Mechanistic Evaluation of the Induction of Lymphoproliferation and Apoptosis Inhibition by Probiotic Bacteria in Mice Infected with Salmonella Enterica

1) Orally challenge defined human microbiota-associated (HMA) BALB/c mice and probiotic-bacteria-treated HMA BALB/c mice with Salmonella enterica and isolate intestinal mucosal-associated lymphoid tissues (MALT) , including Peyer's patches, lamina propria, and mesenteric lymph nodes. <P>
2) Use pathway-focused gene-expression profiles generated from real-time RT-PCR expression arrays to compare signal transduction in MALT from HMA mice treated with or without probiotic bacteria and orally challenged with S. enterica. <P>

3) Develop immunohistochemical (IHC) and in situ hybridization (ISH) conditions to detect the expression of the signal pathway molecules implicated in activation and apoptosis inhibition in mucosal T cells and accessory cells in tissue sections of Peyer's patches, lamina propria, and mesenteric-lymph nodes. <P>

4) Conduct IHC and ISH studies on tissue sections for detection of molecules involved in the regulation of lymphocyte activation and programmed cell-death pathways induced by bacterial-surface antigens. <P>
5) Compare the probiotic-treated and untreated mice for expression of dendritic cell, macrophage, and IEC-derived cytokines.