Enhancing and suppressing effects of recombinant murine macrophage inflammatory proteins on colony formation in vitro by bone marrow myeloid progenitor cells

Abstract

Purified recombinant (r) macrophage inflammatory proteins (MIPs) 1 alpha, 1 beta, and 2 were assessed for effects on murine (mu) and human (hu) marrow colony-forming unit-granulocyte-macrophage (CFU-GM) and burst-forming unit-erythroid (BFU-E) colonies. Recombinant MIP-1 alpha, -1 beta, and -2 enhanced muCFU-GM colonies above that stimulated with 10 to 100 U natural mu macrophage-colony-stimulating factor (M-CSF) or rmuGM-CSF, with enhancement seen on huCFU-GM colony formation stimulated with suboptimal rhuM-CSF or rhuGM-CSF; effects were neutralized by respective MIP-specific antibodies. Macrophage inflammatory proteins had no effects on mu or huBFU-E colonies stimulated with erythropoietin (Epo). However, natural MIP-1 and rMIP-1 alpha, but not rMIP-1 beta or -2, suppressed muCFU-GM stimulated with pokeweed mitogen spleen-conditioned medium (PWMSCM), huCFU-GM stimulated with optimal rhuGM-CSF plus rhu interleukin-3 (IL-3), muBFU- E and multipotential progenitors (CFU-GEMM) stimulated with Epo plus PWMSCM, and huBFU-E and CFU-GEMM stimulated with Epo plus rhuIL-3 or rhuGM-CSF. The suppressive effects of natural MIP-1 and rMIP-1 alpha were also apparent on a population of BFU-E, CFU-GEMM, and CFU-GM present in cell-sorted fractions of human bone marrow (CD34 HLA-DR+) highly enriched for progenitors with cloning efficiencies of 42% to 75%. These results, along with our previous studies, suggest that MIP-1 alpha, -1 beta, and -2 may have direct myelopoietic enhancing activity for mature progenitors, while MIP-1 alpha may have direct suppressing activity for more immature progenitors.

Altered endochondral ossification in collagen X mouse models leads to impaired immune responses

“…It is noteworthy that several of the cytokines/chemokines that are elevated in the collagen X mice are involved in immune cell development/differentiation, immune response, and hematopoiesis (Patchen et al,1991; Jacobsen et al,1994; Eng et al,1995; Broxmeyer,2001). In particular, chemokines CTACK and 6Ckine assist in the movement and homing of leukocytes (Argiles and Lopez‐Soriano,1999; Handel et al,2005), and cytokines IL‐4, IL‐12, and IL‐13 have been implicated in enhancing hematopoiesis (Jacobsen et al,1994; Keller et al,1994; Eng et al,1995), whereas, macrophage inflammatory protein‐1 alpha (MIP‐1α), which is decreased in the collagen X Tg mice and perinatal lethal subsets, is implicated in inhibiting hematopoiesis (Broxmeyer et al,1990; Bodine et al,1991; Eaves et al,1993). Furthermore, it may be of relevance that many of these factors, including IL‐4, IL‐6, IL‐12, IL‐13, CTACK, and 6Ckine, bind to HSPGs (Table 1, highlighted in blue) (Patchen et al,1991; Jacobsen et al,1994; Keller et al,1994; Eng et al,1995; Broxmeyer,2001).…”

Diaminofluorene stain detects erythroid differentiation in immature haemopoietic cells treated with EPO, IL‐3, SCF, TGFβ1, MIP‐1α and IFNγ

“…However, the expression of MIP‐1 α has been reported as increased in some bone marrow failure syndromes such as Aplastic Anaemia (33, 34). The myelosuppressive effects of MIP‐1 α have been extensively investigated and MIP‐1 α has been further implicated in negative stem cell regulation (35–39). Of the three cell lines used here, MIP‐1 α was only significantly suppressive for the HEL cell line, which showed reductions in both cell number and haemoglobin production.…”

Expression of Flt3-ligand by the endothelial cell

“…However, the action of MIP-1␣ or TGF-␤ may be inhibitory or stimulatory on the proliferation of hematopoietic progenitors depending on the differentiation stage of the progenitors and/or the presence of other cytokines. [49][50][51][52][53][54] In a stromal cul-ture context, MIP-1␣ was found together with IL-3 and diffusible factors produced by the stromal cells to support the growth of human LTBMC-initiating cells. 55 Discrepancies observed may reflect indirect effects of these mediators via release of cytokines by accessory cells or stromal cells.…”