title: A method for cloning T-lymphocytic precursors in agar.
abstract: A new technique for the culture of T-lymphocytic colonies is reported. The method may be regarded as a human lymphocyte precursor cell assay, as is the myeloid colony culture for granulocyte-macrophage progenitors. The colonies arise under the simultaneous stimulation of phytohemagglutin and a leukocyte feeder. A linear relationship is found between colony numbers and cell numbers plated. The colonies represent aggregates of lymphoblast-like cells, the majority of which are capable of E-rosette formation, are responsive in mixed lymphocyte cultures, and do not exhibit surface immunoglobulins. Their density distribution profile is very similar to that of myeloid colony-forming cells. The finding that most of these colony-forming cells are recovered in the so-called lymphocyte-free stem cell fraction following density fractionation suggests that they originate from a lymphocytic precursor.
mesh_terms: D000362:Agar; D001854:Bone Marrow Cells; D002478:Cells, Cultured; D002999:Clone Cells; D003114:Colony-Forming Units Assay; D005455:Fluorescent Antibody Technique; D006801:Humans; D007158:Immunologic Techniques / Q000379:methods; D008213:Lymphocyte Activation; D007959:Lymphocyte Culture Test, Mixed; D012397:Rosette Formation; D013601:T-Lymphocytes / Q000276:immunology*
chemical_list: D000362:Agar