Cell-to-Cell Interaction in T Cell Differentiation

点击翻译按钮获取中文摘要

The thymic microenvironment supporting the T cell development has been presumed to be constructed through interaction between thymic epithelial cells and T cell progenitors. This idea, however, has not been based on exact experimental evidence. The present study aims at clarifying the role of T lineage cells in constructing the thymic environment. By culturing single progenitors together with a deoxyguanosine-treated fetal thymus (FT) lobe, we found that only the T cell progenitor but not B cell or myeloid progenitors are able to support the construction of the thymic microenviroment. Thymic T cell progenitors from Rag2^<-/-> mice, which show differentiation arrest at the CD44^-CD25^+ stage, were found to be similarly effective. These results indicate that T lineage cells at precursor stages, play a pivotal role in constructing the thymic microenvironment.We also investigated the expression of several genes in thymic stromal cells and T lineage cells during early stages of T cell development by RT-PCR.So far, we found that Notch 1, Notch 2, Jagged 1, Jagged 2 were expressed in both epithelial cells and T lineage cells, whereas VCAM1 and FGF were exclusively expressed in ephithelial cells. At present, we are investigating the role of cell-to-cell interaction in the expression of these genes.