In this study we examined the potential inhibition by interferon-gamma (IFN gamma) of the early stages of low density lipoprotein (LDL) oxidation mediated by human peripheral blood mononuclear cells (PBMC) and monocyte-derived macrophages (MDM) in Ham's F-10 medium supplemented with physiological amounts of L-tryptophan (Trp). We assessed LDL oxidation by measuring the consumption of LDL's major antioxidant (i.e., alpha-tocopherol) and targets for oxidation (cholesteryllinoleate and cholesterylarachidonate), together with the accumulation of cholesterylester hydroperoxides and the increase in relative
Abstract. These days, Mycobacterium tuberculosis (Mtb) bacil is estimated to have infected one third of the world's population. World Health Organization (WHO) data shows that in 2011 there were 8.7 million case of tuberculosis (TB) or equivalent to 125 cases per 100.000 of the world’s population. Some studies have been done to understand the role of certain genes toward the susceptibility of TB patients, most of those studies focused on genes that are involved in signal pathway of interferongamma (IFN-γ). Interferongamma is one of the cytokine that has a role in pathogenesis of pulmonary tuberculosis. Single nucleotide polymorphism of IFN-γ at +874 T/A position in the first intron is reported to have association with pulmonary TB in different population. The aim of this study is to investigate the genetic variation of IFN-γ in +874 T/A and its relation with IFN-γ plasma level in pulmonary tuberculosis patients. The study’s method is cross sectional. Blood sample was taken from the veins of new AFB (Acid-Fast Bacillus) positive tuberculosis patients. Purification examination of Deoxyribonucleic Acid (DNA) and Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) for determining the genotype of IFN-γ genes and the level of IFN-γ is measured using Enzyme Linked Analysis Techniques Immunosorbent Assay (ELISA). The data is presented using tables and pictures. There is a significant association between IFN-γ +874T/A genetic variations with the plasma level of IFN-γ. There is a domination of IFN-γ +874T/A heterozygote genotype found in pulmonary TB population with positive +1of AFB and far advanced lesion on chest x-ray.
BioMed CentralVirology Journal ss Open AcceResearch Synergistic inhibition of human cytomegalovirus replication by interferon alpha/beta and interferon gamma Bruno Sainz Jr?, Heather L LaMarca?, Rober[.]
We examined the potential of interferongamma (IFN-gamma) to ameliorate the physiologic defect of chronic granulomatous disease (CGD) by studying its effects on CGD phagocyte superoxide generation, NADPH oxidase kinetics, cytochrome b559 content, and expression of X-CGD (the gene for the X-linked disease). Granulocytes and macrophages from three patients in two kindreds with "variant" X-linked CGD (i.e., with very low, but detectable, baseline superoxide-generating activity) responded to IFN-gamma with enhanced nitroblue tetrazolium reduction and two- to eightfold increases in superoxide generation. IFN-gamma did not augment the respiratory burst activity of phagocytes from patients with "classic" CGD (i.e., no detectable baseline superoxide generation) or autosomal variant CGD. Incubation of a responding patient's granulocytes with IFN-gamma nearly doubled the maximal velocity for the NADPH oxidase, but did not change its abnormal Michaelis constant. Although the interferon-treated CGD granulocytes produced superoxide at a rate 40% of normal, the cytochrome b spectrum remained undetectable. IFN-gamma treatment of cultured
ABSTRACT. We have found that children with com- plete interferongamma (IFN ␥ ) receptor deficiency, un- like patients with other genetic defects predisposing them to mycobacterial diseases, have very high levels of IFN ␥ in their plasma. This unexpected observation pro- vides a simple and accurate diagnostic method for com- plete IFN ␥ receptor deficiency in children with clinical disease caused by bacille Calmette-Gue´rin vaccines or environmental nontuberculous mycobacteria. Pediatrics 2001;107(4). URL: http://www.pediatrics.org/cgi/content/ full/107/4/e48; interferongamma, mycobacteria, genetic susceptibility, immunodeficiency, plasma.
antigen of mice that do not express the gene coding for interferon-gamma (GKO) with that of their normal littermates (WT). GKO and WT mice on a BALB/c background were exposed to 150 microg of the thermophilic bacteria Saccharopolyspora rectivirgula or saline alone, for three consecutive days a week, for 3 wk. After exposure to antigen, WT mice developed a marked granulomatous inflammation associated with an increase in lung weight and numbers of cells in bronchoalveolar lavage fluid (BAL). Although GKO mice also exhibited an increase in lung weight and numbers of cells in BAL fluid, they developed minimal inflammation and no granulomas after a similar exposure to antigen. To further evaluate if the lack of a response to antigen in GKO mice was due to lack of IFN-gamma, we replaced this mediator via intraperitoneal injections. When given replacement IFN-gamma, the GKO mice developed granulomatous inflammation in the lung. These studies show that IFN- gamma is essential for the expression […]
METHODS After induction with isopropyl β-D-1-thiogalactopyranoside, the protein was extracted by sonication followed by solubilization in 8 M urea buffer. Protein was then re-natured and purified with a GST chromatography column. The isolated protein was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot using anti-GST antibodies, and its concentration was determined using the Bradford method. Each group of splenocytes was treated with 25 μg/ ml of the recombinant protein (GST-RpfB), GST, and phytohemagglutinin. Antigen induction was repeated twice at 24 and 72 hours. The supernatant was collected at 96 hours and interferongamma (IFNγ), interleukin (IL-12, IL-4, and IL-10) levels were measured with enzyme-linked immunosorbent assays.
