Application of IFN-γ/IL-2 FluoroSpot assay for distinguishing active tuberculosis from non-active tuberculosis: A cohort study

Currently available Interferon-γ release assay cannot reliably differentiate active TB (ATB) from non-active TB (non-ATB). This study aimed to evaluate the diagnostic accuracy of the IFN-γ/IL-2 FluoroSpot assay, which can simultaneously detect IFN-γ and IL-2 secretion, for differentiating ATB from non-ATB. 191 suspected ATB patients with positive T-SPOT.TB results were consecutively recruited. 64 (33.5%) participants had ATB, including 22 (34.4%) microbiologically or histologically confirmed TB and 42 (65.6%) clinically diagnosed TB. 119 (62.3%) cases were non-ATB and 8 (4.2%) were clinically indeterminate. After being stimulated with ESAT-6 and CFP-10 antigens, the median frequency and proportion of IFN-γ⁺IL-2^- T cells were significantly higher in the ATB group than the non-ATB group (P < .001). The areas under the ROC curves of IFN-γ⁺IL-2^- T cells were larger than those of total IFN-γ⁺ T cells (0.788 vs. 0.739, p = .323). With a cutoff value of 25 SFCs/250,000 PBMCs for frequency, sensitivity and specificity of this assay were 73.4% and 69.8% respectively. When combining the frequency and proportions of IFN-γ⁺IL-2^- T cells, the sensitivity and specificity were increased to 95.3% in parallel testing and 83.2% in serial testing respectively. In conclusion, IFN-γ/IL-2 FluoroSpot assay is conducive for the diagnosis of ATB in patients with positive T-SPOT.TB results.

CD4+CD25+ Regulatory T Cells Decreased CD8+IL-4+Cells in a Mouse Model of Allergic Asthma

Interleukin (IL)-4-producing-CD8 (cytotoxic T cells, Tc) contribute to lung eosinophilia and airway hyper-responsiveness (AHR) to an antigen. CD4+CD25+ regulatory T cells (Tregs) attenuate airway inflammation and AHR. This study investigated whether Tregs decrease Tc2frequencies in ovalbumin (OVA)-induced asthma model of mice. Female C57BL/6 mice were sensitized with OVA intraperitoneally and challenged with OVA intranasally to induce allergic asthma model. Tregs were sorted by fluorescence activated cell sorting (FACS) and magnetic activated cell sorting (MACS) microbeads. OVA-sensitized mice were injected with Tregs or phosphate buffer saline (PBS) by tail vein ahead of the first challenge. Airway inflammation and airway hyper-responsiveness (AHR)were evaluated by histological analysis and invasive method, respectively. OVA-specific IgE and cytokine levels were detected by ELISA. Flow cytometry was used to detect the percentages of Tc1 and Tc2. Gata3 and T-bet mRNA was determined by quantitative PCR (qPCR). OVA-sensitized and challenged mice displayed typical asthma features, which included eosinophilic airway inflammation, higher levels of Th2 cytokines and AHR. Gata3 mRNA, Tc2 frequencies and OVA-specific IgE levels were significantly increased in OVA-sensitized and challenged mice. Compared to PBS treatment, Tregs decreased Tc2 frequencies, airway inflammation, Th2 cytokine levels and AHR in OVA-sensitized and challenged mice. IL-13 levels were negatively correlated with Tc1 frequencies and with IFNg levels in experimental mice. Our results demonstrated that Tregs could prevent airway inflammation and AHR by decreasing Tc2 frequencies and cytokine levels in OVA-induced asthma model of mice, supporting Tregmight be as a potent therapeutic target for alleviating airway inflammation and AHR.

A label-free IFN-γ aptasensor based on target-triggered allosteric switching of aptamer beacon and streptavidin-inorganic hybrid composites

A label-free electrochemical aptasensor was developed for the sensitive detection of interferon-gamma (IFN-γ). To do this, a diblock dual-aptamer allosteric hairpin (DDAH) was designed, followed by conjugation with gold nanoparticles (DDAH&AuNP). The presence of target destroyed the stable hairpin structure, and then the catalytic cleavage of DNAzymes removed the IFN-γ-binding molecules, triggering the allosteric switching from inactive hairpin to active streptavidin aptamer (A-DDAH&AuNP) in homogeneous system. Moreover, streptavidin-inorganic hybrid nanoflowers decorated with graphene composites (SFG) were synthesized and used as substrates to modify glassy carbon electrodes (SFG/GCE). SFG specifically bind to the A-DDAH&AuNP to realize high-efficient readout of signals. Under the optimal conditions and by using differential pulse stripping voltammetry (DPSV), the response peak currents increases linearly with the logarithm of the IFN-γ concentration in the range between 0.1 pg mL^-1 and 500 ng/mL. The detection limit is as low as 19 fg mL^-1. The aptasensor also has excellent electrochemical performances, which exhibits broad application prospects in biometric analysis.

