Articles: regulatory-t-lymphocytes.
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It is well established that CD4CD25 regulatory T cells (Tregs) downregulate inflammatory immune responses and help to maintain immune homeostasis. Recent reports have shown that ligation of germline encoded pattern recognition receptors such as Toll-like receptors can stimulate Tregs and therefore implicate Tregs in the pathophysiology of sepsis and other inflammatory diseases. In this report, we show that injection of lipopolysaccharide (LPS) leads to expansion of CD4CD25FoxP3 Tregs, suggesting that these cells may play an important role in immune regulation in LPS-induced acute inflammation. ⋯ Unlike LPS, depletion of Tregs followed by concanavalin A (Con A) challenge does not result in mortality, suggesting that Treg depletion does not globally influence all models of acute inflammation. We authenticate our findings by showing that depletion of Tregs leads to mortality in a nonlethal Escherichia coli challenge accompanied by elevated serum levels of proinflammatory cytokines. Collectively, our results indicate that in addition to regulation of LPS-induced acute inflammation, Tregs help to improve bacterial clearance and promote survival in an acute model of bacterial infection.
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Am. J. Respir. Crit. Care Med. · Jun 2013
Comparative StudyRegulatory T cells attenuate mycobacterial stasis in alveolar and blood-derived macrophages from patients with tuberculosis.
There are hardly any data about the frequency of CD4(+)CD25(+)Foxp3(+) regulatory T cells (T-Regs) in the lungs of patients with active tuberculosis (TB). ⋯ In patients with TB the alveolar compartment is enriched for CD4(+) T-Regs. Peripheral blood-derived T-Regs decrease the ability of alveolar and monocyte-derived macrophages to restrict the growth of Mycobacterium tuberculosis in the presence of effector cells. Collectively, these data suggest that CD4(+)CD25(+)FoxP3(+) T-Regs subvert antimycobacterial immunity in human TB.
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Acute lung injury (ALI) is characterized by alveolar injury and uncontrolled inflammation. Since most cases of ALI resolve spontaneously, understanding the endogenous mechanisms that promote ALI resolution is important to developing effective therapies. Previous studies have implicated extracellular adenosine signaling in tissue adaptation and wound healing. ⋯ While Treg numbers in cd73(-/-) mice were similar to controls, cd73-deficient Tregs had attenuated immunosuppressive functions. Moreover, adoptive transfer of cd73-deficient Tregs into Rag(-/-) mice emulated the observed phenotype in cd73(-/-) mice, while transfer of wild-type Tregs was associated with normal ALI resolution. Together, these studies implicate CD73-dependent adenosine generation in Tregs in promoting ALI resolution.
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The present study aimed to determine the protective effects and the underlying mechanisms of curcumin on ovalbumin (OVA)-induced allergic inflammation in a mouse model of allergic asthma. Asthma mice model was established by ovalbumin. A total of 60 mice were randomly assigned to six experimental groups: control, model, dexamethasone (2 mg/kg), and curcumin (50 mg/kg, 100 mg/kg, 200 mg/kg). ⋯ Flow cytometry (FCM) studies demonstrated that curcumin remarkably inhibited Th17 cells and significantly increased Treg cells. The results in vivo show ovalbumin-induced significantly broke Treg/Th17 balance; curcumin treatments markedly attenuated the inflammatory in asthma model by regulating Treg/Th17 balance. Our findings support the possible use of curcumin as a therapeutic drug for patients with allergic asthma.
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Am. J. Clin. Oncol. · Jun 2013
Tumor-infiltrating lymphocytes, tumor characteristics, and recurrence in patients with early breast cancer.
The balance in the immune system between immune surveillance against non-self-antigens and tolerance of self-antigens is known to be associated with the prognosis of breast cancer patients. However, immunologic signals in tumor microenvironment according to biological characteristics of cancer cells have not been clearly elucidated. CD4(+) T cells, CD8(+) T cells, and forkhead box P3-positive (Foxp3) regulatory T cells (Tregs) are the main keys for immune surveillance and tolerance, respectively. We evaluated the correlations between the immunologic balance and tumor characteristics and their impact on recurrence. ⋯ Our data showed that lymph node metastases, immunopositivity of p53 and Ki67, and non-triple-negative tumors were associated with high regulatory T-cell infiltration. The role of immunologic balance as a prognostic marker for recurrence must be evaluated more clearly in the future study.