Browsing by Subject "EPITOPE"

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  • Belanov, Sergei S.; Bychkov, Dmitrii; Benner, Christian; Ripatti, Samuli; Ojala, Teija; Kankainen, Matti; Lee, Hong Kai; Tang, Julian Wei-Tze; Kainov, Denis E. (2015)
    Here we analyzed whole-genome sequences of 3,969 influenza A(H1N1)pdm09 and 4,774 A(H3N2) strains that circulated during 2009-2015 in the world. The analysis revealed changes at 481 and 533 amino acid sites in proteins of influenza A(H1N1)pdm09 and A(H3N2) strains, respectively. Many of these changes were introduced as a result of random drift. However, there were 61 and 68 changes that were present in relatively large number of A(H1N1)pdm09 and A(H3N2) strains, respectively, that circulated during relatively long time. We named these amino acid substitutions evolutionary markers, as they seemed to contain valuable information regarding the viral evolution. Interestingly, influenza A(H1N1)pdm09 and A(H3N2) viruses acquired non-overlapping sets of evolutionary markers. We next analyzed these characteristic markers in vaccine strains recommended by the World Health Organization for the past five years. Our analysis revealed that vaccine strains carried only few evolutionary markers at antigenic sites of viral hem agglutinin (HA) and neuraminidase (NA). The absence of these markers at antigenic sites could affect the recognition of HA and NA by human antibodies generated in response to vaccinations. This could, in part, explain moderate efficacy of influenza vaccines during 2009-2014. Finally, we identified influenza A(H1N1)pdm09 and A(H3N2) strains, which contain all the evolutionary markers of influenza A strains circulated in 2015, and which could be used as vaccine candidates for the 2015/2016 season. Thus, genome-wide analysis of evolutionary markers of influenza A(H1N1)pdm09 and A(H3N2) viruses may guide selection of vaccine strain candidates.
  • Wang, Yilin; Hedman, Lea; Perdomo, Maria F.; Elfaitouri, Amal; Bolin-Wiener, Agnes; Kumar, Arun; Lappalainen, Maija; Soderlund-Venermo, Maria; Blomberg, Jonas; Hedman, Klaus (2016)
    Background: Human parvovirus B19 (B19V), cytomegalovirus (CMV) and Toxoplasma gondii (T. gondii) may cause intrauterine infections with potentially severe consequences to the fetus. Current serodiagnosis of these infections is based on detection of antibodies most often by EIA and individually for each pathogen. We developed singleplex and multiplex microsphere-based Suspension Immuno Assays (SIAs) for the simultaneous detection of IgG antibodies against B19V, CMV and T. gondii. Methods: We tested the performances of SIAs as compared to in-house and commercial reference assays using serum samples from well-characterized cohorts. Results: The IgG SIAs for CMV and T. gondii showed good concordance with the corresponding Vidas serodiagnostics. The B19V IgG SIA detected IgG in all samples collected >10 days after onset of symptoms and showed high concordance with EIAs (in-house and Biotrin). The serodiagnostics for these three pathogens performed well in multiplex format. Conclusions: We developed singleplex and multiplex IgG SIAs for the detection of anti-B19V,-CMV and -T. gondii antibodies. The SIAs were highly sensitive and specific, and had a wide dynamic range. These components thus should be suitable for construction of a multiplex test for antibody screening during pregnancy.