14-3-3ζ-A Novel Immunogen Promotes Inflammatory Cytokine Production

The presence of autoantibodies against 14-3-3ζ in human autoimmune diseases indicates its antigenic function. However, neither the cause nor the consequence of this newly-identified antigenic function of 14-3-3ζ protein is known. To address this, we investigated the immunological functions of 14-3-3ζ by studying ex vivo effects on human peripheral blood mononuclear cells (PBMC) proliferation, polarization, and cytokine production. Exogenous 14-3-3ζ promoted PBMC proliferation and T cell polarization toward Th1 and Th17 populations. Significant increases in IFN-γ and IL-17 levels were observed in the presence of 14-3-3ζ. A specific increase in Th1 cells and IFN-γ production provided strong evidence for MHC class II presentation of 14-3-3ζ antigen. Particularly HLA-DRB1^*0401 allele strongly promoted 14-3-3ζ-induced IFN-γ producing cells. In contrast, prednisolone treatment suppressed both 14-3-3ζ-induced T cell polarization and cytokine production. Overall, we show that MHC presentation and the adaptor functions of 14-3-3ζ participate in promoting IFN-γ and IL-17 production, two of the cytokines commonly associated with autoimmune diseases. To the best of our knowledge, this is the first report describing the ex vivo antigenic function of 14-3-3ζ with human PBMC, thereby providing the basis of its immunological role in human diseases.

IL-27 enhances IL-15/IL-18-mediated activation of human natural killer cells

BACKGROUND

Natural killer (NK) cells are an emerging new tool for cancer immunotherapy. To develop NK cell therapeutics from peripheral blood mononuclear cells (PBMCs) of healthy donors, substantial expansion of primary NK cells is necessary because of the very low number of these cells in peripheral blood. In this study, we aimed to investigate the effect of various cytokine alone or combinations, in expanded NK cells and to analyze the synergetic effect of cytokine combinations.

METHODS

Human NK cells were isolated from healthy donor PBMC. Purified NK cells were stimulated with single cytokines or combinations of IL-2, IL-15, IL-18, and IL-27. The expanded NK cells were characterized by flow cytometry, cytotoxicity assay, calcein AM assay and Western blot.

RESULTS

We investigated the synergistic effects of each cytokine, namely, IL-2, IL-15, IL-18, and IL-27, on human NK cells isolated from PBMCs of healthy donors and cultured for 21 days. We identified that IL-15/IL-18/IL-27-mediated activation of NK cells most potently increased NK cell proliferation, cytotoxicity, and IFN-ɣ secretion compared with the activation observed with other treatments, including IL-2, IL-15, and IL-15/IL-18. Additionally, the expression of DNAM-1, NKG2D, CD69, and natural cytotoxicity receptors (NCRs; NKp30 and NKp44) increased on day 21 compared to that on day 0, demonstrating the activation of NK cells. In vitro, expanded NK cells were highly cytotoxic against cancer cells, displaying increased perforin and granzyme B accumulation.

CONCLUSIONS

Taken together, these results indicated that IL-27 can synergize on NK cell expansion and activation with IL-15 and IL-18. In addition, we described an improved culture method for ex vivo expansion of human NK cells with IL-15/IL-18/IL-27 stimulation and characterized the response of NK cells to this stimulation.

Insights into teleost interferon-gamma biology: An update

Interferon-gamma (IFN-ϒ) is probably one of the most relevant cytokines orchestrating the immune response in vertebrates. Although the activities mediated by this molecule are well known in mammals, several aspects of the IFN-ϒ system in teleosts remain a riddle to scientists. Numerous studies support a potentially similar role of the fish IFN-ϒ signalling pathway in some well-described immunological processes induced by this cytokine in mammals. Nevertheless, the existence in some teleost species of duplicated ifng genes and an additional gene derived from ifng known as interferon-γ-related (ifngrel), among other things, raises new interesting questions about the mode of action of these various molecules in fish. Moreover, certain IFN-ϒ-mediated activities recently observed in mammals are still fully unknown in fish. Another attractive but mainly unexplored curious property of IFN-ϒ in vertebrates is its potential dual role depending on the type of pathogen. In addition, some aspects mediated by this molecule could favour the resolution of a bacterial infection but be harmful in the context of a viral disease, and vice versa. This review collects old and new aspects of IFN-ϒ research in teleosts and discusses new questions and pathways of investigation based on recent discoveries in mammals.

[Research progress in secreting sytokines interferon-gamma and interleukin-17 of T helper 1 and 17 cells on periodontitis]

Periodontal disease (PD) is an infection-driven chronic inflammatory disease characterized by the inflammation of tooth-supporting tissues and the destruction of the associated alveolar bone. The immune response of the host to periodontal pathogens infection determines the course and progress of the disease. The effects of secreting cytokines interferon-gamma (IFN-γ) and interleukin-17 (IL-17) of T helper 1 cells (Th1) and T helper 17 cells (Th17) on the development of periodontitis has attracted much attention. IFN-γ is a potential immune-modulatory cytokine and can mediate cellular immune responses by activating various immune cells of the host such as macrophages. As one of the most potential bone physiological regulation mediators, IL-17 is closely related with alveolar bone resorption in periodontitis. This review elaborated the relationship between IFN-γ and IL-17 in the progress of periodontitis, providing new explanations into the development of periodontitis and alveolar bone destruction caused by the host immune response.

