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Thermostable H1 hemagglutinin stem with M2e epitopes provides broad cross-protection against group1 and 2 influenza A viruses

Year: 2022

Type: article

Abstract: Hemagglutinin (HA) stem-based vaccines have limitations in providing broad and effective protection against cross-group influenza viruses, despite being a promising universal vaccine target.To overcome the limited cross-protection and low efficacy by HA stem vaccination, we genetically engineered a chimeric conjugate of thermostable H1 HA stem and highly conserved M2e repeat (M2e-H1stem), which was expressed at high yields in Escherichia coli.M2e-H1stem protein presented native-like epitopes reactive to antisera of live virus infection.M2e-H1stem protein vaccination of mice induced strong M2e-and HA stem-specific immune responses, conferring broadly effective cross-protection against both antigenically distinct group 1 (H1N1, H5N1, and H9N2 subtypes) and group 2 (H3N2 and H7N9 subtypes) seasonal and pandemic potential influenza viruses.M2e-H1stem vaccination generated CD4 + and CD8 + T cell responses and antibody-dependent cytotoxic cellular and humoral immunity, which contributed to enhancing cross-protection.Furthermore, comparable broad cross-group protection was observed in older aged mice after M2e-H1stem vaccination.This study provides evidence warranting further development of chimeric M2e-stem proteins as a promising universal influenza vaccine candidate in adult and aged populations.

Source: Molecular Therapy — Methods & Clinical Development

DOI: 10.1016/j.omtm.2022.05.007