RESUMEN
We evaluated replication-defective poxvirus vectors (modified vaccinia Ankara [MVA] and fowlpox [FPV]) in a homologous and heterologous vector prime-boost vaccination regimen containing matching HIV inserts (MVA-HIV and FPV-HIV) given at months 0, 1, 3, 5 and 7 in 150 healthy HIV-negative vaccinia-naïve participants. FPV-HIV alone was poorly immunogenic, while the high dose (10(9)pfu/2 ml) of MVA-HIV alone elicited maximal responses after two injections: CD4+ and CD8+ T-cell responses in 26/55 (47.3%) and 5/60 (8.3%) of participants, respectively, and IFN-γ ELISpot responses in 28/62 (45.2%). The infrequent CD8+ T-cell responses following MVA-HIV priming were boosted only by the heterologous (FPV-HIV) construct in 14/27 (51.9%) of participants post 4th vaccination. Alternatively, HIV envelope-specific binding antibodies were demonstrated in approximately two-thirds of recipients of the homologous boosting regimen, but in less than 20% of subjects after the heterologous vector boost. Thus, a heterologous poxvirus vector prime-boost regimen can induce HIV-specific CD8+ T-cell and CD4+ T-cell responses, which may be an important feature of an optimal regimen for preventive HIV vaccination.
Asunto(s)
Vacunas contra el SIDA/inmunología , Portadores de Fármacos , Virus de la Viruela de las Aves de Corral/genética , Vectores Genéticos , Infecciones por VIH/prevención & control , VIH-1/inmunología , Virus Vaccinia/genética , Vacunas contra el SIDA/genética , Adolescente , Adulto , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Femenino , Anticuerpos Anti-VIH/sangre , VIH-1/genética , Humanos , Inmunización Secundaria/métodos , Masculino , Factores de Tiempo , Vacunación/métodos , Adulto JovenRESUMEN
Poxvirus vaccine vectors, although capable of eliciting potent immune responses, pose serious health risks in immunosuppressed individuals. We therefore constructed five novel recombinant vaccinia virus vectors which contained overlapping deletions of coding regions for the B5R, B8R, B12R, B13R, B14R, B16R, B18R, and B19R immunomodulatory gene products and assessed them for both immunogenicity and pathogenicity. All five of these novel vectors elicited both cellular and humoral immunity to the inserted HIV-BH10 env comparable to that induced by the parental Wyeth strain vaccinia virus. However, deletion of these immunomodulatory genes did not increase the immunogenicity of these vectors compared with the parental vaccinia virus. Furthermore, four of these vectors were slightly less virulent and one was slightly more virulent than the Wyeth strain virus in neonatal mice. Attenuated poxviruses have potential use as safer alternatives to current replication-competent vaccinia virus. Improved vaccinia virus vectors can be generated by deleting additional genes to achieve a more significant viral attenuation.
Asunto(s)
Vacunas contra el SIDA/inmunología , Vectores Genéticos/genética , Infecciones por VIH/inmunología , Virus Vaccinia/genética , Virus Vaccinia/patogenicidad , Animales , Femenino , Eliminación de Gen , Anticuerpos Anti-VIH/sangre , Proteína gp120 de Envoltorio del VIH/genética , Inmunización , Inmunización Secundaria , Dosificación Letal Mediana , Ratones , Ratones Endogámicos BALB C , Vacunas Sintéticas/inmunología , VirulenciaRESUMEN
PURPOSE: The poor immunogenicity of tumor antigens and the antigenic heterogeneity of tumors call for vaccine strategies to enhance T-cell responses to multiple antigens. Two antigens expressed noncoordinately on most human carcinomas are carcinoembryonic antigen (CEA) and MUC-1. We report here the construction and characterization of two viral vector vaccines to address these issues. EXPERIMENTAL DESIGN: The two viral vectors analyzed are the replication-competent recombinant vaccinia virus (rV-) and the avipox vector, fowlpox (rF-), which is replication incompetent in mammalian cells. Each vector encodes the transgenes for three human costimulatory molecules (B7-1, ICAM-1, and LFA-3, designated TRICOM) and the CEA and MUC-1 transgenes (which also contain agonist epitopes). The vectors are designated rV-CEA/MUC/TRICOM and rF-CEA/MUC/TRICOM. RESULTS: Each of the vectors is shown to be capable of faithfully expressing all five transgenes in human dendritic cells (DC). DCs infected with either vector are shown to activate both CEA- and MUC-1-specific T-cell lines to the same level as DCs infected with CEA-TRICOM or MUC-1-TRICOM vectors. Thus, no evidence of antigenic competition between CEA and MUC-1 was observed. Human DCs infected with rV-CEA/MUC/TRICOM or rF-CEA/MUC/TRICOM are also shown to be capable of generating both MUC-1- and CEA-specific T-cell lines; these T-cell lines are in turn shown to be capable of lysing targets pulsed with MUC-1 or CEA peptides as well as human tumor cells endogenously expressing MUC-1 and/or CEA. CONCLUSION: These studies provide the rationale for the clinical evaluation of these multigene vectors in patients with a range of carcinomas expressing MUC-1 and/or CEA.
