Project description:Tuberculosis (TB) is responsible for the majority of mortality and morbidity associated with infectious diseases worldwide. The characterization of exact molecular components of immune response associated with protection against TB may help design more effective therapeutic interventions. In this study, we aimed to characterize the immune signature of memory T cells associated with latent infection with Mycobacterium tuberculosis. Transcriptomic profiling using RNA sequencing was performed on memory CD4 and CD8 T cells isolated from individuals with latent tuberculosis, as well as from tuberculosis negative healthy controls. Overall, we found specific gene signatures in each cell subset that could successfully discriminate between individuals with latent tuberculosis and healthy controls.
Project description:Tuberculosis (TB) is responsible for the majority of mortality and morbidity associated with infectious diseases worldwide. The characterization of exact molecular components of immune response associated with protection against TB may help design more effective therapeutic interventions. In this study, we aimed to characterize the immune signature of memory T cells associated with latent infection with Mycobacterium tuberculosis. Transcriptomic profiling using RNA sequencing was performed on memory CD8 T cells isolated from individuals with latent tuberculosis, as well as from tuberculosis negative healthy controls. Overall, we found specific gene signatures in each cell subset that could successfully discriminate between individuals with latent tuberculosis and healthy controls.
Project description:Tuberculosis (TB) is responsible for the majority of mortality and morbidity associated with infectious diseases worldwide. The characterization of exact molecular components of immune response associated with protection against TB may help design more effective therapeutic interventions. In this study, we aimed to characterize the immune signature of memory T cells associated with latent infection with Mycobacterium tuberculosis. Transcriptomic profiling using RNA sequencing was performed on memory CD4 T cells isolated from individuals with latent tuberculosis, as well as from tuberculosis negative healthy controls. Overall, we found specific gene signatures in each cell subset that could successfully discriminate between individuals with latent tuberculosis and healthy controls.
Project description:Latent tuberculosis infection (LTBI) relies on a homeostasis of macrophages and Mycobacterium tuberculosis (Mtb). The small heat shock protein, Mtb Hsp16.3 (also known as latency-associated antigen), plays an important role in Mtb persistence within macrophages. However, the mechanism of LTBI remains elusive. The aim of this study was to delineate LTBI-related miRNA expression in U937 macrophages expressing Mtb Hsp16.3 protein. This study intends to explore the potential function of miRNAs in the interaction of macrophages with Mtb Hsp16.3 and provide insights for investigating the role of macrophage homeostasis in LTBI.
Project description:Granulomas are the pathological hallmark of tuberculosis (TB). In individuals latently infected with Mycobacterium tuberculosis (M. tb), the bacteria are thought to reside within the granulomas in a nonreplicating dormant state due to the lack of oxygen and nutrients. However, a portion of these individuals will develop active TB and little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4 mutant of M. marinum caused latent infection in adult zebrafish, which is characterized by the stable bacterial loads, constant number of non-necrotized granulomas in fewer organs, and reduced immune responses compared to zebrafish infected with the wild type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4 mutant was defective in resuscitation from hypoxia-induced dormancy and that the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from latent infection and that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection thereby reducing the incidences of active TB.
Project description:Granulomas are the pathological hallmark of tuberculosis (TB). In individuals latently infected with Mycobacterium tuberculosis (M. tb), the bacteria are thought to reside within the granulomas in a nonreplicating dormant state due to the lack of oxygen and nutrients. However, a portion of these individuals will develop active TB and little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4 mutant of M. marinum caused latent infection in adult zebrafish, which is characterized by the stable bacterial loads, constant number of non-necrotized granulomas in fewer organs, and reduced immune responses compared to zebrafish infected with the wild type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4 mutant was defective in resuscitation from hypoxia-induced dormancy and that the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from latent infection and that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection thereby reducing the incidences of active TB.
Project description:Granulomas are the pathological hallmark of tuberculosis (TB). In individuals latently infected with Mycobacterium tuberculosis (M. tb), the bacteria are thought to reside within the granulomas in a nonreplicating dormant state due to the lack of oxygen and nutrients. However, a portion of these individuals will develop active TB and little is known on the bacterial mechanisms/factors involved in this process. In this study, we found that WhiB4, an oxygen sensor and a transcription factor, plays a critical role in disease progression and reactivation of Mycobacterium marinum (M. marinum) infection in zebrafish. We show that the whiB4 mutant of M. marinum caused latent infection in adult zebrafish, which is characterized by the stable bacterial loads, constant number of non-necrotized granulomas in fewer organs, and reduced immune responses compared to zebrafish infected with the wild type bacteria or the complemented strain. The mutant bacteria in zebrafish were also less responsive to antibiotic treatments. Moreover, the whiB4 mutant was defective in resuscitation from hypoxia-induced dormancy and that the DosR regulon was dysregulated in the mutant. Taken together, our results suggest that WhiB4 is a major driver of reactivation from latent infection and that WhiB4 is an attractive target for the development of novel therapeutics, which may help to prevent the reactivation of latent infection thereby reducing the incidences of active TB.