Researchers identify a key molecule required for surviving flu infections in the April edition of Nature Immunology.
The molecule, NCR1, is an activating receptor expressed on "natural killer cells" (NK cells), which are the early responders in the immune system. Mice that lacked expression of NCR1 died when exposed to influenza virus, although their non-mutant siblings survived. The data suggest NCR1 recognition of the flu virus plays a crucial role in defending individuals soon after influenza infection.
NCR1-like molecules are expressed on NK cells found in every mammal examined to date, including the NK cell receptor called Ly94 in humans. NCR1 recognizes the hemagglutinin proteins expressed on the surface of influenza viruses. Although NCR1-deficient NK cells could accumulate in the lungs of infected mice, they were unable to destroy viral-infected cells and soon succumbed to the infection.
The researchers showed that mice of different genetic backgrounds displayed a similar lack of flu resistance when they lacked the NCR1 receptor. The findings reported here thus have the potential to impact anti-influenza strategies that are applicable to human flu infections.
Ofer Mandelboim (Hebrew University, Jerusalem, Israel)
Abstract available online.
(C) Nature Immunology press release.
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