RESUMO
The development of immunologic interventions that can target the viral reservoir in HIV-1-infected individuals is a major goal of HIV-1 research. However, little evidence exists that the viral reservoir can be sufficiently targeted to improve virologic control following discontinuation of antiretroviral therapy. Here we show that therapeutic vaccination with Ad26/MVA (recombinant adenovirus serotype 26 (Ad26) prime, modified vaccinia Ankara (MVA) boost) and stimulation of TLR7 (Toll-like receptor 7) improves virologic control and delays viral rebound following discontinuation of antiretroviral therapy in SIV-infected rhesus monkeys that began antiretroviral therapy during acute infection. Therapeutic vaccination with Ad26/MVA resulted in a marked increase in the magnitude and breadth of SIV-specific cellular immune responses in virologically suppressed, SIV-infected monkeys. TLR7 agonist administration led to innate immune stimulation and cellular immune activation. The combination of Ad26/MVA vaccination and TLR7 stimulation resulted in decreased levels of viral DNA in lymph nodes and peripheral blood, and improved virologic control and delayed viral rebound following discontinuation of antiretroviral therapy. The breadth of cellular immune responses correlated inversely with set point viral loads and correlated directly with time to viral rebound. These data demonstrate the potential of therapeutic vaccination combined with innate immune stimulation as a strategy aimed at a functional cure for HIV-1 infection.
Assuntos
Adenoviridae/genética , Vacinas contra a SAIDS/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/terapia , Vírus da Imunodeficiência Símia/imunologia , Receptor 7 Toll-Like/imunologia , Vaccinia virus/genética , Vacinas contra a AIDS/genética , Vacinas contra a AIDS/imunologia , Animais , Antirretrovirais/administração & dosagem , DNA Viral/análise , DNA Viral/sangue , Feminino , Vetores Genéticos/genética , Infecções por HIV/imunologia , Infecções por HIV/terapia , Imunidade Celular , Imunidade Inata , Macaca mulatta , Masculino , RNA Viral/análise , RNA Viral/sangue , Vacinas contra a SAIDS/genética , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Vírus da Imunodeficiência Símia/genética , Vírus da Imunodeficiência Símia/crescimento & desenvolvimento , Vírus da Imunodeficiência Símia/isolamento & purificação , Fatores de Tempo , Receptor 7 Toll-Like/genética , Carga Viral/imunologiaRESUMO
An important focus in vaccine research is the design of vaccine vectors with low seroprevalence and high immunogenicity. Replication-incompetent lymphocytic choriomeningitis virus (rLCMV) vectors do not elicit vector-neutralizing antibody responses, and homologous prime-boost regimens with rLCMV vectors induce boostable and protective T cell responses to model antigens in mice. However, cellular and humoral immune responses following homologous rLCMV vaccine regimens have not been rigorously evaluated in non-human primates (NHPs). To test whether rLCMV vectors constitute an effective vaccine platform in NHPs, we developed rLCMV vectors expressing SIVmac239 Env and Gag antigens and assessed their immunogenicity in mice and cynomolgus macaques. Immunization with rLCMV vaccine vectors expressing SIV Env and Gag was effective at generating SIV-specific T cell and antibody responses in both mice and NHPs. Epitope mapping using SIV Env in C57BL/6 mice demonstrated that rLCMV vectors induced sustained poly-functional responses to both dominant and subdominant epitopes. Our results suggest the potential of rLCMV vectors as vaccine candidates. Future SIV challenge experiments in rhesus macaques will be needed to assess immune protection by these vaccine vectors.
Assuntos
Antígenos Virais/imunologia , Portadores de Fármacos , Vírus da Coriomeningite Linfocítica/genética , Vacinas contra a SAIDS/imunologia , Vírus da Imunodeficiência Símia/imunologia , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/genética , Macaca fascicularis , Camundongos Endogâmicos C57BL , Vacinas contra a SAIDS/administração & dosagem , Vacinas contra a SAIDS/genética , Vírus da Imunodeficiência Símia/genética , Linfócitos T/imunologia , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/genética , Vacinas Atenuadas/imunologia , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologiaRESUMO
HIV-1-specific broadly neutralizing antibodies (bNAbs) can protect rhesus monkeys against simian-human immunodeficiency virus (SHIV) challenge. However, the site of antibody interception of virus and the mechanism of antibody-mediated protection remain unclear. We administered a fully protective dose of the bNAb PGT121 to rhesus monkeys and challenged them intravaginally with SHIV-SF162P3. In PGT121-treated animals, we detected low levels of viral RNA and viral DNA in distal tissues for seven days following challenge. Viral RNA-positive tissues showed transcriptomic changes indicative of innate immune activation, and cells from these tissues initiated infection after adoptive transfer into naïve hosts. These data demonstrate that bNAb-mediated protection against a mucosal virus challenge can involve clearance of infectious virus in distal tissues.