T-Cell Development in Early Partially DecapitatedChicken Embryos

摘要

We have evaluated the immunohistological and cytofluorometric changes that occur in thethymus of chicken embryos partially decapitated at 33-38 hr of incubation (DCx embryos)in an attempt to analyze possible neuroendocrinological influences on T-cell differentiationand, indirectly, the ontogeny of the so-called neuroendocrine-immune network. Thethymus of DCx embryos shows important variations that profoundly and selectively affectdifferent T-cell subsets, but not the nonlymphoid cell components of thymic stroma. Thesemodifications include the accumulation of cell precursors, mainly DN (CD4-CD8-) cellsand immature CD8highCD4-cells, which expand but do not differentiate, resulting in anextreme decline of both DP (CD4+CD8+) cells and TcR c-expressing cells. Accordingly,both subcapsulary and outer cortex increase in size, whereas the deep cortex and principallythe thymic medulla almost disappear in DCx embryos. In contrast, other T-cell subsets ofDCx embryos, largely CDgglowCD4-cells and TcRγδ-expressing cells do not undergosignificant variations throughout thymic ontogeny.