COLONY GROWTH OF HUMAN HEMATOPOIETIC PROGENITOR CELLS IN THE ABSENCE OF SERUM IS SUPPORTED BY A PROTEINASE-INHIBITOR IDENTIFIED AS ANTILEUKOPROTEINASE

Citation
Hm. Goselink et al., COLONY GROWTH OF HUMAN HEMATOPOIETIC PROGENITOR CELLS IN THE ABSENCE OF SERUM IS SUPPORTED BY A PROTEINASE-INHIBITOR IDENTIFIED AS ANTILEUKOPROTEINASE, The Journal of experimental medicine, 184(4), 1996, pp. 1305-1312
Citations number
25
Categorie Soggetti
Immunology,"Medicine, Research & Experimental
ISSN journal
00221007
Volume
184
Issue
4
Year of publication
1996
Pages
1305 - 1312
Database
ISI
SICI code
0022-1007(1996)184:4<1305:CGOHHP>2.0.ZU;2-B
Abstract
Serum contains many growth factors and nutrients that stimulate colony formation of hematopoietic progenitor cells (HPC) in semisolid cultur es. In the absence of serum, no proliferation of HPCs could be obtaine d in semisolid medium cultures of partially purified bone marrow cells in the presence of multiple hematopoietic growth factors, insulin, ch olesterol, and purified clinical-grade human albumin, This appeared to be due to a suppressive activity induced by monocyte- and T lymphocyt e-depleted accessory cells on CD34(+) HPCs. Serum-free conditioned med ium from the bladder carcinoma cellline 5637 could replace serum to su pport the growth of HPCs in these cultures, After gel filtration and r everse-phase high-performance liquid chromatography of 5637 supernatan ts, this activity could be attributed to a 15-kD protein that was furt her identified by NH2-terminal sequence analysis as the serine protein ase inhibitor antileukoproteinase (ALP). The growth-supportive activit y from the 5637 conditioned medium and the (partially) purified fracti ons could be completely neutralized by a polyclonal rabbit IgG antibod y against human ALP (huALP). Similar supportive effects on the growth of HPC could be obtained in the presence of recombinant huALP, We demo nstrated that the COOH-terminal domain of ALP containing the proteinas e inhibitory activity was responsible for this effect. alpha-1 protein ase inhibitor was capable of similar support of in vitro HPC growth. T hese results illustrate that proteinase inhibitors play an important r ole in the in vitro growth of hematopoietic cells by the neutralizatio n of proteinases produced by bone marrow accessory cells. This may be of particular relevance for in vitro expansion of human hematopoietic stem cells in serum-free media.