Meeting Abstract

P3.94  Tuesday, Jan. 6  Interleukin 2 expression in the big brown bat Eptesicus fuscus ELLISON, JA*; TURMELLE, AS; MENDONCA, MT; MCCRACKEN, GF; RUPPRECHT, CE; Auburn Univ.; Univ. of Tennessee; Auburn Univ.; Univ. of Tennessee; Centers for Disease Control and Prevention ellisj1@auburn.edu

Bats have recently been recognized as hosts and vectors to a variety of emerging pathogens but very little is known about their immune system. As part of a larger study to investigate susceptibility of big brown bats (Eptesicus fuscus) to rabies virus infection, we evaluated expression of interleukin-2 (IL-2) in a standardized in vitro assay, to measure immunocompetence in individual big brown bats. IL-2 is necessary for the development of T-cell immunologic memory, and the expansion of antigen-specific T cell clones, but only partial cDNA sequences are available for any bat interleukins. We compared IL-2 gene sequences in GenBank from 16 different mammalian species and found several regions that were 78-80% conserved, from which degenerate forward and reverse primers for RT-PCR were designed. Concanavalin A (ConA), a T-cell mitogen which specifically induces IL-2 production, was used to stimulate in vitro expression of IL-2 in whole blood samples from big brown bats. Total RNA was extracted from stimulated white blood cells, and sequence data from amplified products shared 85% identity with reference IL-2 sequences. The proposed bat IL-2 sequences most closely resembled those found in humans (Homo sapiens). A semi-quantitative RT-PCR analysis detected dose-dependent induction of IL-2 message from white blood cells in response to ConA stimulation, whereas IL-2 expression was not detected from un-stimulated controls. This is the first study to investigate the IL-2 gene expression response in chiropteran hosts.