Immunological and gene expression responses to aSalmonellainfection in the chicken intestine

Abstract

-Besides infection in humans, Salmonella enteritidis can also cause serious illness in young chickens. However, the genetic and immunological parameters important for the disease in chickens are not well characterized. In this study, processes in the chicken intestine in response to a Salmonella infection were investigated in two different chicken lines. One-day-old chickens were orally infected with Salmonella. T-cell subpopulations, phagocytic properties of intestinal mononuclear cells and RNA expression levels of the jejunum were investigated. The two chicken lines differed in the amount of cfu in the liver and growth retardation after the infection. Differences in phagocytic activity of intestinal mononuclear cells were found between control and Salmonella infected chickens. The number of CD4 + T-cells of the intestine decreased after the Salmonella infection in one chicken line, while the number of CD8 + T-cells increased in both chicken lines, but the time post infection of this increase differed between the lines. In one chicken line the expression levels of the genes carboxypeptidase M and similar to ORF2 decreased after the Salmonella infection, which might be related to a decrease in the amount of macrophages. With the microarray, ten genes were found that were regulated in only one of the chicken lines, while we found six genes regulated in response to the infection in both chicken lines. So differences in genetic background of the chickens influence the intestinal host response of the Salmonella infection as observed by phagocytic activity, gene expression and changes in the number of T-cell subpopulations and macrophages.immunology / microarray / Salmonella / T-cell

Avaliação da resposta imunológica da mucosa intestinal de frangos de corte desafiados com diferentes sorovares de Salmonella

“…Outros estudos avaliaram a interação dessas células em agregados linfoides intestinais após infecção oral com Salmonella em aves jovens (Sasai et al 2000, Berndt et al 2007, Hemert et al 2007. As células T CD8+ desempenham um importante papel no combate das infecções primárias por salmonelas, assim como a resposta por IgA e leucócitos polimorfonucleados (Berndt & Methener 2001).…”

“…Em contrapartida, Hemert et al (2007) mostraram diminuição na contagem destas células no jejuno ao primeiro e ao quinto dia pós-inoculação oral de 0,2 ml de 10 5 UFC/ml de Salmonella Enteritidis quando comparado com o controle negativo.…”

Identification of Key Genes in the Response toSalmonella enterica Enteritidis,Salmonella enterica Pullorum, and Poly(I:C) in Chicken Spleen and Caecum

“…For instance, van Hemert et al identified differential expression of genes by microarray experiments in intestinal tissue sampled from chicks infected with S. Enteritidis and uninfected individuals [8–10]. Similarly, Schokker et al identified 20 key hub genes by analyzing a time series of microarray data of intestinal tissues collected at different time points after day-old chicks were infected with S. Enteritidis [11].…”

An assessment of opportunities to dissect host genetic variation in resistance to infectious diseases in livestock

“…Associations have also been reported with a variety of candidate genes (Kramer et al, 2003;Malek et al, 2004), which include MHC polymorphisms and NRAMP Lamont et al, 2002;Liu et al, 2003). Gene expression differences in response to the bacteria have been found (Van Hemert et al, 2006 and, as well as significant changes in cytokine expression (Kaiser et al, 2006) and in common processes in the chicken intestine (Van Hemert et al, 2007). Clearly, host genetic variations to Salmonella infections in poultry are being studied extensively and, given the developed state of chicken genomic tools, Salmonella is a high-priority candidate for OG studies.…”