Mouse thymus reticulo-epithelial (RE) cells in vitro: isolation cultivation and preliminary characterization

The reticulo-epithelial (RE) cells of the thymus are presumably playing a crucial role in the differentiation of the T lineage lymphoid cells, but how this happens is still a matter for speculation. This paper describes a method for rapid preparation of thymic RE cells with as little damage as possible, their culture, and the analysis of their membrane antigens and of other cytological properties. The cultured cells are pleiomorphic, but at least two types can be distinguished, one being round and very villous, the other one being flat and very cystic. Thymus RE cells have species specific surface antigens and large amounts of H-2 antigen. The possible presence of theta antigen is unclear. Most cells have no detectable Tla antigen. In vitro, they show some uptake of normal mouse serum immunoglobulins. RE cells show a surface migration of ligand-bound membrane antigen; such a capping is much slower than for lymphocytes, and is inhibited by 10 mM NaN3; The drug also causes the apparition of long microprojections (or retraction fibres) on the villous RE cell type, as is also caused by a slight fixation with formalin. Type C virus particles are found in RE cells from AKR mice as young as 1 day.