Fig. 2: Characterization of M2e-H3 stalk protein antigenicity, stability, and its cross-reactivity.
From: A chimeric thermostable M2e and H3 stalk-based universal influenza A virus vaccine
A, E, and F The antigenicity of purified M2e-H3 stalk protein was determined by standard ELISA using antibodies specific for M2e (14C2), HA2 domain (rabbit poly IgG Abs) purified against HA2 epitopes including aa1-13 (poly HA2#1–13) or aa14-27 (poly HA2#14-27), and polyclonal antibodies (pAbs) against recombinant HA proteins from different subtypes (H1N1, H5N1, H3N2, H7N9); antisera of mice infected with influenza A live viruses (rgH5N1, H3N2, rgH7N9) were used. B–D Thermostability of M2e-H3 stalk protein was evaluated after storage at different temperatures (4, 20, 37, 50 °C) for 11 days by determination of retaining antigenicity. A Antigen reactivity specific to conserved HA2 FP and M2e antibodies. B Thermostable M2e-H3 stalk protein reactivity to 14C2 mAb. C Thermostable M2e-H3 stalk protein reactivity to FP pAb. D Thermostable M2e-H3 stalk protein reactivity to H5N1 virus antisera. E M2e-H3 stalk protein reactivity to pAbs against HA proteins from group 1(G1) viruses (H1N1, H5N1) and group 2 (G2) viruses (H3N2, H7N9). F M2e-H3 stalk protein reactivity against the antisera of live G1 and G2 influenza A viruses. Ctrl: BSA control. Mock: Naïve mice sera. Statistical significance was determined by using one-way ANOVA followed by Tukey’s Multiple Comparison Test or two-way ANOVA followed by Bonferroni post-test; error bars indicate mean ± SEM; *P < 0.05;**P < 0.01; ***P < 0.001.
