Dengue Virus and Its Relation to Human Glycoprotein IIb/IIIa Revealed by Fluorescence Microscopy and Flow Cytometry

Sepsis - it is all about the platelets

Sepsis is accompanied by thrombocytopenia and the severity of the thrombocytopenia is associated with mortality. This thrombocytopenia is characteristic of disseminated intravascular coagulation (DIC), the sepsis-associated coagulopathy. Many of the pathogens, both bacterial and viral, that cause sepsis also directly activate platelets, which suggests that pathogen-induced platelet activation leads to systemic thrombosis and drives the multi-organ failure of DIC. In this paper we review the mechanisms of platelet activation by pathogens and the evidence for a role for anti-platelet agents in the management of sepsis.

Selective Tropism of Dengue Virus for Human Glycoprotein Ib

Since the hemorrhage in severe dengue seems to be primarily related to the defect of the platelet, the possibility that dengue virus (DENV) is selectively tropic for one of its surface receptors was investigated. Flow cytometric data of DENV-infected megakaryocytic cell line superficially expressing human glycoprotein Ib (CD42b) and glycoprotein IIb/IIIa (CD41 and CD41a) were analyzed by our custom-written software in MATLAB. In two-dimensional analyses, intracellular DENV was detected in CD42b+, CD41+ and CD41a+ cells. In three-dimensional analyses, the DENV was exclusively detected in CD42b+ cells but not in CD42b- cells regardless of the other expressions. In single-cell virus-protein analyses, the amount of DENV was directly correlated with those of CD42b at the Pearson correlation coefficient of 0.9. Moreover, RT- PCR and apoptosis assays showed that DENV was able to replicate itself and release its new progeny from the infected CD42b+ cells and eventually killed those cells. These results provide evidence for the involvement of CD42b in DENV infection.