Génétique de la susceptibilité à l’Influenza aviaire chez les oiseaux domestiques – GenAviFlu

Avian flu has recently emerged as a major problem for animal health and a major risk for public health, because of the H5N1 variant. The AI viruses exhibit many variants and can evolve quickly. The genetic variability of the susceptibility to AI viruses is not known for domestic birds. The objective of this project is to improve the knowledge of the genetic factors controlling the immune response of chicken and common duck to two H5N1 variants, highly or moderately pathogenic, as well as the response to different vaccine constructions (recombinant herpesvirus or inert vaccine). The study will include 16 breeds or selected lines of chickens, and 8 breeds or selected lines of ducks, chosen in France and in Vietnam, according to previous data on their disease resistance, MHC genotype and importance for poultry production. The within-breed polymorphism will be studied on 720 individuals by sequencing 4 genes chosen for their role in disease resistance (BF2 and TAP2 of MHC, Mx, Nramp1). The same 720 individuals will be challenged for infection by one or the other of the H5N1 variants. Challenges will be performed in confined facilities for 10 birds per breed or line. A first set of experiments will compare the susceptibility of all genotypes to the two H5N1 variants. Then, the mechanisms of immune response will be studied on a subset of the lines previously tested, by a transcriptome approach and by quantitative RT-PCR, following infection by the variant with a low virulence. The expected results are the finding of significant differences between genotypes for susceptibility to avian flu, and the identification of genes and genes’pathways differentially expressed following infection or vaccination.