Submitted to: Federation of American Societies for Experimental Biology Conference
Publication Type: Abstract only
Publication Acceptance Date: 12/1/2003
Publication Date: 12/2/2003
Citation: Lippolis, J.D., Goff, J.P., Reinhardt, T.A. 2004. Comparative proteomic analysis of normal and periparturient bovine neutrophils demonstrating a reduction of myeloperoxidase during transition [abstract]. Experimental Biology Meeting. Paper No. 776.3. Interpretive Summary:
Technical Abstract: Neutrophils constitute a primary effector of the host immune response to an infectious pathogen. Normally low numbers of neutrophils reside in a health mammary gland; however, infection and subsequent release of chemoattractants results in the rapid influx of activated neutrophils into the site of infection. Periparturient dairy cows exhibit signs of immunosuppression that correlate with a higher incidence of mastitis. Furthermore, periparturient immunosuppression includes a significant reduction of neutrophil function. To better understand the nature of the periparturient immunosuppression, neutrophils from dairy cows were isolated greater than 21 days prior to calving (normal function) and shortly after calving (immunosuppressed) and compared using differential mass spectrometry. Proteomes of the immunosuppressed and normal neutrophils were labeled with isotope-coded affinity tags (ICAT), digested and subjected to nano-flow LC-MSMS analysis. Neutrophil proteins were identified and quantitated; interestingly, myeloperoxidase was shown to be reduced three-fold around parturition, whereas cathelicidin 1 and beta defensin were unaffected. Myeloperoxidase is a strongly bactericidal neutrophil enzyme that generates reactive oxidants and is considered an important component of neutrophil's ability to destroy bacteria.