Articles: regulatory-t-lymphocytes.
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Sepsis-triggered immune paralysis including T-cell dysfunction increases susceptibility to infections. Statins exert beneficial effects in patients with sepsis, although the mechanisms remain elusive. Herein, we hypothesized that simvastatin may attenuate T-cell dysfunction in abdominal sepsis. ⋯ Lastly, it was found that simvastatin reduced CLP-induced bacteremia. In conclusion, these novel findings suggest that simvastatin is a powerful regulator of T-cell immune dysfunction in abdominal sepsis. Thus, these protective effects of simvastatin on T-cell functions help to explain the protective effect of statins in patients with sepsis.
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Immune mechanisms and autoimmunity seem to play a significant role in idiopathic pulmonary arterial hypertension (IPAH) pathogenesis and/or progression, but the pathophysiology is still unclear. Recent evidence has demonstrated a detrimental involvement of leptin in promoting various autoimmune diseases by controlling regulatory T-lymphocytes. Despite this knowledge, the role of leptin in IPAH is currently unknown. ⋯ Circulating regulatory T-lymphocyte numbers were comparable in all groups, and the percentage of those expressing leptin receptor was higher in IPAH and SSc-PAH compared with controls, whereas their function was reduced in IPAH and SSc-PAH patients compared with controls, in a leptin-dependent manner. Furthermore, endothelial cells from IPAH patients synthesised more leptin than controls. Our data suggest that endothelial-derived leptin may play a role in the immunopathogenesis of IPAH.
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Clin. Exp. Metastasis · Oct 2012
Reduction of circulating regulatory T cells by intravenous high-dose interferon alfa-2b treatment in melanoma patients.
High-dose interferon alfa-2b (IFNα-2b) is the only approved adjuvant systemic therapy for resected, high risk melanoma in the United States (Fecher and Flaherty, in Natl Compr Cancer Netw 7:295-304, 2009). Recently, two important meta-analyses of randomized trials (Wheatley et al., in J Clin Oncol, 2007; Mocellin et al. in J Natl Cancer Inst, 2010) investigating IFNα-2b versus observation in high risk melanoma patients, showed that adjuvant IFNα-2b has an impact both on relapse-free survival (RFS) and overall survival (OS) independently by dosage, duration and route compared with observation in high risk melanoma patients. Despite of an absolute benefits of 3 % (Wheatley et al., in J Clin Oncol, 2007), this treatment is associated with significant toxicity, which impacts on patient quality of life. ⋯ The presence of Tregs in tumor-draining lymph nodes and tumors provides a potential inhibitory population that may block or balance effector cell function. Thus, depletion of Tregs or blockade of Treg function using targeted antibodies or other strategies might be able to remove Treg suppression and enhance antitumor immunity (Viguier et al., in J Immunol 173:1444-1453, 2004). We conducted an observational study to examine whether the induction phase of the FDA-approved HDI regimen administered iv in patients with stage 3-4 melanoma (20 MU/m(2) intravenously (IV) five times per week for 4 weeks) reduced the number of Treg cells in the peripheral blood.
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Neuroimmune crosstalk in neuropathic pain is a key contributor to pain hypersensitivity following nervous system injury. CD4+CD25+Foxp3+ regulatory T cells (Tregs) are endogenous immune suppressors, reducing T-cell proliferation and proinflammatory cytokine production. Currently, the role of Tregs in neuropathic pain is unknown. ⋯ Furthermore, depletion of Tregs by a CD25 antibody in mice with a partial sciatic nerve ligation resulted in prolonged mechanical pain hypersensitivity. These findings suggest that Tregs play a role in endogenous recovery from neuropathy-induced pain. Thus, this T-cell subset may be specifically targeted to alleviate chronic neuropathic pain.