Brucellosis is a global disease and the world's most prevalent zoonosis. All cases in livestock and most cases in humans are caused by members of the genus that possess a surface O-polysaccharide (OPS) comprised of a rare monosaccharide 4-deoxy-4-formamido-D-mannopyranose assembled with α1,2 and α1,3 linkages. The OPS of the bacterium is the basis for serodiagnostic tests for brucellosis.
View Article and Find Full Text PDFTwo strains of mice (BALB/c and CB6F1) were vaccinated with a range of Bacille Calmette-Guérin (BCG) Danish doses from 3 × 10 to 30 CFU/mouse, followed by aerosol infection with Mtb (H37Rv or West-Beijing HN878 strain). The results indicated that both strains of mice when infected with HN878 exhibited significant protection in their lungs with BCG doses at 3 × 10-3000 CFU (BALB/c) and 3 × 10-300 CFU (CB6F1). Whereas, a significant protection was seen in both strains of mice with BCG doses at 3 × 10-300 CFU when infected with H37Rv.
View Article and Find Full Text PDFHeterologous BCG prime-boost regimens represent a promising strategy for an urgently required improved tuberculosis vaccine. Identifying the mechanisms which underpin the enhanced protection induced by such strategies is one key aim which would significantly accelerate rational vaccine development. Experimentally, airway vaccination induces greater efficacy than parenteral delivery; in both conventional vaccination and heterologous boosting of parenteral BCG immunisation.
View Article and Find Full Text PDFTuberculosis (TB) is the biggest cause of human mortality from an infectious disease. The only vaccine currently available, bacille Calmette-Guérin (BCG), demonstrates some protection against disseminated disease in childhood but very variable efficacy against pulmonary disease in adults. A greater understanding of protective host immune responses is required in order to aid the development of improved vaccines.
View Article and Find Full Text PDFConventional dendritic cells (cDC) are professional antigen-presenting cells that induce immune activation or tolerance. Two functionally specialised populations, termed cDC1 and cDC2, have been described in humans, mice, ruminants and recently in pigs. Pigs are an important biomedical model species and a key source of animal protein; therefore further understanding of their immune system will help underpin the development of disease prevention strategies.
View Article and Find Full Text PDFBoosting BCG using heterologous prime-boost represents a promising strategy for improved tuberculosis (TB) vaccines, and adenovirus (Ad) delivery is established as an efficacious boosting vehicle. Although studies demonstrate that intranasal administration of Ad boost to BCG offers optimal protection, this is not currently possible in cattle. Using Ad vaccine expressing the mycobacterial antigen TB10.
View Article and Find Full Text PDFTuberculosis (TB) remains a global pandemic, in both animals and man, and novel vaccines are urgently required. Heterologous prime-boost of BCG represents a promising strategy for improved TB vaccines, with respiratory delivery the most efficacious to date. Such an approach may be an ideal vaccination strategy against bovine TB (bTB), but respiratory vaccination presents a technical challenge in cattle.
View Article and Find Full Text PDFBovine tuberculosis (bTB) remains a globally significant veterinary health problem. Defining correlates of protection can accelerate the development of novel vaccines against TB. As the cultured IFNγ ELISPOT (cELISPOT) assay has been shown to predict protection and duration of immunity in vaccinated cattle, we sought to characterize the phenotype of the responding T-cells.
View Article and Find Full Text PDFIt is generally assumed that the inbred mouse strains BALB/c (H-2(d)) and C57BL/6 (H-2(b)) respond to mycobacterial infection with distinct polarisation of T helper responses, with C57BL/6 predisposed to Th1 and BALB/c to Th2. We investigated this in a BCG-immunisation, Mycobacterium bovis challenge model. Following immunisation, lung and spleen cell cytokine responses to in vitro re-stimulation with a cocktail of seven secreted, immunogenic, recombinant mycobacterial proteins were determined.
View Article and Find Full Text PDFTuberculosis (TB) remains one of the most important infectious diseases of man and animals, and the only available vaccine (BCG) requires urgent replacement or improvement. To facilitate this, the protective mechanisms induced by BCG require further understanding. As a live attenuated vaccine, persistence of BCG bacilli in the host may be a crucial mechanism.
View Article and Find Full Text PDFPrevious experiments for the identification of novel diagnostic or vaccine candidates for bovine tuberculosis have followed a targeted approach, wherein specific groups of proteins suspected to contain likely candidates are prioritized for immunological assessment (for example, with in silico approaches). However, a disadvantage of this approach is that the sets of proteins analyzed are restricted by the initial selection criteria. In this paper, we describe a series of experiments to evaluate a nonbiased approach to antigen mining by utilizing a Gateway clone set for Mycobacterium tuberculosis, which constitutes a library of clones expressing 3,294 M.
View Article and Find Full Text PDFThe assessment of antigen-specific T cell responses by intracellular cytokine staining (ICS) has become a routine technique in studies of vaccination and immunity. Here, we highlight how the duration of in vitro antigen pre-stimulation, combined with the cytokine accumulation period, are critical parameters of these methods. The effect of varying these parameters upon the diversity and frequency of multifunctional CD4 T cell subsets has been investigated using a murine model of TB vaccination and in cattle naturally infected with Mycobacterium bovis.
View Article and Find Full Text PDFBovine tuberculosis (bTb) remains a major and economically important disease of livestock. Improved ante-mortem diagnostic tools would help to underpin novel control strategies. The definition of biomarkers correlating with disease progression could have impact on the rational design of novel diagnostic approaches for bTb.
View Article and Find Full Text PDFTo more closely understand the mechanisms of how BCG vaccination confers immunity would help to rationally design improved tuberculosis vaccines that are urgently required. Given the established central role of CD4 T cells in BCG induced immunity, we sought to characterise the generation of memory CD4 T cell responses to BCG vaccination and M. bovis infection in a murine challenge model.
View Article and Find Full Text PDFBackground: In the present study, we applied microarray technology to define biosignatures by microarray transcriptome analysis in lung and spleen samples after BCG vaccination and M. bovis infection of BALB/c mice. The aims were two-fold, namely to define biosignatures that could predict vaccine success before challenge, and biomarker patterns that correlated with anamnestic protective responses following exposure to virulent M.
View Article and Find Full Text PDFTuberculosis (TB) remains one of the most important infectious diseases of humans and animals. Mycobacterium bovis BCG, the only currently available TB vaccine, demonstrates variable levels of efficacy; therefore, a replacement or supplement to BCG is required. Protein subunit vaccines have shown promise but require the use of adjuvants to enhance their immunogenicity.
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