Submitted to: Avian Immunology Group Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2004
Publication Date: 9/1/2004
Citation: Okamura, M., Lillehoj, H.S., Raybourne, R., Babu, U., Heckert, R.A. 2004. Avian macrophage response against salmonellosis and the effect of ifn-gamma and cpg motif o the intracellular survival of salmonella. Avian Immunology Group Meeting, p. 91.
Technical Abstract: Salmonella is known to induce apoptosis in host macrophages although the organisms are the facultative intracellular bacteria causing systemic dissemination by their survival within the host macrophages. Apoptosis may lead to systemic dissemination by repeating the process in which the intracellular bacteria are released outside the cells, thereby resulting in phagocytosis of Salmonella by new phagocytes again. In this study, the interaction of chicken macrophages and Salmonella enterica serovars Enteritidis and Typhimurium (SE and ST, respectively), which have been isolated frequently from the cases of human food poisoning and poultry farms, were compared. The results showed that SE was less prone to induce apoptosis and nitric oxide (NO) production in macrophages compared to ST. This difference may account for the type of host response which is associated with different serovars of Salmonella. Moreover, we investigated the effects of CpG oligodinucleotide (ODN) and interferon gamma (IFN-g) on Salmonella-infected macrophages. CpG ODN induced iNOS-dependent apoptosis accompanied by high NO production in Salmonella-infected macrophages. IFN-g, on the other hand, induced apoptosis, elicited NO production, and reduced the bacterial replication within the macrophages. These results clearly demonstrated that CpG ODN and IFN-g enhance host innate immunity against Salmonella making them of high potential use for the immunoenhancement of protective immunity against salmonellosis. (This work was supported by the grant from USDA National Food Safety Initiative Grant 00-51110-9739)