New biomarkers of tuberculosis (TB) risk and disease are critical for the urgently needed control of the ongoing TB pandemic. In a prospective multisite study across Subsaharan Africa, we analyzed ...metabolic profiles in serum and plasma from HIV-negative, TB-exposed individuals who either progressed to TB 3-24 months post-exposure (progressors) or remained healthy (controls). We generated a trans-African metabolic biosignature for TB, which identifies future progressors both on blinded test samples and in external data sets and shows a performance of 69% sensitivity at 75% specificity in samples within 5 months of diagnosis. These prognostic metabolic signatures are consistent with development of subclinical disease prior to manifestation of active TB. Metabolic changes associated with pre-symptomatic disease are observed as early as 12 months prior to TB diagnosis, thus enabling timely interventions to prevent disease progression and transmission.
Antigen-specific, MHC-restricted αβ T cells are necessary for protective immunity against Mycobacterium tuberculosis, but the ability to broadly study these responses has been limited. In the present ...study, we used single-cell and bulk T cell receptor (TCR) sequencing and the GLIPH2 algorithm to analyze M. tuberculosis-specific sequences in two longitudinal cohorts, comprising 166 individuals with M. tuberculosis infection who progressed to either tuberculosis (n = 48) or controlled infection (n = 118). We found 24 T cell groups with similar TCR-β sequences, predicted by GLIPH2 to have common TCR specificities, which were associated with control of infection (n = 17), and others that were associated with progression to disease (n = 7). Using a genome-wide M. tuberculosis antigen screen, we identified peptides targeted by T cell similarity groups enriched either in controllers or in progressors. We propose that antigens recognized by T cell similarity groups associated with control of infection can be considered as high-priority targets for future vaccine development.
Human papillomavirus (HPV) E6 and E7 oncoproteins are attractive targets for T-cell-based immunotherapy of cervical cancer. In this study, we demonstrate that dendritic cells (DCs) pulsed with HPV16 ...E7 protein are not only recognized in vitro by E7-specific CTLs but also elicit E7-specific CTL responses in vivo, associated with protection against a challenge with syngeneic HPV16-induced tumor cells. Vaccination with soluble E7 protein in incomplete Freund's adjuvant likewise induces E7-specific CTL responses associated with tumor protection. The presence of HPV16 E7-specific CTLs in vivo and the observation that depletion of CD8+ cells completely abolishes tumor protection demonstrate that CTLs are the major effector cells in mediating antitumor activity. The in vivo involvement of DCs in the activation of protective CTLs is suggested by the surface display of E7 peptide-loaded MHC class I molecules on these cells after E7 protein immunization. These data show that HPV16 E7 protein-pulsed DCs, as well as the administration of E7 protein antigen in adjuvant, can effectively stimulate tumor-specific MHC class I-restricted CD8+ T-cell-mediated protective immunity to HPV16-induced cancers.
BACKGROUND: The incidence of coeliac disease varies internationally. AIMS: To assess the incidence of childhood coeliac disease in The Netherlands and to study the clinical features and the presence ...of associated disorders. SUBJECTS: Identified cases of childhood coeliac disease in The Netherlands in 1993-4 by means of the Dutch Paediatric Surveillance Unit. METHODS: Inclusion criteria were born in The Netherlands, diagnosed with at least one biopsy of the small bowel in 1993-4 and age at diagnosis 0-14 years. The data were cross checked by the Dutch Network and National Database of Pathology and compared with data from a previous study on childhood coeliac disease, 1975-90. RESULTS: A total of 193 coeliac patients were identified by means of the Surveillance Unit, another 20 through the National Database of Pathology. The mean crude incidence rate of diagnosed childhood coeliac disease was 0.54/1000 live births, which is in the range of rates found in other western European countries and significantly higher than the mean crude incidence rate of 0.18/1000 live births found in The Netherlands in 1975-90. The clinical presentation was classic: chronic diarrhoea, abdominal distension, and growth failure. Associated disorders were present in 11.7% of the cases. CONCLUSIONS: The incidence of diagnosed childhood coeliac disease in The Netherlands seems to have increased significantly during the past few years. In a period of 20 years no significant changes could be found in the clinical picture at preentation of coeliac disease in Dutch children.
Production of IFN-γ guarantees helpful T cell-mediated immunity against
Mycobacterium tuberculosis infection. We have evaluated the in vitro immune responses to
M. tuberculosis antigens using IFN-γ ...production among 43 Brazilian tuberculosis (TB) patients prior to and after specific treatment, and 18 community controls. Peripheral blood mononuclear cells (PBMC) were cultivated in the presence either of purified protein derivative, ferritin, 10
kDa, 38
kDa, MPT59, Ag85A or Ag85B. Also, the two
M. tuberculosis and
M. bovis heat-shock proteins (hsp) 65 and 70
kDa were compared, and 5 day supernatants were harvested for cytokine detection by ELISA. The results showed that the overall profile of primary PBMC in response to most
M. tuberculosis antigens was well correlated, since high IFN-γ levels were induced by Ag85A, Ag85B, 38
kDa, ferritin and 10
kDa, as well as
M. tuberculosis hsp65 in TB patients. In addition, analysis was carried out of the in vitro expression of activation molecules on lymphocytes, as CD25 and CD69 expression assessed in 17 TB patients showed induction on CD4+ T cells by Ag85B. Overall, significantly low responses were found in untreated, in comparison with the treated TB patients. Furthermore, internal community but not healthy control individuals have higher immune responses than do TB patients.
In this study, we used an HLA-A2 transgenic mouse model to investigate the effects of pulmonary delivery of a new DNA plasmid encoding eight HLA-A*0201-restricted T-cell epitopes from
Mycobacterium ...tuberculosis formulated in chitosan nanoparticles. It was shown that the chitosan-DNA formulation was able to induce the maturation of dendritic cells (DCs) while chitosan solution alone could not, indicating the DNA was released from the particles and able to stimulate DCs. Pulmonary administration of the DNA plasmid incorporated in chitosan nanoparticles was shown to induce increased levels of IFN-γ secretion compared to pulmonary delivery of plasmid in solution or the more frequently used intramuscular immunization route. These results indicate that pulmonary delivery of DNA vaccines against tuberculosis may provide an advantageous delivery route compared to intramuscular immunization, and that increased immunogenicity can be achieved by delivery of this DNA encapsulated in chitosan nanoparticles.
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