A lymphocyte that is part of a Peyer's patch. These cells have a major role in driving the immune response to antigens sampled from the intestinal lumen, and in regulating the formation of follicle-associated epithelium and M cells in Peyer's patches by converting intestitial enterocytes into M cells. [ http://www.ncbi.nlm.nih.gov/pubmed/23525039 http://www.ncbi.nlm.nih.gov/pubmed/9252325 https://orcid.org/0000-0003-4183-8865 ]