Effects of normal mouse serum on the IL-3-induced proliferation of bone
marrow cells
CA Dahl and C Lindqvist
Department of Immunology, Karolinska Institute, Stockholm, Sweden.
Normal mouse serum (NMS) devoid of colony-stimulating factor (CSF) was
found to enhance the interleukin 3 (IL-3)-driven colony formation of bone
marrow in vitro. Inclusion of NMS in bone marrow colony-forming assays
resulted in greatly increased numbers of colonies and clusters following
seven days incubation; however, incubation of bone marrow with NMS before
the colony-forming assay had no effect on resultant colony number. The
levels of serum-enhancing activity (SEA) did not appear to vary
significantly with age and in part was species restricted, in that human
and guinea pig serum did not enhance mouse bone marrow colony formation.
Conversely, NMS had no effect on human bone marrow colony formation. Levels
of SEA were found to vary between strains, as did the degree to which bone
marrow from various strains was enhanced by the serum. Serum fractionation
studies indicated three active fractions with molecular weights of 800-900
Kd, 60-70 Kd, and 20- 30 Kd. The fraction at 800-900 Kd inhibited colony
formation at high concentrations and enhanced colony formation on dilution,
whereas the two other active fractions contained enhancing activity at all
concentrations tested. These results would indicate that normal serum can
play a greater role in colony-forming assays than nutritional supplements.
The relationship of the SEA factors to other factors that have been
reported to modulate bone marrow colony formation is discussed.
Volume 73,
Issue 3,
pp. 700-705,
02/15/1989
Copyright © 1989 by The American Society of Hematology
