W1186 CARD15/NOD2 Mediates Susceptibility to Yersinia Pseudotuberculosis

course of bacterial localization and the immune response of antigen-specific CD4+ T cell in C.rodentium infection remain to be seen.Method and Result: C. rodentium which express GFP constitutively (CR/GFP) has been established by the transformation with the GFPexpression vector.The expression of GFP was confirmed by flow cytometry and fluorescence microscopy.To examine the localization of C.rodentium, 3-week-old wild-type mice were orally inoculated with CR/GFP.CR/GFP were detected on the cell surface at the colon at day 3 and some were also detected in the CD11b positive cells such as macrophages or dendtiric cells of the colon.The bacterial number in the section of the infected colon and in the feces were increased until day 14.To examine the antigen-specific immune response of CD4 + T cell in C.rodentium infection, OVA-expressing C.rodentium which produce chicken ovalbumin constitutively (CR/OVA) have also been established by the transformation with OVA producing plasmid.The antigenic expression of OVA was confirmed by western blot and T cell-proliferation assay.IgM and IgG response against OVA were detected 2 weeks after oral infection with CR/OVA.Next, to examine the C.rodentium-specific T cell response, CFSE systems were utilized.Wild-type mice were infected with CR/OVA at day 1.CFSE labeled OVA-specific CD4+ T cells (OT-II cells) were adoptively transferred at day 12 and then, MLN were collected at day 15.Proliferation of OVA-specific CD4+ T cells were demonstrated by the detection of multiple cell CD4+ division of CFSE-loaded transgenic T cells.Moreover, enhanced cytokine production of IFN-γ and IL-4 were also detected after In Vitro stimulation with OVA.Conclusion: These studies show the natural course and host immune response in C. rodentium infection.These model systems are useful to examine the mucosal immunity against C.rodentium infection in detail.