Influenza infection leads to increased susceptibility to subsequent bacterial superinfection by impairing NK cell responses in the lung.

TY - JOUR

T1 - Influenza infection leads to increased susceptibility to subsequent bacterial superinfection by impairing NK cell responses in the lung.

AU - Small, Cherrie-Lee

AU - Shaler, Christopher R

AU - McCormick, Sarah

AU - Jeyanathan, Mangalakumari

AU - Damjanovic, Daniela

AU - Brown, Earl G

AU - Arck, Petra

AU - Jordana, Manel

AU - Kaushic, Charu

AU - Ashkar, Ali A

AU - Xing, Zhou

PY - 2010

Y1 - 2010

N2 - Influenza viral infection is well-known to predispose to subsequent bacterial superinfection in the lung but the mechanisms have remained poorly defined. We have established a murine model of heterologous infections by an H1N1 influenza virus and Staphylococcus aureus. We found that indeed prior influenza infection markedly increased the susceptibility of mice to secondary S. aureus superinfection. Severe sickness and heightened bacterial infection in flu and S. aureus dual-infected animals were associated with severe immunopathology in the lung. We further found that flu-experienced lungs had an impaired NK cell response in the airway to subsequent S. aureus bacterial infection. Thus, adoptive transfer of naive NK cells to the airway of prior flu-infected mice restored flu-impaired antibacterial host defense. We identified that TNF-alpha production of NK cells played an important role in NK cell-mediated antibacterial host defense as NK cells in flu-experienced lungs had reduced TNF-alpha expression and adoptive transfer of TNF-alpha-deficient NK cells to the airway of flu-infected mice failed to restore flu-impaired antibacterial host defense. Defected NK cell function was found to be an upstream mechanism of depressed antibacterial activities by alveolar macrophages as contrast to naive wild-type NK cells, the NK cells from flu-infected or TNF-alpha-deficient mice failed to enhance S. aureus phagocytosis by alveolar macrophages. Together, our study identifies the weakened NK cell response in the lung to be a novel critical mechanism for flu-mediated susceptibility to bacterial superinfection.

AB - Influenza viral infection is well-known to predispose to subsequent bacterial superinfection in the lung but the mechanisms have remained poorly defined. We have established a murine model of heterologous infections by an H1N1 influenza virus and Staphylococcus aureus. We found that indeed prior influenza infection markedly increased the susceptibility of mice to secondary S. aureus superinfection. Severe sickness and heightened bacterial infection in flu and S. aureus dual-infected animals were associated with severe immunopathology in the lung. We further found that flu-experienced lungs had an impaired NK cell response in the airway to subsequent S. aureus bacterial infection. Thus, adoptive transfer of naive NK cells to the airway of prior flu-infected mice restored flu-impaired antibacterial host defense. We identified that TNF-alpha production of NK cells played an important role in NK cell-mediated antibacterial host defense as NK cells in flu-experienced lungs had reduced TNF-alpha expression and adoptive transfer of TNF-alpha-deficient NK cells to the airway of flu-infected mice failed to restore flu-impaired antibacterial host defense. Defected NK cell function was found to be an upstream mechanism of depressed antibacterial activities by alveolar macrophages as contrast to naive wild-type NK cells, the NK cells from flu-infected or TNF-alpha-deficient mice failed to enhance S. aureus phagocytosis by alveolar macrophages. Together, our study identifies the weakened NK cell response in the lung to be a novel critical mechanism for flu-mediated susceptibility to bacterial superinfection.

U2 - 10.4049/jimmunol.0902772

DO - 10.4049/jimmunol.0902772

M3 - SCORING: Zeitschriftenaufsatz

VL - 184

SP - 2048

EP - 2056

JO - J IMMUNOL

JF - J IMMUNOL

SN - 0022-1767

IS - 4

M1 - 4

ER -