1. Variation in Gamma Interferon Responses to Different Infecting Strains of Mycobacterium tuberculosis in Acid-Fast Bacillus Smear-Positive Patients and Household Contacts in Antananarivo, Madagascar
- Author
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Maherisoa Ratsitorahina, Alimuddin Zumla, Vaomalala Raharimanga, Soa Fy Andriamandimby, H. Ramarokoto, Brigitte Gicquel, Niaina Rakotosamimanana, Vincent Richard, Jim F. Huggett, Jean-Louis Soares, Voahangy Rasolofo-Razanamparany, T. Mark Doherty, Graham A. W. Rook, Unité des Mycobactéries [Antananarivo, Madagascar] (IPM), Institut Pasteur de Madagascar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Unité d'Epidémiologie [Antananarivo, Madagascar] (IPM), Statens Serum Institut [Copenhagen], Laboratoire National des Mycobactéries, Ministry of Health, Madagascar, University College of London [London] (UCL), Génétique mycobactérienne - Mycobacterial genetics, Institut Pasteur [Paris], Financement européen, and Institut Pasteur [Paris] (IP)
- Subjects
Microbiology (medical) ,MESH: Mycobacterium tuberculosis ,Tuberculosis ,MESH: Interferon-gamma ,Clinical Biochemistry ,Immunology ,Virulence ,Disease ,MESH: Madagascar ,Mycobacterium tuberculosis ,Interferon-gamma ,03 medical and health sciences ,Immune system ,Species Specificity ,Antigen ,Genotype ,Madagascar ,IFN-gamma response ,medicine ,Clinical Laboratory Immunology ,Humans ,MESH: Species Specificity ,Immunology and Allergy ,MESH: Data Collection ,Interferon gamma ,030304 developmental biology ,Antigens, Bacterial ,[SDV.GEN]Life Sciences [q-bio]/Genetics ,0303 health sciences ,MESH: Humans ,spoligotyping ,biology ,030306 microbiology ,Data Collection ,MESH: Host-Pathogen Interactions ,biology.organism_classification ,medicine.disease ,Virology ,3. Good health ,MESH: Leukocytes, Mononuclear ,M. tuberculosis genotype ,Host-Pathogen Interactions ,Leukocytes, Mononuclear ,[SDV.IMM]Life Sciences [q-bio]/Immunology ,MESH: Antigens, Bacterial ,medicine.drug - Abstract
The majority of healthy individuals exposed to Mycobacterium tuberculosis will not develop tuberculosis (TB), though many may become latently infected. More precise measurement of the human immune response to M. tuberculosis infection may help us understand this difference and potentially identify those subjects most at risk of developing active disease. Gamma interferon (IFN-γ) production has been widely used as a proxy marker to study infection and to examine the human immune response to specific M. tuberculosis antigens. It has been suggested that genetically distinct M. tuberculosis strains may invoke different immune responses, although how these differences influence the immune responses and clinical outcome in human tuberculosis is still poorly understood. We therefore evaluated the antigen-specific IFN-γ production responses in peripheral blood mononuclear cells from two cohorts of subjects recruited in Antananarivo, Madagascar, from 2004 to 2006 and examined the influence of the infecting M. tuberculosis strains on this response. The cohorts were sputum-positive index cases and their household contacts. Clinical strains isolated from the TB patients were typed by spoligotyping. Comparison of the IFN-γ responses with the spoligotype of the infecting clinical strains showed that “modern” M. tuberculosis strains, like Beijing and Central Asian (CAS) strains, tended to induce lower IFN-γ responses than “ancient” strains, like East African-Indian (EAI) strains, in index cases and their household contacts. These results suggest that new strains may have evolved to induce a host response different from that of ancient strains. These findings could have important implications in the development of therapeutic and diagnostic strategies.
- Published
- 2010