Human Peyer’s Patch T Cells Are Sensitized to Dietary Antigen and Display a Th Cell Type 1 Cytokine Profile

Open Access
Publisher Website
Google Scholar
Abstract
Animal studies have demonstrated that feeding Ags induces regulatory (Th2, Th3) cells in Peyer’s patches (PP), which migrate to the periphery and produce immunomodulatory cytokines such as IL-4, IL-10, or TGF-β. In this work we have attempted to extend this paradigm to man by analyzing the response of human PP T cells to in vitro challenge with the common dietary Ag β-lactoglobulin (βlg) of cow’s milk. PP T cells stimulated with βlg showed enhanced proliferation compared with blood T cells from the same patient. Increased expression of CD25 and the Th1-associated chemokine receptor CCR5 was also seen on CD4+ and CD8+ PP T cells, but not blood T cells, stimulated with βlg. By enzyme-linked immunospot assay and RT-PCR, the PP T cell recall response to βlg and casein was dominated by IFN-γ, with negligible IL-4, IL-5, IL-10, or TGF-β. To help explain the PP T cell response to βlg, we examined IL-12 expression. Both IL-12p40 and -p35 transcripts were abundantly expressed in PP, but not in adjacent normal ileal mucosa. Immunoreactive IL-12p40-containing cells were present below the PP dome epithelium. Furthermore, in culture, PP, but not paired PBMC, spontaneously released IL-12p70. These results suggest that the human response to oral Ags in the gut may be different from that in rodents.

This publication has 37 references indexed in Scilit: