Project description:West Nile virus (WNV) is a mosquito-borne RNA flavivirus and the cause of more than 31,000 cases in the USA from 1999-2011 including 1, 262 fatalities. WNV infections are typically asymptomatic, but some patients, especially the elderly and immunocompromised, may experience severe neurological disease and even death. Control of WNV infection by the immune system is multifactorial. We profiled antibody, cytokine responses and gene expression from a stratified cohort of WNV subjects to define immune responses that contribute to disease severity and outcome. Differential gene expression by human PBMCs from asymptomatic and severe patients with WNV infection were generated by microarray.
Project description:West Nile virus (WNV) is a mosquito-borne RNA flavivirus which has caused more than 31,000 cases in the USA from 1999-2011 including 1,262 fatalities. WNV infections are typically asymptomatic, but some patients, especially the elderly and immunocompromised, may experience severe neurological disease and even death. Control of WNV infection by the immune system is multifactorial. We profiled antibody and cytokine responses from a stratified cohort of WNV subjects to define immune responses that contribute to disease severity. While antibody levels were not significantly different between asymptomatic and severely ill subjects in our cohort, subjects with severe infections had lower levels of serum IL-4. Further, we detected 158 genes that were differentially expressed by asymptomatic and severely infected cohorts and using cluster analysis correlated WNV susceptibility with IL-4 related gene expression pathways. Our results suggest an important contribution for IL4 in more severe responses to WNV.