Arising from the need to increase the detection rate of M. bovis- infected animals in exposed herds, the interferon-gamma assay (IFNγ) was developed as an an- cillary test to improve the sensitivity of testing of cattle when used in parallel with the tuberculin skin test. The principle of the ELISA assay is to detect and quantify release of the IFNγ cytokine when heparinised whole blood is incubated with bovine and avian tuberculin (PPD), normally within the first 8-24 hours post-collec- tion . In a summary of many trials conducted to as- sess the performance characteristics of the IFN γ test, the sensitivity varied between 73.0% and 100%, with a median value of 87.6%. Its median specificity was 96.6%, with a range of 85.0–99.6% . In initial studies con- ducted in Ireland the sensitivity and specificity of the IFN γ test were estimated at 56.2-87.7% and 88.1-96.6%, respectively, depending on the cut-off values used . In a separate study, Gormley et al., estimated sensitivity to be 88% based on detection of tuberculous lesions at post-mortem and a specificity of 95% in herds with a 5-year TB free history . LCA analysis on high and low TB prevalence herds in Ireland provided a sensitivity estimate of 63.1-70.1% and specificity of 86.8-89.4% . Because its sensitivity appears to be higher than the SICTT, the IFNγ assay is primarily used to detect the maximum number of infected animals in a herd or in a region when interpreted in parallel with the tuberculin test. However, the increased sensitivity of the diagnostic regime can result in a decrease in diagnostic specificity. Both the source and concentration of tuberculins used in the IFNγ test has been shown to affect the perfor- mance of test . The relatively low specificity of the IFNγ test in comparison with the SICTT has con- strained its usage in TB free herds undergoing sur- veillance testing, as it is likely that an unacceptable number of false positive non-specific reactors would be identified.
Interferons (IFNs) were first described in 1957 by Issacs and Lindenmann as substances that restrict viral repli- cation. In the 1970s, these substances were further cha- racterized based on the inducing properties and cell type expression patterns. Interferon-γ (IFN-γ) was first named Immune IFN, then later Type II IFN. The major sources of IFN-γ are natural killer (NK) cells, T cells and NKT cells, and its receptor is expressed ubiquitously on almost all cell types. Binding of IFN-γ to its receptor triggers the Janus kinase (JAK)/Signal Transducer and Activator of Transcription (STAT) pathway. STAT1 is phosphory- lated, subsequently dimerizes and then translocates into the nucleus to initiate the transcription of target genes. IFN-γ can induce both pro- and anti-inflammatory res- ponses, and its ability to induce these two responses is critical for a balanced immune response. In addition to its function in activating innate immune cells, IFN-γ signaling also plays a role in T cell development. IFN-γ signaling facilitates Th1 development by inducing T-bet
We investigated the antiviral activity and gene induction properties of interferongamma (IFN- ␥ ) compared to type I IFN (IFNa1) in Atlantic salmon. IFN- ␥ protected salmon cells against infectious pancreatic necrosis virus (IPNV)-induced cytopathic effect (CPE), reduced virus titers, and inhibited the synthesis of the viral structural protein VP3. Moreover, IFN- ␥ showed potent antiviral activity against salmonid alphavirus 3 (SAV3) measured as a reduction in virus nsP1 transcripts. IFN- ␥ (a type II IFN) had less specific antiviral activity against IPNV than IFNa1, showing a half-maximal effective concentration of 1.6 ng/ml versus 31 pg/ml determined in the CPE reduction assay. Compared to IFNa1, IFN- ␥ was a more effective inducer of the antiviral protein GBP, several interferon regulatory transcription factors (IRFs), and the chemokine IP-10. The antiviral activity of IFN- ␥ may also in part be ascribed to upregulation of Mx, ISG15, and viperin. These are typical type I IFN-induced genes in mammals and were also more strongly induced by IFNa1 than by IFN- ␥ in salmon cells. Fish and mammalian IFN- ␥ thus show strikingly similar gene induction properties. Interest- ingly, the antiviral activity of IFN- ␥ against IPNV and SAV3 and its ability to induce Mx and ISG15 markedly decreased in the presence of neutralizing antiserum against IFNa1. In contrast, antiIFNa1 had no effect on the induction of IRF-1 and IP-10 by IFN- ␥ . This suggests that the antiviral activity of IFN- ␥ is partially dependent on IFNa induction. However, because antiIFNa1 could not abolish the IFN- ␥ -mediated induction of Mx and ISG15 completely, IFN- ␥ may possibly also induce such genes directly.
