Meeting Abstract

108.6  Saturday, Jan. 7  Avian Immune Responses to Alphavirus Infections FASSBINDER-ORTH, C*; BARAK, V; BROWN, C; Creighton University; Creighton University; University of Tulsa

Immunocompetence is energetically and nutritionally costly, and animals with different life history strategies may exhibit differential investment in parts of their immune systems in response to immune challenges. The house sparrow (Passer domesticus) is a highly successful non-native species in North America that is more susceptible than the native cliff swallow (Petrochelidon pyrrhonota), to Buggy Creek virus (BCRV), an alphavirus vectored by an ectoparasitic swallow bug. Although previous work on alphavirus infections in mammals has suggested that a hyperactive innate immune response (especially prevalent in neonates) leads to a more severe alphavirus infection, details of the avian immune response to alphaviruses has not yet been reported. Additionally, BCRV exists as two distinct lineages (A and B) that differ by about 6% at the nucleotide level. Ecological differences between the two lineages, including preferential infection of vertebrate hosts by lineage A, suggest that these lineages have diverged in their transmission strategies. We experimentally infected adult house sparrows with BCRV lineage A and B and examined the differences in disease severity between the two lineages. Additionally, we sequenced 500 bp regions of 17 different house sparrow genes known to be involved in immune function and examined their relative gene expression levels after BCRV infection using a liquid-phase bead-based, multiplex array. The results obtained from studying this host-pathogen-vector system have the potential to expand our understanding of avian immune responses to arboviruses and also the relationship between avian life history strategies and immune function.