RESUMO
Current efforts to develop Zika virus (ZIKV) subunit vaccines have been focused on pre-membrane (prM) and envelope (E) proteins, but the role of NS1 in ZIKV-specific immune response and protection is poorly understood. Here, we develop an attenuated recombinant vesicular stomatitis virus (rVSV)-based vaccine expressing ZIKV prM-E-NS1 as a polyprotein. This vectored vaccine candidate is attenuated in mice, where a single immunization induces ZIKV-specific antibody and T cell immune responses that provide protection against ZIKV challenge. Co-expression of prM, E, and NS1 induces significantly higher levels of Th2 and Th17 cytokine responses than prM-E. In addition, NS1 alone is capable of conferring partial protection against ZIKV infection in mice even though it does not induce neutralizing antibodies. These results demonstrate that attenuated rVSV co-expressing prM, E, and NS1 is a promising vaccine candidate for protection against ZIKV infection and highlights an important role for NS1 in ZIKV-specific cellular immune responses.
Assuntos
Poliproteínas/imunologia , Proteínas não Estruturais Virais/imunologia , Proteínas não Estruturais Virais/metabolismo , Vacinas Virais/imunologia , Infecção por Zika virus/prevenção & controle , Zika virus/metabolismo , Animais , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Antígenos Virais/genética , Antígenos Virais/imunologia , Antígenos Virais/metabolismo , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Vetores Genéticos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Poliproteínas/genética , Células Th17/metabolismo , Células Th2/metabolismo , Vacinação , Vacinas Atenuadas , Vacinas de DNA/imunologia , Vacinas Sintéticas , Vesiculovirus/imunologia , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/imunologia , Proteínas não Estruturais Virais/genética , Vacinas Virais/genética , Zika virus/genética , Zika virus/imunologia , Infecção por Zika virus/imunologiaRESUMO
The L6 region of bovine adenovirus type 3 (BAdV-3) encodes a non-structural protein named 100K. Rabbit antiserum raised against BAdV-3 100K recognized a protein of 130âkDa at 12-24âh and proteins of 130, 100, 95 and 15âkDa at 36-48âh after BAdV-3 infection. The 100K species localized to the nucleus and the cytoplasm of BAdV-3-infected cells. In contrast, 100K localized predominantly to the cytoplasm of the transfected cells. However, BAdV-3 infection of cells transfected with 100K-enhanced yellow fluorescent protein-expressing plasmid detected fluorescent protein in the nucleus of the cells, suggesting that other viral proteins may be required for the nuclear localization of 100K. Interaction of BAdV-3 100K with BAdV-3 33K protein did not alter the cytoplasmic localization of 100K. However, co-expression of BAdV-3 100K and BAdV-3 protease localized 100K to the nucleolus of the transfected cells. Subsequent analysis suggested that BAdV-3 protease cleaves 100K at two identified potential protease cleavage sites (aa 740-745 and 781-786) in transfected or BAdV-3-infected cells. The cleaved C terminus (107âaa) was localized to the nucleolus of the transfected cells. Further analysis suggested that the cleaved C terminus contains a bipartite nuclear localization signal and utilizes import receptor importin-α3 of the classical importin-α/ß transport pathway for nuclear transport. Successful isolation of recombinant BAdV-3 expressing mutant 100K (substitution of alanine for glycine in the potential protease cleavage site) suggested that cytoplasmic cleavage of BAdV-3 100K by adenoviral protease is not essential for virus replication.
