1.Evaluation of neutralizing antibodies produced by papaya mosaic virus nanoparticles fused to the E2EP3 peptide epitope of Chikungunya envelope
Nor Rashid, N. ; Teoh, T.C. ; Al-Harbi, S.J. ; Yusof, R. ; Rothan, H.A.
Tropical Biomedicine 2021;38(No.1):36-41
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