Meeting Abstract

P3.32  Saturday, Jan. 5  Histological assessment of cellular immune response to the phytohemagglutinin (PHA) skin test in Brazilian free-tailed bats (Tadarida brasiliensis) TURMELLE, Amy/S.*; MENDONCA, Mary/T.; MCCRACKEN, Gary/F.; University of Tennessee, Knoxville, TN; Auburn University, Auburn, AL; University of Tennessee, Knoxville, TN turmelle@utk.edu

Bats are known to be reservoirs to several emerging diseases, and occur globally except for Antarctica. There are few studies that examine ecological and evolutionary correlates with the emergence of pathogens in bats, and data are even sparser on immune function in the Order Chiroptera. Brazilian free-tailed bats are common and abundant in the New World, and are known to be highly gregarious, living in colonies that number in the hundreds to millions. Coupled with striking differences in migratory behavior across their range, there is potential for wide variation in immune response, locally and across the landscape. The PHA skin test has been widely used to test the adaptive immune response in a wide variety of vertebrates, and has been routinely employed in immunoecological studies. Although the test is frequently described as a measure of T cell proliferation, recent studies indicate that it may represent aspects of both innate and adaptive immune responses. To characterize this response in bats, we examined a time-series of histological sections from the PHA and saline injection areas in 36 Brazilian free-tailed bats. Our results suggest that bats show a typical mammalian response, with diverse leukocyte traffic, within 6 hours and up to 21 hours following PHA challenge. Following challenge, there is a significant presence of lymphocytes and heterophils at the site of injection, which is absent from control (saline only) areas. Our results also indicate significant variation in the individual immune response, and may aid our understanding of disease emergence in natural populations of bats.