Joanes Joseph - Academia.edu (original) (raw)

Papers by Joanes Joseph

Research paper thumbnail of Molecular Characterization of Heterologous HIV1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

Journal of Biomedicine and Biotechnology, 2010

Research paper thumbnail of Fermi Gases with Tunable Interactions

Fermi gases with magnetically tunable interactions provide a clean and controllable laboratory sy... more Fermi gases with magnetically tunable interactions provide a clean and controllable laboratory system for modelling interparticle interactions between fermions. Near a Feshbach resonance, the s-wave scattering length diverges and Fermi gases are strongly interacting, enabling tests of nonperturbative many-body theories in a variety of disciplines, from high temperature superconductors to neutron matter and quark-gluon plasmas. We measure the entropy and energy of this model system, enabling model-independent comparison with thermodynamic predictions. Our experiments on the expansion dynamics of rotating strongly interacting Fermi gases reveal extremely low viscosity hydrodynamics. Combining the thermodynamic and hydrodynamic measurements enables an estimate of the ratio of the shear viscosity to the entropy density. A strongly interacting Fermi gas in the normal fluid regime is found to be a nearly perfect fluid, where the ratio of the viscosity to the entropy density is close to a universal minimum that has been conjectured by string theory methods. In the weakly interacting regime near a zero crossing in the s-wave scattering length, we observe coherently prepared Fermi gases that slowly evolve into long-lived spin-segregated states that are far from equilibrium and weakly damped.

Research paper thumbnail of Sound in a strongly-interacting Fermi gas

Sound propagation in an optically-trapped gas of strongly interacting fermionic ^6Li atoms is stu... more Sound propagation in an optically-trapped gas of strongly interacting fermionic ^6Li atoms is studied. The atoms are prepared as a 50/50 mixture of the two lowest-energy internal states. Strong interactions are achieved by applying a magnetic field in the vicinity of a broad (834 G) s-wave Feshbach resonance. A sound wave is excited by locally applying a pulse of a repulsive blue-light potential. We measure the propagation of the excitation along the axial direction of the cigar-shaped cloud.

Research paper thumbnail of Safety and Immunogenicity of Novel Recombinant BCG and Modified Vaccinia Virus Ankara Vaccines in Neonate Rhesus Macaques

Journal of Virology, 2010

Although major inroads into making antiretroviral therapy available in resource-poor countries ha... more Although major inroads into making antiretroviral therapy available in resource-poor countries have been made, there is an urgent need for an effective vaccine administered shortly after birth, which would protect infants from acquiring human immunodeficiency virus type 1 (HIV-1) through breast-feeding. Bacillus Calmette-Guérin (BCG) is given to most infants at birth, and its recombinant form could be used to prime HIV-1-specific responses for a later boost by heterologous vectors delivering the same HIV-1-derived immunogen. Here, two groups of neonate Indian rhesus macaques were immunized with either novel candidate vaccine BCG.HIVA 401 or its parental strain AERAS-401, followed by two doses of recombinant modified vaccinia virus Ankara MVA.HIVA. The HIVA immunogen is derived from African clade A HIV-1. All vaccines were safe, giving local reactions consistent with the expected response at the injection site. No systemic adverse events or gross abnormality was seen at necropsy. Both AERAS-401 and BCG.HIVA 401 induced high frequencies of BCG-specific IFN-␥-secreting lymphocytes that declined over 23 weeks, but the latter failed to induce detectable HIV-1-specific IFN-␥ responses. MVA.HIVA elicited HIV-1-specific IFN-␥ responses in all eight animals, but, except for one animal, these responses were weak. The HIV-1-specific responses induced in infants were lower compared to historic data generated by the two HIVA vaccines in adult animals but similar to other recombinant poxviruses tested in this model. This is the first time these vaccines were tested in newborn monkeys. These results inform further infant vaccine development and provide comparative data for two human infant vaccine trials of MVA.HIVA.

Research paper thumbnail of Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques

Journal of Virology, 2010

Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity... more Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA 401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA 401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankaravectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA 401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.

Research paper thumbnail of P17-17. Newborn mice vaccination with rBCG:HIVA + MVA:HIVA enhances HIV1-specific immune responses. Influence of age and immunization routes

Research paper thumbnail of Molecular Characterization of Heterologous HIV1gp120 Gene Expression Disruption in Mycobacterium bovis BCG Host Strain: A Critical Issue for Engineering Mycobacterial Based-Vaccine Vectors

Journal of Biomedicine and Biotechnology, 2010

Research paper thumbnail of Fermi Gases with Tunable Interactions

Fermi gases with magnetically tunable interactions provide a clean and controllable laboratory sy... more Fermi gases with magnetically tunable interactions provide a clean and controllable laboratory system for modelling interparticle interactions between fermions. Near a Feshbach resonance, the s-wave scattering length diverges and Fermi gases are strongly interacting, enabling tests of nonperturbative many-body theories in a variety of disciplines, from high temperature superconductors to neutron matter and quark-gluon plasmas. We measure the entropy and energy of this model system, enabling model-independent comparison with thermodynamic predictions. Our experiments on the expansion dynamics of rotating strongly interacting Fermi gases reveal extremely low viscosity hydrodynamics. Combining the thermodynamic and hydrodynamic measurements enables an estimate of the ratio of the shear viscosity to the entropy density. A strongly interacting Fermi gas in the normal fluid regime is found to be a nearly perfect fluid, where the ratio of the viscosity to the entropy density is close to a universal minimum that has been conjectured by string theory methods. In the weakly interacting regime near a zero crossing in the s-wave scattering length, we observe coherently prepared Fermi gases that slowly evolve into long-lived spin-segregated states that are far from equilibrium and weakly damped.

