Submitted to: American Journal of Veterinary Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/3/2001
Publication Date: N/A
Interpretive Summary: Respiratory tract diseases are a leading cause of loss from disease in the cattle, sheep, and goat industries. Annual loss in the United States is estimated to exceed one billion dollars. Losses are from mortality, reduced feed efficiency, and slaughter condemnations, as well as prevention and treatment measures. Currently, not all the factors involved in natural linnate immunity or adaptive immunity are known by scientists and veterinarians. As part of our ongoing studies to identify innate anti- microbial peptides, we found that anionic peptides, originally purified from sheep lung cells and fluid, were also found in normal cattle lung cells and fluids. Anionic peptide production was not increased following a variety of pro-inflammatory substances, and greater amounts of anionic peptide in normal lung compared to diseased lung suggests stored anionic peptide may be constitutively produced and rapidly expended during the disease process. This observation suggests that anionic peptides are present in lung cells and fluid of cattle in a distribution similar to sheep and that infection or acute inflammation does not enhance anionic peptide production. This would be an important factor in preventing or treating shipping fever of cattle. Corollary benefits include an increase in the profitability and international competitiveness of the U. S. cattle industry, a stronger rural economy, and a continued supply of inexpensive, wholesome beef and beef products for the American consumer.
Technical Abstract: Anionic peptides (AP) are small antimicrobial peptides originally purified from sheep bronchoalveolar lavage (BAL) fluid and lung. The objective of this study was to establish the presence of AP in normal and pneumonic lungs of cattle. Six healthy neonatal Holstein calves and four healthy young adult calves were inoculated with inflammatory stimuli or saline by fiberoptic bronchoscopy. Lung tissue was collected for electrophoresis, western blot analysis, and immunohistochemistry. Western blots and immunohistochemistry in normal and pneumonic lung tissue from neonatal calves and young adult cattle detected AP. In western blots, four bands were seen. These bands were consistent with those seen in western blots of sheep lung and trachea and most likely represent the proposed intact zymogen prior to post-translational cleavage. Immunohistochemistry of cattle lung tissue, both normal and infected, had a pattern of immuno- reactivity similar to sheep lung tissue. In contrast to inducible anti- microbial peptides, AP production was not increased following a variety of pro-inflammatory substances, and greater AP-IR in non-inflamed lung compared to inflamed lung suggests stored AP may be constitutively produced and rapidly expended in acute inflammation. This work demonstrated that AP is present in lung and BAL fluid of cattle in a distribution similar to sheep and that infection or acute inflammation does not enhance AP production.