GLORIA

GEOMAR Library Ocean Research Information Access

X

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Online Resource
    Online Resource
    Infection Biology of a Novel α-Crystallin of Mycobacterium tuberculosis : Acr2
    The American Association of Immunologists ; 2005
    In:  The Journal of Immunology Vol. 174, No. 7 ( 2005-04-01), p. 4237-4243
    Details
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 174, No. 7 ( 2005-04-01), p. 4237-4243
    Abstract: Heat shock proteins assist the survival of Mycobacterium tuberculosis (MTB) but also provide a signal to the immune response. The gene most strongly induced by heat shock in MTB is Rv0251c, which encodes Acr2, a novel member of the α-crystallin family of molecular chaperones. The expression of acr2 increased within 1 h after infection of monocytes or macrophages, reaching a peak of 18- to 55-fold by 24 h. Inhibition of superoxide action reduced the intracellular increase in acr2. Despite this contribution to the stress response of MTB, the gene for acr2 appears dispensable; a deletion mutant (Δacr2) was unimpaired in log phase growth and persisted in IFN-γ-activated human macrophages. Acr2 protein was strongly recognized by cattle with early primary Mycobacterium bovis infection and by healthy MTB-sensitized people. Within the latter group, those with recent exposure to infectious tuberculosis had, on average, 2.6 times the frequency of Acr2-specific IFN-γ-secreting T cells than those with more remote exposure (p = 0.009). These data show that, by its up-regulation early after entry to cells, Acr2 gives away the presence of MTB to the immune response. The demonstration that there is infection stage-specific immunity to tuberculosis has implications for vaccine design.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    URL: Article
    DOI: 10.4049/jimmunol.174.7.4237
    RVK:
    XA 54100
    RVK:
    XA 10000
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2005
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 2
    Online Resource
    Online Resource
    Cytotoxic Mediators in Paradoxical HIV–Tuberculosis Immune Reconstitution Inflammatory Syndrome
    The American Association of Immunologists ; 2015
    In:  The Journal of Immunology Vol. 194, No. 4 ( 2015-02-15), p. 1748-1754
    Details
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 194, No. 4 ( 2015-02-15), p. 1748-1754
    Abstract: Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) frequently complicates combined antiretroviral therapy and antituberculosis therapy in HIV-1–coinfected tuberculosis patients. The immunopathological mechanisms underlying TB-IRIS are incompletely defined, and improved understanding is required to derive new treatments and to reduce associated morbidity and mortality. We performed longitudinal and cross-sectional analyses of human PBMCs from paradoxical TB-IRIS patients and non-IRIS controls (HIV-TB–coinfected patients commencing antiretroviral therapy who did not develop TB-IRIS). Freshly isolated PBMC stimulated with heat-killed Mycobacterium tuberculosis H37Rv (hkH37Rv) were used for IFN-γ ELISPOT and RNA extraction. Stored RNA was used for microarray and RT-PCR, whereas corresponding stored culture supernatants were used for ELISA. Stored PBMC were used for perforin and granzyme B ELISPOT and flow cytometry. There were significantly increased IFN-γ responses to hkH37Rv in TB-IRIS, compared with non-IRIS PBMC (p = 0.035). Microarray analysis of hkH37Rv-stimulated PBMC indicated that perforin 1 was the most significantly upregulated gene, with granzyme B among the top five (log2 fold difference 3.587 and 2.828, respectively), in TB-IRIS. Downstream experiments using RT-PCR, ELISA, and ELISPOT confirmed the increased expression and secretion of perforin and granzyme B. Moreover, granzyme B secretion reduced in PBMC from TB-IRIS patients during corticosteroid treatment. Invariant NKT cell (CD3+Vα24+) proportions were higher in TB-IRIS patients (p = 0.004) and were a source of perforin. Our data implicate the granule exocytosis pathway in TB-IRIS pathophysiology. Further understanding of the immunopathogenesis of this condition will facilitate development of specific diagnostic and improved therapeutic options.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    URL: Article
    DOI: 10.4049/jimmunol.1402105
    RVK:
    XA 54100
    RVK:
    XA 10000
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2015
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 3
    Online Resource
    Online Resource
    IFN-γ- and TNF-Independent Vitamin D-Inducible Human Suppression of Mycobacteria: The Role of Cathelicidin LL-37
    The American Association of Immunologists ; 2007
    In:  The Journal of Immunology Vol. 178, No. 11 ( 2007-06-01), p. 7190-7198
    Details
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 178, No. 11 ( 2007-06-01), p. 7190-7198
