Human cytotoxic T lymphocytes directed to seasonal influenza A viruses cross-react with the newly emerging H7N9 virus

CE van de Sandt, JHCM Kreijtz, G de Mutsert… - Journal of …, 2014 - Am Soc Microbiol
CE van de Sandt, JHCM Kreijtz, G de Mutsert, MM Geelhoed-Mieras, MLB Hillaire…
Journal of virology, 2014Am Soc Microbiol
In February 2013, zoonotic transmission of a novel influenza A virus of the H7N9 subtype
was reported in China. Although at present no sustained human-to-human transmission has
been reported, a pandemic outbreak of this H7N9 virus is feared. Since neutralizing
antibodies to the hemagglutinin (HA) globular head domain of the virus are virtually absent
in the human population, there is interest in identifying other correlates of protection, such as
cross-reactive CD8+ T cells (cytotoxic T lymphocytes [CTLs]) elicited during seasonal …
Abstract
In February 2013, zoonotic transmission of a novel influenza A virus of the H7N9 subtype was reported in China. Although at present no sustained human-to-human transmission has been reported, a pandemic outbreak of this H7N9 virus is feared. Since neutralizing antibodies to the hemagglutinin (HA) globular head domain of the virus are virtually absent in the human population, there is interest in identifying other correlates of protection, such as cross-reactive CD8+ T cells (cytotoxic T lymphocytes [CTLs]) elicited during seasonal influenza A virus infections. These virus-specific CD8+ T cells are known to recognize conserved internal proteins of influenza A viruses predominantly, but it is unknown to what extent they cross-react with the newly emerging H7N9 virus. Here, we assessed the cross-reactivity of seasonal H3N2 and H1N1 and pandemic H1N1 influenza A virus-specific polyclonal CD8+ T cells, obtained from HLA-typed study subjects, with the novel H7N9 virus. The cross-reactivity of CD8+ T cells to H7N9 variants of known influenza A virus epitopes and H7N9 virus-infected cells was determined by their gamma interferon (IFN-γ) response and lytic activity. It was concluded that, apart from recognition of individual H7N9 variant epitopes, CD8+ T cells to seasonal influenza viruses display considerable cross-reactivity with the novel H7N9 virus. The presence of these cross-reactive CD8+ T cells may afford some protection against infection with the new virus.
American Society for Microbiology