A versatile fluorometric aptasensing scheme based on the use of a hybrid material composed of polypyrrole nanoparticles and DNA-silver nanoclusters: application to the determination of adenosine, thrombin, or interferon-gamma

The authors describe a versatile aptasensing scheme based on the use of polypyrrole nanoparticles (PPyNPs) and DNA-silver nanoclusters (DNA-AgNCs) for multiple target detection. The DNA-AgNCs consist of two functional domains, viz. (a) a nucleation domain for attaching the metal core of the nanoclusters, and (b) a recognition domain which consists of a single-stranded aptamer. In the absence of analytes, the single-strand recognition domain will be absorbed onto the surface of the PPyNPs through π stacking and hydrophobic interactions. As a result, the red fluorescence of the DNA-AgNCs (with excitation/emission peaks at 535/625 nm) is quenched by the PPyNPs. On introducing the analytes, the DNA-AgNCs will bind them. This leads to the desorption of DNA-AgNCs and the recovery of the red fluorescence. Based on the above strategy, a versatile, sensitive and selective aptasensor was established for detection of adenosine, thrombin and interferon-gamma. The method was applied to the detection of the above targets in (spiked) serum samples and gave satisfactory results, with detection limit of 0.58 nM for IFN-γ, 0.39 nM for adenosine, and 2.2 nM for thrombin. The use of PPyNPs results in uniquely low non-specific absorption and in improved analytical results in case of real-sample analysis when compared to previously reported methods. Graphical abstract Schematic illustration of DNA-silver nanoclusters and polypyrrole nanoparticles in an aptasensor for detection of multiple targets.

Survival of an epidemic MDR strain of Mycobacterium tuberculosis and its non-prosperous variant within activated macrophages

The fitness of a pathogen results from the interaction of multiple factors favoring either epidemiological success or failure. Herein, we studied the performance of the M strain, a highly successful multidrug resistant Mycobacterium tuberculosis genotype, and its non-prosperous variant, the 410 strain, in activated human monocyte-derived macrophages. Both strains showed comparable ability to induce necrotic cell death and to survive in apoptotic macrophages. Of the various macrophage activation conditions tested, none led to an enhanced control of the outbreak strain. The combination of 1,25(OH)₂ vitaminD3 and IFN-γ favored significantly the control of the non-prosperous 410 strain. These observations indicate that the ability of the M strain to survive within the hostile intracellular milieu is conserved, and the overall fitness cost paid by this genotype would be low. Our results provide additional evidence on bacterial traits that may have contributed to the epidemiological success of the M strain.

Interferon regulatory factor 3 plays a role in macrophage responses to interferon-γ

IFN-γ produced during viral infections activates the IFN-γ receptor (IFNGR) complex for STAT1 transcriptional activity leading to expression of Interferon Regulatory Factors (IRF). Simultaneous activation of TBK/IKKε via TLR3 during viral infections activates the transcription factor IRF3. Together these transcription factors contributes to expression of intracellular proteins (e.g. ISG49, ISG54) and secreted proteins (e.g. IFN-β, IP-10, IL-15) that are essential to innate antiviral immunity. Here we examined the role of IRF3 in expression of innate anti-viral proteins produced in response to IFN-γ plus TLR3 agonist. Wild-type (WT) and IRF3KO RAW264.7 cells, each with ISG54-promoter-luciferase reporter vectors, were stimulated with IFN-γ, poly I:C, or both together. ISG54 promoter activity was significantly reduced in IRF3KO RAW264.7 cells responding to IFN-γ, poly I:C, or IFN-γ plus poly I:C, compared with WT RAW264.7 cells. These data were confirmed with western blot and qRT-PCR. Primary macrophages and dendritic cells (DCs) from IRF3KO mice also showed decreased ISG54 in response to IFN-γ, poly I:C, or IFN-γ plus poly I:C compared with those from WT mice. Moreover, pharmacological inhibition of TBK/IKKε significantly reduced ISG54 promoter activity in response to IFN-γ, poly I:C, or IFN-γ plus poly I:C. Similarly, expression of ISG49 and IL-15, but not IP-10, was impaired in IRF3KO RAW264.7 cells responding to IFN-γ or poly I:C, which also had impaired STAT1 phosphorylation and IRF1 expression. These data show that IRF3 contributes to IFN-γ/IFNGR signaling for expression of innate anti-viral proteins in macrophages.

Co-treatment with interferon-γ and 1-methyl tryptophan ameliorates cardiac fibrosis through cardiac myofibroblasts apoptosis

Cardiac remodeling characterized by cardiac fibrosis is a pathologic process occurring after acute myocardial infarction. Fibrosis can be ameliorated by interferon-gamma (IFN-γ), which is a soluble cytokine showing various effects such as anti-fibrosis, apoptosis, anti-proliferation, immunomodulation, and anti-viral activities. However, the role of IFN-γ in cardiac myofibroblasts is not well established. Therefore, we investigated the anti-fibrotic effects of IFN-γ in human cardiac myofibroblasts (hCMs) in vitro and whether indoleamine 2,3-dioxygenase (IDO), induced by IFN-γ and resulting in cell cycle arrest, plays an important role in regulating the biological activity of hCMs. After IFN-γ treatment, cell signaling pathways and DNA contents were analyzed to assess the biological activity of IFN-γ in hCMs. In addition, an IDO inhibitor (1-methyl tryptophan; 1-MT) was used to assess whether IDO plays a key role in regulating hCMs. IFN-γ significantly inhibited hCM proliferation, and IFN-γ-induced IDO expression caused cell cycle arrest in G0/G1 through tryptophan depletion. Moreover, IFN-γ treatment gradually suppressed the expression of α-smooth muscle actin. When IDO activity was inhibited by 1-MT, marked apoptosis was observed in hCMs through the induction of interferon regulatory factor, Fas, and Fas ligand. Our results suggest that IFN-γ plays key roles in anti-proliferative and anti-fibrotic activities in hCMs and further induces apoptosis via IDO inhibition. In conclusion, co-treatment with IFN-γ and 1-MT can ameliorate fibrosis in cardiac myofibroblasts through apoptosis.

