IL-7 Receptor alpha+ CD3(-) Cells in the Embryonic Intestine Induces the Organizing Center of Peyer's Patches

Int Immunol. 1999 May;11(5):643-55. doi: 10.1093/intimm/11.5.643.

Abstract

Peyer's patch (PP) organogenesis proceeds through three histologically distinct steps: formation of organizing centers expressing VCAM-1 and ICAM-1 in segregated regions of the intestine at 15.5 days post-coitus (d.p.c.) (step I), accumulation of blood cells expressing different sets of surface markers to this region at 16.5-17.0 d.p.c. (step II), and entry of CD3+ and B220+ lymphocytes just before birth (step III). PP formation of both Il7ra-/- and Lta-/- mice is impaired from step I, suggesting involvement of the two molecules at the same timing in PP organogenesis. Expression of lymphotoxin (LT) alpha and LTbeta in IL-7 receptor (IL-7R) alpha+ cells in the intestine indicates that defects of Il7ra-/- and Lta-/- mice are due to functional inability of IL-7Ralpha+ cells in the induction of PP anlage. Blocking of IL-7Ralpha function by a single injection of the antagonistic mAb in 15.5 d.p.c. embryos suppressed appearance of VCAM-1(+) spots and expression of LTalpha and LTbeta in the intestine, which eventually resulted in mice without PP but are otherwise normal. Intestinal IL-7Ralpha+ cells are lymphoid in morphology but CD3(-) and functional in both nu/nu and Rag2-/- mice. These results implicate IL-7Ralpha+ CD3(-) cells as the direct inducer of the organizing center of PP.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CD3 Complex / analysis*
  • Female
  • Intestines / embryology*
  • Lymphocyte Subsets / physiology
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Peyer's Patches / embryology*
  • Pregnancy
  • Receptors, Interleukin-7 / analysis
  • Receptors, Interleukin-7 / physiology*

Substances

  • CD3 Complex
  • Receptors, Interleukin-7