Mechanisms of resistance to Salmonella enteritidis infections in Leghorn chicks conferred by Salmonella enteritidis-immune lymphokines /
Five experiments are reported where the functional activity of Salmonella enteritidis- (SE) immune lymphokines (ILK) was characterized to evaluate the mechanism(s) of resistance to SE-induced organ infectivity and mortality in neonatal Leghorn chicks. First, administration of ILK, but not Salmonell...
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1995.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=742162561&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | Five experiments are reported where the functional activity of Salmonella enteritidis- (SE) immune lymphokines (ILK) was characterized to evaluate the mechanism(s) of resistance to SE-induced organ infectivity and mortality in neonatal Leghorn chicks. First, administration of ILK, but not Salmonella enteritidis- immune monokines, caused a significant reduction in SE organ invasion (P <.01) and SE- induced mortality during the initial 48 h (P < .001). Second, prophylactic, but not therapeutic, administration of ILK either 30 @n or 6 d before SE challenge caused a significant reduction (P < .005 and P < . 00 1, respectively) in SE organ invasion. Administration of ILK either prophylactically or therapeutically caused a significant increase in the number of circulating polymorphonuclear leukocytes (PMNs). Third, both ]ILK alone and dexamethasone (DEX) + ILK caused a reduction (58% and 46% reduction, respectively) in SE organ invasion. With the exception of PMN chemotaxis, ILK was resistant to the anti-inflammatory effects of DEX in the in vitro PMN functional assays. Fourth, either ILK or serum derived from ILK-treated, SE-challenged chicks caused significant increases (P < .0001) in the number of colony- forming units of bone marrow cells from neonatal chicks. The colony-stimulating activity was heat and acid stable, but trypsin sensitive and supported the growth and differentiation of granulocytic colonies from bone marrow cells. Finally, ELK caused a significant reduction (P < .000 1) in the myeloid:erythroid ratio of the bone marrow derived from ]ILK-treated, SE-challenged chicks four h after SE challenge. Furthermore, there was a significant increase (P <.0001) in the in vitro chemotactic activity of chick bone marrow cells to serum derived from ILK-treated, SE-challenged chicks and greater than 85% of the migrating bone marrow cells were granulocytic cells. Taken together, these data suggest that ILK-mediated protection against SE organ invasion in neonatal chicks may be caused by the colony-stimulating activity in ILK which expands and activates circulating PMNs before SE colonizes and invades the intestine. |
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| Item Description: | Vita. "Major Subject: Veterinary Microbiology". |
| Physical Description: | xii, 135 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |