Table 1.
Leukocyte | Peak Accumulation in the Lung Following IAV Infection | Immunoprotection Roles | Immunopathology Roles |
---|---|---|---|
Monocyte | 5 days [36] | Pro-inflammatory cytokine production [37], differentiation into dendritic cells [9] | Excessive pulmonary inflammation and tissue damage leading to mortality [38] |
Alveolar macrophage | 2 days [39] | Phagocytosis of infected cells [39], prevention of epithelial cell infection [40] |
Excessive pulmonary inflammation and tissue damage leading to mortality [41] |
Dendritic cell | 10 days [36] | Type I IFN production [42], activation and recruitment of antigen-specific T cells [36] | Excessive pulmonary inflammation and tissue damage leading to mortality [43] |
Neutrophil | 3–5 days [44] | Pro-inflammatory cytokine production [44], phagocytosis of infected cells [39], anti-bacterial granule release and NETosis to limit viral replication [45], recruitment of CD8+ T cells [46] |
Excessive pulmonary inflammation, ROS production [47] and tissue damage leading to mortality [48] |
Natural killer cell | 2–4 days [49], 6 days [50] | Pro-inflammatory cytokine production [51], cytotoxicity of IAV infected cells [49], recruitment of dendritic cells and T cells to mediastinal lymph node [52], enhancement of CTL responses [53] | Excessive lung inflammation, increased phagocyte and neutrophil recruitment [54] |