CELL-SURFACE CHANGES OF HEMATOPOIETIC-CELLS DURING NORMAL AND LEUKEMIC DIFFERENTIATION - AN IMMUNOSCANNING ELECTRON-MICROSCOPY STUDY

Hemopoietic cells display a wide range of cell surface antigens which are either lineage specific or acquired during differentiation. Monocl onal antibodies can be used, in conjunction with colloidal gold marker s, to identify under the scanning electron microscopy (SEM) at the sin gle cell level, specific lineage or maturation stages in the hemopoiet ic bone marrow. Normal bone marrow cells, either gradient separated or purified by immune-magnetic methods and leukemic cell samples, which can be considered as ''frozen'' stages of hemopoietic differentiation, have been studied with this method. Typical cell surface morphologies , which characterize immature progenitor cells and cells committed or differentiated towards the lymphoid, myeloid, erythroid and megakaryoc ytic lineage have been identified. Correlations between cell surface f eatures and some hemopoietic cells functions have been attempted on th e basis of these findings.