Interleukin-13 selectively suppresses the growth of human macrophage
progenitors at the late stage
O Sakamoto, M Hashiyama, A Minty, M Ando and T Suda
Department of Cell Differentiation, IMEG, Kumamoto University School of
Medicine, Japan.
Interleukin-13 (IL-13) is a pleiotropic cytokine that inhibits the
production of inflammatory cytokines of monocytes. We investigated the
effects of IL-13 on the clonal growth of human hematopoietic progenitors.
IL-13 alone did not support any colony formation. IL-13 markedly suppressed
macrophage colonies that were formed in the presence of IL-3 and
erythropoietin, granulocyte-macrophage colony- stimulating factor, or
macrophage colony-stimulating factor. Macrophage colony cells showed
dendritic cell-line morphology and cellular aggregates. IL-13 did not
affect granulocyte colony and erythroid burst formation. Delayed addition
of IL-13 and replating onto the culture dishes with IL-13 showed that
macrophage colony formation was suppressed during days 8 and 14 of culture.
These results indicate that IL-13 affects the growth of the late stage of
committed macrophage progenitors. Single-cell culture of isolated
CD34+CD33+ cells with IL- 13 confirmed that macrophage colony formation was
significantly suppressed. These results show that IL-13 directly suppresses
the proliferation of differentiating macrophages. In addition, these
suppressive effects of IL-13 were synergistic with IL-4. Furthermore, in
the liquid culture of bone marrow cells in the presence of IL-13, the
number of CD14 (monocyte-macrophage antigen)-positive cells decreased and
CD18 (LFA-1 beta)-positive cells increased. It is concluded that IL-13
affects the growth of the late stage of macrophage precursors as well as
mature monocytes. Induction of differentiation of human monocytes may be
correlated with the suppression of their progenitors.
Volume 85,
Issue 12,
pp. 3487-3493,
06/15/1995
Copyright © 1995 by The American Society of Hematology
