Hybrid flagellin as a T cell independent vaccine scaffold.
BACKGROUND
To extend the potency of vaccines against infectious diseases, vaccines should be able to exploit multiple arms of the immune system. One component of the immune system that is under-used in vaccine design is the subset of B cells known to be capable of responding to repetitive antigenic epitopes and differentiate into plasma cells even in the absence of T cell help (T-independent, TI).


RESULTS
To target vaccine responses from T-independent B cells, we reengineered a bacterial Flagellin (FliC) by replacing its exposed D3 domain with a viral envelope protein from Dengue virus (DENV2). The resulting hybrid FliC protein (hFliC) was able to form stable filaments decorated with conformationally intact DENV2 envelope domains. These filaments were not only capable of inducing a T cell-dependent (TD) humoral antibody response, but also significant IgM and IgG3 antibody response in a helper T cell repertoire-restricted transgenic mouse model.


CONCLUSIONS
Our results provide proof-of-principle demonstration that a reengineered hybrid FliC could be used as a platform for polymeric subunit vaccines, enhancing T cell-dependent and possibly inducing T-independent antibody responses from B-1 B cells as well.
Division of Biomedical Sciences, School of Medicine, University of California Riverside, California, 92521, USA. kbenn001@ucr.edu.|Bioengineering Interdepartmental Graduate Program, California, USA. kbenn001@ucr.edu.
Kaila M
KM
Bennett
Department of Bioengineering, University of California Riverside, California, 92521, USA. rgorh001@ucr.edu.
Ronald D
RD
Gorham
Division of Biomedical Sciences, School of Medicine, University of California Riverside, California, 92521, USA. vgust001@ucr.edu.
Veronica
V
Gusti
Division of Biomedical Sciences, School of Medicine, University of California Riverside, California, 92521, USA. ltrin005@ucr.edu.
Lien
L
Trinh
Department of Bioengineering, University of California Riverside, California, 92521, USA. dmorikis@engr.ucr.edu.
Dimitrios
D
Morikis
Division of Biomedical Sciences, School of Medicine, University of California Riverside, California, 92521, USA. david.lo@ucr.edu.
David D
DD
Lo
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D005408:Flagellin / Q000737:chemistry / Q000276:immunology*; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D051379:Mice; D015202:Protein Engineering; D019779:Salmonella enterica / Q000737:chemistry / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology; D014612:Vaccines / Q000737:chemistry / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000276:immunology*
D000939:Epitopes; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D014612:Vaccines; D014759:Viral Envelope Proteins; D005408:Flagellin