Early and sustained innate immune response defines pathology and death in nonhuman primates infected by highly pathogenic influenza virus.

This study revealed important similarities but also critical differences between the H5N1 and 1918-reassortant viruses, highlighting aspects of the host–pathogen interface caused by highly virulent influenza viruses. Animals assigned to 4 experimental groups (n = 8) matched for age, weight, and sex, were inoculated by intratracheal, intranasal, tonsillar, and conjunctival routes with a total of 107 pfu of A/Vietnam/1203/2004 (H5N1) virus, A/Texas/36/91 (H1N1) virus or reassortants of this virus containing either 2 (HA, NA) or 3 (HA, NA, NS) genes from the 1918 virus. Two animals per group were scheduled for sacrifice on days 1, 2, 4, and 7. Two additional animals were used as uninfected control animals and killed on day 7. Oligoarray analyses consisted of comparing array profiles of individual lung samples (with representative pathology and degree of infection) from infected animals to pooled equal masses of mRNA from all lung lobes of 7 reference cynomolgus macaques obtained through the tissue program of the University of Washington National Primate Research Center. There are 2 technical array replicates fro each sample.