|Ferro, Pamela - TAMU|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: January 30, 2002
Publication Date: N/A
Technical Abstract: Pattern recognition receptors (PRR) are a critical component of the innate immune response and the hosts¿ ability to recognize self from infectious non-self. Scavenger receptors (SR), a type of PRR, are cell surface glycoproteins involved in receptor-mediated phagocytosis of polyanionic ligands. Heterophils, the avian equivalent to the mammalian neutrophil, are important phagocytic cells involved in the innate immune response of the neonatal chicken. We have previously identified the presence of Toll-like receptors on avian heterophils and are interested in determining whether SR are also present on these cells. Heterophils were isolated from the peripheral blood of 2-3 day old chicks and treated with various doses (1-50 ug/ml) of fucoidan, a known SR class A ligand. The ability of fucoidan-treated and control heterophils to phagocytize Salmonella enteritidis (SE) was evaluated. The percentage of heterophils that phagocytized SE was significantly (p < 0.0003) lower in heterophils that were pre-treated with 1-10 ug/ml fucoidan for 30 minutes prior to the addition of SE when compared to non-treated heterophils. The overall phagocytic index (PI) (PI = percentage of heterophils with SE x average number of SE per heterophil) was also significantly (p = 0.02) decreased in the fucoidan-treated heterophils when compared to control heterophils. These results demonstrate that chicken heterophils have class A SR that contribute, in part, to the recognition and phagocytosis of SE in vitro.