Involvement of type I immune responses in swine-origin H1N1 influenza virus infection

Institute of Neurology, Department of Neurosciences, Catholic University, Rome, Italy.
Human immunology (Impact Factor: 2.14). 05/2011; 72(8):632-5. DOI: 10.1016/j.humimm.2011.04.006
Source: PubMed


Swine-origin H1N1 influenza virus (S-OIV) appeared in 2009 with a higher incidence rate among children. Although fever was the most common symptom, some complicated cases occurred. We evaluated the percentages of effector T cells, B cells, and regulatory T cells in peripheral blood from 5 children infected by S-OIV (1 with acute necrotizing encephalitis, 2 with pneumonia, and 2 without complications), 5 children with seasonal influenza, and 5 healthy children. We found higher percentages of T-bet(+) CD4(+)CD8(+) T cells, monocytes, and B cells, granzyme B(+) and perforin(+) CD4(+), and CD8(+) T cells in affected children with both seasonal and H1N1 influenza than in controls, whereas both groups demonstrated similar percentages of CD4(+)CD25(+)Foxp3(+) regulatory T cells. In infected children with complications we observed high percentages of perforin(+) and interferon-γ(+) CD4(+) and CD8(+) T cells associated with low percentages of T regulatory cells. Our data suggest a dysregulation of antipathogen type I immune responses in complicated S-OIV infections.

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