Asunto(s)
Vacunas contra el Cáncer/genética , Vectores Genéticos/genética , Transgenes/genética , Animales , Antígeno B7-1/genética , Antígeno B7-1/inmunología , Antígenos CD58/genética , Antígenos CD58/inmunología , Vacunas contra el Cáncer/inmunología , Antígeno Carcinoembrionario/genética , Antígeno Carcinoembrionario/inmunología , Línea Celular , Línea Celular Tumoral , Células Cultivadas , Citotoxicidad Inmunológica/inmunología , Células Dendríticas/citología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Citometría de Flujo , Virus de la Viruela de las Aves de Corral/genética , Humanos , Immunoblotting , Molécula 1 de Adhesión Intercelular/genética , Molécula 1 de Adhesión Intercelular/inmunología , Interferón gamma/biosíntesis , Mucina-1/genética , Mucina-1/inmunología , Recombinación Genética , Linfocitos T/citología , Linfocitos T/inmunología , Linfocitos T/metabolismo , Transfección , Transgenes/inmunología , Virus Vaccinia/genéticaRESUMEN
Induction of mucosal anti-human immunodeficiency virus type 1 (HIV-1) T-cell responses in males and females will be important for the development of a successful HIV-1 vaccine. An HIV-1 envelope peptide, DNA plasmid, and recombinant modified vaccinia virus Ankara (rMVA) expressing the H-2D(d)-restricted cytotoxic T lymphocyte P18 epitope were used as immunogens to test for their ability to prime and boost anti-HIV-1 T-cell responses at mucosal and systemic sites in BALB/c mice. We found of all prime-boost combinations tested, an HIV-1 Env peptide subunit mucosal prime followed by systemic (intradermal) boosting with rMVA yielded the maximal induction of gamma interferon (IFN-gamma) spot-forming cells in the female genital tract and colon. However, this mucosal prime-systemic rMVA boost regimen was minimally immunogenic for the induction of genital, colon, or lung anti-HIV-1 T-cell responses in male mice. We determined that a mucosal Env subunit immunization could optimally prime an rMVA boost in female but not male mice, as determined by the magnitude of antigen-specific IFN-gamma responses in the reproductive tracts, colon, and lung. Defective mucosal priming in male mice could not be overcome by multiple mucosal immunizations. However, rMVA priming followed by an rMVA boost was the optimal prime-boost strategy for male mice as determined by the magnitude of antigen-specific IFN-gamma responses in the reproductive tract and lung. Thus, prime-boost immunization strategies able to induce mucosal antigen-specific IFN-gamma responses were identified for male and female mice. Understanding the cellular and molecular basis of gender-determined immune responses will be important for optimizing induction of anti-HIV-1 mucosal immune responses in both males and females.
