Publications by authors named "Dheenadhayalan V"

The Consortium on Adventitious Agent Contamination in Biomanufacturing (CAACB) collected historical data from 20 biopharmaceutical industry members on their experience with the in vivo adventitious virus test, the in vitro virus test, and the use of next generation sequencing (NGS) for viral safety. Over the past 20 years, only three positive in vivo adventitious virus test results were reported, and all were also detected in another concurrent assay. In more than three cases, data collected as a part of this study also found that the in vivo adventitious virus test had given a negative result for a sample that was later found to contain virus.

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Background: We report a first-in-human trial evaluating safety and immunogenicity of a recombinant BCG, AERAS-422, over-expressing TB antigens Ag85A, Ag85B, and Rv3407 and expressing mutant perfringolysin.

Methods: This was a randomized, double-blind, dose-escalation trial in HIV-negative, healthy adult, BCG-naïve volunteers, negative for prior exposure to Mtb, at one US clinical site. Volunteers were randomized 2:1 at each dose level to receive a single intradermal dose of AERAS-422 (>10(5)-<10(6)CFU=low dose, ≥10(6)-<10(7)CFU=high dose) or non-recombinant Tice BCG (1-8×10(5)CFU).

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Vaccines to protect against tuberculosis (TB) are urgently needed. We performed a case-control analysis to identify immune correlates of TB disease risk in Bacille Calmette-Guerin (BCG) immunized infants from the MVA85A efficacy trial. Among 53 TB case infants and 205 matched controls, the frequency of activated HLA-DR(+) CD4(+) T cells associates with increased TB disease risk (OR=1.

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Background: MVA85A and AERAS-402 are two clinically advanced viral vectored TB vaccine candidates expressing Mycobacterium tuberculosis antigens designed to boost BCG-induced immunity. Clinical trials with candidate malaria vaccines have demonstrated that adenoviral vector based priming immunisation, followed by MVA vector boost, induced high levels of immunity. We present the safety and immunogenicity results of the first clinical trial to evaluate this immunisation strategy in TB.

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Background: Several novel tuberculosis vaccines are currently in clinical trials, including AERAS-402, an adenovector encoding a fusion protein of Mycobacterium tuberculosis antigens 85A, 85B, and TB10.4. A multicentred trial of AERAS-402 safety and immunogenicity in healthy infants was conducted in three countries in sub-Saharan Africa, using an adaptive design.

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Background: The safety and immunogenicity of a replication deficient adenovirus serotype 35 tuberculosis (TB) vaccine containing gene inserts for Antigens (Ag) 85A, Ag85B and TB10.4 (AERAS-402/AD35.TB-S) was evaluated in previously BCG vaccinated, HIV-infected South African adults with baseline CD4 counts >350 cells/mm(3).

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Bacille Calmette-Guérin (BCG), the only licensed vaccine for the prevention of tuberculosis (TB), provides only limited protection against certain forms of Mycobacterium tuberculosis (Mtb) infection. While infection with Mtb can be treated with antibiotics, the therapy is expensive, toxic, and requires several months for treatment. In addition, the emergence of drug resistant strains limits the impact of antibiotics and underlines the importance of developing a more effective vaccine to control this disease.

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A powder vaccine intended for aerosol delivery was formulated by spray drying the Ad35-vectored tuberculosis (TB) AERAS-402 vaccine with mannitol-based stabilizers. Thermodynamic properties, water absorption, particle size distribution and morphology of the powders were evaluated. Virus survival during spray drying and storage was determined by medium Tissue Culture Infectious Dose (TCID(50)).

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Despite the extensive success with the introduction of M. bovis Bacille Calmette-Guérin (BCG), tuberculosis (TB) remains a major global epidemic infecting between 8 and 9 million people annually with an estimated 1.7 million deaths each year.

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Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), has infected approximately two billion individuals worldwide with approximately 9.2 million new cases and 1.6 million deaths annually.

