title: TREM-1, MDL-1, and DAP12 expression is associated with a mature stage of myeloid development.
abstract: The triggering receptor expressed on myeloid cells (TREM-1) and the myeloid DAP12-associating lectin (MDL-1) are two recently identified receptors which associate non-covalently with DAP12 to form receptor complexes involved in monocytic activation and inflammatory response. In this study, we investigated whether the expression of TREM-1, MDL-1, and DAP12 correlated with myelomonocytic differentiation. Northern and RT-PCR revealed a strong expression of TREM-1, MDL-1, and DAP12 in peripheral blood-derived CD14(+) mature monocytes in contrast to undifferentiated bone marrow CD34(+) stem cells, and in the differentiated versus undifferentiated U937 cells. TREM-1 and MDL-1 RNA expression was also more elevated in adult than fetal tissues and in normal than malignant cells. These findings suggest that the TREM-1/DAP12 and MDL-1/DAP12 signaling pathways are features of mature differentiated myelomonocytic cells. In addition, expression of an alternative mRNA TREM-1 splice variant (TREM-1sv) was detected that might translate into a soluble receptor with potential as a regulator of myeloid activation.
authors.affiliation: Texas Children's Cancer Center and Department of Pediatrics, Baylor College of Medicine, 6621 Fannin Street, MC3-3320, Houston, TX 77030, USA. mgingras@txccc.org
authors.forename: Marie-Claude
authors.initials: MC
authors.lastname: Gingras
authors.forename: Hélène
authors.initials: H
authors.lastname: Lapillonne
authors.forename: Judith F
authors.initials: JF
authors.lastname: Margolin
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002454:Cell Differentiation; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D006801:Humans; D037181:Lectins, C-Type; D007938:Leukemia / Q000378:metabolism; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D011956:Receptors, Cell Surface / Q000235:genetics*; D011971:Receptors, Immunologic / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000073871:Triggering Receptor Expressed on Myeloid Cells-1
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C509771:CLEC5A protein, human; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; C408842:TREM1 protein, human; C498715:TREM2 protein, human; C110546:TYROBP protein, human; D000073871:Triggering Receptor Expressed on Myeloid Cells-1