IL1B and infection: For example, lung neutrophils constitutively express pro-IL-1β.175 Recently it has been shown that neutrophils regulate the production of IL-1β by alveolar macrophages (AMs) during infection with IAV.58 However, during RSV infection, no differences in IFN-α, IL-1β, or IL-6 levels in BAL were detected after neutrophil depletion,176 suggesting neutrophils do not modulate the cytokine production by AMs during RSV infection.