人胸腺髓质部一种新的表达B细胞抗原的星状细胞群

THE HUMAN THYMIC MEDULLA CONTAINS A NOVEL ASTEROID CELL POPULATION EXPRESSING B LYMPHOCYTE ANTIGENS

9 fetal and 7 juvenile thymuses were used to identify the asteroid cells on the frozen sections by immunohistochemical method. The results indicated that the thymic medulla, except B cells, contains a type of larger cells with small cytoplasmic processes, which has in common with B cell antigens, such as 1gM, 1gA, Leu14, BA-1, HLA-DR and light chain-Kappa, but they do not express OKB-2. Moreover, the asteroid cells do not reactive with T cell antibody and follicular dendritic cell antibody, and lack of ANAE activity. The asteroid cells in the fetal thymus are constantly located in the corticomedullary region, while, in the juveniles, the asteroid cells are mainly distributed within medulla or in the vicinity of Hassall's corpuscles. As regards the function of asteroid cells is not clear. Based on their distribution, it is probably associated with T cell maturation. On the morphologic ground, the asteroid cells are similar to interdigitating cells in thymus, the relationship between them has been discussed.