Lactobacillus plantarum is known to reduce the inflammatory response of macrophages in vitro and decrease inflammation in vivo during colitis. A predominance of M2, anti-inflammatory, macrophages correlates with a reduced severity of colitis. The purpose of this study was to determine if L. plantarum-conditioned media is able to produce an anti-inflammatory macrophage response during Salmonella-induced colitis while also reducing inflammation. Female C57BL/6 mice were infected with Salmonella after streptomycin pretreatment, then gavaged with L. plantarum-conditioned media (or a control) four hours prior to infection and twenty-four hours post-infection, they were sacrificed forty-eight hours post-infection. Samples of the intestines, blood, peritoneal exudate macrophages, spleen derived macrophages, and bone marrow-derived macrophages were collected. L. plantarum-conditioned media was found to limit inflammation in a dose related manner. Inflammation was measured by cecum histology, myeloperoxidase activity in the intestine, and monocyte chemoattractant protein-1 levels in the blood. IκB-α levels in the intestinal epithelium were measured by Western blot and degradation was reduced by L. plantarum-conditioned media treatment of Salmonella infected mice. Macrophages from L. plantarum-conditioned media treated Salmonella infected mice were found to have an M2 phenotype that was not found in any other treatment group. The phenotype markers arginase-1 and Ym-1 were found to be elevated in L. plantarum-conditioned media treated Salmonella infected mice by Western blot, while Src homology 2-containing inositol phosphatase-1 was reduced. Flow cytometry for the M2 markers CD206 and CD14 along with the M1 markers CD16 and CCR7 showed a similar M2 phenotype shift of macrophages from L. plantarum-conditioned media treated Salmonella infected mice. The cytokine profile of macrophages from L. plantarum-conditioned media treated Salmonella infected mice was anti-inflammatory with elevated IL-10 and decreased IL-6, IL-12, and TNF-α supporting the M2 phenotype. The protective effects of L. plantarum-conditioned media were found to be at least partially macrophage dependent in a macrophage transfer experiment. In vitro, L. plantarum-conditioned media was also found to produce M2 phenotype macrophages but have no effect on phagocytic or bactericidal function. In conclusion, L. plantarum-conditioned media provides a novel means of producing an anti-inflammatory immune response during Salmonella infection without compromising the host’s ability to combat infection. / Thesis (Master, Microbiology & Immunology) -- Queen's University, 2011-09-29 10:07:20.666
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:OKQ.1974/6789 |
| Date | 29 September 2011 |
| Creators | TAYLOR, MICHELLE MARIE |
| Contributors | Queen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.)) |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
| Relation | Canadian theses |
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