Developmental regulation of α1,3-fucosyltransferase expression in CD34 positive progenitors and maturing myeloid cells isolated from normal human bone marrow

Abstract

The adhesive interactions of hemopoietic cells within the bone marrow regulate their distribution, growth, and development. Fucosylated structures, of which sialyl Lewis x has been most extensively studied, are important ligands for selectins, but little is known about their function or regulation during normal hemopoietic development. We have studied alpha 1,3-fucosyltransferase activity in CD34 positive progenitors and myeloid cells at different stages of maturation isolated form normal human bone marrow, together with mRNA levels of Fuc-TIV and Fuc-TVII. Enzyme activity measured with H type 2 acceptor was present at all stages but was markedly elevated in fractions of early myeloid cells enriched for promyelocytes, correlating with the appearance of Lewis x on these cells, and thereafter fell progressively as cells matured. Activity measured with 3'sialyllactosamine was present in CD34+ cells and at all stages of maturation. Levels were low in promyelocyte/myelocyte transitional cells and increased, relative to those measured with H type 2, during the later stages of maturation; these changes correlate directly with a maturation-related increase in sialyl Lewis x expression. Using competitive quantitative RT-PCR, mRNA levels of Fuc-TIV and Fuc-TVII were similar in CD34+ cells, early myeloid and late myeloid cells. The significance of these findings in relation to fucosyltransferase activity, the synthesis of selectin ligands and differences between normal cells and leukemic cell lines is discussed.

Polymorphonuclear Leukocytes from Individuals Carrying the G329A Mutation in the α1,3-Fucosyltransferase VII Gene (FUT7) Roll on E- and P-Selectins

“…The expression of FUT7 mRNA was similar in the Q/Q individual compared with nonmutated individuals. Studies on human myeloid cell lines have shown that there is a reciprocal expression of Fuc-TIV and Fuc-TVII during cell differentiation (8,(35)(36)(37). When the promyelocytic cell line HL60 was allowed to differentiate in the presence of DMSO, there was an increase in cell surface expression of SLe x and a concomitant fall in the expression of the CD65s Ag.…”

Human α(1,3)-Fucosyltransferase IV (FUTIV) Gene Expression Is Regulated by Elk-1 in the U937 Cell Line

“…In lung tumors, FUTIV and FUTVII expression levels were inversely correlated with patient prognosis (11). FUTIV expression has also been studied in purified myeloid lineage cells and cell lines induced to differentiate (15)(16)(17). Typically, differentiated cells lose surface Le x expression accompanied by a decrement in FUTIV transcript levels as compared with undifferentiated cells.…”

“…Expression is regulated during normal development (16,19,20) and in tumors (11)(12)(13). We sought to identify the trans-acting factors responsible for up-regulating FUTIV expression in tumor cell lines.…”

CD15 Expression in Mature Granulocytes Is Determined by α1,3-Fucosyltransferase IX, but in Promyelocytes and Monocytes by α1,3-Fucosyltransferase IV

“…In fact, we demonstrated in a previous study that FUT9 preferentially transfers a fucose to the GlcNAc residue at the distal LN unit of the polylactosamine chain, resulting in the Le X (CD15) structure, whereas the other ␣1,3FUTs preferentially transfer a fucose to the GlcNAc residue at the inner LN unit of the polylactosamine chain (25). This implied that FUT9 exhibits stronger activity than the other ␣1,3FUTs for forming the CD15 epitope that is recognized by anti-Le X (anti-CD15) antibodies.It has been reported that FUT4 and FUT7 are expressed in human leukocytes, but FUT3, 5 and 6 are not (23,26,27). The carbohydrates modified by both FUT4 and FUT7 can function…”

“…It has been reported that FUT4 and FUT7 are expressed in human leukocytes, but FUT3, 5 and 6 are not (23,26,27). The carbohydrates modified by both FUT4 and FUT7 can function as ligands for E-selectin and P-selectin (28,29).…”