High levels of the pro-inflammatory cytokine tumour necrosis factor (TNF) have been associated with many diseases including rheumatoid arthritis (RA), ankylosing spondylitis (AS), inflammatory bowel disease (IBD) and psoriasis. Although it has been clear for twenty-five years that TNF plays a major role in RA and AS, two major questions remain unanswered: (1) What mechanism underlies the loss of control of TNF levels in patients? (2) How does TNF exert its detrimental effects? Nonetheless, biological anti-TNF drugs have become the most successful treatment of these conditions with a third of patients entering remission, and the global market for biological TNF inhibitors is now estimated at around US$35 billions. However, their use is limited by their cost, the fact that they need to be injected, non-negligible side effects and the development of resistance due to the protein (thus antigenic) nature of these TNF inhibitors. It looks inevitable that new approaches to lower the amount of TNF should be considered. To do this, a better understanding of the regulation of TNF expression is necessary.Read more
It was established that in a mononuclear fraction polyoxidonium inhibited the TNF-alpha production and stimulated the IL-1 beta and IL-6 production. In LPS-induced mononuclear cultures polyoxidonium inhibited the IL-6 production and had no statistically significant effect on the synthesis of TNF-alpha and IL-1 beta. Polyoxidonium had no effect on TNF-alpha, IL-6 and IL-1 beta production by purified monocytes. The addition of polyoxidonium with dexamethasone to the cultures only in monocyte fraction enhanced the IL-1 beta production as compared with the effect of dexamethasone alone. Data obtained allow suggesting that under certain conditions polyoxidonium could alleviate pronounced suppressive influence of glucocorticoids on a secretory activity of effectors of innate immunity.Read more
Hepatitis C virus (HCV) is the major cause of hepatocellular carcinoma (HCC). The risk to develop HCC increases with the severity of liver inflammation and hepatic fibrosis. It is believed that a balance between the releases of pro- and anti-inflammatory cytokines will determine the clinical course of HCV and the risk to develop HCC. The inteleukin-10 (IL-10) and the tumor necrosis factor alpha (TNF-α) play key roles in the Th1 and Th2 balance during the inflammatory response against HCV. The aim of the present study was to investigate the association between polymorphisms in TNF-α -308 G>A (rs1800629), IL-10 -1082 G>A (rs1800896) and -819/-592 (rs1800871/rs1800872) with HCC risk in individuals with HCV. The present study evaluated 388 chronic HCV patients. Polymorphisms were determined by real-time PCR. Diplotypes associated with low IL-10 production and the TNF-α GG genotype were significantly associated with HCC occurrence after multivariate logistic regression analysis (P = 0.027 and P = 0.029, respectively). Additionally, the IL-10 -819 (-592) TT (AA) genotype was significantly associated with multiple nodules and HCC severity according to BCLC staging (P = 0.044 and P = 0.025, respectively). Patients carrying low production haplotypes of IL-10 and the TNF-α GG genotype have higher risk to develop HCC. J. Med. Virol. 88:1587-1595, 2016. © 2016 Wiley Periodicals, Inc.Read more
To investigate the relation of healing outcomes and three factors in nasal fluid before and after endoscopic sinus surgery (ESS), including platelet derived growth factor (PDGF), tumour necrosis factor-alpha (TNF-alpha) and hyaluronic acid (HA).
We compared the amounts of PDGF, TNF-alpha, HA among the three stages in 22 patients operated for nasal polyposis. The concentrations of PDGF, TNF-alpha, HA were compared before and after operation between good healing and poor healing at 12th week, and gender, age, body mass, preoperative stage were also compared. Finally, we performed a multiple logistic regression model to assess whether the healing quality was associated with gender, age, body mass, preoperative stage, and concentrations of PDGF, TNF-alpha, HA before ESS.
(1) A significant difference in the concentrations of PDGF and HA could be demonstrated between the first and second stage, or between the first and third stage. But there was no difference in TNF-alpha among three stages. (2) The healing quality after ESS was significantly and independently correlated to the age of patient and preoperative PDGF concentrations in nasal secretions, the younger, the better healing. The lower PDGF concentration, the better healing, and vice versa.
