Gene expression and antibody response in chicken against Salmonella Typhimurium challenge

Authors: DAR, MASHOOQ - University Of Agricultural Sciences; URWAT, UNEEB - University Of Agricultural Sciences; AHMAD, SYED - University Of Agricultural Sciences; AHEMD, RAASHID - University Of Agricultural Sciences; KUSHOO, ZAHID - University Of Agricultural Sciences; DAR, TANVEER - University Of Agricultural Sciences; SHAH, RIAZ - University Of Agricultural Sciences; Heidari, Mohammad

Submitted to: Poultry Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/18/2018
Publication Date: 12/28/2018
Publication URL: https://handle.nal.usda.gov/10113/6471072
Citation: Dar, M.A., Urwat, U., Ahmad, S.M., Ahemd, R., Kushoo, Z.A., Dar, T.A., Shah, R.A., Heidari, M. 2018. Gene expression and antibody response in chicken against Salmonella Typhimurium challenge. Poultry Science. 98(5):2008-2013. https://doi.org/10.3382/ps/pey560.
DOI: https://doi.org/10.3382/ps/pey560

Interpretive Summary: Salmonellosis in humans is the most prevalent food borne bacterial disease worldwide that is most commonly caused by Salmonella enterica mainly originating from the farm animals. Food borne diseases in humans caused by Salmonella remain a major public health concern worldwide and are commonly associated with the consumption of broiler meat contaminated with this bacterium. In this study, we investigated antibody response and expression pattern of several immune related genes in experimentally infected chickens with Salmonella Typhimurium. Data showed higher titer of IgG and IgM antibodies in the infected group in comparison to age-matched control group. Gene expression analysis revealed significant increase in the expression of natural resistance associated macrophage protein (NRAMP, a metal ion transporter family that functions in various organisms ranging from bacteria to humans) in the infected group when compared to the un-infected control birds. The peak expression of NRAMP1 gene was at 3 dpi in liver, 5 dpi in spleen and 7 dpi in caecum of the infected chicken, while the peak expression of NRAMP2 gene was seen at 5 dpi in liver, 8 dpi in spleen and 8 dpi in caecum. The mRNA expression levels of pro-inflammatory cytokines (IFN-gamma, IL-12 and IL-18) reached peak levels in different tissues (liver, spleen and caecum) at different days post infection. The present study aims in better understanding of immunological responses in salmonella infected chickens during the progression of the disease that will help in developing reliable selection methods for Salmonella resistant chickens.

Technical Abstract: Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) is a primary avian pathogen responsible for severe intestinal pathology in younger chickens and economic losses to poultry industry. Furthermore, Salmonella Typhimurium is also able to cause infection in humans, characterized by acute gastrointestinal disease and typhoid fever. A study was conducted to investigate antibody response and expression kinetics of NRAMP1, NRAMP2, IFN-', IL-12, and IL-18 genes in broiler chicken at 0, 1, 3, 5, 7, 9, 11, 13 and 15 dpi following experimental infection of Salmonella Typhimurium. Immunological studies showed higher titers of IgG and IgM in the infected group as compared to the age-matched un-infected control group. The Real-Time PCR-based gene expression analysis revealed significant increase of NRAMPI gene in the infected group as compared to their respective controls (P<0.05). The peak expression of NRAMP1 gene was at 3 dpi in liver, 5 dpi in spleen and 7 dpi in caecum of the infected chicken, while the peak expression of NRAMP2 gene was seen at 5 dpi in liver, 8 dpi in spleen and 8 dpi in caecum. Accordingly, the mRNA expression levels of IFN-gamma, IL-12 and IL-18 genes reached peak levels in different tissues (liver, spleen and caecum) at different days post infection. The present study aims in better understanding of immunological responses by gene expression profiling in salmonella infected chickens during the progression of the disease which can help in developing reliable selection programs for increasing Salmonella resistance.