Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junín computer virus (JUNV) a member of the family. hypothesized that thrombocytopenia results from a viral-triggered alteration of the megakaryo/thrombopoiesis process. Therefore we evaluated the effect of JUNV on megakaryopoiesis using an model of human being CD34+ cells stimulated with thrombopoietin. Our results showed that CD34+ cells are infected with JUNV inside a restricted fashion. Illness was transferrin receptor 1 (TfR1)-dependent and the surface manifestation of TfR1 was higher in infected cultures suggesting a novel arenaviral dissemination strategy in hematopoietic progenitor cells. Although proliferation survival and commitment in JUNV-infected ethnicities were normal viral illness impaired thrombopoiesis by reducing proplatelet formation platelet launch and P-selectin externalization via a bystander effect. The decrease in platelet Pravadoline launch was also TfR1-dependent mimicked by poly(I:C) and type I interferon (IFN α/β) was implicated as a key paracrine mediator. Among the relevant molecules studied only the transcription element NF-E2 showed a moderate decrease in manifestation in megakaryocytes from either infected ethnicities or after type I IFN treatment. Moreover type I IFN-treated megakaryocytes offered ultrastructural abnormalities resembling the reported thrombocytopenic NF-E2?/? Pravadoline mouse phenotype. Our study introduces a potential mechanism for thrombocytopenia in VHF and additional diseases associated with improved Pravadoline bone marrow type I IFN levels. Author Summary Argentine hemorrhagic fever (AHF) is an endemo-epidemic disease caused by Junín computer virus (JUNV). Although a recently launched live attenuated vaccine offers proven to be effective AHF remains a potentially lethal illness and JUNV is considered to be a potential Ednra biological weapon. Like additional viral hemorrhagic fevers (VHF) AHF individuals present fever with a combination of neurological and bleeding complications. Although the causes of the bleeding are poorly recognized impaired hemostasis and endothelial cell function as well as low platelet counts have been explained. With this study we have examined the effect of JUNV on an model of platelet production. We found that neither illness of Pravadoline hematopoietic progenitors with JUNV nor poly(I:C) (a double-stranded RNA that mimics viral illness) affected cell survival or megakaryocyte generation. However these treatments triggered the main anti-viral cytokines produced by sponsor type I IFN (IFN α/β) which acted inside a Pravadoline paracrine fashion and led to abnormal platelet formation. Thus this study identifies type I IFN as a new regulator that selectively affects the last methods of megakaryocyte life-span and it suggests a potential mechanism for thrombocytopenia in AHF and additional diseases associated with improved bone marrow type I IFN levels. Intro Viral hemorrhagic fever (VHF) is an acute systemic febrile syndrome caused by a diverse group of RNA viruses from your viral family members -. Individuals with this syndrome present with a combination of Pravadoline fever prostration malaise and differing examples of hematological complications  . When severe individuals with VHF can present with generalized bleeding that results from alterations of the vascular endothelium blood coagulation parts and platelet levels -. Moreover a plasma platelet aggregation inhibitor has been described in individuals with different types of VHF  . These findings suggest that different etiologic providers of VHF may share common processes for disturbing hemostasis during illness leading to a systemic and frequently fatal disease. In fact thrombocytopenia is one of the most consistent findings among human being individuals and experimental animal models of VHF and it is used as a major diagnostic feature in individuals with VHF  . However the causes of the thrombocytopenia associated with VHF remain poorly recognized. With this connection disseminated intravascular coagulation (DIC) could clarify platelet consumption; nevertheless the event of DIC in VHF infections is definitely inconclusive at least for the arenavirus family . Therefore a high level of splenic sequestration or impaired megakaryo/thrombopoiesis could be the major physiopathogenic.