Identification of differentially activated cell-signaling networks associated with pichinde virus pathogenesis by using systems kinomics.

Phosphorylation plays a key role in regulating many signaling pathways. Although studies investigating the phosphorylated forms of signaling pathways are now commonplace, global analysis of protein phosphorylation and kinase activity has lagged behind genomics and proteomics. We have used a kinomics approach to study the effect of virus infection on host cell signaling in infected guinea pigs. Delineating the host responses which lead to clearance of a pathogen requires the use of a matched, comparative model system. We have used two passage variants of the arenavirus Pichinde, used as a biosafety level 2 model of Lassa fever virus as it produces similar pathologies in guinea pigs and humans, to compare the host cell responses between infections which lead to either a mild, self-limiting infection or lethal disease. Using this model, we can begin to understand the differences in signaling events which give rise to these markedly different outcomes. By contextualizing these data using pathway analysis, we have identified key differences in cellular signaling matrices. By comparing these differentially involved networks, we have identified a number of key signaling "nodes" which show differential phosphorylations between mild and lethal infections. We believe that these nodes provide potential targets for the development of antiviral therapies by acting at the level of the host response rather than by directly targeting viral proteins.

Differential signaling networks induced by mild and lethal hemorrhagic fever virus infections.

The family Arenaviridae includes several National Institutes of Allergy and Infections Diseases category A select agents which cause hemorrhagic fever. There are few vaccines available, and treatment is limited to ribavirin, which varies in efficacy. Development of new antiviral compounds has been hindered by a lack of understanding of the molecular basis of pathogenesis. We used two variants of Pichinde virus, one attenuated and one virulent in the guinea pig model, to delineate the host determinants which lead to either viral clearance or lethal disease. By analyzing protein level changes using pathway analysis, we have identified key intermediates which may be targets for therapeutic intervention.