Dengue virus (DENV) is a significant global health concern, causing millions of infections annually. The virus is transmitted by Aedes mosquitoes and can lead to severe diseases such as dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). Among the various proteins encoded by the dengue virus, nonstructural protein 1 (NS1) plays a crucial role in the virus’s life cycle and pathogenesis.
NS1 is a 48-kDa glycoprotein that is highly conserved among all flaviviruses . It is essential for viral replication and is involved in various functions within infected cells, on the cell surface, and in its secreted form. NS1 is initially expressed as a monomer in infected cells and later forms dimers and hexamers . The protein is known to interact with other nonstructural proteins, such as NS4A and NS4B, to facilitate viral replication .
NS1 is highly immunogenic and induces strong antibody responses in infected individuals . These antibodies can be both protective and pathogenic. On the one hand, NS1-specific antibodies can mediate antibody-dependent cellular cytotoxicity (ADCC) and activate natural killer (NK) cells, contributing to the immune response against the virus . On the other hand, NS1 can induce endothelial hyperpermeability and vascular leakage, leading to severe disease manifestations .
Recombinant NS1c refers to the C-terminal region of the NS1 protein produced using recombinant DNA technology. This recombinant protein is used in various research and diagnostic applications. For instance, recombinant NS1c is employed in enzyme-linked immunosorbent assays (ELISAs) to detect NS1-specific antibodies in patient sera . Additionally, it is used in vaccine development to elicit protective immune responses against dengue virus .
The use of recombinant NS1c has significantly advanced our understanding of dengue virus pathogenesis and immune responses. Studies have shown that NS1-specific antibodies can cross-react with different dengue virus serotypes, providing insights into the mechanisms of immune protection and enhancement . Furthermore, recombinant NS1c is being explored as a potential vaccine candidate to induce protective immunity without causing adverse effects associated with natural infection .