Leukocyte-associated immunoglobulin-like receptor-1 is expressed on human megakaryocytes and negatively regulates the maturation of primary megakaryocytic progenitors and cell line.
Biochem Biophys Res Commun
; 405(1): 128-33, 2011 Feb 04.
Article
em En
| MEDLINE
| ID: mdl-21216234
ABSTRACT
Leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) is an inhibitory collagen receptor which belongs to the immunoglobulin (Ig) superfamily. Although the inhibitory function of LAIR-1 has been extensively described in multiple leukocytes, its role in megakaryocyte (MK) has not been explored so far. Here, we show that LAIR-1 is expressed on human bone marrow CD34(+)CD41a(+) and CD41a(+)CD42b(+) cells. LAIR-1 is also detectable in a fraction of human cord blood CD34(+) cell-derived MK that has morphological characteristics of immature MK. In megakaryoblastic cell line Dami, the membrane protein expression of LAIR-1 is up-regulated significantly when cells are treated with phorbol ester phorbol 12-myristate 13-acetate (PMA). Furthermore, cross-linking of LAIR-1 in Dami cells with its natural ligand or anti-LAIR-1 antibody leads to the inhibition of cell proliferation and PMA-promoted differentiation when examined by the MK lineage-specific markers (CD41a and CD42b) and polyploidization. In addition, we also observed that cross-linking of LAIR-1 results in decreased MK generation from primary human CD34(+) cells cultured in a cytokines cocktail that contains TPO. These results suggest that LAIR-1 is a likely candidate for an early marker of MK differentiation, and provide initial evidence indicating that LAIR-1 serves as a negative regulator of megakaryocytopoiesis.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Células-Tronco
/
Megacariócitos
/
Receptores Imunológicos
/
Diferenciação Celular
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article