Standardization of cytokine flow cytometry assays.

Background: Cytokine flow cytometry (CFC) or intracellular cytokine staining (ICS) can quantitate antigen-specific T cell responses in settings such as experimental vaccination. Standardization of ICS among laboratories performing vaccine studies would provide a common platform by which to compare the immunogenicity of different vaccine candidates across multiple international organizations conducting clinical trials. As such, a study was carried out among several laboratories involved in HIV clinical trials, to define the inter-lab precision of ICS using various sample types, and using a common protocol for each experiment (see additional files online).

Lymphoepithelial interactions trigger specific regulation of gene expression in the M cell-containing follicle-associated epithelium of Peyer's patches.

In the intestine, the follicle-associated epithelium (FAE) of Peyer's patches (PP) performs Ag sampling as the first step in developing immune responses. Depending on the species, this epithelium contains 10-50% of M cells, which act as regulated gates in epithelial barriers that can be used opportunistically by pathogens to invade their host. However, the mechanisms involved in the differentiation and uptake processes of M cells are not known, in part because their limited number in the intestinal mucosa has hampered molecular and biochemical studies.