Currently, there are no licensed vaccines or therapies available against chikungunya virus (CHIKV), and these were subjects discussed during a CHIKV meeting recently organized in Langkawi, Malaysia. In this review, we chart the approaches taken in both areas. Because of a sharp increase in new data in these fields, the present paper is complementary to previous reviews by Weaver et al. in 2012 and Kaur and Chu in 2013 . The most promising antivirals so far discovered are reviewed, with a special focus on the virus-encoded replication proteins as potential targets. Within the vaccines in development, our review emphasizes the various strategies in parallel development that are unique in the vaccine field against a single disease.
Chikungunya virus (CHIKV) infection is the cause of acute symptoms and chronic symmetrical polyarthritis associated with long-term morbidity and mortality. Currently, there is no available licensed vaccine or particularly useful drug for human use against CHIKV infection. This study was conducted to evaluate the efficacy of antibodies produced by papaya mosaic virus (PapMV) nanoparticles fused to E2EP3 peptide of CHIKV envelope as a recombinant CHIKV vaccine. PapMV, PapMV-C- E2EP3, and E2EP3-N-PapMV were produced in E. coli with an approximate size of 27 to 30 kDa. ICR mice (5 to 6 weeks of age) were injected subcutaneously with 25 micrograms of vaccine construct, and ELISA measured the titer of CHIKV specific IgG antibodies. The results showed that both recombinant proteins E2EP3-N-PapMV and PapMVC-E2EP3 were able to induce IgG antibodies production in immunized mice against CHIKV while immunization with recombinant PapMV showed no IgG antibodies induction. The neutralizing activity of the antibodies generated by either E2EP3-N-PapMV or PapMV-C-E2EP3 exhibited similar inhibition to CHIKV replication in Vero cells using the cells based antibody neutralizing assay and analyzed by plaque formation assay. This study showed the effectiveness of nanoparticles vaccine generated by fusing epitope peptide of CHIKV envelope to papaya mosaic virus envelope in inducing a robust immune response in mice against CHIKV. The data showed that levels of neutralizing antibodies correlate with a protective immune response CHIKV replication.
Matched MeSH terms: Chikungunya Fever/prevention & control
Chikungunya virus (CHIKV) outbreaks have led to a serious economic burden, as the available treatment strategies can only alleviate disease symptoms, and no effective therapeutics or vaccines are currently available for human use. Here, we report the use of a new cost-effective approach involving production of a recombinant antiviral peptide-fusion protein that is scalable for the treatment of CHIKV infection. A peptide-fusion recombinant protein LATA-PAP1-THAN that was generated by joining Latarcin (LATA) peptide with the N-terminus of the PAP1 antiviral protein, and the Thanatin (THAN) peptide to the C-terminus, was produced in Escherichia coli as inclusion bodies. The antiviral LATA-PAP1-THAN protein showed 89.0% reduction of viral plaque formation compared with PAP1 (46.0%), LATA (67.0%) or THAN (79.3%) peptides alone. The LATA-PAP1-THAN protein reduced the viral RNA load that was 0.89-fold compared with the untreated control cells. We also showed that PAP1 resulted in 0.44-fold reduction, and THAN and LATA resulting in 0.78-fold and 0.73-fold reductions, respectively. The LATA-PAP1-THAN protein inhibited CHIKV replication in the Vero cells at an EC50 of 11.2μg/ml, which is approximately half of the EC50 of PAP1 (23.7μg/ml) and protected the CHIKV-infected mice at the dose of 0.75mg/ml. We concluded that production of antiviral peptide-fusion protein in E. coli as inclusion bodies could accentuate antiviral activities, enhance cellular internalisation, and could reduce product toxicity to host cells and is scalable to epidemic response quantities.