title: Effect of Salmonella infection on cecal tonsil regulatory T cell properties in chickens.
abstract: Two studies were conducted to study regulatory T cell [Treg (CD4⁺CD25⁺)] properties during the establishment of a persistent intestinal infection in broiler chickens. Four-day-old broiler chicks were orally gavaged with 5 × 10⁶ CFU/mL Salmonella enteritidis (S. enteritidis) or sterile PBS (control). Samples were collected at 4, 7, 10, and 14 d postinfection. There was a significant (P < 0.05) increase in the number of CD4⁺CD25⁺ cells by d 4 postinfection that increased steadily throughout the course of the 14-d infection, whereas the number of CD4⁺CD25⁺ cells in the noninfected controls remained steady throughout the study. CD4⁺CD25⁺ cells from cecal tonsils of S. enteritidis-infected birds had a higher (P < 0.05) IL-10 mRNA content than CD4⁺CD25⁺ cells from the noninfected controls at all time-points studied. The amount of IL-2 mRNA content in the cecal tonsil CD4⁺CD25⁻ cells from the infected birds did not differ (P > 0.05) when compared to that of noninfected control birds. At a lower effector/responder cell ratio of 0.25:1, CD4⁺CD25⁺ cells from cecal tonsils of Salmonella-infected birds suppressed T cell proliferation at d 7 and 14 post-S. enteritidis infection, while CD4⁺CD25⁺ cells from noninfected control groups did not suppress T cell proliferation. In the second studu, 1-day-old chickens were orally gavaged with PBS (control) or 1.25 × 10⁸ CFU/bird S. enteritidis. At 7 and 21 d post-Salmonella infection, CD25⁺ cells collected from cecal tonsils of S. enteritidis-infected birds and restimulated in vitro with Salmonella antigen had higher (P < 0.05) IL-10 mRNA content compared to those in the control group. Spleen CD4⁺CD25⁺, CD4⁺, and CD8⁺ cell percentage did not differ (P > 0.05) between the Salmonella-infected and control birds. In conclusion, a persistent intestinal S. enteritidis infection increased the Treg percentage, suppressive properties, and IL-10 mRNA amounts in the cecal tonsils of broiler birds.
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster, OH 44691.
authors.forename: Revathi
authors.initials: R
authors.lastname: Shanmugasundaram
authors.affiliation: USDA-Agricultural Research Service (ARS), Plains Area, College Station, TX 77845.
authors.forename: Michael H
authors.initials: MH
authors.lastname: Kogut
authors.affiliation: USDA-Agricultural Research Service (ARS), Plains Area, College Station, TX 77845.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Arsenault
authors.affiliation: USDA-Agricultural Research Service (ARS), Plains Area, College Station, TX 77845.
authors.forename: Christina L
authors.initials: CL
authors.lastname: Swaggerty
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster, OH 44691.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Cole
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster, OH 44691.
authors.forename: John M
authors.initials: JM
authors.lastname: Reddish
authors.affiliation: Department of Animal Sciences, Ohio Agricultural Research and Development Center, Wooster, OH 44691 selvaraj.7@osu.edu.
authors.forename: Ramesh K
authors.initials: RK
authors.lastname: Selvaraj
mesh_terms: D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology; D002432:Cecum; D002645:Chickens; D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D011201:Poultry Diseases / Q000276:immunology / Q000382:microbiology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012481:Salmonella Infections, Animal / Q000150:complications*; D012477:Salmonella enteritidis; D050378:T-Lymphocytes, Regulatory / Q000502:physiology*
chemical_list: D016207:Cytokines; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger
keywords: IL-10; Salmonella; Tregs; persistance