INVESTIGADORES
JAQUENOD DE GIUSTI Carolina
artículos
Título:
Expression and functionality of type I interferon receptor in the megakaryocytic lineage
Autor/es:
S. NEGROTTO; C. JAQUENOD DE GIUSTI; M.J. LAPPONI; J. ETULAIN; L. RIVADENEYRA; R.G. POZNER; R.M. GOMEZ; M. SCHATTNER
Revista:
JOURNAL OF THROMBOSIS AND HAEMOSTASIS
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2011 vol. 9 p. 2477 - 2485
ISSN:
1538-7933
Resumen:
Background: Type I interferons (IFN-I) negatively regulate megakaryo/thrombopoiesis. However, expression of the IFN-I receptor (IFNAR) in the megakaryocytic lineage is poorly characterized. Objectives: To study the expression and functionality of IFNAR in the megakaryocytic lineage. Methods and results: Although IFNAR mRNA was found in every cell type studied, its protein expression showed differences between them. According to flow cytometry and immunofluorescence, IFNAR1 was observed in Meg-01, Dami, CD34+ cells and megakaryocytes, but not in proplatelets or platelets.Immunoblotting assays showed that IFNAR1 and IFNAR2 were highly expressed in all cell types, except in platelets where it was barely detectable. Regarding IFNAR1, 130- and 90-kDa bands were detected inMeg-01 andDami, whereas 130- and 60-kDa bands were found in CD34+ cells and megakaryocytes. Activation of megakaryocytic IFNAR by IFN-b induced pSTAT1/2 and upregulated the antiviral genes IRF7 and MXA. The latter response was completely suppressed byIFNAR blockade. In contrast, the low levels of IFNAR in platelets were not functional as pSTAT1/2, aggregation and P-selectin expression were not induced by IFN-I. In addition,megakaryocytes increased IFN-I transcript levels and produced IFN-b upon stimulation with PolyI:C, a synthetic dsRNA that mimics viral infection. Conclusions: Early progenitors and mature megakaryocytes, but not platelets, express functional IFNAR and synthetize/release IFN-b, revealing not only that megakaryo/thrombopoiesis regulation by IFN-I is associated with a specific interaction with its receptor, but also that megakaryocytesmay play a role in the antiviral defense by being both IFN producers and responders.