Control of allograft rejection in mice by applying a novel neuropeptide, cortistatin.
ABSTRACT The action of cortistatin (CST), a novel cyclic neuropeptide, as an anti-inflammatory factor has been studied, but few investigations have explored the immunomodulatory role of CST in transplantation. In the present study, we examined whether CST affects the alloimmune response in a mouse model of skin transplantation and the effects of CST on T lymphocytes.
BALB/c (H-2K(d)) recipient mice (n=70) were divided into seven groups (n=10 per group) and given an intraperitoneal injection of CST or a somatostatin analog, SMS 201-995 (octreotide), on the day of skin transplantation from C57BL/6 (B6) (H-2K(b)) donors. Injections were continued for 7 consecutive days. Groups 1-3 received CST at doses of 0.02, 0.2, or 2 mg/kg, respectively. Groups 4-6 received SMS 201-995 at the same doses. Group 7 was a control group and received injections of phosphate buffered saline. Survival of the allografts was recorded. A semiquantitative reverse transcriptase polymerase chain reaction study of Foxp3 expression and a flow cytometry study of CD4 and CD25 markers of T lymphocytes were conducted to determine whether CD4(+)CD25(+) Foxp3(high) regulatory T cells (T(reg)) were generated in vivo.
BALB/c mice given CST (0.2 or 2 mg/kg) had prolonged graft survival (median survival time [MST], 13 and 14 days, respectively; P<0.05 compared with controls). SMS 201-995 at the same concentrations did not have a significant effect on allograft survival (MST, 8 days for both groups). We found more than a twofold increase of CD4(+)CD25(+) T(reg) cells in the CD4(+) T-cell population and the expression of Foxp3 was up-regulated in the CST treatment groups, compared with control and SMS 201-995 treatment groups.
In our study, CST induced a significant prolongation in survival time of allogeneic skin grafts and increased the generation of CD4(+)CD25(+) Foxp 3(high) T(reg) cells. These results suggest that CST may become a new modality in controlling allograft rejection.
[Show abstract] [Hide abstract]
ABSTRACT: Cortistatin is a cyclic-neuropeptide produced by brain cortex and immune cells that shows potent anti-inflammatory activity. In this article, we investigated the effect of cortistatin in two models of experimental autoimmune encephalomyelitis (EAE) that mirror chronic and relapsing-remitting multiple sclerosis. A short-term systemic treatment with cortistatin reduced clinical severity and incidence of EAE, the appearance of inflammatory infiltrates in spinal cord, and the subsequent demyelination and axonal damage. This effect was associated with a reduction of the two deleterious components of the disease, namely, the autoimmune and inflammatory response. Cortistatin decreased the presence/activation of encephalitogenic Th1 and Th17 cells in periphery and nervous system, and downregulated various inflammatory mediators, whereas it increased the number of regulatory T cells with suppressive effects on the encephalitogenic response. Moreover, cortistatin regulated glial activity and favored an active program of neuroprotection/regeneration. We further used cortistatin-deficient mice to investigate the role of endogenous cortistatin in the control of immune responses. Surprisingly, cortistatin-deficient mice were partially resistant to EAE and other inflammatory disorders, despite showing competent inflammatory/autoreactive responses. This unexpected phenotype was associated with elevated circulating glucocorticoids and an anxiety-like behavior. Our findings provide a powerful rationale for the assessment of the efficacy of cortistatin as a novel multimodal therapeutic approach to treat multiple sclerosis and identify cortistatin as a key endogenous component of neuroimmune system.The Journal of Immunology 08/2013; 191(5). DOI:10.4049/jimmunol.1300384 · 5.36 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: During the last two decades, research into the modulation of immunity by the neuroendocrine system has flourished, unravelling significant effects of several neuropeptides, including somatostatin (SRIH), and especially cortistatin (CST), on immune cells. Scientists have learnt that the diffuse neuroendocrine system can regulate the immune system at all its levels: innate immunity, adaptive immunity, and maintenance of immune tolerance. Compelling studies with animal models have demonstrated that some neuropeptides may be effective in treating inflammatory disorders, such as sepsis, and T helper 1-driven autoimmune diseases, like Crohn's disease and rheumatoid arthritis. Here, the latest findings concerning the neuroendocrine control of the immune system are discussed, with emphasis on SRIH and CST. The second part of the review deals with the immune response to neuroendocrine tumors (NETs). The anti-NET immune response has been described in the last years and it is still being characterized, similarly to what is happening for several other types of cancer. In parallel with investigations addressing the mechanisms by which the immune system contrasts NET growth and spreading, ground-breaking clinical trials of dendritic cell vaccination as immunotherapy for metastatic NETs have shown in principle that the immune reaction to NETs can be exploited for treatment.Neuroendocrinology 01/2012; 95(4):267-76. DOI:10.1159/000334612 · 4.93 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Induction of antigen-specific tolerance is critical to prevent autoimmunity, to maintain immune homeostasis, and to achieve transplant tolerance. In addition to their classic role as sentinels of the immune response, dendritic cells (DCs) play important roles in maintaining peripheral tolerance through the induction/activation of regulatory T (Treg) cells. The possibility of generating tolerogenic DCs opens new therapeutic perspectives in autoimmune and inflammatory diseases. Characterizing endogenous factors that contribute to the development of tolerogenic DCs is highly relevant. Some neuropeptides that are produced during the ongoing inflammatory response have emerged as endogenous anti-inflammatory agents that participate in the regulation of the processes that ensure self-tolerance. Here, we examine the latest research findings indicating that the role of these neuropeptides in immune tolerance is partially mediated through differential effects on DC functions, which depend on the differentiation and activation states. Importantly, neuropeptides such as vasoactive intestinal peptide, pituitary adenylate cyclase-activating polypeptide, and melanocyte-stimulating hormone have demonstrated an ability to induce tolerogenic DCs with the capacity to generate CD4 and CD8 Treg cells. The possibility of generating or expanding ex vivo tolerogenic DCs with neuropeptides indicates the therapeutic potential for autoimmune diseases and graft-versus-host disease after allogeneic transplantation in humans.Human immunology 05/2009; DOI:10.1016/j.humimm.2009.01.020 · 2.28 Impact Factor