tetano
Editor, Senior Moderator
J Virol. 2017 Jul 19. pii: JVI.01050-17. doi: 10.1128/JVI.01050-17. [Epub ahead of print]
[h=1]Synthetic TLR4 and TLR7 ligands work additively via MyD88 to induce protective antiviral immunity in mice.[/h] Goff PH[SUP]1,[/SUP][SUP]1[/SUP], Hayashi T[SUP]2[/SUP], He W[SUP]1,[/SUP][SUP]1[/SUP], Yao S[SUP]2[/SUP], Cottam HB[SUP]2[/SUP], Tan GS[SUP]1[/SUP], Crain B[SUP]2[/SUP], Krammer F[SUP]1[/SUP], Messer K[SUP]3[/SUP], Pu M[SUP]3[/SUP], Carson DA[SUP]3[/SUP], Palese P[SUP]4,[/SUP][SUP]3[/SUP], Corr M[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] We have previously demonstrated that the combination of synthetic small molecule Toll-like receptor 4 (TLR4) and TLR7 ligands is a potent adjuvant for recombinant influenza virus hemagglutinin, inducing rapid and sustained immunity protective against influenza viruses in homologous, heterologous and heterosubtypic murine challenge models. Combining TLR4 and TLR7 ligands balances Th1/Th2-type immune responses for long-lived cellular and neutralizing humoral immunity against the viral hemagglutinin. Here, we demonstrate that the protective response induced in mice by this combined adjuvant is dependent upon TLR4 and TLR7 signaling via myeloid differentiation primary response gene 88 (MyD88), indicating that the adjuvants function in vivo via their known receptors with negligible off-target effects to induce protective immunity. The combined adjuvant acts via MyD88 in both bone marrow and non-bone marrow derived, radioresistant cells to induce hemagglutinin-specific antibodies and protect mice against influenza virus challenge. The protective efficacy generated by immunizing with this adjuvant and recombinant hemagglutinin antigen could be transferred with serum from immunized mice to recipient mice in a homologous, but not a heterologous, H1N1 viral challenge model. Depletion of CD4[SUP]+[/SUP] cells after an established humoral response in immunized mice did not impair protection from a homologous challenge; however, it did significantly impair recovery from a heterologous challenge virus, highlighting an important role for vaccine-induced CD4[SUP]+[/SUP] cells in cross-protective vaccine efficacy. The combination of the two TLR agonists allowed for significant dose reduction of each component to achieve a level of protection equivalent to that afforded by either single agent at full dose.Importance Development of novel adjuvants is needed to enhance immunogenicity to provide better protection from seasonal influenza virus infection and improve pandemic preparedness. We show here that several dose combinations of synthetic TLR4 and TLR7 ligands are potent adjuvants for recombinant influenza virus hemagglutinin antigen to induce humoral and cellular immunity against viral challenges. The components of the combined adjuvant work additively to enable both antigen and adjuvant dose sparing while retaining efficacy. Understanding an adjuvant's mechanism of action is a critical component for preclinical safety evaluation, and we demonstrate here that a combined TLR4 and TLR7 adjuvant signals via the appropriate receptors and the MyD88 adaptor protein. This novel adjuvant combination contributes to a more broadly protective vaccine while demonstrating an attractive safety profile.
Copyright ? 2017 American Society for Microbiology.
PMID: 28724768 DOI: 10.1128/JVI.01050-17
[h=1]Synthetic TLR4 and TLR7 ligands work additively via MyD88 to induce protective antiviral immunity in mice.[/h] Goff PH[SUP]1,[/SUP][SUP]1[/SUP], Hayashi T[SUP]2[/SUP], He W[SUP]1,[/SUP][SUP]1[/SUP], Yao S[SUP]2[/SUP], Cottam HB[SUP]2[/SUP], Tan GS[SUP]1[/SUP], Crain B[SUP]2[/SUP], Krammer F[SUP]1[/SUP], Messer K[SUP]3[/SUP], Pu M[SUP]3[/SUP], Carson DA[SUP]3[/SUP], Palese P[SUP]4,[/SUP][SUP]3[/SUP], Corr M[SUP]5[/SUP].
[h=3]Author information[/h]
[h=3]Abstract[/h] We have previously demonstrated that the combination of synthetic small molecule Toll-like receptor 4 (TLR4) and TLR7 ligands is a potent adjuvant for recombinant influenza virus hemagglutinin, inducing rapid and sustained immunity protective against influenza viruses in homologous, heterologous and heterosubtypic murine challenge models. Combining TLR4 and TLR7 ligands balances Th1/Th2-type immune responses for long-lived cellular and neutralizing humoral immunity against the viral hemagglutinin. Here, we demonstrate that the protective response induced in mice by this combined adjuvant is dependent upon TLR4 and TLR7 signaling via myeloid differentiation primary response gene 88 (MyD88), indicating that the adjuvants function in vivo via their known receptors with negligible off-target effects to induce protective immunity. The combined adjuvant acts via MyD88 in both bone marrow and non-bone marrow derived, radioresistant cells to induce hemagglutinin-specific antibodies and protect mice against influenza virus challenge. The protective efficacy generated by immunizing with this adjuvant and recombinant hemagglutinin antigen could be transferred with serum from immunized mice to recipient mice in a homologous, but not a heterologous, H1N1 viral challenge model. Depletion of CD4[SUP]+[/SUP] cells after an established humoral response in immunized mice did not impair protection from a homologous challenge; however, it did significantly impair recovery from a heterologous challenge virus, highlighting an important role for vaccine-induced CD4[SUP]+[/SUP] cells in cross-protective vaccine efficacy. The combination of the two TLR agonists allowed for significant dose reduction of each component to achieve a level of protection equivalent to that afforded by either single agent at full dose.Importance Development of novel adjuvants is needed to enhance immunogenicity to provide better protection from seasonal influenza virus infection and improve pandemic preparedness. We show here that several dose combinations of synthetic TLR4 and TLR7 ligands are potent adjuvants for recombinant influenza virus hemagglutinin antigen to induce humoral and cellular immunity against viral challenges. The components of the combined adjuvant work additively to enable both antigen and adjuvant dose sparing while retaining efficacy. Understanding an adjuvant's mechanism of action is a critical component for preclinical safety evaluation, and we demonstrate here that a combined TLR4 and TLR7 adjuvant signals via the appropriate receptors and the MyD88 adaptor protein. This novel adjuvant combination contributes to a more broadly protective vaccine while demonstrating an attractive safety profile.
Copyright ? 2017 American Society for Microbiology.
PMID: 28724768 DOI: 10.1128/JVI.01050-17