|Lee, Eun-Kyung - IA STATE UNIV., AMES, IA|
|Kehrli Jr, Marcus|
Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 14, 1995
Publication Date: N/A
Technical Abstract: Leukocyte adhesion molecules important in the initial stages of the inflammatory response mediate the adhesion of neutrophils to endothelial cells prior to emigrating into infection sites. It has been reported that some periparturient cows have a marked reduction in the capacity to respond to bacterial infection of the mammary gland. An experiment was designed to determine the expression of the beta2 integrin (CD18) family of adhesion molecules and L-selectin (CD62L) on neutrophils from periparturient cows and neonatal calves. Constituitive CD18 and CD62L expression on neutrophils was determined by flow cytometry using specific monoclonal antibodies. Platelet=activating factor (PAF) was used to activate neutrophils in vitro to measure down-regulation of CD62L and up-regulation of CD18 on activated neutrophils. Mean fluorescence intensity values for both constituitive and PAF-stimulated CD18 expression on neutrophils from cows and calves were highest at parturition, then declined during the first 15 hours postpartum. Similarly, CD62L declined dramatically by 9 hours after calving. Constituitive CD18 and CD62L levels on cow neutrophils recovered to prepartum values within two weeks and two days postpartum, respectively.