Pandemic Swine-Origin H1N1 Influenza A Virus Isolates Show Heterogeneous Virulence in Macaques

Abstract

The first influenza pandemic of the new millennium was caused by a newly emerged swine-origin influenza virus (SOIV) (H1N1). This new virus is

2009 Pandemic H1N1 Influenza Virus Causes Disease and Upregulation of Genes Related to Inflammatory and Immune Responses, Cell Death, and Lipid Metabolism in Pigs

“…These studies report augmented immune responses associated with cytokine, chemokine, and interferon release and a cell death response mediated by the more pathogenic influenza viruses. Similarly, pH1N1 infection of nonhuman primates resulted in higher proinflammatory gene expression and cytokine production than infection with seasonal influenza virus, which was resolved as animals recovered from infection (46). Our results in pigs somewhat mirror these findings in macaques as we showed an early increase of proinflammatory gene expression in infected pigs that was resolved as all of the animals in the study recovered.…”

“…A limited number of studies have examined the relationship between lipid metabolism and influenza virus infection (3,46). In the present study, pH1N1 was associated with an overall increase in lipid metabolism genes at 5 dpi, whereas the IA30 virus induced a significant concordant decrease in a network of related lipid metabolism and cell death genes which were related to the molecule PPARG.…”

Differential Host Determinants Contribute to the Pathogenesis of 2009 Pandemic H1N1 and Human H5N1 Influenza A Viruses in Experimental Mouse Models

“…26 Recently, some 2009 pH1N1 strains presented heterogeneous virulence in a macaque model. 27 Clearly, more studies using several pH1N1 isolates from mild and severe cases are needed in BALB/c and C57BL/6J mice and other mammalian models to identify an adequate model for the studies of pH1N1 pathogenesis and their correlation with clinical outcomes in humans.…”

2009 pandemic H1N1 influenza A virus strains display differential pathogenicity in C57BL/6J but not BALB/c mice

“…Interestingly heterogeneous virulence of pH1N1 strains has been recently reported in macaques. 15 Here, we propose the C57BL/6J mouse strain as a suitable and convenient small animal model to identify and characterize novel pH1N1 pathogenicity markers. Viral determinants identified in C57BL/6J mice will need further evaluation in other animal models, such as ferrets, guinea pigs or macaques.…”