Application of monocyte-derived cell lines to the study of phagocyte function in bovine brucellosis /
| Main Author: | |
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1991.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | A system was developed to study the interactions between Brucella abortus strain 2308 and the bovine immune system during phagocytosis, intracellular bacterial killing, and antigen processing and presentation to T lymphocytes. Studies utilized monocyte-derived macrophages harvested from animals which were phenotypically resistant (R) and susceptible (S) to infection with Brucella abortus. Macrophages phagocytosed live B. abortus without opsonization. Phagocytosis was inhibited in macrophages from R by the peptide RGDS, outer membrane-peptidoglycan complex from B. abortus strain RB51, anti-LFA-1 monoclonal antibody, anti-C3 antiserum, fibronectin, purified O-Antigen from B. abortus lipopolysaccharide, mannan, and heat-aggregated IgG. Phagocytosis by macrophages from both R and S was inhibited by outer membrane-peptidoglycan complex, anti-LFA-1 monoclonal antibody, O-Antigen and heat-aggregated IgG. The peptide RGES did not inhibit phagocytosis by macrophages from R or S. These findings bespeak the specificity and importance of the RGD peptide in functioning as a receptor for the binding and phagocytosis of this organism in R. Phagocytosis in both R and S appeared to be mediated by binding to LFA-1 and mediated by either a cell wall component and/or O-Antigen. In S, phagocytosis in the presence of several inhibitors implies an additional or augmented mechanism of uptake, which may directly relate to the pathogenesis of brucellosis. Monocyte-derived macrophages functioned similarly to mammary macrophages in controlling the intracellular proliferation of B. abortus. Cells from R controlled intracellular bacterial proliferation, while cells from S did not. Presentation of protein antigens of B. abortus to oligoclonal T lymphocyte cultures by macrophages from both R and S was inhibited similarly by chloroquine, monensin, cerulenin, brefeldin A, NH4CI, and suramin, but not by leupeptin. Oligoclonal T lymphocytes enhanced the control of intracellular proliferation of B. abortus in both R and S. T lymphocytes alone had no effect on bacterial proliferation. These data suggest enhancement of bactericidal activity of the cultured macrophages by lymphokines produced by the T lymphocytes, or direct cytotoxicity by the T lymphocytes. This system for study of bovine immune function should serve as a basis for future studies to more clearly delineate the interactions between B. abortus and its bovine host. |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Veterinary Pathology." |
| Physical Description: | x, 115 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |