| Dengue virus (DENV) has become a huge public health concern around the world with no vaccine or antivirals available. More than one-third of the world's population is living in areas at risk of infection. To conquer the dengue disease, a better understanding of virus-host interactions and development of the appropriate therapeutic treatments are required. In this dissertation, we first broadly reviewed the factors involved in dengue viral entry and the role of tight junctions as a pathogen target. Second, we developed, optimized and validated a high throughput screening (HTS) assay for anti-dengue virus drug screening. Taking advantage of using live virus, this assay is able to examine the effects of both viral and host factors throughout the whole viral life cycle. Viral entry, the first step of the dengue lifecycle, provides attractive therapeutic targets. Although various factors have been described as playing a role in dengue virus entry, little is known about the initial virus attachment and binding. Thus, in an effort to obtain better understanding of virus-host interactions involved in the early stage of dengue infection, this screening assay was used to evaluate potential host factors. In the third part, we specifically described and characterized claudin-1 as a potential entry factor required for efficient dengue entry. Briefly, we showed that dengue entry was hampered in claudin-1 depleted cells, resulting in delayed development of cytopathology and decreased progeny virus production. This was further evidenced by rescued dengue entry in cells with restored claudin-1 expression. Functional analysis using recombinant claudin-1 mutants revealed a direct interaction with the viral prM protein. Collectively, these studies suggested a role of claudin-1 in efficient DENV entry.;In summary, this dissertation provides new insights into dengue virus-host interactions and, for the first time, provides evidence that tight junctions act as a pathogen target in dengue virus infection. |
