Submitted to: Society for Leukocyte Biology Meetings Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 11/9/2001
Publication Date: N/A
Technical Abstract: Cells belonging to the innate arm of the immune system must recognize antigens by pattern recognition receptors (PRR) that recognize pathogen- associated molecular patterns (PAMP) such as lipopolysaccharide (LPS) found in the cell wall of gram-negative bacteria and lipoteichoic acid (LTA) found in the cell wall of gram-positive bacteria. Experiments were conducted to stimulate oxidative burst of chicken heterophils with gram- negative Salmonella enteritidis (SE) or gram-positive Staphylococcus aureus (SA). Heterophils isolated from neonatal chicks were exposed to SE or SA for 30 minutes and luminol-dependent chemiluminescence was used to quantitate oxidative burst. A significant increase in oxidative burst was observed from heterophils when stimulated with both SE (48%) and SA (114%). We then evaluated the effect of purified LTA and LPS on oxidative burst of avian heterophils and also observed a significant increase in oxidative burst from heterophils when stimulated with LPS (25%) and LTA (89%). Further experiments using polymyxin B (47%), anti-human CD14 Ab (61%), anti-human TLR2 Ab (71%), and anti-human TLR4 Ab (72%) as antagonists to LPS were shown to significantly reduce oxidative burst. Therefore, these data demonstrate the interaction of PAMPs from gram positive and gram-negative bacteria with avian heterophils stimulate oxidative burst via TLR2, TLR4, and CD14.