title: Influence of immunomodulation on the development of Listeria monocytogenes infection in aged guinea pigs.
abstract: We investigated the impact of immunomodulation on the development of listeriosis within an aged population of guinea pigs after an intragastric challenge with Listeria monocytogenes. Supplementation with vitamin E for 35 days significantly increased the level of cytotoxic T cells (CD8(+)), while treatment with cyclosporin A resulted in a 25% decrease of CD8(+) T cells. In the animals receiving the low dose (10(2) CFU) of L. monocytogenes, 50% of the control-group animals became infected. Only 22% of animals receiving the orthomolecular dose of vitamin E became infected, whereas animals that were immunosuppressed had an infection rate of 89%. In the immunosuppressed group three animals (16%) developed listerial infection with a quantifiable bacterial level of 0.3-3 log CFU g(-1) of organ in the spleen and liver. In the high-dose study, the population of L. monocytogenes was consistently 1 log CFU g(-1) lower in the spleen or liver of the vitamin E-supplemented group, compared with the control and cyclosporin A-treated animals. At day 4, a significant increase in the levels of CD8(+) during listerial infection occurred in vitamin E-supplemented animals, suggesting an increased ability to produce CD8(+) T cells. The results suggest that immunomodulation of the host can influence listerial infection within an aged population of guinea pigs.
authors: Department of Food Science, Rutgers, The University of New Jersey, New Brunswick, NJ 08901, USA.
authors: Hoan-Jen E
authors: HJ
authors: Pang
authors: Chih-Yu
authors: CY
authors: Lo
authors: Karl R
authors: KR
authors: Matthews
mesh_terms: D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D015169:Colony Count, Microbial; D016572:Cyclosporine / Q000008:administration & dosage / Q000276:immunology; D004195:Disease Models, Animal; D005260:Female; D005434:Flow Cytometry; D006168:Guinea Pigs; D007155:Immunologic Factors / Q000494:pharmacology*; D008089:Listeria monocytogenes / Q000276:immunology* / Q000502:physiology; D008088:Listeriosis / Q000276:immunology*; D008099:Liver / Q000382:microbiology; D050296:Microbial Viability; D013154:Spleen / Q000382:microbiology; D014810:Vitamin E / Q000008:administration & dosage / Q000276:immunology
chemical_list: D007155:Immunologic Factors; D014810:Vitamin E; D016572:Cyclosporine