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| ISV Paper of the Month |
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May 2011 |
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Programming the magnitude and persistence of antibody
responses with innate immunity |
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Kasturi SP, Skountzou I, Albrecht RA, Koutsonanos D, Hua
T, Nakaya HI, Ravindran R, Stewart S, Alam M, Kwissa M, Villinger F, Murthy N, Steel
J, Jacob J, Hogan RJ, García-Sastre A, Compans R, Pulendran B |
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Nature 2011 Feb 24;470:543-547 |
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Many successful vaccines induce persistent antibody responses
that can last a lifetime. The mechanisms by which they do so remain unclear, but
emerging evidence indicates that they activate dendritic cells via Toll-like receptors
(TLRs). For example, the yellow fever vaccine YF-17D, one of the most successful
empiric vaccines ever developed, activates dendritic cells via multiple TLRs to
stimulate proinflammatory cytokines. Triggering specific combinations of TLRs in
dendritic cells can induce synergistic production of cytokines, which results in
enhanced T-cell responses, but its impact on antibody responses remain unknown.
Learning the critical parameters of innate immunity that program
such antibody responses
remains a major challenge in vaccinology. Here we demonstrate that immunization
of mice with synthetic nanoparticles containing antigens plus ligands that signal
through TLR4 and TLR7 induces synergistic increases in antigen-specific, neutralizing
antibodies compared to immunization with nanoparticles containing antigens plus
a single TLR ligand. Consistent with this there was enhanced persistence of germinal
centres and of plasma-cell responses, which persisted in the lymph nodes for >1.5
years. Surprisingly, there was no enhancement of the early short-lived plasma-cell
response relative to that observed with single TLR ligands. Molecular profiling
of activated B cells, isolated 7 days after immunization, indicated that there was
early programming towards B-cell memory. Antibody responses were dependent on direct
triggering of both TLRs on B cells and dendritic cells, as well as on T-cell help.
Immunization protected completely against lethal avian and swine influenza virus
strains in mice, and induced robust immunity against pandemic H1N1 influenza in
rhesus macaques. |
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