Serum CXCL11 correlates with pulmonary outcomes and disease burden in sarcoidosis

BACKGROUND

Sarcoidosis is a systemic granulomatous disease of unknown etiology that affects the lungs in 90% of patients, but has a wide range of disease manifestations and outcomes including chronic and progressive courses. Noninvasive biomarkers are needed to assess these outcomes and guide decisions for long term monitoring and treatment. Interferon-gamma (IFN-γ)-inducible chemotactic cytokines (chemokines), CXCL9, CXCL10 and CXCL11, show promise in this regard because they have been implicated in the pathogenesis of and reflect the burden of granulomatous inflammation. CXCL11 has been reported to have unique functional properties in modulating adaptive immunity in model systems so our goal was to examine serum levels of CXCL11 in relation to clinical outcomes in a heterogeneous cohort of sarcoidosis subjects.

METHODS

CXCL19, CXCL10, and CXCL11 serum levels were measured in sarcoidosis and healthy subjects using ELISA assay. We determined relationships between CXCL11 and standard clinical inflammatory markers, expression of IFN-γ-related genes in whole blood, organ involvement, dyspnea scores, and measures of pulmonary function.

RESULTS

In a cross-sectional analysis of 104 sarcoidosis subjects, serum CXCL11 was significantly elevated compared to 49 healthy controls (p < 0.001). CXCL11 was positively correlated with CXCL9 and CXCL10 (p < 0.001), sedimentation rate (p < 0.01), and mean expression of three IFN-γ-related genes in whole blood (GBP1, STAT1, and STAT2) (p < 0.001). CXCL11 was inversely correlated with FVC %predicted (%pred) and FEV1 %pred and higher levels were associated with higher patient-reported dyspnea scores. We found positive correlations between CXCL11 and number of organs involved. Using survival analyses, we found that CXCL11 levels were predictive of future pulmonary function test (PFT) decline (log rank <0.001 and HR of log₁₀(CXCL11) = 5.1, 95% CI 1.2-21, p = 0.026).

CONCLUSIONS

The pattern of expression of serum CXCL11 in sarcoidosis patients suggests that this blood measure could be helpful in identifying patients that need longer-term monitoring for progressive thoracic and extra-thoracic sarcoidosis.

[The effect of miR-155 on HBV replication and PTEN expression in vivo]

Objective: To construct the mmu-miR-155 eukaryotic overexpression vector pmR-155 and to investigate its effect on HBV replication and expression of PTEN in vivo. Methods: The mmu-mir-146a precursor gene fragment pre-mmu-mir-146a was amplified by PCR, then connected to the pmR-mCherry plasmid vector after double enzyme digestion, the accuracy of recombinant vector was verified by colony PCR、double enzyme digestion and sequencing; then the recombinant vector was transfected HBV transgene mice(Experimental Group)with hydrodynamics-based injection via vena caudalis, and pmR-mCherry plasmid、PBS were respectively transfected into the mice as Empty plasmid Group、Blank Group. The concentration of IFN-γ in the serum was detected by ELISA. The expression of SOCS1、PTEN mRNA in the liver was detected by qPCR at 30d post-transfectioned. The Western blot was performed to detect the changes in SOCS1、PTEN、HBX in the liver tissue at 30 d post-transfectioned. The results were analyzed with Student's t-test, or one-way analysis of variance and the least significant difference test. Results: the colony PCR、double enzyme digestion and sequencing verified that the gene was inserted into the pmR-mCherry vector. Compared with Blank Group, the expression of miR-155 in the Experimental Group was significantly increased(t = 8.90, P < 0.01); the concentration of IFN-γ in the Experimental Group was significantly increased(F = 26.58, P < 0.01); the mRNA(F(SOCS1 mRNA) = 19.72, P < 0.01; F(PTEN mRNA) = 7.38, P < 0.05) and protein(F(SOCS1) = 50.30, P < 0.01; F(PTEN) = 129.00, P < 0.01) expression of COCS1、PTEN was significantly decreased in the Experimental group and the protein of HBX was also significantly(F(HBX) = 77.97, P < 0.01). Conclusion: The pmR-155 eukaryotic overexpression vector is successfully constructed, this recombinant vector can express miR-155 stably; miR-155 can down-regulate cocs1、PTEN gene expression and up-regulate the expression of IFN-γ, it can inhibit the replication of HBV and a potential targets to treating hepatocellular carcinoma.

[Functional effects of killer cell lectin-like receptor subfamily G member 1 on natural killer cells in chronic hepatitis B infection]

Objective: To study the functional effects of killer cell lectin-like receptor subfamily G member 1 (KLRG1) expression on natural killer cells (NK cell) in chronic hepatitis B virus infection (HBV). Methods: Peripheral blood mononuclear cells (PBMC) were extracted from 120 patients with chronic hepatitis B virus infection and 19 healthy persons. The frequency of NK cells and KLRG1+ NK cells in peripheral blood was detected by flow cytometry. Interferon-γ levels secreted by NK cells were detected in peripheral blood. Statistical analysis of experimental data was performed using GraphPad Prism 6.03 software. Results: The frequency of NK cells in HBV-infected group (16.92% ± 7.9%) was not significantly different from that in healthy controls (10.57% ± 6.5%). The frequency of KLRG1+NK cells in HBV-infected group was significantly higher (49.43% ± 21.2%) than that to healthy control group (31.60% ± 17.9%), (t = 7.347 6, P < 0.001). IFN-γ secretion of KLRG1 + NK cells in HBV-infected patients (2.59% ± 1.0%) were significantly lower than healthy controls (5.96% ± 2.4%), (P = 0.009). Conclusion: HBV infection can increase the expression of KLRG1 in NK cells and further reduce the secretion of IFN-γ in NK cells, which may be an important cause for chronic HBV infection.

