Academic Journal
Direct inhibition of T-cell responses by the Cryptococcus capsular polysaccharide glucuronoxylomannan.
| العنوان: | Direct inhibition of T-cell responses by the Cryptococcus capsular polysaccharide glucuronoxylomannan. |
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| المؤلفون: | Lauren E Yauch, Jennifer S Lam, Stuart M Levitz |
| المصدر: | PLoS Pathogens, Vol 2, Iss 11, p e120 (2006) |
| بيانات النشر: | Public Library of Science (PLoS), 2006. |
| سنة النشر: | 2006 |
| المجموعة: | LCC:Immunologic diseases. Allergy LCC:Biology (General) |
| مصطلحات موضوعية: | Immunologic diseases. Allergy, RC581-607, Biology (General), QH301-705.5 |
| الوصف: | The major virulence factor of the pathogenic fungi Cryptococcus neoformans and C. gattii is the capsule. Glucuronoxylomannan (GXM), the major component of the capsule, is a high-molecular-weight polysaccharide that is shed during cryptococcosis and can persist in patients after successful antifungal therapy. Due to the importance of T cells in the anticryptococcal response, we studied the effect of GXM on the ability of dendritic cells (DCs) to initiate a T-cell response. GXM inhibited the activation of cryptococcal mannoprotein-specific hybridoma T cells and the proliferation of OVA-specific OT-II T cells when murine bone marrow-derived DCs were used as antigen-presenting cells. Inhibition of OT-II T-cell proliferation was observed when either OVA protein or OVA323-339 peptide was used as antigen, indicating GXM did not merely prevent antigen uptake or processing. We found that DCs internalize GXM progressively over time; however, the suppressive effect did not require DCs, as GXM directly inhibited T-cell proliferation induced by anti-CD3 antibody, concanavalin A, or phorbol-12-myristate-13-acetate/ionomycin. Analysis of T-cell viability revealed that the reduced proliferation in the presence of GXM was not the result of increased cell death. GXM isolated from each of the four major cryptococcal serotypes inhibited the proliferation of human peripheral blood mononuclear cells stimulated with tetanus toxoid. Thus, we have defined a new mechanism by which GXM can impart virulence: direct inhibition of T-cell proliferation. In patients with cryptococcosis, this could impair optimal cell-mediated immune responses, thereby contributing to the persistence of cryptococcal infections. |
| نوع الوثيقة: | article |
| وصف الملف: | electronic resource |
| اللغة: | English |
| تدمد: | 1553-7366 1553-7374 |
| Relation: | http://europepmc.org/articles/PMC1635532?pdf=render; https://doaj.org/toc/1553-7366; https://doaj.org/toc/1553-7374 |
| DOI: | 10.1371/journal.ppat.0020120 |
| URL الوصول: | https://doaj.org/article/734e7c5064df4bf891bc70c5dd4f19a1 |
| رقم الانضمام: | edsdoj.734e7c5064df4bf891bc70c5dd4f19a1 |
| قاعدة البيانات: | Directory of Open Access Journals |
Full Text Finder | تدمد: | 15537366 15537374 |
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| DOI: | 10.1371/journal.ppat.0020120 |