Ontogeny of the gut-associated lymphoid system in man.
Immunoperoxidase histochemistry using monoclonal antibodies to lymphoid/myeloid cells has been used to study the development of the human mucosal immune system in frozen sections of foetal human intestine at different ages. A steady progression of development was seen between 11 and 19 weeks' gestation. At 11 weeks, Peyer's patches were identifiable only as aggregates of strongly HLA-DR+ cells. By 16 weeks these aggregates became colonized with T and B cells, without distinct cellular zonation. By 19 weeks primary B-cell follicles were seen and T cells occupied the inter-follicular zones. There was also a steady increase in the numbers of lamina propria and epithelial T cells between 11 and 19 weeks' gestation. As in postnatal bowel, CD8+ cells predominated in the epithelium and CD4+ cells predominated in the lamina propria. Thus the important T- and B-cell compartments of the mucosal immune system are well established in the human foetal intestine by mid-gestation.
Department of Paediatric Gastroenterology, Medical College of St Bartholomew's Hospital, London, UK.
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MacDonald
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Spencer
D005333:Fetus; D006801:Humans; D007422:Intestines / Q000196:embryology*; D008208:Lymphatic System / Q000196:embryology*; D010581:Peyer's Patches / Q000196:embryology; D013601:T-Lymphocytes / Q000166:cytology