Xu Z, Chokkalingam N, Tello-Ruiz E, Walker S, Kulp DW, Weiner DB. Incorporation of a Novel CD4+ Helper Epitope Identified from Aquifex aeolicus Enhances Humoral Responses Induced by DNA and Protein Vaccinations.
iScience 2020;
23:101399. [PMID:
32763137 PMCID:
PMC7409978 DOI:
10.1016/j.isci.2020.101399]
[Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/25/2020] [Accepted: 07/20/2020] [Indexed: 01/12/2023] Open
Abstract
CD4+ T cells play an important role in the maturation of the antibody responses. Conjugation of identified CD4+ T cell helper epitope to the target antigen has been developed as a strategy to enhance vaccine-induced humoral immunity. In this work, we reported the identification of a novel HLA-IAb helper epitope LS-3 from Aquifex aeolicus. In silico analysis predicted this epitope to have high binding affinity to common human HLA alleles and have complementary binding coverage to the established PADRE epitope. Introduction of HLA-IAb knockout mutations to the LS-3 epitope significantly attenuated humoral responses induced by a vaccine containing this epitope. Finally, engineered fusion of the epitope to a model antigen, influenza hemagglutinin, significantly improved both binding and hemagglutination inhibition antibody responses in mice receiving DNA or protein vaccines. In summary, LS-3 and additional identified CD4+ helper epitopes may be further explored to improve vaccine responses in translational studies.
Identification of a novel CD4+ helper epitope, LS-3, from Aquifex aeolicus
In silico analysis predicts high binding affinity of LS-3 to human HLA-DR alleles
Fusing LS-3 to antigen enhances humoral response by vaccinations
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