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New post-exposure tuberculosis vaccination strategies are being developed to prevent disease in individuals latently infected with Mycobacterium tuberculosis. However, concerns about the potential induction of deleterious Koch-like reactions after immunization of persons with latent tuberculosis has limited progress in assessing the effectiveness of post-exposure vaccination. To evaluate the safety of immunization after M.

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Recent preclinical and epidemiologic studies have suggested that certain Mycobacterium tuberculosis genotypes (in particular, Beijing lineage strains) may be resistant to Mycobacterium bovis BCG vaccine-induced antituberculosis protective immunity. To investigate the strain specificity of BCG-induced protective responses in a murine model of pulmonary tuberculosis, C57BL/6 mice were vaccinated with BCG vaccine and then challenged 2 months later with one of nine M. tuberculosis isolates.

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Evaluation of expression of 16 PE_PGRS genes present in Mycobacterium tuberculosis under various growth conditions demonstrated constitutive expression of 7 genes, variable expression of 7 genes, and no expression of 2 genes. An inverse expression profile for genes PE_PGRS16 and PE_PGRS26 was observed to occur in macrophages and in mice infected with M. tuberculosis.

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Infection of mice with Mycobacterium avium or immunization with a novel PE gene expressed by M. avium (MaPE) showed that a dominant T-cell immune response was elicited. Immunization with an MaPE DNA vaccine protected mice against an aerosol challenge with Mycobacterium tuberculosis, suggesting that mycobacteria express PE antigens with cross-protective T-cell epitopes.

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Research on mycobacteria-specific PE_PGRS genes indicates that they code for cell surface proteins that may influence virulence and the infection of host cells by mycobacteria. In the studies presented here, we have expressed the PE_PGRS 33 gene in a non-pathogenic fast-growing Mycobacterium smegmatis strain and demonstrated that it survives better in macrophage cultures, in vitro as well as in mice after intraperitoneal administration, than the parental strain containing the vector only or a strain expressing only the PE domain of PE_PGRS 33. In macrophages, enhanced colonization by the M.

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The heparin-binding hemagglutinin (HBHA) of Mycobacterium tuberculosis is a surface-expressed adhesin that can affect binding to host cells via a unique, methylated, carboxyl-terminal, lysine-, alanine-, and proline-rich repeat region. It has been implicated in extrapulmonary dissemination of M. tuberculosis from the lung following the initial infection of the host.

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Purified protein derivative (PPD) RT23-recalled T-cell receptor (TCR) V beta expression was studied in the peripheral blood of 42 pulmonary tuberculosis patients and 44 healthy controls from southern India, a region where tuberculosis is endemic. Forty-eight-hour whole-blood cultures in the presence or absence of PPD-RT23 were set up, and at the end of the culture period total RNA was extracted and cDNA was synthesized. Expression of various TCR V beta families was assessed by using family-specific primers.

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Three genes encoding the secreted proteins (antigen 85-A, B, and C) of Mycobacterium avium subsp. paratuberculosis were cloned, sequenced and studied. The complete sequences of these three 85-complex proteins revealed their similarity with 85-complex proteins of other mycobacterial species.

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HLA DRB1*02 and its subtypes predispose individuals for a far-advanced sputum-positive pulmonary tuberculosis transcending ethnic boundaries. Mycobacterium bovis BCG does not afford the desired protection against adult pulmonary tuberculosis, and a spectrum of immune reactivity exists in controls and hospital contacts. All of these findings have been identified and demonstrated in areas of endemicity.

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Setting: Tuberculosis is endemic in south India: sputum positive pulmonary tuberculosis is predisposed by HLA-DR2 in south India and few other populations of the world.

Objective: To study HLA-DRB1, DQB1, DQA1 and DPB1 allelic polymorphism in pulmonary tuberculosis patients and endemic controls from south India.

Design: One hundred and twenty-six, sputum positive pulmonary tuberculosis patients and 87, endemic controls, from Madurai were studied for MHC class II allelic polymorphism by PCR-SSOP method.

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