    Abstract: Vitamin D deficiency is associated with susceptibility to tuberculosis, and its biologically active metabolite, 1α,25 dihydroxyvitamin D3 (1α,25(OH)2D3), has pleiotropic immune effects. The mechanisms by which 1α,25(OH)2D3 protects against tuberculosis are incompletely understood. 1α,25(OH)2D3 reduced the growth of mycobacteria in infected human PBMC cultures in a dose-dependent fashion. Coculture with agonists or antagonists of the membrane or nuclear vitamin D receptors indicated that these effects were primarily mediated by the nuclear vitamin D receptors. 1α,25(OH)2D3 reduced transcription and secretion of protective IFN-γ, IL-12p40, and TNF in infected PBMC and macrophages, indicating that 1α,25(OH)2D3 does not mediate protection via these cytokines. Although NOS2A was up-regulated by 1α,25(OH)2D3, inhibition of NO formation marginally affected the suppressive effect of 1α,25(OH)2D3 on bacillus Calmette Guérin in infected cells. By contrast, 1α,25(OH)2D3 strongly up-regulated the cathelicidin hCAP-18 gene, and some hCAP-18 polypeptide colocalized with CD14 in 1α,25(OH)2D3 stimulated PBMC, although no detectable LL-37 peptide was found in supernatants from similar 1α,25(OH)2D3-stimulated PBMC cultures. A total of 200 μg/ml of the active peptide LL-37, in turn, reduced the growth of Mycobacterium tuberculosis in culture by 75.7%. These findings suggest that vitamin D contributes to protection against TB by “nonclassical” mechanisms that include the induction of antimicrobial peptides.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    URL: Article
    DOI: 10.4049/jimmunol.178.11.7190
    RVK:
    XA 54100
    RVK:
    XA 10000
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2007
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 4
    Online Resource
    Online Resource
    Bioinformatic and Empirical Analysis of Novel Hypoxia-Inducible Targets of the Human Antituberculosis T Cell Response
    The American Association of Immunologists ; 2012
    In:  The Journal of Immunology Vol. 189, No. 12 ( 2012-12-15), p. 5867-5876
    Details
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 189, No. 12 ( 2012-12-15), p. 5867-5876
    Abstract: We analyzed whole genome–based transcriptional profiles of Mycobacterium tuberculosis subjected to prolonged hypoxia to guide the discovery of novel potential Ags, by a combined bioinformatic and empirical approach. We analyzed the fold induction of the 100 most highly induced genes at 7 d of hypoxia, as well as transcript abundance, peptide-binding prediction (ProPred) adjusted for population-specific MHC class II allele frequency, and by literature search. Twenty-six candidate genes were selected by this bioinformatic approach and evaluated empirically using IFN-γ and IL-2 ELISPOT using immunodominant Ags (Acr-1, CFP-10, ESAT-6) as references. Twenty-three of twenty-six proteins induced an IFN-γ response in PBMCs of persons with active or latent tuberculosis. Five novel immunodominant proteins—Rv1957, Rv1954c, Rv1955, Rv2022c, and Rv1471—were identified that induced responses similar to CFP-10 and ESAT-6 in both magnitude and frequency. IL-2 responses were of lower magnitude than were those of IFN-γ. Only moderate evidence of infection stage–specific recognition of Ags was observed. Reconciliation of bioinformatic and empirical hierarchies of immunodominance revealed that Ags could be predicted, providing transcriptomic data were combined with peptide-binding prediction adjusted by population-specific MHC class II allele frequency.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    URL: Article
    DOI: 10.4049/jimmunol.1202281
    RVK:
    XA 54100
    RVK:
    XA 10000
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2012
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
  • 5
    Online Resource
    Online Resource
    Direct Ex Vivo Analysis of Antigen-Specific IFN-γ-Secreting CD4 T Cells in Mycobacterium tuberculosis -Infected Individuals: Associations with Clinical Disease State and Effect of Treatment
    The American Association of Immunologists ; 2001
    In:  The Journal of Immunology Vol. 167, No. 9 ( 2001-11-01), p. 5217-5225
    Details
    In: The Journal of Immunology, The American Association of Immunologists, Vol. 167, No. 9 ( 2001-11-01), p. 5217-5225
    Abstract: The wide spectrum of clinical outcomes following infection with Mycobacterium tuberculosis is largely determined by the host immune response; therefore, we studied several clinically defined groups of individuals (n = 120) that differ in their ability to contain the bacillus. To quantitate M. tuberculosis-specific T cells directly ex vivo, we enumerated IFN-γ-secreting CD4 T cells specific for ESAT-6, a secreted Ag that is highly specific for M. tuberculosis, and a target of protective immune responses in animal models. We found that frequencies of circulating ESAT-6 peptide-specific IFN-γ-secreting CD4 T cells were higher in latently infected healthy contacts and subjects with minimal disease and low bacterial burdens than in patients with culture-positive active pulmonary tuberculosis (p = 0.009 and p = 0.002, respectively). Importantly, the frequency of these Ag-specific CD4 T cells fell progressively in all groups with treatment (p = 0.005), suggesting that the lower responses in patients with more extensive disease were not due to tuberculosis-induced immune suppression. This population of M. tuberculosis Ag-specific Th1-type CD4 T cells appears to correlate with clinical phenotype and declines during successful therapy; these features are consistent with a role for these T cells in the containment of M. tuberculosis in vivo. Such findings may assist in the design and evaluation of novel tuberculosis vaccine candidates.
    Type of Medium: Online Resource
    ISSN: 0022-1767 , 1550-6606
    URL: Article
    DOI: 10.4049/jimmunol.167.9.5217
    RVK:
    XA 54100
    RVK:
    XA 10000
    Language: English
    Publisher: The American Association of Immunologists
    Publication Date: 2001
    detail.hit.zdb_id: 1475085-5
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Online Resource
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...