing neutrophils and monocytes initially decreased. Subsequently, IL-12 levels were restored, and IL-10 expression rose above baseline in both cell types. Increased IL-10 production by neutrophils and monocytes during MV infection may play a role in measles-induced immunosuppression.