Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS


RECOMBINANT BCG Sintesi della relazione

Project ID: ICA4-CT-2000-30032
Finanziato nell'ambito di: FP5-INCO 2
Paese: France

immunogenicity and protective efficacy of rBCG-M. bovis antigen KO strains

Current immunodiagnostic tests for tuberculosis (TB) do not allow to differentiate between vaccination with Mycobacterium bovis BCG or infection with M. bovis or M. tuberculosis. This is a major drawback for the use of BCG as a vector to develop new candidate vaccines both against TB and other pathogens. Thus the development of differential diagnostics is a major issue. As a proof of concept, we have deleted the genes encoding two well-characterized immunodominant antigens, MPB70 and MPB83 from M. bovis BCG. Since we feared that these antigens might be of high importance for BCG persistence, we decided to construct our mutant strain in a naturally low-producing strain i.e. the BCG Pasteur strain 1173P2. The double knock-out strain did not show impaired persistence in mice after intravenous inoculation as compared to wildtype BCG. Moreover, both strains induced similar protection against an aerosol challenge with virulent M. tuberculosis H37Rv in mice. These data indicate that MPB70 and 83 antigens are not fully required for inducing protection by BCG vaccination in preclinical models. Thus, these two antigens might become good candidates to dicriminate BCG vaccination from infection with bacteria from the M. tuberculosis complex.

Reported by

Institut Pasteur
Unité de Génétique Mycobacterienne Institut Pasteur 25 rue du Dr Roux
75015 Paris
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