29 research outputs found

    Mycobacterium tuberculosis Recall Antigens Suppress HIV-1 Replication in Anergic Donor Cells via CD8+ T Cell Expansion and Increased IL-10 Levels

    No full text
    International audienceMycobacterium tuberculosis (MTb) is the leading cause of death in the setting of AIDS. MTb enhances the pathogenicity and accelerates the course of HIV disease and, furthermore, infection with HIV-1 increases the risk of reactivation or reinfection with MTb. In this study, we show that host-specific recall responses to one pathogen, MTb, has a direct effect upon the regulation of a second pathogen, HIV-1. Using cells from immunocompetent former tuberculosis (TB) patients who displayed either a persistently positive (responsive) or negative (anergic), delayed-type hypersensitivity (DTH) reaction to intradermal injection of purified protein derivative (PPD), we investigated the effect of recall Ags to MTb upon the replication of HIV-1 primary isolates in vitro. We show that HIV-1 replication of a T cell-tropic isolate was significantly impaired in MTb-stimulated PBMC from PPD-anergic donors. Furthermore, these donors displayed a significant increase in CD8 T cells and IL-10 levels and lower levels of IL-2 and TNF-relative to PPD-responsive donors in response to PPD stimulation. Strikingly, CD8 T cell depletion and blocking of IL-10 significantly increased HIV-1 replication in these PPD-anergic donors, indicating that an immunosuppressive response to MTb recall Ags inhibits HIV-1 replication in PPD-anergic individuals. Therefore, immunotherapeutic approaches aimed at recapitulating Ag-specific MTb anergy in vivo could result in novel and effective approaches to inhibit HIV-1 disease progression in MTb/HIV-1 coinfection

    Mycobacterium tuberculosis

    No full text

    Series 2344 www

    No full text
    The billions of people with latent tuberculosis infection serve as the seedbeds for future cases of active tuberculosis. Virtually all episodes of tuberculosis disease are preceded by a period of asymptomatic Mycobacterium tuberculosis infection; therefore, identifying infected individuals most likely to progress to disease and treating such subclinical infections to prevent future disease provides a crucial opportunity to interrupt tuberculosis transmission and reduce the global burden of tuberculosis disease. Programmes focusing on single strategies rather than comprehensive programmes that deliver an integrated arsenal for tuberculosis control might continue to struggle. Tuberculosis preventive therapy is a poorly used method that is essential for controlling the reservoirs of disease that drive the epidemic. Comprehensive control strategies that combine preventive therapy for the most high-risk populations and communities with improved case-fi nding and treatment, control of transmission, and health systems strengthening could ultimately lead to worldwide tuberculosis elimination. In this Series paper we outline challenges to implementation of preventive therapy and provide pragmatic suggestions for overcoming them. We further advocate for tuberculosis preventive therapy as the core of a renewed worldwide focus to implement a comprehensive epidemic control strategy that would reduce new tuberculosis cases to elimination targets. This strategy would be underpinned by accelerated research to further understand the biology of subclinical tuberculosis infections, develop novel diagnostics and drug regimens specifi cally for subclinical tuberculosis infection, strengthen health systems and community engagement, and enhance sustainable large scale implementation of preventive therapy programmes

    Controlling the seedbeds of tuberculosis: diagnosis and treatment of tuberculosis infection

    Get PDF
    Submitted by Repositório Arca ([email protected]) on 2019-04-24T17:44:00Z No. of bitstreams: 1 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Approved for entry into archive by Janaína Nascimento ([email protected]) on 2019-08-21T13:52:01Z (GMT) No. of bitstreams: 2 ve_Molebogeng_Rangaka_etal_INI_2105.pdf: 210482 bytes, checksum: 16686d418d75ede7047f3e4fb7ff27c6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5)Made available in DSpace on 2019-08-21T13:52:01Z (GMT). No. of bitstreams: 2 ve_Molebogeng_Rangaka_etal_INI_2105.pdf: 210482 bytes, checksum: 16686d418d75ede7047f3e4fb7ff27c6 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2015University College London. Institute of Epidemiology and Health. London, UK / University of Cape Town. Institute of Infectious Disease and Molecular Medicine. Cape Town, South Africa.Fundação Oswaldo Cruz. Instituto Nacional de Infectologia Evandro Chagas. Rio de Janeiro, RJ, Brasil.University of Sydney. Children’s Hospital at Westmead. Sydney, Australia / Centre for Research Excellence in Tuberculosis. Sydney, Australia.Cambodian Health Committee. Phnom Penh, Cambodia.University of Witwatersrand. Perinatal HIV Research Unit. Soweto, South Africa.National Institute for Research on Tuberculosis. Chennai, India.Johns Hopkins University. School of Medicine. Center for Tuberculosis Research. Baltimore, MD, USA.The billions of people with latent tuberculosis infection serve as the seedbeds for future cases of active tuberculosis. Virtually all episodes of tuberculosis disease are preceded by a period of asymptomatic Mycobacterium tuberculosis infection; therefore, identifying infected individuals most likely to progress to disease and treating such subclinical infections to prevent future disease provides a crucial opportunity to interrupt tuberculosis transmission and reduce the global burden of tuberculosis disease. Programmes focusing on single strategies rather than comprehensive programmes that deliver an integrated arsenal for tuberculosis control might continue to struggle. Tuberculosis preventive therapy is a poorly used method that is essential for controlling the reservoirs of disease that drive the epidemic. Comprehensive control strategies that combine preventive therapy for the most high-risk populations and communities with improved case-fi nding and treatment, control of transmission, and health systems strengthening could ultimately lead to worldwide tuberculosis elimination. In this Series paper we outline challenges to implementation of preventive therapy and provide pragmatic suggestions for overcoming them. We further advocate for tuberculosis preventive therapy as the core of a renewed worldwide focus to implement a comprehensive epidemic control strategy that would reduce new tuberculosis cases to elimination targets. This strategy would be underpinned by accelerated research to further understand the biology of subclinical tuberculosis infections, develop novel diagnostics and drug regimens specifi cally for subclinical tuberculosis infection, strengthen health systems and community engagement, and enhance sustainable large scale implementation of preventive therapy programmes

    Antigen-specific and persistent tuberculin anergy in a cohort of pulmonary tuberculosis patients from rural Cambodia

    No full text
    International audiencePurified protein derivative (PPD) skin testing is used to identify persons infected with Mycobacterium tuberculosis (Mtb) and to assess cell-mediated immune responses to Mtb. However, lack of skin induration to intradermal injection of PPD or PPD anergy is observed in a subset of patients with active tuberculosis (TB). To investigate the sensitivity and persistence of PPD reactivity and its in vitro correlates during active TB disease and after successful chemotherapy, we evaluated the distribution of skin size indura-tion after intradermal injection of PPD among 364 pulmonary TB patients in Cambodia. A subset of 25 pulmonary TB patients who had a positive skin reaction to mumps andor candida antigens showed persistent anergy to PPD after successful completion of TB therapy. Strikingly, in vitro stimulation of T cells from persistently anergic TB patients with mumps but not PPD resulted in T cell proliferation, and lower levels of IL-2 and IFN-and higher levels of IL-10 were detected in PPD-stimulated cellular cultures from PPD-anergic as compared with PPD-reactive pulmonary TB patients. These results show that anergy to PPD is antigen-specific and persistent in a subset of immunocompetent pulmonary TB patients and is characterized by antigen-specific impaired T cell proliferative responses and a distinct pattern of cytokine production including reduced levels of IL-2
    corecore