Editorial: Live or let die--does HIV exacerbate tuberculosis by attenuating M. tuberculosis-induced apoptosis?

摘要

TB remains the leading cause of bacterial-mediated mortality with 9.2 million new cases of TB reported in 2006 [1]. The susceptibility of HIV+ individuals to TB has fueled the spread of tuberculous disease, and HIV is the single most powerful risk factor for the development of TB [1]. As such, dissecting the factors that promote susceptibility to TB in HIV+ individuals is an urgent priority. HIV+ individuals exhibit increased susceptibility to tuberculous disease even with relatively preserved CD4+ T lymphocyte counts [2, 3], and this risk remains high after effective anti-retroviral therapy and immune reconstitution [4, 5]. This is suggestive of an early and persistent defect in immunity to Mtb, which is independent of the overall total CD4+ T lymphocyte count. The nature of this defect is unknown but may reside in the Mtb-specific adaptive immune response, where it could be a result of quantitative or qualitative differences in T cell responses or alternatively, in the innate immune response.