Asunto(s)
Vacunas contra el SIDA/inmunología , Linfocitos T CD8-positivos/inmunología , Colon/inmunología , Genitales/inmunología , VIH-1/inmunología , Vacunas Sintéticas/inmunología , Animales , Femenino , Inmunización , Interferón gamma/biosíntesis , Interleucina-2/biosíntesis , Pulmón/inmunología , Masculino , Ratones , Ratones Endogámicos BALB C , Caracteres Sexuales , Virus Vaccinia/inmunologíaRESUMEN
A therapeutic vaccine for individuals infected with HIV-1 and treated with antiretroviral therapy (ART) should be able to replenish virus-specific CD4+ T-cells and broaden the virus-specific CD8+ T-cell response in order to maintain CD8+ T-cell function and minimize viral immune escape after ART cessation. Because a combination of DNA and recombinant poxvirus vaccine modalities induces high levels of virus-specific CD4+ T-cell response and broadens the cytolytic activity in naive macaques, we investigated whether the same results could be obtained in SIVmac251-infected macaques. The macaques studied here were long-term nonprogressors that naturally contained viremia but were nevertheless treated with a combination of antiviral drugs to assess more carefully the effect of vaccination in the context of ART. The combination of a DNA expressing the gag and pol genes (DNA-SIV-gp) of SIVmac239 followed by a recombinant fowlpox expressing the same SIVmac genes (FP-SIV-gp) was significantly more immunogenic than two immunizations of FP-SIV-gp in SIVmac251-infected macaques treated with ART. The DNA/FP combination significantly expanded and broadened Gag-specific T-cell responses measured by tetramer staining, ELISPOT, and intracellular cytokine staining and measurement of ex vivo cytolytic function. Importantly, the combination of these vaccine modalities also induced a sizeable expansion in most macaques of Gag-specific CD8-(CD4+) T-cells able to produce TNF-alpha. Hopefully, this modality of vaccine combination may be useful in the clinical management of HIV-1-infected individuals.
Asunto(s)
Epítopos Inmunodominantes/inmunología , Virus de la Influenza A/genética , Macaca mulatta/inmunología , Macaca mulatta/virología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Vacunas de ADN/inmunología , Vacunas Virales/inmunología , Animales , Linfocitos T CD8-positivos/inmunología , Progresión de la Enfermedad , Virus de la Influenza A/fisiología , VacunaciónRESUMEN
Nearly all human immunodeficiency virus (HIV) infections are acquired mucosally, and the gut-associated lymphoid tissues are important sites for early virus replication. Thus, vaccine strategies designed to prime virus-specific cytotoxic T lymphocyte (CTL) responses that home to mucosal compartments may be particularly effective at preventing or containing HIV infection. The Salmonella type III secretion system has been shown to be an effective approach for stimulating mucosal CTL responses in mice. We therefore tested DeltaphoP-phoQ attenuated strains of Salmonella enterica serovar Typhimurium and S. enterica serovar Typhi expressing fragments of the simian immunodeficiency virus (SIV) Gag protein fused to the type III-secreted SopE protein for the ability to prime virus-specific CTL responses in rhesus macaques. Mamu-A*01(+) macaques were inoculated with three oral doses of recombinant Salmonella, followed by a peripheral boost with modified vaccinia virus Ankara expressing SIV Gag (MVA Gag). Transient low-level CTL responses to the Mamu-A*01 Gag(181-189) epitope were detected following each dose of Salmonella. After boosting with MVA Gag, strong Gag-specific CTL responses were consistently detected, and tetramer staining revealed the expansion of Gag(181-189)-specific CD8(+) T-cell responses in peripheral blood. A significant percentage of the Gag(181-189)-specific T-cell population in each animal also expressed the intestinal homing receptor alpha4beta7. Additionally, Gag(181-189)-specific CD8(+) T cells were detected in lymphocytes isolated from the colon. Yet, despite these responses, Salmonella-primed/MVA-boosted animals did not exhibit improved control of virus replication following a rectal challenge with SIVmac239. Nevertheless, this study demonstrates the potential of mucosal priming by the Salmonella type III secretion system to direct SIV-specific cellular immune responses to the gastrointestinal mucosa in a primate model.