RESUMO
Introduction: Atopic diseases have been steadily increasing over the past decades and effective disease-modifying treatment options are urgently needed. These studies introduce a novel synthetic Toll-like receptor 4 (TLR4) agonist, INI-2004, with remarkable efficacy as a therapeutic intranasal treatment for seasonal allergic rhinitis. Methods: Using a murine airway allergic sensitization model, the impact of INI-2004 on allergic responses was assessed. Results: One or two intranasal doses of INI-2004 significantly reduced airway resistance, eosinophil influx, and Th2 cytokine production - providing strong evidence of allergic desensitization. Further investigations revealed that a liposomal formulation of INI-2004 exhibited better safety and efficacy profiles compared to aqueous formulations. Importantly, the liposomal formulation demonstrated a 1000-fold increase in the maximum tolerated intravenous dose in pigs. Pre-clinical GLP toxicology studies in rats and pigs confirmed the safety of liposomal INI-2004, supporting its selection for human clinical trials. Discussion: These findings lay the groundwork for the ongoing clinical evaluation of INI-2004 in allergic rhinitis as a stand-alone therapy for individuals poly-sensitized to multiple seasonal allergens. The study underscores the significance of innovative immunotherapy approaches in reshaping the landscape of allergic rhinitis management.
Assuntos
Administração Intranasal , Modelos Animais de Doenças , Receptor 4 Toll-Like , Animais , Receptor 4 Toll-Like/agonistas , Camundongos , Suínos , Feminino , Lipossomos , Rinite Alérgica Sazonal/imunologia , Rinite Alérgica Sazonal/tratamento farmacológico , Alérgenos/imunologia , Alérgenos/administração & dosagem , Dessensibilização Imunológica/métodos , Ratos , Citocinas/metabolismo , Camundongos Endogâmicos BALB CRESUMO
Most known synthetic toll-like receptor 4 (TLR4) agonists are carbohydrate-based lipid-A mimetics containing several fatty acyl chains, including a labile 3-O-acyl chain linked to the C-3 position of the non-reducing sugar known to undergo cleavage impacting stability and resulting in loss of activity. To overcome this inherent instability, we rationally designed a new class of chemically more stable synthetic TLR4 ligands that elicit robust innate and adaptive immune responses. This new class utilized a diamino allose phosphate (DAP) scaffold containing a nonhydrolyzable 3-amide bond instead of the classical 3-ester. Accordingly, the DAPs have significantly improved thermostability in aqueous formulations and potency relative to other known natural and synthetic TLR4 ligands. Furthermore, the DAP analogues function as potent vaccine adjuvants to enhance influenza-specific antibodies in mice and provide protection against lethal influenza virus challenges. This novel set of TLR4 ligands show promise as next-generation vaccine adjuvants and stand-alone immunomodulators.
Assuntos
Adjuvantes de Vacinas , Receptor 4 Toll-Like , Animais , Camundongos , Fatores Imunológicos , Adjuvantes Imunológicos/farmacologia , Adjuvantes Imunológicos/química , Ligantes , Anticorpos AntiviraisRESUMO
Most licensed seasonal influenza vaccines are non-adjuvanted and rely primarily on vaccine-induced antibody titers for protection. As such, seasonal antigenic drift and suboptimal vaccine strain selection often results in reduced vaccine efficacy. Further, seasonal H3N2 influenza vaccines demonstrate poor efficacy compared to H1N1 and influenza type B vaccines. New vaccines, adjuvants, or delivery technologies that can induce broader or cross-seasonal protection against drifted influenza virus strains, likely through induction of protective T cell responses, are urgently needed. Here, we report novel lipidated TLR7/8 ligands that act as strong adjuvants to promote influenza-virus specific Th1-and Th17-polarized T cell responses and humoral responses in mice with no observable toxicity. Further, the adjuvanted influenza vaccine provided protection against a heterologous H3N2 influenza challenge in mice. These responses were further enhanced when combined with a synthetic TLR4 ligand adjuvant. Despite differences between human and mouse TLR7/8, these novel lipidated imidazoquinolines induced the production of cytokines required to polarize a Th1 and Th17 immune response in human PBMCs providing additional support for further development of these compounds as novel adjuvants for the induction of broad supra-seasonal protection from influenza virus.
