The review presents the properties and significance of soluble forms of Tumor Necrosis Factor-alfa receptors in physiology and pathology of human organism. Special attention was turned to the possibility of practical application of those forms of the receptors in the therapy of diseases caused by excessive activity of TNF-alfa.
Introduction: Cancer-associated retinopathy (CAR) is a paraneoplastic neurological syndrome resulting in progressive loss of vision and clinical signs of retinal degeneration. It is associated with various types of cancer and is also considered to be an autoimmune disorder that involves cross-reaction between autoantibodies and retinal proteins. The aim of this study was to establish whether immunoreactivity to retinal antigens (RAs) observed in patients with breast cancer is accompanied by any visual impairments. Materials and Methods: Sera of 295 patients with diagnosed breast cancer were screened for the presence of anti-RAs antibodies using immunoblotting. Cellular immunoreactivity to RAs present in retinal extracts and to purified recoverin and arrestin was determined by means of a lymphocyte proliferation assay. Six patients with high-titer antibodies to RAs then underwent ophthalmic and neurological examinations. Results: Four serum samples contained high-titer antibodies to a 46-kDa protein, most probably retinal ?-enolase, three had antibodies to a 48-kDa protein identified as retinal arrestin, while 56-, 43-, 41-, and 34-kDa antigens were recognized only by one serum sample each. Moreover, weak cellular response to all the RAs tested was observed in one patient and another patient responded only to retinal extract. Two of the examined patients displayed symptoms of CAR. Conclusions: Immunoreactivity to RAs in patients with breast cancer may also be present in cases without clinical signs of CAR.
Cerebellar degeneration may be recognized as a remote effect of a growing tumor. We have analysed serum concentrations of tumor necrosis factor-? (TNF-?), macrophage chemoattractant protein-1 (MCP-1), thyroxine and insulin to elucidate the pathomechanism which may be of importance for the development of central degeneration in cachectic Morris hepatoma bearing rats. Serum TNF-? and MCP-1 levels were evaluated by means of the ELISA system, while thyroxine and insulin were estimated by radioimmunoassay. Microscopic examination using hematoxylin-eosin, Nissl and Kl?ver?Barrera staining revealed an atrophy in the cerebellum, homogenization changes of Purkinje cells and decreased cell density of the granular layer. In the Morris hepatoma bearing animals serum MCP-1 content was elevated while TNF-, thyroxine and insulin concentrations were decreased. This study has demonstrated that circulating TNF- and MCP-1, together with decreased levels of insulin and thyroxine accompany and may produce a milieu of factors involved in mechanisms of the development of cerebellar degeneration in cachectic hepatoma bearing rats.
The effect of recombinant human granulocyte-macrophage colony-stimulating growth factor (rHuGM-CSF) treatement on in vitro interferon (IFN) and tumor necrosis factor (TNF) production in peripheral blood cells of 46 patients with acute myelogenous leukemia (AML) was examined. GM-CSF significant enhanced virus-induced IFN- production in blood cells (containing 70% of blasts) of 28 patients with M4-M5 AML according to the French-American-British (FAB) classification and also phytohemagglutinin (PHA)-induced IFN- production in blood cells (containing 68% of blasts) of 18 patients with AML M0-M3 type. In control blood cells (25 healthy persons) GM-CSF enhanced PHA-induced IFN- but did not influence IFN- production. In the presence of GM-CSF, TNF- titers induced with lipopolysaccharide were also higher in control blood cells but not in cells of patients with M0-M3 or M4-M5 type of AML. The significance of GM-CSF-enhanced IFN- and IFN- production in antimicrobial and antileukemic immune reactions which can develop during GM-CSF therapy is discussed.
CD40, a member of the growing tumor necrosis factor receptor (TNF-R) family of molecules, functions as a transmembrane signal receptor in both hematopoietic and non-hematopoietic cell types, although its physiological roles are less well understood in the latter. Much has been learned over the past decade about the role of CD40 signaling in various cellular functions. In addition, some of the molecular events which occur subsequent to CD40 engagement have been characterized, although much remains to be understood. This review will summarize the known important biological roles of CD40, and discuss what is currently known about how CD40 signals.
Despite the numerous reports on the role of tumor necrosis factor-alpha (TNF-alpha) in the brain neuropathology, very little is known about the mechanisms by which TNF-alpha may mediate neuroprotection. Different hypotheses pertain to the molecular and cellular effectors triggered by the activation of TNF receptors (TNFRI and TNFR2). They are focused on diminishing the production of nitric oxide and free radicals, alteration of excitatory amino acids neurotransmission, maintenance of neuronal calcium homeostasis and induction of neurotrophic factors synthesis. In this review all these data are summarized. Moreover, possible explanations for the inconsistent data concerning the TNF-alpha effect on neuron are discussed.
Hematopoietic stem cell transplantation (HSCT) is a curative treatment of many hematological disorders. Recent studies have shown the associations between polymorphic features of cytokine-encoding genes and the incidence of post-transplant complications in the recipients of allogeneic HSCT. This review focuses on the relationship between the polymorphic patterns of patient genes encoding tumor necrosis factor (TNF)-alpha and TNF-beta and the manifestation of post-transplant complications, acute graft-versus-host disease (aGvHD), generation of toxic lesions, and mortality. Discussed in more detail are the relationships of TNFd microsatellites and polymorphisms within the promoter region of the TNF-alpha-encoding gene (TNFA) in the position (?308) and within the first intron of the TNF-beta-encoding gene (TNFB). It appeared that heterozygosity within the TNFA promoter and the first intron of the TNFB gene increased the susceptibility to severe grades III?IV of toxic complications, while the presence of the TNFd3 homozygous genotype was associated with a higher risk of severe aGvHD and early mortality in patients after allogeneic HSCT. These results imply that donor-recipient genotyping, extended to cytokine loci, may be of prognostic value for transplantation outcome.
