Efeitos cardiovasculares da transferência adotiva de linfócitos T reguladores em camundongos submetidos à infusão crônica de angiotensina II e de aldosterona / Cardiovascular effects of adoptive transfer of regulatory T lymphocytes in mice submitted to chronic infusion of angiotensin II and aldosterone

A angiotensina (Ang) II e aldosterona induzem hipertensão arterial por mecanismos em parte mediados pela imunidade adaptativa, envolvendo linfócitos T auxiliares respondedores (Tresp). Os linfócitos T reguladores (Treg) são capazes de suprimir os efeitos pró-inflamatórios do sistema imune. O presente estudo avaliou se a transferência adotiva de Treg é capaz de prevenir a hipertensão e a lesão vascular induzidas pela AngII ou pela aldosterona, em dois protocolos distintos. No protocolo com Ang II, camundongos machos C57BL/6 sofreram a injeção endovenosa de Treg ou Tresp, sendo depois infundidos com Ang II (1ug/kg/min), ou salina (grupo controle) por 14 dias. No protocolo com aldosterona, um outro conjunto de animais sofreu injeções de Treg ou Tresp, sendo depois infundido com aldosterona (600ug/kg/d) ou salina (grupo controle), pelo mesmo intervalo de tempo. O grupo tratado com aldosterona recebeu salina 1% na água. Tanto o grupo Ang II como aldosterona apresentaram elevação da pressão arterial sistólica (43% e 31% respectivamente), da atividade da NADPH oxidase na aorta (1,5 e 1,9 vezes, respectivamente) e no coração (1,8 e 2,4 vezes, respectivamente) e uma redução da resposta vasodilatadora à acetilcolina (de 70% e 56%, respectivamente), quando comparados com os respectivos controles (P<0,05). Adicionalmente, a administração de Ang II proporcionou um aumento rigidez vascular (P<0,001), na expressão de VCAM-1 nas artérias mesentéricas (P<0,05), na infiltração aórtica de macrófagos e linfócitos T (P<0,001) e nos níveis plasmáticos das citocinas inflamatórias interferon (INF)-y, interleucina (IL)-6, Tumor necrosis factor (TNF)-a e IL-10 (P<0,05). Ang II causou uma queda de 43% no número de células Foxp3+ no córtex renal, enquanto que a transferência adotiva de Treg aumentou as células Foxp3+ em duas vezes em comparação com o controle. A administração de Treg preveniu o remodelamento vascular induzido pela aldosterona, observado na relação média/lúmen...

Angiotensin (Ang) II and aldosterone (aldo) induce hypertension through mechanisms in part mediated by adaptive immunity and T responder lymphocytes. T regulatory (Treg) lymphocytes suppress pro-inflammatory mediators of the immune system. We questioned whether Treg adoptive transfer will blunt Ang II or aldo-induced hypertension and vascular injury, by evaluating two distinct protocols. In the Ang II protocol, male C57BL/6 mice were injected i.v. with Treg or T responder cells, and then infused with Ang II (1ug/kg/min) or saline, for 14 days. In the aldosterone protocol, another set of animals was injected with Treg or T responder cells, and then infused with aldosterone (600ug/kg/d) or saline, for the same period. The aldosterone group received saline 1% in drinking water. Both Ang II and aldosterone treated mice presented an increase in systolic blood pressure (43% and 31% respectively), of NADPH oxidase activity in aorta (1.5 and 1.9 fold, respectively) and heart (1.8 and 2.4 fold respectively) and an impaired vasodilatory response do acetylcholine (by 70% and 56% respectively), when compared to their controls (P<0.05). In addition, Ang II administration resulted in increased vascular stiffness (P<0.001), mesenteric artery vascular cell adhesion molecule (VCAM-1) expression (P<0.05), aortic macrophage and T cell infiltration (P<0.001), and the plasma levels of the inflammatory cytokines INF-y, IL-6, TNF-a, and IL-10 (P<0,05). And II caused a 43% decrease in the number of Foxp3+ cells in the renal cortex, while Treg adoptive transfer increased Foxp3+ cells 2-fold compared to control. Treg administration prevented aldosterone-induced vascular remodelling, as observed by media to lumen ratio and media cross sectional area analysis of mesenteric arteries (P<0,05). All the above were prevented by Treg but not by T responder cell adoptive transfer. These results demonstrate that Treg suppress Ang II of aldo-mediated vascular injury and BP elevation...

Proportion of CD4+CD25+ regulatory T lymphocyte in peripheral blood of patients with gynecologic cancer / 대한산부인과학회지

OBJECTIVE: Recently the existence of a CD4+CD25+ regulatory (Treg) population has been described in rodents and humans. It is unclear how the immune response cells interact to tumor cells effectively, but the malignant tumor cell growth was suppressed by the main effect of T lymphocytes and natural killer cells in experimental studies using various biologic response modifier. This study was performed to investigate the proportion of CD4+CD25high Tregs and expression of Foxp3 in Peripheral blood (PBL)s in patients with cervical, ovarian or uterine cancers. METHODS: Blood samples were collected from 10 healthy women and a total of 40 patients with gynecologic cancer at department of Obstetrics and Gynecology, Asan Medical Center, Seoul, Korea, from March 2005 to September 2005, were enrolled in study group. Information regarding patient history and tumor stage was recorded. They were diagnosed at same center at first, and never been treated any therapy. The population of CD4+CD25+high Tregs as a percentage of total CD4+cells was evaluated by flow cytometric analysis. We measured the proportion of Treg cell that co-express CD4 and CD25 in the peripheral blood lymphocytes form patients with either cervical, ovarian uterine cancer or carcinoma in situ of cervix. Expression of Foxp3 in the CD4+subsets defined by electrophoresis. RESULTS: The following tumor entities were included cervical cancer (n=10. 7 in stage I, 1 in stage II, 1 in stage III, 1 in stage IV); ovarian cancer (n=10. 4 in stage I, 0 in stage II, 5 in stage III, 1 in stage IV), ; uterine cancer (n=10. 9 in stage I, 0 in stage II, 0 in stage III, 1 in stage IV). In cervical cancer patient, ovarian cancer patients, uterine cancer patients and healthy women, the proportion of CD4+CD25high Tregs was 4.53% (SD 2.30), 6.89% (SD 7.81), 4.37% (SD 2.43) and 0.87% (SD 0.57) of the total CD4+cells respectively. The proportion of CD4+CD25+high T cells was significantly higher in cervical cancer patients (p=0.016), ovarian cancer patients (p=0.001) and uterine cancer patients (p=0.038) when compared with healthy women. But there was no significant difference in proportion of CD4+CD25+ Tregs comparing with healthy women. Expression of Foxp3 was significantly thicker in tumor-associated lymphocytes than control T cells by electrophoresis. CONCLUSION: In conclusion, our data suggested that the increase in frequency of regulatory T cells might play a role in modulation of the immune response against cervical, ovarian, uterine cancer could be important in design of immunotherapeutic approaches.