Assuntos
Imidazóis/imunologia , Vírus da Influenza A Subtipo H1N1/fisiologia , Vírus da Influenza A Subtipo H3N2/fisiologia , Vírus da Influenza B/fisiologia , Vacinas contra Influenza/imunologia , Influenza Humana/imunologia , Infecções por Orthomyxoviridae/imunologia , Quinolinas/imunologia , Células Th1/imunologia , Células Th17/imunologia , Adjuvantes Imunológicos , Animais , Reações Cruzadas , Modelos Animais de Doenças , Feminino , Células HEK293 , Humanos , Imidazóis/síntese química , Imunidade Heteróloga , Imunidade Humoral , Lipídeos/síntese química , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Quinolinas/síntese química , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistasRESUMO
To increase vaccine immunogenicity, modern vaccines incorporate adjuvants, which serve to enhance immune cross-protection, improve humoral and cell-mediated immunity, and promote antigen dose sparing. Pattern recognition receptors (PRRs), including the Toll-like receptor (TLR) family are promising targets for development of agonist formulations for use as vaccine adjuvants. Combinations of co-delivered TLR4 and TLR7/8 ligands have been demonstrated to have synergistic effects on innate and adaptive immune response. Here, we create liposomes that stably co-encapsulate CRX-601, a synthetic TLR4 agonist, and UM-3004, a lipidated TLR7/8 agonist, within the liposomal bilayer in order to achieve co-delivery, allow tunable physical properties, and induce in vitro and in vivo immune synergy. Co-encapsulation demonstrates a synergistic increase in IL-12p70 cytokine output in vitro from treated human peripheral blood mononuclear cells (hPBMCs). Further, co-encapsulated formulations give significant improvement of early IgG2a antibody titers in BALB/c mice following primary vaccination when compared to single agonist or dual agonists delivered in separate liposomes. This work demonstrates that co-encapsulation of TLR4 and lipidated TLR7/8 agonists within the liposomal bilayer leads to innate and adaptive immune synergy which biases a Th1 immune response. Thus, liposomal co-encapsulation may be a useful and flexible tool for vaccine adjuvant formulation containing multiple TLR agonists.
Assuntos
Adjuvantes Imunológicos/administração & dosagem , Compostos Heterocíclicos com 3 Anéis/administração & dosagem , Imunidade Humoral/imunologia , Monossacarídeos/administração & dosagem , Vacinas/administração & dosagem , Animais , Sistemas de Liberação de Medicamentos , Sinergismo Farmacológico , Feminino , Compostos Heterocíclicos com 3 Anéis/imunologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Humanos , Leucócitos Mononucleares/imunologia , Lipossomos , Camundongos , Camundongos Endogâmicos BALB C , Monossacarídeos/imunologia , Monossacarídeos/farmacologia , Células Th1/imunologia , Receptor 4 Toll-Like/agonistas , Receptor 7 Toll-Like/agonistas , Receptor 8 Toll-Like/agonistas , Vacinas/imunologiaRESUMO
Immunization is key to preventing infectious diseases, a leading cause of death early in life. However, due to age-specific immunity, vaccines often demonstrate reduced efficacy in newborns and young infants as compared to adults. Here, we combined in vitro and in vivo approaches to identify adjuvant candidates for early life immunization. We employed newborn and adult bone marrow-derived dendritic cells (BMDCs) to perform a screening of pattern recognition receptor agonists and found that the stimulator of interferon genes ligand 2'3'-cGAMP (hereafter cGAMP) induces a comparable expression of surface maturation markers in newborn and adult BMDCs. Then, we utilized the trivalent recombinant hemagglutinin (rHA) influenza vaccine, Flublok, as a model antigen to investigate the role of cGAMP in adult and early life immunization. cGAMP adjuvantation alone could increase rHA-specific antibody titers in adult but not newborn mice. Remarkably, as compared to alum or cGAMP alone, immunization with cGAMP formulated with alum (Alhydrogel) enhanced newborn rHA-specific IgG2a/c titers ~400-fold, an antibody subclass associated with the development of IFNγ-driven type 1 immunity in vivo and endowed with higher effector functions, by 42 days of life. Highlighting the amenability for successful vaccine formulation and delivery, we next confirmed that cGAMP adsorbs onto alum in vitro. Accordingly, immunization early in life with (cGAMP+alum) promoted IFNγ production by CD4+ T cells and increased the proportions and absolute numbers of CD4+ CXCR5+ PD-1+ T follicular helper and germinal center (GC) GL-7+ CD138+ B cells, suggesting an enhancement of the GC reaction. Adjuvantation effects were apparently specific for IgG2a/c isotype switching without effect on antibody affinity maturation, as there was no effect on rHA-specific IgG avidity. Overall, our studies suggest that cGAMP when formulated with alum may represent an effective adjuvantation system to foster humoral and cellular aspects of type 1 immunity for early life immunization.