The natural antiviral immunity of human lymphocytes, leukocyte from peripheral blood and whole-blood cultures was studied using the method of infection with two viruses belonging to different taxonomic groups, vesicular stomatitis virus (VSV) and encephalomyocarditis virus (EMCV). The kinetics of virus replication in both kinds of cultures and the dependence of culture infection on pre-infection incubation time were studied. When the cultures were infected immediately after preparation, most of them were found to be resistant to the viruses. However, when they were infected after several (1-5) days of incubation, VSV and EMCV multiplied in the cultures to high titers. The time of losing the resistance was individually differentiated. The results indicate the presence of a non-specific antiviral immunity characteristic for individuals. The antiviral immunity of healthy donors was compared with that of people suffering from recurrent infections of the upper respiratory tract. This latter group expressed statistically significant lower innate immunity than healthy donors. However there were no differences in interferon (IFN) and tumor necrosis factor (TNF) production between these groups. In order to examine the contribution of the endogenous IFNs and TNF alpha in maintaining innate immunity, specific antibodies against IFN alpha, IFN beta, IFN gamma and TNF alpha were added to VSV-infected leukocytes resistant to infection. The antibodies reduced the antiviral resistance in 9 of 16 experiments. The results suggest that both: endogenous interferons and TNF alpha may participate in the constitution of innate immunity, though they are not the only mediators of it.
Simultaneous evaluation of cytokines and their soluble receptor production and serum levels can be helpful in understanding the local and systemic immune response of a tumor-bearing host. In the present study we examined the serum levels of TNF-, IL-6 and their soluble receptors sTNFRp55, sTNFRp75 and sIL-6R compareded with their production by the polymorphonuclear neutrophils (PMN) from cancer patients. Examinations were carried out in patients with adenocarcinoma breast cancer and squamous cell carcinoma of the oral cavity and related to the clinical course and to different phases of therapy. Secretion of IL-6, sTNFRp55 and sTNFRp75 by PMN appeared to be dependent on tumor type, clinical progression of disease as well as on therapy, suggesting a significant role of these cells at different phases of the immune response to cancer associated with these mediators. Changes in values of TNF-alpha, IL-6 and their soluble receptors in sera of both cancer groups, dependent on tumor type, clinical progression and cancer therapy, could have a diagnostic and prognostic role in cancer disease.
Changes in the secretory activity of two transplantable melanoma lines (differing in many biological features) as regards nitric oxide (NO) and interleukin 6 (IL-6), tumor necrosis factor (TNF-), oncostatin M (OSM) secretion were the subject of the present study. Obtained results show that a spontaneous alteration of the hamster?s native melanoma line in to an amelanotic one is accompanied by a global change of the secretory activity but there was not distinct correlation between the endogenous cytokine secretion and NO secretion by cells of both melanoma lines.
Infection with Mycobacterium tuberculosis (MTB) is accompanied by an intense local inflammatory response which may be critical to the pathogenesis of tuberculosis. Activation of components of the innate immune response, such as recruitment of polymorphonuclear (PMN) and mononuclear phagocytes and induction of pro-inflammatory cytokines, such as tumor necrosis factor alpha (TNF-alpha), by MTB occurs early after MTB infection, however, may persist as the organism establishes itself within granulomas. MTB and its protein and non-protein components are potent in induction of cytokines and chemokines from PMN and monocytes. This review focuses on the interaction of MTB and the host with regard to activation of the innate immune response. It also attempts to identify the potential impact of this early response on the subsequent pathogenesis of MTB, and its role in development and extent of tuberculosis. Insights into the initiation and persistent of the inflammatory response may allow the application of anti-inflammatory agents as adjuncts in the treatment of tuberculosis.
Polymorphonuclear leukocytes (neutrophils) apoptosis is an important mechanism regulating the life span and some functions of neutrophils at inflamed sites. The opioid peptides are present in the peripheral circulation and their concentrations rapidly increase as the result of stress and inflammation. The effect of opioid peptides such as met-enkephalin (M-ENK) and beta-endorphin (beta-END) on tumor necrosis factor alpha (TNF-alpha)-induced apoptosis in human neutrophils in vitro was investigated. Neutrophils isolated from peripheral blood were cultured in the absence or presence of 106-1010 M of opioid peptides for 8, 12 and 18 hours. Features of apoptotic neutrophils were measured by flow cytometric method based on analysis of apoptotic nuclei (DNA content). We found that M-ENK and beta-END enhanced both non-induced and TNF-alpha-induced neutrophil apoptosis in vitro in a dose-dependent manner. The effect of opioid peptides on modulation of neutrophil apoptosis was not reversed by opioid-receptor antagonist naloxone. The results suggest that M-ENK and beta-END can regulate neutrophil life span via apoptosis and in this way may participate in resolution of inflammation.