A model scheme for human hematopoietic cell differentiation as determined by multiple markers of leukemia-lymphomas.

The analysis of leukocyte differentiation has been greatly enhanced by developments in three areas of methodology: Firstly by the establishment of relatively stable permanent hematopoietic cell lines of a variety of origin, secondly by the development of numerous specific polyclonal and monoclonal heterologous antibodies to various leukocyte antigens, and thirdly by the introduction of many functional assays of both hematopoietic progenitor cells and mature leukocyte subsets aided by various new cell culture and cell separation procedures. We have been primarily intgrested in characterizing both permanent leukemialymphoma cells and fresh uncultured leukemia-lymphoma cells. At the present, we have a total of 74 proven human leukemialymphoma cell lines in the laboratory. These lines include T-cell, B-cell, lymphoid precursor, myelomonocyte, erythroid, and histiocytic lineages [6,7]. The advantages of using leukemia-lymphoma are twofold: (1) individual leukemia-lymphoma presents an expanded monoclonal population and (2) the marker profile reflects an arrested Stage of various point of hematopoietic cell differentiation [4, 51. Furthermore, all antigens found in the leukemia-lymphoma cells are not tumor specific, but these antigens appear to be the normal gene products. In contrast, the normal hematopoietic cell populations are extremely heterogeneous,