guidelines of occupational safety and health legislation (OSH) HCWs are screened routinely depending on risk assessment. All HCWs working in pulmonary wards and labs (contact with contagious TB-material or TB cases) are screened every year. All other HCWs are routinely screened every third year. After exposure to a TB index case all close contacts were examined within the scope of contact investigation . In accordance with the national guideline the Interferon-gamma release assay (IGRA) is used for the screening procedures. Early detection and treatment of LTBI are also recommended to prevent pro- gression from latent TB infection to active TB .
Even though DNER did not in ﬂ uence macrophage polarisation, its expression levels are signi ﬁ cantly elevated in M1 macrophages (Fig. 2b), which could suggest a role in signalling pathway regulation. To further analyse the downstream cascade of DNER in M1 macro- phages, we performed gene set enrichment analysis (GSEA). Investigat- ing a combination of 270 REACTOME pathway gene sets, revealed that interferon signalling was the most enriched pathway in WT M1 com- pared to DNER de ﬁ cient M1 BMDM (Fig. 2c, d). Given the diversity and complexity of interferon signalling, we next determined which type of interferon pathway is impaired in DNER de ﬁ cient mice. Interest- ingly, induction of type II interferon (Ifng), but not type I (Ifnb1), was signi ﬁ cantly abrogated in M1 polarised DNER de ﬁ cient compared to WT BMDM (Fig. 2e). Supporting the idea of Ifng as a possible down- stream target of DNER, IFNγ signalling was found to be enriched in WT M1 (Fig. 2f, Supplementary Fig. 2f). Furthermore, GSEA from an on- line available dataset of monocyte derived macrophages (MDM) ob- tained from healthy and COPD patients (GSE8608) , revealed an enriched IFNγ pathway in COPD MDM (Fig. 2g). It should be considered that T cells, speci ﬁ cally Th1 cells, serve as a major source of IFNγ. How- ever, in vitro differentiated WT T cell subpopulations showed very low expression of Dner, therefore making it unlikely that DNER regulates IFNγ in T cells (Supplementary Fig. 3f). Hence, these data indicated that DNER is signi ﬁ cantly enhanced in M1 macrophages where it specif- ically regulates IFNγ expression.
In a mouse model of Ps, plaques can be induced by local IL-23 injection, and this is IL-22-dependent . Therefore, the increased proportion of cells making IL-22 alone (that is, without IL-17 or IFNγ) in Ps skin compared to joints was of particular interest, given that this has not previously been studied in patients with both skin and joint disease . This preponderance of Th22 cells in skin was in marked contrast to the findings in SF, where they were not elevated. IL-22-producing cells, though in- creased in PsA PB and expressing CCR6, might not be recruited to the joint, perhaps because of a dominant ef- fect of skin-specific homing receptors. It has previously been reported that T cells in PsA SF lack expression of CLA, which is seen on skin T cells in Ps .
ABSTRACT Natural killer (NK) cells are equipped to innately produce the cytokine gammainterferon (IFN- ␥ ) in part because they basally express high levels of the signal transducer and activator of transcription 4 (STAT4). Type 1 interferons (IFNs) have the potential to activate STAT4 and promote IFN-␥ expression, but concurrent induction of elevated STAT1 negatively regulates access to the pathway. As a consequence, it has been difficult to detect type 1 IFN stimulation of NK cell IFN- ␥ during viral infec- tions in the presence of STAT1 and to understand the evolutionary advantage for maintaining the pathway. The studies reported here evaluated NK cell responses following infections with lymphocytic choriomeningitis virus (LCMV) in the compartment handling the earliest events after infection, the peritoneal cavity. The production of type 1 IFNs, both IFN-␣ and IFN-␤, was shown to be early and of short duration, peaking at 30 h after challenge. NK cell IFN- ␥ expression was detected with overlapping kinetics and required activating signals delivered through type 1 IFN receptors and STAT4. It took place under conditions of high STAT4 levels but preceded elevated STAT1 expression in NK cells. The IFN-␥ response reduced viral burdens. Interestingly, increases in STAT1 were delayed in NK cells compared to other peritoneal exudate cell (PEC) populations. Taken together, the studies demonstrate a novel mechanism for stimulating IFN- ␥ production and elucidate a biological role for type 1 IFN access to STAT4 in NK cells.