CXCL12 expression in aborted mouse uteri induced by IFN-γ: Potential anti-inflammatory effect involves in endometrial restoration after abortion in mice

Anti-inflammation is a key process to restore tissue integrity and function. CXCL12 is a homeostasis chemokine, which plays a coordinating role in organogenesis, tumorigenesis and regeneration. In the present study we found that the uterus of abortion mice showed different histo-morphological changes with the development of abortion. The expression of chemokine CXCL12 and its receptor CXCR4 in abortion uterus showed a time-dependent pattern. Compared with normal pregnancy, the expression of CXCL12 and CXCR4 did not change in the uterus of GD7 abortion mice, but increased significantly in the uterus of GD8 and GD10 abortion mice. However, the expression of IFN-γ increased significantly in the uterus of GD7 abortion mice, while there was no significant change detected in GD8 aborted mice uterus. Our further data show that the expression of CXCL12 is not regulated by IFN-γ in endometrial stromal cell culture system in vitro. The treatment of CXCL12 significantly inhibits the expression of IFN-γ in in vitro cultured stromal cells and splenic monocytes. This suggests that CXCL12 may play an anti-inflammatory role in the uterus of abortion mice to promote the process of endometrial restoration after abortion, rather than participate in the process of abortion as a response molecule of IFN-γ.

High expression of IDO1 and TGF-β1 during recurrence and post infection clearance with Chlamydia trachomatis, are independent of host IFN-γ response

Background

Chlamydia trachomatis infections in women continue to be a major public health concern due to their high prevalence and consequent reproductive morbidities. While antibiotics are usually efficient to clear the Chlamydia, repeat infections are common and may contribute to pathological outcomes. Interferon-gamma (IFN-γ)-mediated immunity has been suggested to be protective against reinfection, and represent an important anti-chlamydial agent, primarily via the induction of indoleamine-2,3 dioxygenase 1 (IDO1) enzyme. IDO1 catalyzes the degradation of tryptophan, which can eliminate C. trachomatis infection in vitro. Here, we sought to measure IDO1 expression levels and related immune markers during different C. trachomatis infection statuses (repeated vs single infection vs post antibiotic treatment), in vitro and in vivo.

Methods

In this study, we measured the expression levels of IDO1 and immune regulatory markers, transforming growth factor β1 (TGF-β1) and forkhead box P3 (FoxP3), in vaginal swab samples of C. trachomatis-infected women, with either single or repeated infection. In addition, we used an in vitro co-culture model of endometrial carcinoma cell-line and peripheral blood mononuclear cells (PBMCs) to measure the same immune markers.

Results

We found that in women with repeated C. trachomatis infections vaginal IDO1 and TGF-β1 expression levels were significantly increased. Whereas, women who cleared their infection post antibiotic treatment, had increased levels of IDO1 and TGF-β1, as well as FoxP3. Similarly, using the in vitro model, we found significant upregulation of IDO1 and TGF-β1 levels in the co-culture infected with C. trachomatis. Furthermore, we found that in PBMCs infected with C. trachomatis there was a significant upregulation in IDO1 levels, which was independent of IFN-γ. In fact, C. trachomatis infection in PBMCs failed to induce IFN-γ levels in comparison to the uninfected culture.

Conclusions

Our data provide evidence for a regulatory immune response comprised of IDO1, TGF-β1 and FoxP3 in women post antibiotic treatment. In this study, we demonstrated a significant increase in IDO1 expression levels in response to C. trachomatis infection, both in vivo and in vitro, without elevated IFN-γ levels. This study implicates IDO1 and TGF-β1 as part of the immune response to repeated C. trachomatis infections, independently of IFN-γ.

Electronic supplementary material

The online version of this article (10.1186/s12879-019-3843-4) contains supplementary material, which is available to authorized users.

Digging deeper in the differential effects of inflammatory and psychosocial stressors in remitted depression: Effects on cognitive functioning

BACKGROUND

Major Depressive Disorder (MDD) covers a wide spectrum of symptoms, including cognitive dysfunction, which can persist during remission. Both inflammatory states and psychosocial stress play a role in MDD pathogenesis.

METHODS

The effects of inflammatory (i.e., Salmonella typhi vaccine) and psychosocial stressor (i.e., Trier Social Stress Test), as well as their combination were investigated on cognition in women (aged 25-45 years, n = 21) with (partially) remitted MDD and healthy controls (n = 18) in a single-blind placebo-controlled study. In a crossover design, patients received on the first day one of the aforementioned interventions and on the other day a placebo, or vice versa, with a washout period of 7-14 days. Short-term and verbal memory, working memory, attention, verbal fluency, information processing speed, psychomotor function, and measures of attentional bias to emotions were measured. Exploratory analyses were performed to assess the correlation between biomarkers of inflammation and the Hypothalamic-Pituitary-Adrenal axis and cognitive functioning.

RESULTS

In patients, inflammatory stress decreased information processing speed and verbal memory, and increased working memory; after psychosocial stress, there was an increase in attention. There was also an increased negative attentional bias in patients after inflammatory stress. Neither stressor had any effect in controls.

LIMITIATIONS

Limitations are the relatively small sample size and antidepressant use by a part of the participants. The effects of the stressors were also measured a relatively short period after administration.

CONCULSION

Patients were sensitive to the cognitive effects of inflammation and psychosocial stress on cognition, while controls were not.

