Mapping Clinical and Expression QTL in a Sex-Dependent Effect of Host Susceptibility to Influenza H3N2/HK/1/68-MA20

Seasonal influenza outbreaks and recurrent influenza pandemics present major challenges to public health. By studying immunological responses to influenza in different host species, it may be possible to discover common mechanisms of susceptibility in response to various influenza strains. This could lead to novel therapeutic targets with wide clinical application. Using a mouse-adapted strain of influenza (A/HK/1/68-MA20 [H3N2]), we produced a mouse model of severe influenza (p-flu) that reproduces the hallmark high viral load and overexpression of cytokines associated with susceptibility to p-flu in humans. We mapped genetic determinants of the host response using a panel of 29 closely related mouse strains (AcB/BcA panel of recombinant congenic strains) created from influenza-susceptible A/J and influenza-resistant C57BL/6J (B6) mice. Combined clinical quantitative trait loci (cQTL) and lung expression QTL (eQTL) mapping identified candidate genes for two sex-specific QTLs on chromosomes 2 and 17. The former includes the previously described Hc gene, a deficit of which is associated with the susceptibility phenotype in females. The latter includes the phospholipase gene Pla2g7 and Tnfrsf21, a member of the tumor necrosis factor receptor superfamily. Confirmation of the gene underlying the chromosome 17 QTL may reveal new strategies for influenza treatment.

54

Boivin GA, Pothlichet J, Skamene E, Brown EG, Loredo-Osti JC, Sladek R, Vidal SM