Dengue hemorrhagic fever-associated immunomediators induced via maturation of dengue virus nonstructural 4B protein in monocytes modulate endothelial cell adhesion molecules and human microvascular endothelial cells permeability

Abstract

We previously demonstrated that dengue virus (DENV) nonstructural 4B protein (NS4B) induced dengue hemorrhagic fever (DHF)-associated immunomediators in THP-1 monocytes. Moreover, cleavage of NS4AB polyprotein by the NS2B3 protease, significantly increased immunomediator production to levels found after DENV infection. In this report using primary human microvascular endothelial cells (HMVEC) transwell permeability model and HMVEC monolayer, we demonstrate that the immunomediators secreted in the supernatants of DENV-infected monocytes increase HMVEC permeability and expression of ICAM-1, VCAM-1 and E-selectin. Moreover, maturation of NS4B via cleavage of 2KNS4B is sufficient to induce immunomediators that cause HMVEC phenotypic changes, which appear to be synergistically induced by TNFα and IL-8. These data suggest that therapies targeting the maturation steps of NS4B, particularly 2KNS4B processing, may reduce overall DHF-associated immunomediator levels, thereby reducing DHF-associated morbidity and mortality. Alternatively, TNFα inhibitors may be a valid intervention strategy during the later stages of infection to prevent DHF progression.

Immune-mediated cytokine storm and its role in severe dengue

“…NS2A, NS2B, NS4B and NS5 proteins have been shown to interfere with type I interferon (IFN) signaling [12,13]. NS5 and NS4B have been demonstrated to induce the production of chemokines and proinflammatory mediators [14,15]. NS proteins are important targets of the cell mediated immune system, especially CD8+ T cells.…”

Non-Canonical Roles of Dengue Virus Non-Structural Proteins

“…Regarding other DENV NSPs, the expression of NS5 was shown to promote the induction of IL-8 expression and secretion in HEK293-transfected cells [56], and both NS5 and NS4B induce the secretion of immunomediators in THP-1 monocytes, being this action enhanced when NS4B is linked to the 2K peptide [57]. In addition, it was observed that the conditioned media of 2K-NS4B-transfected THP1 cells contained IL-8 and TNFα in levels that induce endothelial cell permeability and increased expression of adhesion molecules [58]. NS5 also interacts with death-domain-associate protein (Daxx), a transcription repressor shown to be important to induce expression of the cytokine RANTES [59].…”

The Cytokine Response of U937-Derived Macrophages Infected through Antibody-Dependent Enhancement of Dengue Virus Disrupts Cell Apical-Junction Complexes and Increases Vascular Permeability

“…Few articles have associated the increased vascular permeability observed in primary endothelial cells with the presence of particular mediators, like the high-mobility group box 1 protein (HMGB1) (53), the macrophage migration inhibitory factor (MMIF) (54), IL-8 (55), matrix metalloproteinase 9 (MMP-9) (56), and the nonstructural protein 4 (NS4B) of DENV (57). Regarding DENV infection and cytokines, TNF-␣, IL-6, IL-8, IL-10, and IL-12 are thought to be associated with potentially fatal plasma leakage (17), and some of these soluble factors are known to alter barrier permeability in epithelial or endothelial cells in vitro (58)(59)(60).…”