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Previous issue date: 2013-03-27 / The elderly population, characterized as people over 60 years old, has grown rapidly in recent years in Brazil, and with this increase in life expectancy, age-related changes appear, for example, immunosenescence. Some studies have shown that there are differences in the immunological profile of the elderly, often related to the numbers of T cells. The immune risk profile (IRP) has been defined as CD4/CD8 T-cell ratio <1 and positivity for serum anti-cytomegalovirus (CMV) antibodies. In this study, we investigated patterns of activation and differentiation of T lymphocytes by flow cytometry in an elderly population in IRP, compared with elderly people without risk profile (non-IRP), seeking to identify additional markers for this risk profile immune. For this study we recruited 60 elderly SUS patients in Porto Alegre, aged 60 years, 30 IRP and 30 non-IRP. Lymphocytes were isolated and stimulated in vitro to evaluate the production of cytokines and the expression of transcription factors. The subpopulations of T lymphocytes found were consistent with previous studies in which IRP patients had fewer naive and central memory T cells, as well as an increase was observed in the percentage of T cells CD8 + CD28-T cells and CD8 + PD-1 + in the IRP individuals. Furthermore, there was a reduction in mean fluorescence intensity (MFI) of transcription factors to canonical subtypes of T cell help (CD4 +) in IRP patients when compared to patients without IRP. The percentages of the different subtypes (TH1, TH2, TH17; Treg) of these cells were not different between the two groups. After stimulation with anti-CD3/anti-CD28 antibodies in culture for 24 hours, the concentration of cytokines in culture supernatants increased, but no significant differences between the two groups were found, except for IL-10, which was higher in IRP patients before stimulation. These results suggested that transcriptional mechanisms important in the differentiation of helper T cells are altered in IRP patients, which may affect the immune response of these individuals. / A popula??o de idosos, caracterizada como pessoas com mais de 60 anos, vem aumentando muito nos ?ltimos anos no Brasil, e com esse aumento da expectativa de vida surgem altera??es relacionadas com a idade, por exemplo, a imunossenesc?ncia. Alguns estudos t?m demonstrado que existem diferen?as no perfil imunol?gico dos idosos, frequentemente relacionadas ao n?mero de c?lulas T. O perfil de risco imune (IRP) tem sido definido como taxa de c?lulas T CD4/CD8<1 e soro positividade para citomegalov?rus (CMV). Neste estudo, n?s investigamos padr?es de ativa??o e diferencia??o de linf?citos T, por citometria de fluxo, em uma popula??o idosa IRP, comparando com a popula??o idosa sem perfil de risco (n?o-IRP), buscando identificar marcadores adicionais para esse perfil de risco imune. Foram recrutados para esse estudo 60 idosos da rede SUS (sistema ?nico de sa?de) de Porto Alegre, com idade superior a 60 anos, sendo 30 IRP e 30 n?o-IRP. Linf?citos foram isolados e estimulados in vitro para avaliar a produ??o de citocinas e a express?o de fatores de transcri??o. As subpopula??es de linf?citos T encontradas foram condizentes com estudos anteriores em que os pacientes IRP possu?am menos c?lulas T naive e de mem?ria central, assim como foi observado um aumento nas porcentagens das c?lulas T CD8+CD28- e das c?lulas T CD8+PD-1+. Al?m disso, foi observada uma redu??o na m?dia de intensidade de fluoresc?ncia (MFI) dos fatores de transcri??o can?nicos para subtipos de c?lulas T de ajuda (CD4+) em pacientes IRP quando comparados com pacientes n?o-IRP. As porcentagens dos diferentes subtipos (TH1; TH2; TH17; Treg) dessas c?lulas n?o foram diferentes entre os dois grupos. Ap?s estimula??o com anticorpos anti-CD3/anti-CD28 em cultura por 24h, a concentra??o de citocinas no sobrenadante das culturas aumentou, mas n?o houve diferen?a significativa entre os dois grupos em rela??o ? concentra??o das citocinas em geral, exceto na IL-10 antes da estimula??o, que foi maior em pacientes IRP. Esses resultados sugerem que mecanismos transcricionais importantes para a diferencia??o de c?lulas T de ajuda est?o alterados em pacientes IRP, o que pode afetar a resposta imune desses indiv?duos.
| Identifer | oai:union.ndltd.org:IBICT/oai:tede2.pucrs.br:tede/5472 |
| Date | 27 March 2013 |
| Creators | Ornaghi, Ana Paula Maciel |
| Contributors | Bonorino, Cristina |
| Publisher | Pontif?cia Universidade Cat?lica do Rio Grande do Sul, Programa de P?s-Gradua??o em Biologia Celular e Molecular, PUCRS, BR, Faculdade de Bioci?ncias |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da PUC_RS, instname:Pontifícia Universidade Católica do Rio Grande do Sul, instacron:PUC_RS |
| Rights | info:eu-repo/semantics/openAccess |
| Relation | 8198246930096637360, 600, 600, 36528317262667714 |
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