During the wound healing of nasal mucosa, the levels of PDGF, TNF-alpha, HA are different at each postoperative stage. Age and PDGF concentrations preoperatively are suitable factors to predict the healing quality after ESS.Read more
To investigate how lymphocytes induce hepatocyte apoptosis.
Liver injury was elicited by the trinitrobenzenesulfonic acid (TNBS) in picryl chloride (PCI)-sensitized mice. An ear swelling was also triggered with TNBS to confirm its eliciting ability. An in vitro assay for inducing hepatocyte apoptosis was established.
TNBS significantly elicited liver injury as well as ear swelling in PCl-sensitized mice. In the liver injury, hepatocyte apoptosis was detected 6 h after TNBS treatment. Cyclosporin A inhibited both ear swelling and hepatocyte apoptosis. When spleen cells from PCl-sensitized mice were co-cultured for 24 h with those from normal mice that had been treated with TNBS for 20 min, the supernatant collected showed a strong apoptosis-inducing activity for hepatocytes. The apoptosis was significantly reduced when the spleen cells from PCl-sensitized mice were treated previously with anti-CD3 or anti-CD4 antibody. By treating the cells, galactosamine and cycloheximide also lowered the apoptosis-inducing activity and decreased TNF-alpha and IL-2 productions. However, galactosamine treatment of hepatocytes greatly facilitated their susceptibility to supernatant-induced apoptosis. By contrast, cycloheximide completely blocked the facilitation.
CD4+ T cells in mice with liver injury may cause hepatocyte apoptosis by releasing cytokines including TNF-alpha and IL-2.Read more
Activation of macrophages and other immune components to release a series of proinflammatory cytokines is one of the first events in innate resistance to intracellular infections. Severe manifestations of tuberculosis (TB) could be caused by alterations in the balance of these cytokines. In this study, lymphokine-activated killer (LAK) cells of TB patients and normal individuals were generated by stimulation with cytokines in vitro. The LAK cells of both groups were further triggered with allogeneic tumor targets. Cytokines interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha), and granulocyte-macrophage colony-stimulating factor (GM-CSF) were estimated in the supernatants generated in the two groups. The aim was to see if infection with TB influenced the secretory capacity of the immune cells in vitro. Reduced cytokine profiles were observed in TB patients, indicating defective interactions between patient effector cells with allogeneic transformed cells compared with normal individuals. Partial restoration of IFN-gamma production was seen with a combination of cytokines interleukin-2 (IL-2) and IL-12 in TB patients. Based on the in vitro observations, we hypothesize that in vivo also there is diminished immune cell activation of effector cells in response to the presence of infected macrophages. This probably leads to a diminished secretory function that can be corrected by the use of such cytokines as IL-2 and IL-12. The effector populations of TB patients are probably in a state of target-induced anergy, allowing the bacteria to thrive, and immunomodulatory cytokines that improve the host immune response toward countering mycobacterial infection.Read more
A significant incidence of systemic lupus erythematosus (SLE), the severity of lupus nephritis and varying responses to treatment rationalize the search for novel biomarkers of disease activity. The aim of the study was to assess whether antibodies against monomeric C reactive protein (anti-mCRP) are associated with the presence of lupus nephritis, correlate with disease activity, and whether they can serve to evaluate a response to treatment.
The study involved 74 patients with lupus nephritis, 29 patients with systemic lupus without renal involvement and 31 patients with primary glomerulonephritis; the control group included 31 healthy volunteers. Interleukin-6 and tumor necrosis factor alpha were measured using commercially available ELISA tests. The presence of anti-mCRP in the serum was tested with the use of in-house ELISA.
The highest prevalence and concentrations of antibodies against monomeric C-reactive protein were observed among patients with lupus nephritis, as compared to other groups. The elevated level of anti-mCRP was associated with standard clinical and laboratory indicators of SLE activity. Moreover, the highest concentrations of both Il-6 and TNF-α were observed for patients with the most severe nephropathy. A significant decrease in anti-mCRP and cytokines' levels in the course of treatment was observed.
