HERNANDEZ MOURA SILVA
Projetos de Pesquisa
Unidades Organizacionais
3 resultados
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- Rethinking the multiple roles of B cells in organ transplantation(2013) COELHO, Veronica; SAITOVITCH, David; KALIL, Jorge; SILVA, Hernandez MouraPurpose of review To discuss the B-cell diverse functions in organ transplantation, highlighting the emerging debate on the role of regulatory B cells (Bregs). We underscore the need to re-examine and integrate data on B-cell functional activities, aiming to discriminate their regulatory (REG) and inflammatory (INFLAMMA) functions and to translate this knowledge for the development of novel immunomodulatory therapeutic strategies and to rethink the current ones. Recent findings Data from both experimental models and clinical trials point that B cells of various phenotypes have immunoregulatory activity and play an important role in controlling graft inflammation. Data on the state of operational tolerance, in kidney transplantation, suggest the relevance of preserving a healthy B-cell compartment - in numbers and in the Breg capacity to activate the CD40/STAT3 signalling pathway - for achieving and maintaining homeostasis. Moreover, autoantibodies also comprise transplant immunobiology and it seems that not all alloantibodies are deleterious. Summary The role of B cells, in organ transplantation, can no longer be taken as mere generators of plasma cells, which produce alloantibodies deleterious to the graft. B cells also seem to integrate a complex immunoregulatory network in organ transplantation, with Bregs of various phenotypes and possibly also antibodies. The functional discrimination of REG/INFLAMMA B-cell roles needs to be considered in the clinical setting.
- Preserving the B-Cell Compartment Favors Operational Tolerance in Human Renal Transplantation(2012) SILVA, Hernandez M.; TAKENAKA, Maisa C. S.; MORAES-VIEIRA, Pedro M. M.; MONTEIRO, Sandra M.; HERNANDEZ, Maristela O.; CHAARA, Wahiba; SIX, Adrien; AGENA, Fabiana; SESTERHEIM, Patricia; BARBE-TUANA, Florencia Maria; SAITOVITCH, David; LEMOS, Francine; KALIL, Jorge; COELHO, VeronicaTransplanted individuals in operational tolerance (OT) maintain long-term stable graft function after completely stopping immunosuppression. Understanding the mechanisms involved in OT can provide valuable information about pathways to human transplantation tolerance. Here we report that operationally tolerant individuals display quantitative and functional preservation of the B-c ell compartment in renal transplantation. OT exhibited normal numbers of circulating total B cells, naive, memory and regulatory B cells (Bregs) as well as preserved B-cell receptor repertoire, similar to healthy individuals. In addition, OT also displayed conserved capacity to activate the cluster of differentiation 40 (CD40)/signal transducer and activator of transcription 3 (STAT3) signaling pathway in Bregs, in contrast, with chronic rejection. Rather than expansion or higher activation, we show that the preservation of the B-cell compartment favors OT. Online address: http://www.molmed.org doi: 10.2119/molmed.2011.00281
- GATA3 and a dominant regulatory gene expression profile discriminate operational tolerance in human transplantation(2012) MORAES-VIEIRA, Pedro Manoel M.; TAKENAKA, Maisa C. S.; SILVA, Hernandez M.; MONTEIRO, Sandra Maria; AGENA, Fabiana; LEMOS, Francine; SAITOVITCH, David; KALIL, Jorge; COELHO, VeronicaSome organ-transplanted patients achieve a state of ""operational tolerance"" (01) in which graft function is maintained after the complete withdrawal of immunosuppressive drugs. We used a gene panel of regulatory/inflammatory molecules (FOXP3, GATA3, 100, TGFB1, TGFBR1/TBX21, TNF and IFNG) to investigate the gene expression profile in peripheral blood mononuclear cells of renal-transplanted individuals experiencing OT compared to transplanted individuals not displaying OT and healthy individuals (HI). OT subjects showed a predominant regulatory (REG) profile with higher gene expression of GATA3, FOXP3, TGFB1 and TGFB receptor 1 compared to the other groups. This predominant REG gene expression profile displayed stability over time. The significant GATA3 gene and protein expressions in OT individuals suggest that a Th2 deviation may be a relevant pathway to OT. Moreover, the capacity of the REG/INFLAMMA gene panel to discriminate OT by peripheral blood analysis indicates that this state has systemic repercussions.