Cytokine gene expression in chicken cecal tonsils following treatment with probiotics and Salmonella infection.
Probiotics are currently employed for control of pathogens and enhancement of immune response in chickens. In this study, we investigated the underlying immunological mechanisms of the action of probiotics against colonization of the chicken intestine by Salmonella enterica subsp. enterica serovar Typhimurium (Salmonella serovar Typhimurium). Birds received probiotics by oral gavage on day 1 of age and, subsequently, received Salmonella serovar Typhimurium on day 2 of age. Cecal tonsils were removed on days 1, 3 and 5 post-infection (p.i.), RNA was extracted and subjected to real-time quantitative RT-PCR for measurement of interleukin (IL)-6, IL-10, IL-12 and interferon (IFN)-gamma gene expression. There was no significant difference in IL-6 and IL-10 gene expression in cecal tonsils of chickens belonging to various treatment groups. Salmonella serovar Typhimurium infection resulted in a significant increase in IL-12 expression in cecal tonsils on days 1 and 5p.i. However, when chickens were treated with probiotics prior to experimental infection with Salmonella, the level of IL-12 expression was similar to that observed in uninfected control chickens. Treatment of birds with probiotics resulted in a significant decrease in IFN-gamma gene expression in cecal tonsils of chickens infected with Salmonella compared to the Salmonella-infected birds not treated with probiotics. These findings reveal that repression of IL-12 and IFN-gamma expression is associated with probiotic-mediated reduction in intestinal colonization with Salmonella serovar Typhimurium.
Department of Pathobiology, Ontario Veterinary College, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Hamid R
HR
Haghighi
Mohamed Faizal
MF
Abdul-Careem
Rozita A
RA
Dara
James R
JR
Chambers
Shayan
S
Sharif
D000818:Animals; D002432:Cecum / Q000187:drug effects / Q000378:metabolism; D002645:Chickens; D016207:Cytokines / Q000235:genetics*; D004305:Dose-Response Relationship, Drug; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D014066:Palatine Tonsil / Q000187:drug effects / Q000378:metabolism* / Q000382:microbiology; D011201:Poultry Diseases / Q000188:drug therapy* / Q000235:genetics* / Q000276:immunology / Q000382:microbiology; D019936:Probiotics / Q000494:pharmacology* / Q000627:therapeutic use; D012481:Salmonella Infections, Animal / Q000188:drug therapy* / Q000235:genetics* / Q000276:immunology; D012486:Salmonella typhimurium / Q000502:physiology*
D016207:Cytokines