[Role of ash2 (absent, small, or homeotic)-like and Jumonji domain-containing protein 3 on histone methylation of interferon-gamma gene and their associations with vascular damage of Kawasaki disease]

Objective: To investigate the impacts of ash2 (absent, small, or homeotic)-like (Ash2L) and Jumonji domain-containing protein 3 (Jmjd3) on histone methylation of interferon-gamma(IFN-γ) gene and association with vascular damage of Kawasaki disease (KD) in acute phase. Methods: This study was performed among 36 children with KD in acute phase (KD group) and 28 age-matched health children (control group), who were treated or underwent physical examination in our hospital between February 2015 and June 2016. Patients were further divided into KD groups with or without coronary artery lesions (KD-CAL(+) , 16 cases; KD-CAL(-), 20 cases). All KD patients were treated with intravenous immunoglobulin. The proportion of type 1 helper T(Th1) cells and protein levels of IFN-γ, T-box expressed in T cells(T-bet), phosphorylated signal transducer and activator of transcription 1(pSTAT1) and phosphorylated signal transducer and activator of transcription 4(pSTAT4) were analyzed by flow cytometry.Chromatin immunoprecipitation was performed to determine histone methylation (histone H3 tri-methyl K4(H3K4me3), histone H3 tri-methyl K27(H3K27me3)) and binding levels of Ash2L, Jmjd3 and Ezh2 associated with IFN-γ in CD4(+) T cells. Quantitative real-time PCR was used to determine mRNA levels of IFN-γ, interferon γ receptor 1(IFN-γR1), interferon γ receptor 2(IFN-γR2), interleukin 12 receptor subunit beta 1(IL-12Rβ1), interleukin 12 receptor subunit beta 2(IL-12Rβ2), interleukin 18 receptor subunit beta α(IL-18Rα), interleukin 18 receptor subunit beta β(IL-18Rβ), tumor necrosis factor receptor 1(TNFR1), toll-like receptor 4(TLR4), receptor interacting serine/threonine kinase 1(RIP-1) and myeloid differentiation primary response gene 88(MyD88) in CD4(+) T cells. Plasma concentrations of IFN-γ, interleukin 12(IL-12), interleukin 18(IL-18) and tumor necrosis factor α(TNF-α) were measured by enzyme-linked Immunosorbent assay. Results: (1)The proportion of Th1 and its protein level of IFN-γ were significantly higher in KD group than those in control group and higher in KD-CAL(+) group than in KD-CAL(-) group (all P<0.05), and lower after treatment than before treatment (all P<0.05). (2)Compared with control group, mRNA level of IFN-γ and IFN-γ-associating H3K4me3 was increased, while level of IFN-γ associating H3K27me3 in CD4(+) T cells was reduced in KD group (all P<0.05), which resulted in a higher rate of H3K4me3/H3K27me3 (P<0.05) in KD group, which was positively correlated with IFN-γ mRNA in KD group(r=0.55, P<0.05). Similar results were found between KD-CAL(+) group and KD-CAL(-) group (all P<0.05). Level of IFN-γ associating H3K27me3 was increased, and mRNA level of IFN-γ and IFN-γ associating H3K4me3 was decreased after treatment than before treatment (all P<0.05). (3)Expression of T-bet protein and binding levels of Ash2L and Jmjd3 with IFN-γ gene were significantly higher in KD group than those in control group(all P<0.05), higher in KD-CAL(+) group than those in KD-CAL(-) group (all P<0.05). These parameters were significantly lower after treatment than before treatment (all P<0.05). Binding level of Ezh2 with IFN-γ gene was similar among various groups (all P>0.05). (4)In comparison with control or after treatment, surface receptors(IFN-γR1/2, IL-12Rβ1/2, IL-18Rα/β, TNFR1 and TLR4) and its downstream molecules(pSTAT1, pSTAT4, RIP(1) and MyD88) in CD4(+) T cells, and plasma concentrations of inflammatory cytokines(IFN-γ, IL-12, IL-18 and TNF-α) were found to be higher in KD group(all P<0.05). These parameters were also higher in KD-CAL(+) group than in KD-CAL(-) group (all P<0.05). Conclusion: Aberrant histone methylation of IFN-γ associating H3K4me3 and H3K27me3 caused by over-binding of Ash2L and Jmjd3 might be involved in immune dysfunction and vascular damage in KD in the acute phase.

Permeability analyses and three dimensional imaging of interferon gamma-induced barrier disintegration in intestinal organoids

The aberrant regulation of the epithelial barrier integrity is involved in many diseases of the digestive tract, including inflammatory bowel diseases and colorectal cancer. Intestinal epithelial cell organoid cultures provide new perspectives for analyses of the intestinal barrier in vitro. However, established methods of barrier function analyses from two dimensional cultures have to be adjusted to the analysis of three dimensional organoid structures. Here we describe the methodology for analysis of epithelial barrier function and molecular regulation in intestinal organoids. Barrier responses to interferon-γ of intestinal organoids with and without epithelial cell-specific deletion of the interferon-γ-receptor 2 gene were used as a model system. The established method allowed monitoring of the kinetics of interferon-γ-induced permeability changes in living organoids. Proteolytic degradation and altered localization of the tight junction proteins claudin-2, -7, and - 15 was detected using confocal spinning disc microscopy with 3D reconstruction. Hessian analysis was used for quantification of re-localization of claudins. In summary, we provide a novel methodologic approach for quantitative analyses of intestinal epithelial barrier functions in the 3D organoid model.

