The Zika virus (ZIKV) is an arthropod-borne virus belonging to the family Flaviviridae and the genus Flavivirus. It was first identified in a rhesus monkey in the Zika forest of Uganda in 1947 . ZIKV is classified into two primary lineages: African and Asian strains, which share over 95% amino acid identity . Unlike the closely related dengue virus (DENV), which has four different serotypes, ZIKV has a single serotype .
The envelope (E) protein of ZIKV plays a crucial role in the virus’s ability to infect host cells. It is responsible for virus attachment, entry, and fusion with the host cell membrane. The E protein is composed of three domains: DI, DII, and DIII. The ectodomain of the E protein, which includes these three domains, is a key target for vaccine development and diagnostic assays .
Recombinant Zika ectodomain refers to the production of the ZIKV E protein ectodomain using recombinant DNA technology. This involves cloning the gene encoding the E protein into an expression vector, which is then introduced into a host cell system (such as E. coli, insect cells, or mammalian cells) to produce the protein. The recombinant protein can be purified and used for various applications, including vaccine development, diagnostic assays, and research studies .
Vaccine Development: The recombinant Zika ectodomain is used in the development of vaccines to elicit an immune response against ZIKV. For example, the Zika Virus Envelope Domain III (zEDIII) recombinant protein has been evaluated as a vaccine candidate. When delivered with a saponin-based nanoadjuvant, it enhances anti-Zika immune responses, including the production of neutralizing antibodies and splenocyte proliferation .
Diagnostic Assays: Recombinant Zika ectodomain proteins are used in serological assays, such as ELISA, to detect antibodies against ZIKV in patient samples. These assays are essential for diagnosing Zika virus infections and monitoring immune responses in clinical trials .
Research Studies: The recombinant Zika ectodomain is also used in research to study the structure and function of the E protein, as well as its interactions with host cell receptors and antibodies. This knowledge is crucial for understanding the mechanisms of ZIKV infection and developing effective therapeutics .