Blockade of dengue virus entry into myeloid cells by endocytic inhibitors in the presence or absence of antibodies

Abstract

BackgroundDengue is the most prevalent arthropod-borne viral human disease in tropical and subtropical regions, caused by four dengue virus (DENV) serotypes. In spite of the increasing global incidence, no specific antiviral therapy is available. Cells of the mononuclear phagocyte lineage are the main targets either for direct antibody (Ab)-independent or Ab-mediated human DENV infection, usually associated to the severe forms of disease. Since the virus entry may be a convenient therapeutic alternative, this study aimed to investigate the mode of DENV internalization into myeloid cells in the absence and presence of DENV Ab and evaluate the inhibitory activity of diverse biochemical inhibitors of endocytosis.Methodology/principal findingsBy infectivity assays and quantitative RT-PCR determinations, it was demonstrated that DENV-2 entry into U937 and K562 cells in the absence of Ab was highly inhibited by the early treatment with ammonium chloride, chlorpromazine and dynasore, but it was not affected by methyl-β-cyclodextrin, indicating that DENV-2 utilizes a low pH-dependent, clathrin- and dynamin-mediated endocytic infectious pathway for the direct entry into both human myeloid cells. To study the Ab-mediated entry of DENV, the experimental conditions for enhancement of infection were established by inoculating immune complexes formed with DENV-2 and the Ab 2H2 or 3H5. The internalization of DENV-2-2H2 or DENV-2-3H5 complexes in both myeloid cells was also dependent on acid pH and dynamin but a differential requirement of the clathrin-mediated endocytic route was observed depending on the FcγR involved in the complex uptake: the infection through FcγRII was dependent on clathrin-coated vesicles whereas the internalization pathway mediated by FcγRI was independent of clathrin. This property was not serotype-specific.Conclusions/significanceDENV entry into myeloid cells in the absence or presence of Ab can be blocked by diverse biochemical inhibitors affecting the cellular factors involved in endocytosis. The identification of the virus-host interactions involved in virus penetration may allow the finding of host-targeted antivirals widely active against diverse pathogenic flaviviruses with similar requirements for virus entry.

Inhibition of the replication of SARS-CoV-2 in human cells by the FDA-approved drug chlorpromazine

“…This first antipsychotic medication was discovered in 1952 by Jean Delay and Pierre Deniker at Sainte Anne hospital (2). In addition to its antipsychotic activity, a growing body of in vitro studies has demonstrated antiviral properties, for example against influenza (3), hepatitis viruses (4), alphaviruses (5), JC virus (6), Japanese encephalitis virus (7), bronchitis-virus (8), MHV-2 (9), Zika virus (10) or dengue virus (11). CPZ has also been shown to have antiviral activity against coronaviruses in multiple studies (12)(13)(14).…”

Antibody-Dependent Enhancement of Viral Infections

“…In vitro studies in monocytic cell lines U937 and K562 have shown that FcγRII-mediated entry occurs through clathrin-coated vesicles, while FcγRI-mediated entry is clathrinindependent. Also, as FcγRII translocates into lipid rafts upon immune complex binding, entry via this receptor is affected by the membrane cholesterol content (Carro et al 2018). In macrophage-like P388D1 cells, antibody-opsonized virus is shown to be internalized by phagocytic uptake facilitated by actin-mediated membrane protrusions which actively search and capture the antibody-bound virus particles, possible by chemotaxis (Ayala-Nunez et al 2016).…”

Extracellular Vesicles in Viral Replication and Pathogenesis and Their Potential Role in Therapeutic Intervention

“…For instance, several viruses, in particular retroviruses, can enter the cells through endocytosis and hijack and use exosomal pathways for their replication and pathogenesis [49]. Viruses such as hepatitis C virus (HCV), West Nile virus (WNV), Zika virus (ZV), and Dengue virus (DENV) enter this pathway by clathrin-mediated or receptor-mediated endocytosis [50][51][52][53][54][55][56]. Another virus that can utilize the endosomal/exosomal system for its replication and pathogenesis is the human immunodeficiency virus (HIV).…”