The fucosylated histo-blood group antigens H type 2 (blood group O, CD173) and Lewis Y (CD174) are expressed on CD34+ hematopoietic progenitors but absent on mature lymphocytes
Yi Cao
1
Anette Merling
1
Uwe Karsten
0
Reinhard Schwartz-Albiez
1
0
Max Delbruck Centre for Molecular Medicine
,
13125 Berlin-Buch
,
Germany
1
Division of Cellular Immunology, German Cancer Research Centre
,
Im Neuenheimer Feld 280, 69120 Heidelberg
,
Germany
-
The expression of LeY, H2, H3, and H4 on a broad variety
of human leukemia cell lines and native lymphocytes as well as
on CD34+ hematopoietic progenitor cells was examined by
flow cytometry and immunocytochemistry. CD34+ leukemia
cell lines (KG1, KG1a, and TF1) and native CD34+
hematopoietic progenitor cells expressed H2 (CD173) and LeY
(CD174). In contrast, CD34 cell lines (HL-60, U937, JOK-1,
Raji, Molt-3, Jurkat, and CEM-C7) and mature
lymphocytes from peripheral blood and tonsils lacked
CD173 and CD174. All cell lines and native lymphocytes as
well as CD34+ precursor cells were negative for H3 and H4.
Immunoprecipitation and consecutive Western blotting
revealed a 170-kDa glycoprotein as the carrier molecule for
the CD173 and CD174 oligosaccharide sequences on CD34+
hematopoietic precursors. The key enzyme for generating
CD173 is the -D-galactoside 2--L-fucosyltransferase
(FUT1). As shown by RT-PCR, FUT1 was expressed in
immature hematopoietic cells but absent in mature
lymphocytes, which indicates that expression of CD173
within the hematopoietic system is regulated at the
transcriptional level by FUT1. Due to their exclusive presence
on CD34+ hematopoietic progenitor cells, CD173 and
CD174 represent novel markers of early hematopoiesis.
The expression of the fucosylated histo-blood group
antigens CD173 and CD174 in CD34+ hematopoietic progenitor
cells and down-regulation of FUT1 in mature lymphocytes
may be important factors influencing the homing process of
hematopoietic stem cells to the bone marrow.
Fucose is an important terminal residue occurring on
oligosaccharide chains of cell surfaceexpressed glycoconjugates.
1To whom correspondence should be addressed
Fucosylated glycans are involved in cellcell and cellmatrix
interactions, differentiation, proliferation, and apoptosis (Varki,
1993). In hematopoietic cells, these glycans play an important
role in the recirculation of lymphocytes from the bloodstream
into lymphatic organs (Stoolman and Rosen, 1983; Gallatin et
al., 1983) and in permitting adhesive contacts between
hematopoietic progenitor cells and bone marrow stromal cells
(Schmitz et al., 1996; Le Marer and Skacel, 1999). The
expression of some fucosylated antigens such as LeX (CD15,
Gal14[Fuc-1-3]GlcNAc-) and sialosyl-LeX (CD15s,
NeuAc23Gal-1-4[Fuc1-3]GlcNAc-) on hematopoietic cells has been
studied (Terstappen et al., 1990; Kannagi, 1997). However, a
systematic and comprehensive analysis of the fucosylated
histo-blood group antigens LewisY (LeY, CD174 [Histo-blood
group antigens H2 and LeY were assigned as CD173 and
CD174, respectively, during the Seventh Workshop and
Conference on Human Leucocyte Differentiation Antigens in
Harrogate in June 2000; Schwartz-Albiez, 2001. In this study we
use the new designations for these oligosaccharide structures.
For new CD designations please refer to http://
gryphon.jr2.ox.ac.uk/.], Fuc1-2Gal1-4(Fuc1-3)GlcNAc1-),
H2 (CD173, Fuc1-2Gal1-4GlcNAc-), H3
(Fuc1-2Gal1-3GalNAc-), and H4
(Fuc1-2Gal1-3GlcNAc1-3Gal1-4Gal1-4Glc-) with regard to their expression on human
hematopoietic cells has not yet been done. We have now
examined the expression of LeY (CD174), H2 (CD173), H3,
and H4 on a broad variety of human leukemia cell lines,
isolated lymphocytes from tonsils and peripheral blood, and
CD34+ hematopoietic precursors derived from peripheral
blood. CD34+ leukemia cell lines such as KG1, KG1a (immature
myeloid cell lines), TF1 (immature erythroblastoid cell line),
and native CD34+ hematopoietic precursor cells were found to
express the CD173 and CD174 antigens. Furthermore, possible
carrier molecules of CD173 and CD174 in CD34+
hematopoietic progenitor cells were analyzed. Because the expression
of the CD173 antigen is regulated by the -D-galactoside
2--Lfucosyltransferase gene (FUT1), we also tested the presence of
FUT1 mRNA by reverse transcription polymerase chain reaction
(RT-PCR) in lymphocytes of early and late stages of
hematopoietic development.
We observed that CD34+ hematopoietic cell lines such as KG1,
KG1a, and TF1 expressed the CD173 and CD174 antigens as
demonstrated by flow cytometric analysis and
immunohistological staining (Figures 1 and 2, Table I). Consequently, native
CD34+ hematopoietic precursor cells enriched from peripheral
Fig. 1. (A, B) Multicolor flow cytometric analysis of H2 and LeY on CD34+
hematopoietic precursor cells from human peripheral blood. Cells were stained
with mAbs specific for H2 (A46-B/B10, IgM) and LeY (A70-C/C8, IgM)
followed by incubation with anti-mouse IgM ( -chain) conjugated to FITC
(fluorescence 1), anti-CD34 (IgG) conjugated to PE (fluorescence 2) or Cy5
(fluorescence 3), anti-CD33 (IgG), or anti-CD38 (IgG) conjugated to PE
(fluorescence 2). (...truncated)