pubmed-article:8026531 | pubmed:abstractText | Immunohistochemistry on frozen sections was used to identify CD8 alpha alpha cells and CD8 alpha beta cells in human intestine. As observed previously, CD8 alpha beta cells predominate (> 95%) in tonsil and post-natal intestine. However in human fetal intestine (16-24 weeks gestation), almost half the CD8+ cells in the lamina propria are CD8 alpha alpha, and many CD8 alpha alpha cells can be identified in the epithelium. In contrast, in the T cell zones of the Peyer's patches, CD8 alpha beta cells are dominant. The CD8 alpha alpha cells are virtually all alpha beta T cell receptor positive. By analogy with the murine system, these CD8 alpha alpha cells in the fetal gut may be directly derived from the marrow, undergoing thymus-independent differentiation in the gut mucosa. | lld:pubmed |