Association of polymorphisms in serotonin and nitric oxide genes with clinical outcome of dengue in Brazilian northeast population

Serotonin and nitric oxide seem to be involved in Dengue virus infection. The aim of this study was to investigate if SNPs in serotonin and nitric oxide are associated with dengue severity. A retrospective case-control study was conducted, with groups of dengue fever (DF; n = 78) and dengue hemorrhagic fever patients (DHF; n = 49). Genotyping was performed using qPCR and PCR. The power of the sample size was calculated by G*power software. The heterozygous SL for 5-HTTLPR SNP was significantly correlated with protection against progression to DHF in the codominant SS/SL/LL (OR = 0.22, 95% CI = 0.06-0.81, p = 0.011) and overdominant models SL vs SS + LL (OR = 0.19, 95% CI = 0.06-0.65, p = 0.003). For the ENOS (rs1799983) SNP, the genotype GT was positively associated with protection for development of the clinical form in DHF compared to dengue fever (OR = 0.39, 95% CI = (0.13-1.14), p = 0.0058) in codominant GG/GT/TT and overdominant model GT vs GG + TT (OR = 0.35, 95% CI = (0.12-1.02), p = 0.04). To our knowledge, this is the first study to identify the association of the serotonin and nitric oxide SNPs with dengue severity.

Hydrogen peroxide mediates pro-inflammatory cell-to-cell signaling: a new therapeutic target for inflammation?

Nitric oxide is now universally recognized as an extracellular signaling molecule. Nitric oxide, produced in one cell, diffuses across the extracellular space and acts with targets in an adjoining cell. In this study, we present proof that hydrogen peroxide – like nitric oxide – acts as a true first (intercellular) messenger for a multitude of pro-inflammatory ligands. RAW 264.7 macrophages were activated with three different ligands, lipopolysaccharide, interferon-gamma or advanced glycation end products in the presence of increasing concentrations of (hydrogen peroxide scavenging) catalase. As inflammatory readouts, nitric oxide and tumor necrosis factor were determined. We hypothesize that hydrogen peroxide travels between cells propagating the signal, then a certain percentage of the readout should be inhibited by catalase in a concentration-dependent manner. The experiment showed concentration-dependent inhibition of nitric oxide and tumor necrosis factor-α production in response to all three ligands/ligand combinations (interferon-gamma, lipopolysaccharide, and chicken egg albumin-derived advanced glycation end product) in the presence of increasing concentration of catalase. For example, catalase inhibited 100% of nitric oxide and 40% of tumor necrosis factor-α production at its highest concentration. Our results suggest that hydrogen peroxide travels through cell membranes into the extracellular space and enters and activates adjacent cells. Like nitric oxide, we suggest that it is a ubiquitous first messenger, able to transmit cell-to-cell pro-inflammatory signals such as nitric oxide and tumor necrosis factor-α. In a therapeutic setting, our data suggest that compounds acting as hydrogen peroxide scavengers might not even need to enter the cell to act as anti-inflammatory drugs.

Carbenoxolone Could Deteriorate Streptozotocin-induced Diabetes through Induction of Heat Shock Protein 70 and IFN-γ in C57BL/6 Mice

Type 1 diabetes (T1D), a spontaneous autoimmune disease, is associated with destruction of insulin-producing β-cells in the pancreas. Since some heat shock proteins (HSP), such as HSP70 exert a protective effect in both tissues and cells, the present study was conducted to elucidate the effects of carbenoxolone (CBX) as an HSP70 inducer on T1D. The disease was induced in male C57BL/6 mice using streptozotocin (STZ) and subjects were allocated to therapeutic 1 and therapeutic 2 groups, as well as negative and positive control groups. The treated mice (therapeutic 1 and therapeutic 2 groups) received 50 mg/kg CBX intraperitoneally every 24 hours, in the therapeutic 1  group the drug was injected before and after disease induction whereas in the therapeutic 2 group the drug was injected only after disease induction. Serum fasting blood sugar (FBS) level, cytokines production (Interferon-gamma (IFN-γ), Interleukin 10 (IL-10), and IL-17), serum HSP70 level and CD4+CD25+Foxp3+ regulatory T cell (Treg) frequency measurements were outperformed 14 days after the last STZ injection. Our results showed that in the treated groups, serum HSP70, IFN-γ, and IL-17 levels were increased in contrast to the untreated groups. The IL-10 level was markedly decreased in comparison to untreated diabetic mice (p<0.05). Moreover, it was found that the frequency of Tregs in treated mice was lower in comparison to the untreated mice but the difference was not significant (p>0.05). Our results confirm that CBX might through HSP70 induction, followed by increasing IFN-γ level leads to suppression of IL-10 production in diabetic mice resulted in toxic effects on pancreatic islet beta cells and deteriorating of disease.

Microscopic polyangiitis secondary to Mycobacterium abscessus in a patient with bronchiectasis: a case report

Background

Non-Tuberculous Mycobacterial–pulmonary disease (NTM-PD) is increasing in incidence and prevalence. Mycobacterium abscessus (M.abscessus) is a rapid growing multi-resistant NTM associated with severe NTM-PD requiring prolonged antibiotic therapy. Complications of therapy are common but reports on direct complications of active NTM-PD are rare. Vasculitis has been described as a rare complication of NTM-PD, most often in individuals with inherited immune defects. This case is the first to describe an ANCA positive vasculitide (Microscopic Polyangiitis) secondary to M.abscessus pulmonary disease.

