A regulatory role for Fc gamma receptors (CD16 and CD32) in hematopoiesis.
Progenitor cells of the T- and B-lineages in mice express (CD32) and Fc gamma RIII (CD16) but as the developing lymphocytes begin to express clonal antigen receptors, CD16 and CD32 are downregulated in T-cells, and CD16 is downregulated in B-cells. Considering that counter-receptors for Fc gamma R occur on thymic and bone marrow stromal cells, the possibility exists that Fc gamma R might participate in some aspect of T- and B-lineage development prior to the stage of antigen receptor expression. Previous studies provided evidence that Fc gamma R can influence murine T-lineage development. In the present studies we found that anti-Fc gamma RII/III mAb accelerated B-lineage development in bone marrow cultures from normal mice, but not in cultures from CD16-/- or CD32-/- mice. Similar results were observed when FACS-purified B-progenitor cells were co-cultured with BMS2, a bone marrow stromal cell line. Fresh bone marrow from CD32-/- mice contained about two-fold more B-lineage cells compared to bone marrow from normal or CD16-/- mice. These studies indicate that the Fc gamma R on B-lineage progenitor cells can influence their further development and add to a growing body of evidence that implicates Fc gamma R as regulatory elements in hematopoiesis.
Department of Pathology, The University of Iowa College of Medicine, Iowa City 52242, USA.
B
B
de Andres
M
M
Hagen
M
M
Sandor
S
S
Verbeek
O
O
Rokhlin
R G
RG
Lynch
D000818:Animals; D002478:Cells, Cultured; D005434:Flow Cytometry; D006410:Hematopoiesis / Q000276:immunology*; D006801:Humans; D051379:Mice; D020297:Mice, Congenic; D017452:Receptors, IgG / Q000378:metabolism / Q000502:physiology*; D013601:T-Lymphocytes / Q000378:metabolism
D017452:Receptors, IgG