Apoptosis and differential gene expression of Mycobacterium bovis infected bovine macrophages /
Mycobacteria are one of the most successful bacterial parasites because they can survive in the hostile environment of the macrophage. In the present study, an extensive search for bovine macrophage genes differentially expressed at 0, 12, and 24h after Mycobacterium bovis infection was conducted. D...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1999.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=730319121&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Mycobacteria are one of the most successful bacterial parasites because they can survive in the hostile environment of the macrophage. In the present study, an extensive search for bovine macrophage genes differentially expressed at 0, 12, and 24h after Mycobacterium bovis infection was conducted. Differential expression of 7 genes was successfully confirmed. Sequence homology identified probe 18 as thymosin β-10, probe 26 as a cysteine protease, probe 27 as the signaling lymphocytic activation molecule, probe 30 as the alveolar macrophage-derived chemotactic factor II, probe 35 as ferritin heavy chain, probe 36 as osteopontin and probe 47 as the serum amyloid A protein. M. bovis infection induced macrophage apoptosis. Macrophages infected with a MOI of 25:1 developed chromatin condensation and DNA fragmentation at 4h and 8h respectively, whereas, changes in chromatin condensation induced by MOIs of 10: l and 1:1 required a longer time and had a reduced number of apostolic cells. M. bovis infection induced both upregulation of thymosin β-10 mRNA and apoptosis in bovine monocyte-derived microphones suggesting that macrophage apoptosis may be linked to the overexpression of thymosin β-10 which is known to prevent actin polymerization and accelerate apoptosis. In an attempt to link the upregulation of thymosin β-10 in microphones with the induction of apoptosis, overexpression and antisense analysis of a mouse macrophage cell line transferred with a construct carrying the thymosin β-10 full length cDNA in the sense orientation and with a second construct containing a shorter version in the opposite orientation were performed. All the clones overimpressing the transient were found to undergo apoptosis at higher rates than parental cells, with statistical differences detected in two of six clones. The expression of thymosin β-10 in the antisense orientation did not ameliorate the rate of apoptosis. Although results from this study are not conclusive, this evidence links the upregulation of thymosin β-10 in M. bovis infected microphones with the increase in cell death through apoptosis. |
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| Item Description: | Vita. "Major Subject: Veterinary Microbiology". |
| Physical Description: | xi, 96 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilm Inc. |
| Bibliography: | Includes bibliographical references (leaves 80-95). |