The study gives further evidence that antibodies against monomeric C-reactive protein may be considered an indicator of renal involvement in patients with SLE. Assessment of anti-mCRP supports monitoring of disease activity and can be used in evaluating the treatment effectiveness.Read more
It is well documented that hypothyroid patients are more susceptible to microbial infections. In order to study whether this impaired response is due to a decrease in production of antitumor molecules or an impaired ability to transmit information in the macrophage, a hypothyroid animal model was used to study the expression of both tumor necrosis factor gene and c-fos protooncogene in peritoneal macrophages. Inbred mice were rendered hypothyroid by an antithyroid drug, methimazole, and the expression of tumor necrosis factor gene and c-fos protooncogene in peritoneal macrophages were studied. Impairment of c-fos and TNF genes were at both transcriptional and translational levels using northern blot analysis, bioassays, and immunocytochemical staining methods. These results indicate that the reduction in signal transduction and in the production of antitumor molecules may cause the poor defense ability of hypothyroid animals.Read more
Mast cells produce proinflammatory cytokines in response to TLR4 ligands, but the signaling pathways involved are not fully described. In this study, the participation of the Src family kinase Fyn in the production of TNF after stimulation with LPS was evaluated using bone marrow-derived mast cells from wild-type and Fyn-deficient mice. Fyn(-/-) cells showed higher LPS-induced secretion of preformed and de novo-synthesized TNF. In both cell types, TNF colocalized with vesicle-associated membrane protein (VAMP)3-positive compartments. Addition of LPS provoked coalescence of VAMP3 and its interaction with synaptosomal-associated protein 23; those events were increased in the absence of Fyn. Higher TNF mRNA levels were also observed in Fyn-deficient cells as a result of increased transcription and greater mRNA stability after LPS treatment. Fyn(-/-) cells also showed higher LPS-induced activation of TAK-1 and ERK1/2, whereas IκB kinase and IκB were phosphorylated, even in basal conditions. Increased responsiveness in Fyn(-/-) cells was associated with a lower activity of protein phosphatase 2A (PP2A) and augmented activity of protein kinase C (PKC)α/β, which was dissociated from PP2A and increased its association with the adapter protein neuroblast differentiation-associated protein (AHNAK, desmoyokin). LPS-induced PKCα/β activity was associated with VAMP3 coalescence in WT and Fyn-deficient cells. Reconstitution of MC-deficient Wsh mice with Fyn(-/-) MCs produced greater LPS-dependent production of TNF in the peritoneal cavity. Our data show that Fyn kinase is activated after TLR4 triggering and exerts an important negative control on LPS-dependent TNF production in MCs controlling the inactivation of PP2Ac and activation of PKCα/β necessary for the secretion of TNF by VAMP3(+) carriers.Read more
Genetically determined interindividual differences in the production of mediators of immune response may influence the outcomes of kidney transplantation. Of the cytokine gene polymorphisms that determine the level of gene expression, TNF-a -08G/A, IFN-g +874T/A and microsatellite (CA)n, TGF-b1 +869T/C and +915G/C, IL-6 -174G/C, and IL-10 -592C/A, -819C/T, and -1082G/A seem to have the strongest impact on graft survival. Increased risk of acute rejection (AR) was demonstrated for high-producing genotypes of pro-inflammatory cytokines such as TNF-a and IFN-g, while the association with polymorphisms of TGF-b1 and IL-10 remains unclear. A high production of profibrotic TGF-b1 is associated with interstitial fibrosis and tubular atrophy (IF/TA). In contrast, high genetically determined IL-6 gene expression played a protective role in the development of chronic rejection (CR). The risk of graft loss was greater among high TNF-a and low TGF-b1 or IL-6 producers. The results of kidney transplantation are also influenced by the donor's cytokine expression profile. Low IL-6 production donor genotype was associated with a higher prevalence of AR, CR, and IF/TA. Low donor transcriptional TGF-b1 gene activity predisposed the recipient to AR episodes and high IFN-g expression to IF/TA development. To date, study results are highly inconsistent, so the applicability of cytokine polymorphism genotyping remains questionable. In summary, it is difficult to conclude whether or not cytokine polymorphism genotyping is useful in the risk assessment of rejection and kidney graft survival and in applying optimal immunosuppressive medication.Read more