Journal of leukocyte biology
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Systemic infections with HPAIVs, such as H5N1, are characterized by cytokine burst and sepsis. We investigated the role of human monocyte-derived macrophages in these events after infection with different influenza virus strains. Macrophages were infected with low pathogenic H1N1 (PR8) or high pathogenic H7N7 (FPV) and H5N1 (KAN-1) subtypes. ⋯ Furthermore, inflammasome activation was impaired significantly in HPAIV-infected macrophages. Interestingly, this finding correlated with a complete suppression of viral protein M2 expression after HPAIV infection, which is known to be involved in influenza viral inflammasome activation. In summary, our data provide first evidences for a strategy of how HPAIVs avoid initial inflammatory responses of macrophages facilitating virus spreading and progression to the systemic stage of disease.