Modulation of humoral immune response to oral BCG vaccination by Mycobacterium bovis BCG Moreau Rio de Janeiro (RDJ) in healthy adults

BACKGROUND: Oral administration of BCG was the route initially used by Calmette and Guérin, but was replaced by intradermal administration in virtually all countries after the Lubeck accident. However, Brazil continued to administer oral BCG Moreau RDJ, which was maintained until the mid-1970s when it was substituted by the intradermal route. Although BCG vaccination has been used in humans since 1921, little is known of the induced immune response. The aim of this study was to analyse immunological responses after oral vaccination with M. bovis BCG Moreau RDJ. METHODS: This study in healthy volunteers has measured cellular and humoral aspects of the immunological response to oral M. bovis BCG Moreau RDJ in Rio de Janeiro, Brazil. T-cell trafficking and Th(1 )and Th(2 )cytokine responses are described, as well as isotype-specific antibody production using novel techniques. RESULTS: Oral immunisation has no adverse effects. We have shown that there are cellular and humoral immunological responses after oral immunisation. Oral revaccination does not induce a positive skin test in responsive individuals and multiple booster orally was able to induce modulation in humoral immunological responses (switch from IgG to IgA) in previously immunised subjects and incapable of inducing tolerance. In contrast, the cellular immune response does not differ between vaccinated individuals with positive and negative skin test reactions. CONCLUSION: All subjects, including those who did not respond to the skin test at study commencement, were capable of mounting humoral and cellular immune response to the antigens tested

Proteomic profile of culture filtrate from the Brazilian vaccine strain Mycobacterium bovis BCG Moreau compared to M. bovis BCG Pasteur

<p>Abstract</p> <p>Background</p> <p>Bacille Calmette-Guerin (BCG) is currently the only available vaccine against tuberculosis (TB) and comprises a heterogeneous family of sub-strains with genotypic and phenotypic differences. The World Health Organization (WHO) affirms that the characterization of BCG sub-strains, both on genomic and proteomic levels, is crucial for a better comprehension of the vaccine. In addition, these studies can contribute in the development of a more efficient vaccine against TB. Here, we combine two-dimensional electrophoresis (2DE) and mass spectrometry to analyse the proteomic profile of culture filtrate proteins (CFPs) from <it>M. bovis </it>BCG Moreau, the Brazilian vaccine strain, comparing it to that of BCG Pasteur. CFPs are considered of great importance given their dominant immunogenicity and role in pathogenesis, being available for interaction with host cells since early infection.</p> <p>Results</p> <p>The 2DE proteomic map of <it>M. bovis </it>BCG Moreau CFPs in the pH range 3 - 8 allowed the identification of 158 spots corresponding to 101 different proteins, identified by MS/MS. Comparison to BCG Pasteur highlights the great similarity between these BCG strains. However, quantitative analysis shows a higher expression of immunogenic proteins such as Rv1860 (BCG1896, Apa), Rv1926c (BCG1965c, Mpb63) and Rv1886c (BCG1923c, Ag85B) in BCG Moreau when compared to BCG Pasteur, while some heat shock proteins, such as Rv0440 (BCG0479, GroEL2) and Rv0350 (BCG0389, DnaK), show the opposite pattern.</p> <p>Conclusions</p> <p>Here we report the detailed 2DE profile of CFPs from <it>M. bovis </it>BCG Moreau and its comparison to BCG Pasteur, identifying differences that may provide relevant information on vaccine efficacy. These findings contribute to the detailed characterization of the Brazilian vaccine strain against TB, revealing aspects that may lead to a better understanding of the factors leading to BCG's variable protective efficacy against TB.</p

Aspects of gastrointestinal immunology and nutrition in human immunodeficiency virus-1 infection in Brazil

Mucosal surfaces have a fundamental participation in many aspects of the human immunodeficiency virus (HIV) infection pathogenesis. In Brazilian HIV-1 infected subjects, loss of weight and appetite are among the most debilitating symptoms. In this review we describe a defined mucosal immunogen that has profound but transient effects on HIV viral load, and we suggest that gut associated lymphoid tissue under constant immunostimulation is likely to provide a major contribution to the total levels of HIV. We also show that hypermetabolism appears to play a role in the wasting process in Brazilian patients coinfected with HIV and tuberculosis