Predominant Th2 cytokine gene expression in lymph node cell cultures from Andes virus-infected deer mice (Peromyscus maniculatus) (P6316)

Abstract

Abstract Deer mice (Peromyscus maniculatus) are the principal reservoir hosts of Sin Nombre virus (SNV), while long-tailed pygmy rice rats (Oligoryzomys longicaudatus) are the principal reservoir hosts of Andes virus (ANDV). These viruses cause the great majority of hantavirus cardiopulmonary syndrome cases in North and South America. The disease in humans is principally an inflammatory immunopathology that results in a pronounced capillary leak syndrome with a 36% fatality rate due to cardiogenic shock. In contrast, infection of rodent reservoirs with their hantaviruses results in life-long persistence, without signs of disease, that appears to be mediated by regulatory T cells. Deer mice are experimentally susceptible to ANDV; however, they clear infection within 56 days. We infected deer mice with SNV or ANDV for 14 days and examined the immune responses to each virus. Lymph node cells from infected deer mice were harvested and cultured with viral antigens to examine expression of 94 immune-related genes by real-time PCR. We found that most of the same genes were expressed in both SNV- and ANDV-infected deer mice; however, the magnitude of gene expression, particularly Th2 genes, were significantly greater in lymph node cells from ANDV-infected deer mice. Together, these results suggest a quantitative effect occurs in the host response to a reservoir hantavirus (SNV) compared to a nonreservoir hantavirus (ANDV) and is associated with persistence or clearance.