Erythroid Cell Proliferation in Human Bone Marrow Suspension Cultures

Abstract

Summary. A simple suspension type culture system has been described for the in vitro maintenance of erythroid cells obtained from adult human bone marrow. In the presence of erythropoietin, normoblasts of all stages of maturation were still present after more than 10 days in culture. Following an initial decline, the numbers of basophilic normoblasts showed an absolute increase, reaching a maximum after about 5 days. Evidence of continued DNA synthesis in these cells, the observation of mitotic figures and the tracing of [3H]thymidine label from early normoblasts to intermediate and late normoblasts in culture further suggests that these cells arise by differentiation from unrecognizable erythroid precursor cells. Despite an apparent reduction in proliferation during the maturation of these cells, this system offers a method for investigating various aspects of erythroid cell differentiation and development.

Haemoglobin Synthesis in Human Fetal Liver Maintained in Short‐Term Tissue Culture

“…As judged by the cell kinetics of the system we are observing oiily one round of erythroid differentiation, similar to that observed in adult bone-marrow cultures in the same conditioiis (Wood, 1974a). Thus there is no evidence for a second round of differentiation as would follow the niovement of cells from the stem-ccll compartment into the erythroid compartment.…”

“…Hbs A and F are syiithcsized in the culture system up to about 12 days and there is an increase in the relative amounts of both haemoglobiiis produced coincident with the proliferation of intermediate and late normoblasts at about days 5-7. The excellcnt correlation of the specific activities of Hbs A and F with their constituent u , p and y chains confirmed I9 that this was true hacmoglobin syiithcsis and that the results were not modified by contamination with other radioactively-labelled proteins produced in the bone-marrow system (Wood et al, 1972;Wood, 1974b). Analysis of the total amounts of globin-cham produced indicate that there is balanced chain production throughout the period of culture and thus the mcchanisin responsible for the co-ordination of M-, paiid y-chain synthesis rcmaiiis intact in the in ilitro system.…”

“…These experiments confirm the observations of Basch (1972) that human fetal haemopoietic tissue is erythropoietin responsive. It is now well cstablishcd that in the abscnce of crythropoietin no erythroid-cell differentiation occurs in a human adult bone marrow maintained in vitro (Lajtha, 1952;Berman& Powsner, 1959;Erslev& Hughes, 1960;Astaldi, 1961;Myhre, 1964a, b, c, d ; Wood, 1974a). In the presciit cxpcrimeiits we found that the fetal erythroid cells maintaiiicd without erythropoietin show some degree of differciitiation which followed the same pattern as that of erythropoietin-treated cultures, although at a very low rate.…”

“…The cells were cultured according to the method of Wood (1974a) with certain modifications. A cell suspension was set up at a final coiiceiitration of 5-6 x 103 nucleated cellsjml in a culture medium containing 50% AB serum/50% medium 199 (Glaxo Laboratories Ltd) to which had been added sodium bicarbonate to a final concentration of 0.088%, penicillin IOO u/ml, streptomycin 0.5 mg/nil and, in some experiments, erythropoietin at a final concentration of 0.3-0.4 u/ml.…”

Experimental Hematology Today

“…enriched lymphocytes (PHA-LyCM) can Mouse humoral factor (5) Activated T-cell factor (1 0) Autologous conditioned medium ( 15) Feeder layer (4) or conditioned medium containing CS (3) Autologous conditioned medium (15) Erythropoietin (22,54) Erythropoietin and mouse environment (28) Mouse spleen environment (28) EBV infection (43) T-GS (39) Immune response (33) stimulate the growth of lymphoid cells containing T-cell markers for several months, and possibly of permanent duration (39). The committed stem cells in this system can probably renew themselves only to a limited degree.…”