Autoimmunoregulation: differential modulation of CD10/neutral endopeptidase 24.11 by tumor necrosis factor and neuropeptides (original) (raw)
Related papers
Journal of Neuroimmunology, 1992
Neuropeptides have been shown to modulate the bidirectional communication between the central nervous and immune systems. The endooligopeptidase (EC 3.4.22.19), originally isolated and characterized in the nervous tissue, was shown to hydrolyse several neuropeptides and to generate enkephalin from enkephalin-containing peptides. This report shows the presence of endopeptidase 22.19 in the rat immune system using both biochemical and immunochemical methods. The specific activity of endopeptidase 22.19 in soluble fraction of lymphocytes was 3-4-fold higher than the one found in the nervous tissue. Among rat blood cells the highest specific activity of endopeptidase 22.19 was found in T lymphocytes, being 2.5-fold higher than the activity found in other leukocytes. Immunocytochemical studies performed in tissues and cells of the immune system indicate the presence of endopeptidase 22.19-1ike enzyme in all types of leukocytes. The occurrence of this enzyme in cells of the immune system can be considered an important step in understanding the metabolism of neuropeptides in the immune system as well as its possible participation as a regulatory enzyme in neuroimmunomodulation.
The role of neuropeptides in immunoregulatory processes
1996
Among the various non-neuronal cell types known to produce and make use of neuropeptides, those of the immune system have received much attention in recent years. Comparative studies in vertebrates and invertebrates have shown that some of these compounds, especially opioid peptides, are engaged in receptormediated autoregulating processes of the immune system as well as the exchange of information with the neuroendocrine system. Most of those activities observed are immunostimulatory, as determined by their effects on conformational changes indicative of immunocyte activation, cellular motility, and phagocytosis. In cooperation with cytokines, opiate alkaloids, and certain regulatory enzymes (neutral endopeptidase 24.11), they form an effective network of messenger molecules. The immunostimulatory effects observed in this system are balanced (counteracted) by the primarily inhibitory influence of morphine and related opiates. These signals are mediated by several types of receptors with different degrees of selectivity. Among 'them the recently identified, opioid insensitive 113 receptor deserves attention on account of its specificity for opiate alkaloids.
Neuropeptides as Pleiotropic Modulators of the Immune Response
Neuroendocrinology, 2011
Although necessary to eliminate pathogens, inflammation can lead to serious deleterious effects in the host if left unchecked. During the inflammatory response, further damage may arise from potential autoimmune responses occurring when the immune cells and molecules that respond to pathogen-derived antigens also react to self-antigens. In this sense, the identification of endogenous factors that control exacerbated immune responses is a key goal for the development of new therapeutic approaches for inflammatory and autoimmune diseases. Some neuropeptides that are produced during the ongoing inflammatory response have emerged as endogenous anti-inflammatory agents that could collaborate in tuning the balanced steady state of the immune system. These neuropeptides participate in maintaining immune tolerance through two distinct mechanisms: by regulating the balance between pro-inflammatory and anti-inflammatory factors, and by inducing the emergence of regulatory T cells with suppres...
Neuropeptide substance P and the immune response
Cellular and molecular life sciences : CMLS, 2016
Substance P is a peptide mainly secreted by neurons and is involved in many biological processes, including nociception and inflammation. Animal models have provided insights into the biology of this peptide and offered compelling evidence for the importance of substance P in cell-to-cell communication by either paracrine or endocrine signaling. Substance P mediates interactions between neurons and immune cells, with nerve-derived substance P modulating immune cell proliferation rates and cytokine production. Intriguingly, some immune cells have also been found to secrete substance P, which hints at an integral role of substance P in the immune response. These communications play important functional roles in immunity including mobilization, proliferation and modulation of the activity of immune cells. This review summarizes current knowledge of substance P and its receptors, as well as its physiological and pathological roles. We focus on recent developments in the immunobiology of...
Neuropeptide Precursor Processing in Immunocytes: Involvement in Neuroimmune Communication
Communication and reciprocal regulation between the nervous, endocrine and immune systems are essential for the stability of the organism. Among others, cytokines, hormones and neuropeptides have been identified as signalling molecules mediating the communication between the three systems. Neuropeptides, originally described in the central nervous system (CNS), were also found to be expressed by immune cells and exhibit a number of immunomodulatory properties (Stefano and Salzet 1999; Salzet, Vieau et al. 2000; Blalock 2005) (Elmquist, Scammell et al. 1997). In the last few years various animal models have served to study neuroimmune mechanisms confirming the view of communication between the neuroendocrine and immune systems via neuropeptide signalling (Stefano and Salzet 1999; Salzet, Vieau et al. 2000; Blalock 2005). Another emerging function of neuropeptides within the immune system is their direct roles in defence. Peptides with antibacterial properties have been shown to be de...
Neuropeptide Control of Bone Marrow Neutrophil Production: A Key Axis for Neuroimmunomodulation
Annals of the New York Academy of Sciences, 2006
A BSTRACT : Nerve fibers project into the bone marrow and terminate in association with stromal cells. Nerve terminals are also associated with antigenprocessing and-presenting cells throughout the body and have been shown to be important in leukocyte trafficking and wound healing as well as hemopoiesis. Here we show that neuropeptide input to the bone marrow is vital to normal granulopoiesis and that deletion of the neuropeptides, substance P, and calcitonin gene-related peptide (CGRP), with the neurotoxin, capsaicin, abrogates normal blood cell production. Norepinephrine, neurokinins a and 2, and vasoactive intestinal peptide all have inhibitory effects on in vitro CFU-GM colony formation. Substance P, neurokinin 1, nerve growth factor, and CGRP have stimulatory effects on CFU-GM. Furthermore, in vitro experiments show that, apart from CGRP, all the neuroactive substances we tested operate through effects on accessory cells, stimulating the release of regulatory molecules that have a direct effect on purified CFU-GM.