Figure 2.

Innate immune response elicited upon hMPV infection. After the detection of hMPV, various types of immune cells are recruited to the lung. Within the innate immune cells, Dendritic cells (DCs), Alveolar Macrophages (AMs), Neutrophils (Neu), Eosinophils (Eos), and Natural Killer cells (NK) can be found. Most of these cells play a role in the pathology of the infection. However, Group 2 Innate Lymphoid Cells 2 (ILC2s) and the role of the Complement System during the infection have not been reported yet, and this lack of information is illustrated with “?” in the figure. The role of the respiratory epithelium in the recruitment of innate immune cells can also be appreciated. Components shaded in blue are elements that contribute to hMPV disease resolving, whereas components shaded in red are considered detrimental and contribute to hMPV pathogenesis overall. Elements shaded in yellow are those whose contributions to hMPV pathology are not well studied or are controversial. The arrows indicate the possible targets of infection.