Full text
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| Author(s): |
Camila de Lollo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Medicina (FM/SBD) |
| Defense date: | 2015-11-25 |
| Examining board members: |
Maria Notomi Sato;
Beatriz Tavares Costa Carvalho;
Dewton de Moraes Vasconcelos
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| Advisor: | Maria Notomi Sato |
| Abstract | |
INTRODUCTION: Infections caused by bacteria or viruses are common in patients with Common Variable Immunodeficiency (CVID), due to antibody deficiency and association with altered function of T cells. OBJECTIVES: To evaluate the effect of Toll-like receptors (TLR) activation using TLR agonists on the monofunctional or polyfunctional T cells in patients with CVID. METHODS: We selected 16 patients with ICV from the Dermatologic Manifestations of Primary Immunodeficiencies Clinic ADEE3003 HC-FMUSP and 16 healthy controls. The methods used for flow cytometry were: a) analysis of peripheral blood B lymphocytes, T lymphocytes were assessed by the activation/maturation profile, follicular T cells (Tfh) and regulatory T cells (Treg); b)evaluation of cytokines and chemokines serum levels and in supernatants of mononuclear cell cultures from peripheral blood (PBMC) stimulated with TLR agonists; c) evaluation of mono and polyfunctional CD4+ T cells secreting IL-17a, IL-22, TNF, IFN-y and IL-10, and expression chronic activation marker of CD38 stimulated by agonists of TLR2, TLR3 and TLR7/8 and polyclonal stimuli such as Staphylococcus aureus enterotoxin B (SEB) and phorbol myristate acetate and ionomycin (PMA / IONO); d) analysis of Tc22 and Th22 cells stimulated with TLR and SEB. RESULTS: In the CVID, the peripheral blood B cells show decreased frequency, being higher frequency of naïve B cells (IgD+ CD19+ CD27-) and lack of memory B cells. Moreover, an increased expression of PD-1, an exhaustion marker, was detected in the CD4+ T cell effector memory (CD45RA- CCR7-) and expression of CD38 on CD8+ T terminally differentiated cells (CD45RA+ CCR7-). In contrast, a decreased frequency of naïve regulatory T cells was detected in the patients with CVID. In CVID patients it was observed increased frequency of T CD4+ TNF+ cells upon TLR2 and TLR7/8 agonists compared to the control group, while under stimulation with PMA /IONO there was a lower frequency of CD4+ and CD8+T cells secreting IFN-y, IL-17a, IL-22 or TNF. The CD8+T cells showed a significant reduction of in the IL-22 response, IFN-? and IL-17a induced by TLR3 activation. However, stimulation with TLR7/8 and SEB were able to increase the frequency of Th22 and TC22 cells in the patients with CVID. In CVID patients it was observed increased frequency of T CD4+ TNF+ cells upon TLR2 and TLR7/8 agonists compared to the control group, while under stimulation with PMA /IONO there was a lower frequency of CD4+ and CD8+ T cells secreting IFN-y, IL-17a, IL-22 or TNF. The CD8+ T cells showed a significant reduction of in the IL-22 response, IFN-y and IL-17a induced by TLR3 activation. However, stimulation with TLR7/8 and SEB were able to increase the frequency of Th22 and TC22 cells in the patients with CVID. In general, CD4+ T cells that secrete simultaneously 4 to 5 cytokines induced by TLR were preserved in CVID. Although polyfunctional CD4+ T cells secreting 3 cytokines were able to respond to TLR2 and TLR7/8 agonists, the CD8+ T cells did not respond to any stimuli. In addition, T cells expressing CD38, showed lower polyfunctionality to the stimuli via TLRs and PMA/IONO. Furthermore, the inflammatory status in the patients with CVID was observed by the increased serum levels of IL-6, CCL-2, CCL-5, CXCL8, CXCL-9, CXCL-10. In contrast, the agonist of TLR7/8 had opposite action inducing CXCL10 and reducing the CXCL9 levels. Noteworthy in CVID, that the reduced secretion of IFN-alfa induced by TLR7/8 was not observed with TLR9 activation. CONCLUSIONS: To date, the CVID findings shows alterations in the T cells, as the low frequency of naïve regulatory T cells and reduced effector response, mainly of CD8+ T cells. However, it emphasizes the adjuvant potential of the TLR7/8 agonist in the T cells activation (AU) | |
| FAPESP's process: | 12/14110-0 - Evaluation of polyfunctional CD4+ T cells and regulatory in the selective IgA deficiency |
| Grantee: | Camila de Lollo |
| Support Opportunities: | Scholarships in Brazil - Master |