Phenotypic features and proliferative ability of thymocytes, splenocytes and peripheral blood lymphocytes of 20-22 weeks human fetuses affected by Down's-syndrome (DS) were studied and compared to those of fetuses of the same gestational age with a normal karyotype. In the thymus of both DS and normal fetuses, the great majority of cells was CD1 +, CD2 +, CD5 +, CD4 +, CD8 +; using double fluorescence analysis, these markers could be detected on the same cell. About 50-60% showed CD3 antigen and about 40-50% presented the αβ T cell receptor. Thymocytes with NK markers (CD16, CD57, CD56) were not found. After stimulation with phytohemagglutin, thymocytes showed a low but detectable proliferative capability, while splenocytes and peripheral blood lymphocytes showed a high responsiveness to the mitogen. These data show that the impaired immune system in DS is not associated with gross abnormalities of phenotypic T cell development in the fetal thymus or with an inability of such fetal cells to proliferate after a mitogenic stimulus.
|Number of pages||8|
|Publication status||Published - 1989|
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