The supernatants were collected and subjected to Western blotting with anti-WNV E protein monoclonal antibody. Discussion WNV NY strains have a highly virulent phenotype compared to the Eg strain which was isolated in Africa. Their enhanced replication click here in peripheral tissues may lead to long-lasting viremia resulting in increasing incidence of viral invasion

to CNS. The interaction of the virus with endothelial cells of blood capillaries could be involved in WNV invasion to target organs. In this study, we assessed the transport of WNV NY99 6-LP strain and Eg strain across human endothelial cells. Our data demonstrate that VLPs of the 6-LP strain were see more transported across human endothelial cells more than VLPs of the Eg strain. Microbial invasion across endothelial cells can occur through transcellular pathway mediated by vesicles, paracellular entry after buy MLN2238 disruption of the tight junctions,

or “”Trojan horse”" mechanism by transport within circulating phagocytic cells [35, 36]. Our data indicate that 6-LP VLPs are transported by a transcellular pathway, because the transport of VLPs was inhibited by the treatment with filipin, a modifier of lipid raft-associated membrane transport. Clathrin-dependent pathways seem to be less important because the treatment with chlorpromazine had no significant effect on the transport of VLPs. Paracellular entry is unlikely to be involved in transport of VLPs because the structure Etofibrate of ZO-1 and the permeability of Dx 70k were not altered during VLP transport. Our data partially support the results by Verma et al. [16] which suggested that WNV crosses HBMVE cells without altering the integrity

of tight junction. The authors concluded that WNV replicates in endothelial cells and the progeny viruses are transported from the apical to basolateral side. However, our data suggest that WNV can be transported across endothelial cells without viral replication. Cell type difference could be the most reasonable explanation, because several studies showed that there are differences between HBMVE cells and HUVEC in the production of growth factors, immunoregulatory factors and adhesion molecules [37–39]. HBMVE cells and HUVEC differentially respond to cytokine treatment resulting in the different cytokine production and leukocyte recruitment [40, 41]. Particularly, modulation of adhesion molecules can affect endocytosis [37]. Therefore, our data seem to reflect events that can occur in peripheral tissues having tight junction such as heart and muscles rather than in CNS. In WNV-infected mice, viral replication in peripheral tissues results in the inflammatory cytokine production such as TNF-α, IL-6 and macrophage migration inhibitory factor [42–45]. Although the role of these cytokines in infection still remains controversial, vascular permeability can be affected by the presence of these cytokines [45].