IL-17-expressing CD4+ cells (TH17 cells) constitute a considerable proportion of lymphocytes in the intestinal lamina propria (LP), even in healthy mice kept under specific pathogen free conditions. TH17 cells are rarely observed in the spleen, mesenteric lymph node, or Peyer’s patches. Germ-free mice or antibiotics (vancomycin and metronidazole)-treated mice show marked reductions in numbers of LP TH17 cells; thus, intestinal commensal bacteria provide a particular environment for the development of LP TH17 cells.
This protocol describes the procedure to isolate LP lymphocytes and to assay for IL-17 expression by intracellular cytokine staining.