Research paper thumbnail of Sound in a strongly-interacting Fermi gas

Sound propagation in an optically-trapped gas of strongly interacting fermionic ^6Li atoms is stu... more Sound propagation in an optically-trapped gas of strongly interacting fermionic ^6Li atoms is studied. The atoms are prepared as a 50/50 mixture of the two lowest-energy internal states. Strong interactions are achieved by applying a magnetic field in the vicinity of a broad (834 G) s-wave Feshbach resonance. A sound wave is excited by locally applying a pulse of a repulsive blue-light potential. We measure the propagation of the excitation along the axial direction of the cigar-shaped cloud.

Research paper thumbnail of Safety and Immunogenicity of Novel Recombinant BCG and Modified Vaccinia Virus Ankara Vaccines in Neonate Rhesus Macaques

Journal of Virology, 2010

Although major inroads into making antiretroviral therapy available in resource-poor countries ha... more Although major inroads into making antiretroviral therapy available in resource-poor countries have been made, there is an urgent need for an effective vaccine administered shortly after birth, which would protect infants from acquiring human immunodeficiency virus type 1 (HIV-1) through breast-feeding. Bacillus Calmette-Guérin (BCG) is given to most infants at birth, and its recombinant form could be used to prime HIV-1-specific responses for a later boost by heterologous vectors delivering the same HIV-1-derived immunogen. Here, two groups of neonate Indian rhesus macaques were immunized with either novel candidate vaccine BCG.HIVA 401 or its parental strain AERAS-401, followed by two doses of recombinant modified vaccinia virus Ankara MVA.HIVA. The HIVA immunogen is derived from African clade A HIV-1. All vaccines were safe, giving local reactions consistent with the expected response at the injection site. No systemic adverse events or gross abnormality was seen at necropsy. Both AERAS-401 and BCG.HIVA 401 induced high frequencies of BCG-specific IFN-␥-secreting lymphocytes that declined over 23 weeks, but the latter failed to induce detectable HIV-1-specific IFN-␥ responses. MVA.HIVA elicited HIV-1-specific IFN-␥ responses in all eight animals, but, except for one animal, these responses were weak. The HIV-1-specific responses induced in infants were lower compared to historic data generated by the two HIVA vaccines in adult animals but similar to other recombinant poxviruses tested in this model. This is the first time these vaccines were tested in newborn monkeys. These results inform further infant vaccine development and provide comparative data for two human infant vaccine trials of MVA.HIVA.

Research paper thumbnail of Novel Recombinant Mycobacterium bovis BCG, Ovine Atadenovirus, and Modified Vaccinia Virus Ankara Vaccines Combine To Induce Robust Human Immunodeficiency Virus-Specific CD4 and CD8 T-Cell Responses in Rhesus Macaques

Journal of Virology, 2010

Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity... more Mycobacterium bovis bacillus Calmette-Guérin (BCG), which elicits a degree of protective immunity against tuberculosis, is the most widely used vaccine in the world. Due to its persistence and immunogenicity, BCG has been proposed as a vector for vaccines against other infections, including HIV-1. BCG has a very good safety record, although it can cause disseminated disease in immunocompromised individuals. Here, we constructed a recombinant BCG vector expressing HIV-1 clade A-derived immunogen HIVA using the recently described safer and more immunogenic BCG strain AERAS-401 as the parental mycobacterium. Using routine ex vivo T-cell assays, BCG.HIVA 401 as a stand-alone vaccine induced undetectable and weak CD8 T-cell responses in BALB/c mice and rhesus macaques, respectively. However, when BCG.HIVA 401 was used as a priming component in heterologous vaccination regimens together with recombinant modified vaccinia virus Ankaravectored MVA.HIVA and ovine atadenovirus-vectored OAdV.HIVA vaccines, robust HIV-1-specific T-cell responses were elicited. These high-frequency T-cell responses were broadly directed and capable of proliferation in response to recall antigen. Furthermore, multiple antigen-specific T-cell clonotypes were efficiently recruited into the memory pool. These desirable features are thought to be associated with good control of HIV-1 infection. In addition, strong and persistent T-cell responses specific for the BCG-derived purified protein derivative (PPD) antigen were induced. This work is the first demonstration of immunogenicity for two novel vaccine vectors and the corresponding candidate HIV-1 vaccines BCG.HIVA 401 and OAdV.HIVA in nonhuman primates. These results strongly support their further exploration.

Research paper thumbnail of P17-17. Newborn mice vaccination with rBCG:HIVA + MVA:HIVA enhances HIV1-specific immune responses. Influence of age and immunization routes