Blood, Vol. 92 No. 9 (November 1), 1998:
pp. 3073-3081
Expression of Macrophage Inflammatory Protein-1
Receptors in Human
CD34+ Hematopoietic Cells and Their Modulation by Tumor
Necrosis Factor- and Interferon-
Jan Dürig,
Erika A. de Wynter,
Christoph Kasper,
Michael A. Cross,
James Chang,
Nydia G. Testa, and
Clare M. Heyworth
From the CRC Section of Haemopoietic Cell and Gene Therapeutics,
Paterson Institute for Cancer Research, Christie Hospital NHS Trust,
Manchester, UK.
Macrophage inflammatory protein-1
(MIP-1) can stimulate growth
inhibitory and potent chemotactic functions in hematopoietic cells. To
investigate whether the action of MIP-1 may be regulated at the
cellular receptor level, we studied the expression and modulation of
MIP-1 receptors on CD34+ cells isolated from normal
bone marrow (NBM), umbilical cord blood (CB), and leukapheresis
products (LP). Expression of MIP-1 receptors on CD34+
cells was analyzed by two-color flow cytometry using a biotinylated MIP-1 molecule. The mean percentage of LP CD34+ cells
expressing the MIP-1 receptors was 67.7 ± 7.2% (mean ± SEM; n
= 22) as compared with 89.9 ± 2.6% (n = 10) and 74.69 ± 7.04%
(n = 10) in CB and NBM, respectively (P = .4).
The expression of the MIP-1 receptor subtypes on LP
CD34+ cells was studied by indirect immunofluorescence
using specific antibodies for the detection of CCR-1, CCR-4, and CCR-5.
Microscopical examination revealed a characteristic staining of the
cytoplasmic cell membrane for all three receptor subtypes. Detailed
analysis of two LP samples showed that 65.8%, 4.4%, and 30.5% of
CD34+ cells express CCR-1, CCR-4, and CCR-5,
respectively. Culture of LP CD34+ cells for 24 to 36 hours in the presence of tumor necrosis factor- (TNF-) and
interferon-
(IFN-) resulted in a significant increase in MIP-1
receptor expression. TNF- induced MIP-1 receptor upregulation in
a time- and concentration-dependent manner. Our results suggest that
inhibitory cytokines produced by the bone marrow microenvironment are
likely to be involved in the regulation of MIP-1 receptor expression
on hematopoietic cells.
© 1998 by The American Society of Hematology.