Case presentation

A 70 year old female with bronchiectasis underwent a clinical decline associated with the growth of M.abscessus and was diagnosed with NTM-PD. Before treatment could be initiated she developed small joint arthralgia and a glove and stocking axonal loss sensorimotor neuropathy. Positive Perinuclear Anti-Neutrophil Cytoplasmic Antibodies (P-ANCA) and Myeloperoxidase-ANCA (MPO-ANCA) titres led to a diagnosis of microscopic polyangiitis. Further investigation revealed reduced interferon-gamma production but no other significant immune dysfunction.

Dual treatment with immunosuppressive therapy (Corticosteroids/Cyclophosphamide) for vasculitis and antimicrobial therapy for M.abscessus NTM-PD was initiated. Clinical stability was difficult to achieve with reductions in immunosuppression triggering vasculitic flares. One flare led to retinal vein occlusion with impending visual loss requiring escalation in immunosuppression to Rituximab infusions. An increase in immunosuppression led to a deterioration in NTM-PD necessitating alterations to antibiotic regimes. Adverse effects including alopecia and Achilles tendonitis have further limited antibiotic choices resulting in a strategy of pulsed intra-venous therapy to stabilise NTM-PD.

Conclusions

This is the first reported case of an ANCA positive vasculitis secondary to M.abscessus pulmonary disease. This rare but important complication had a significant impact on the patient adding to the complexity of an already significant disease and treatment burden. The potential role of reduced interferon-gamma production in this case highlights the importance of investigating immune function in those with mycobacterial infection and the intricate relationship between mycobacterial infection and immune dysfunction. Immune dysfunction caused by genetic defects or immunosuppressive therapy is a known risk factor for NTM-PD. Balancing immunosuppressive therapy with prolonged antimicrobial treatment is challenging and likely to become more common as the number of individuals being treated with biologics and immunosuppressive agents increases.

Vitamin D pathway activation selectively deactivates signal transducer and activator of transcription (STAT) proteins and inflammatory cytokine production in natural killer leukemic large granular lymphocytes

Calcitriol, the active form of vitamin D, has been well documented to act directly on immune cells and malignant cells. Activated T cells are one of the best characterized targets of calcitriol, with effects including decreasing inflammatory cytokine output and promoting anti-inflammatory cytokine production. However, the effects of calcitriol on natural killer (NK) cells are less clear. Reports suggest that only immature NK cell populations are affected by calcitriol treatment resulting in impaired cytotoxic function and cytokine production, while mature NK cells may have little or no response. NK cell large granular lymphocyte leukemia (NK-LGLL) is a rare leukemia with CD3-CD16+CD56+NK cell clonal expansion. The current standard treatments are immunosuppressant therapies, which are not curative. The Janus kinase (JAK) - signal transducer and activator of transcription (STAT) pathway is hyperactivated in LGLL and is one pathway of interest in new drug target investigations. We previously demonstrated the ability of calcitriol to decrease STAT1 tyrosine 701 (p-STAT1) and STAT3 tyrosine 705 (p-STAT3) phosphorylation as well as inflammatory cytokine output of T cell large granular lymphocyte leukemia cells, but did not determine the effects of calcitriol on NK-LGLL. Therefore, in the present study, we investigated whether NKL cells, a model of NK-LGLL, and NK-LGLL patient peripheral blood mononuclear cells (PBMCs) are susceptible to treatment with calcitriol or seocalcitol (EB1089), a potent analog of calcitriol. NKL cells are dependent on interleukin (IL)-2 for survival and we show here for the first time that treatment with IL-2 induced tyrosine phosphorylation of STATs 1 through 6. Both calcitriol and EB1089 caused significant upregulation of the vitamin D receptor (VDR). IL-2 induction of p-STAT1 and p-STAT3 phosphorylation was significantly decreased after calcitriol or EB1089 treatment. Additionally, IL-10, interferon (IFN)-γ, and FMS-like tyrosine kinase 3 ligand (Flt-3L) extracellular output was significantly decreased at 100 nM EB1089 and intracellular IL-10 was decreased with either calcitriol or EB1089 treatment. We treated NK-LGLL patient PBMCs with calcitriol or EB1089 and found decreased p-STAT1 and p-STAT3 while VDR increased, which matched the NKL cell line data. We then measured 75 serum cytokines in NK-LGLL patients (n = 8) vs. age- and sex-matched normal healthy donors (n = 8), which is the first serum cytokine study for this LGLL subtype. We identified 15 cytokines, including IL-10 and Flt-3L, which were significantly different between normal donors and NK-LGLL patients. Overall, our results suggest that activating the vitamin D pathway could be a mechanism to decrease STAT1 and 3 activation and inflammatory cytokine output in NK-LGLL patients.

Direct Antiviral Mechanisms of Interferon-Gamma

Interferon-gamma (IFNG) is a pleiotropic cytokine that modulates both innate and adaptive immune networks; it is the most potent activator of macrophages and a signature cytokine of activated T lymphocytes. Though IFNG is now appreciated to have a multitude of roles in immune modulation and broad-spectrum pathogen defense, it was originally discovered, and named, as a secretory factor that interferes with viral replication. In contrast to the prototypical type I interferons produced by any cells upon viral infection, only specific subsets of immune cells can produce IFNG upon infection or stimulation with antigen or mitogen. Still, virtually all cells can respond to both types of interferons. This makes IFNG a versatile anti-microbial cytokine and also gives it a unique position in the antiviral defense system. The goal of this review is to highlight the direct antiviral mechanisms of IFNG, thereby clarifying its antiviral function in the effective control of viral infections.