Bovine mastitis due to bacterial infection is one of the most costly diseases affecting the dairy industry. The polymorphonuclear neutrophils (PMNs) present in milk have a central protective role against invading pathogens, However, the manner by which PMNs traverse the secretory epithelia and the relationship between PMN diapedesis and the epithelial damage are unclear. This in vitro study investigated the process and rate of bovine PMN transepithelial migration. The bovine mammary epithelial cell line, MAC-T, formed a confluent monolayer with characteristic tight junctions, polarity and functional barrier to the dye trypan blue. In the first series of experiments, neutrophils were added into the upper compartment of the culture insert and stimulated to migrate across the epithelium in an apical-to-basal direction by the addition of Staphylococcus aureus to the lower compartment. Light and transmission electron microscopy revealed the following series of events for PMN transmigration: (1) adherence of PMNs to the surface of the epithelium; (2) projection of pseudopods toward the intercellular junction; (3) migration between adjacent epithelial cells; and (4) re-approximation of epithelial cell membranes and reformation.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.22761 |
| Date | January 1994 |
| Creators | Lin, Yongqing |
| Contributors | Zhao, Xin (advisor) |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Animal Science.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001462328, proquestno: MM05584, Theses scanned by UMI/ProQuest. |
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