Macrophage inflammatory protein (MIP)-1 beta abrogates the capacity of MIP-1 alpha to suppress myeloid progenitor cell growth.
The effects of recombinant murine macrophage inflammatory protein (MIP)-1 beta and MIP-2 on the suppressive activity of MIP-1 alpha were tested using colony formation by human and murine bone marrow burst-forming unit-erythroid (BFU-E), colony-forming unit-granulocyte erythroid macrophage, megakaryocyte (CFU-GEMM), and colony-forming unit-granulocyte macrophage (CFU-GM) progenitor cells. MIP-1 beta, but not MIP-2, when added with MIP-1 alpha to cells, blocked the suppressive effects of MIP-1 alpha on both human and murine BFU-E, CFU-GEMM, and CFU-GM colony formation. Similar results were observed regardless of the early acting cytokines used: human rGM-CSF plus human rIL-3, and two recently described potent cytokines, a genetically engineered human rGM-CSF/IL-3 fusion protein and MGF, a c-kit ligand. The more potent the stimuli, the greater the suppressive activity noted. Pulse treatment of hu bone marrow cells with MIP-1 alpha at 4 degrees C for 1 h was as effective in inhibiting colony formation as continuous exposure of cells to MIP-1 alpha, and the pulsing effect with MIP-1 alpha could not be overcome by subsequent exposure of cells to MIP-1 beta. Also, pulse exposure of cells to MIP-1 beta blocked the activity of subsequently added MIP-1 alpha. For specificity, the action of a nonrelated myelosuppressive factor H-ferritin, was compared. MIP-1 alpha and H-ferritin were shown to act on similar target populations of early BFU-E, CFU-GEMM, and CFU-GM. MIP-1 beta did not block the suppressive activity of H-ferritin. Also, hemin and an inactive recombinant human H-ferritin mutein counteracted the suppressive effects of the wildtype H-ferritin molecule, but did not block the suppressive effects of MIP-1 alpha. These results show that MIP-1 beta's ability to block the action of MIP-1 alpha is specific. In addition, the results suggest that MIP-1 alpha and MIP-beta can, through rapid action, modulate early myeloid progenitor cell proliferation.
Department of Medicine (Hematology/Oncology), Indiana University School of Medicine, Indianapolis 46202.
H E
HE
Broxmeyer
B
B
Sherry
S
S
Cooper
F W
FW
Ruscetti
D E
DE
Williams
P
P
Arosio
B S
BS
Kwon
A
A
Cerami
D001853:Bone Marrow / Q000187:drug effects; D001854:Bone Marrow Cells; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D054407:Chemokine CCL4; D016207:Cytokines / Q000494:pharmacology*; D005293:Ferritins / Q000494:pharmacology; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000494:pharmacology; D006412:Hematopoietic Stem Cells / Q000187:drug effects*; D006801:Humans; D007377:Interleukin-3 / Q000494:pharmacology; D019402:Macrophage Inflammatory Proteins; D015846:Monokines / Q000494:pharmacology*
D054407:Chemokine CCL4; D016207:Cytokines; D007377:Interleukin-3; D019402:Macrophage Inflammatory Proteins; D015846:Monokines; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D005293:Ferritins