Early neutralizing IgG response to Chikungunya virus in infected patients targets a dominant linear epitope on the E2 glycoprotein.
Bottom Line: E2EP3 is located at the N-terminus of the E2 glycoprotein and prominently exposed on the viral envelope.Screening of E2EP3 across different patient cohorts and in non-human primates demonstrated the value of this epitope as a good serology detection marker for CHIKV infection already at an early stage.Mice vaccinated by E2EP3 peptides were protected against CHIKV with reduced viremia and joint inflammation, providing a pre-clinical basis for the design of effective vaccine against arthralgia-inducing CHIKV and other alphaviruses.
Affiliation: Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore.Show MeSH
Related in: MedlinePlus
Mentions: At median 10 days pio, almost all of the patients from this cohort were sero-positive for E2EP3 IgG3 antibodies (Supporting information Fig 4). To further validate the specificity and versatility of E2EP3 as a suitable early detection target, we screened plasma samples from another 36 CHIKV-infected patients collected from a separate cohort together with plasma obtained from 11 healthy donors (Fig 6). Here, plasma were again collected during the early convalescent phase (median 10 days pio) and tested for anti-E2EP3 IgG3 antibodies by ELISA (Fig 6B). Whole virus was used as a reference (Fig 6A). As in the previous cohort, specific E2EP3-binding was detected in virtually all CHIKV-infected patients with a clear segregation from the sero-negative healthy control donors (Fig 6A and B). Similar results were also obtained in a cohort from Malaysia where early convalescence samples of median 14 days pio were collected at outbreaks a few months later (Sam et al, 2009). Likewise, all of the patients screened were sero-positive for E2EP3, while no reactivity against the epitope was detected in healthy donors (Fig 6C and D). Thus, E2EP3 specific IgG3 antibodies appear to be a common early marker for CHIKV-infections at the population level.
Affiliation: Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), Biopolis, Singapore.