Role of Interferon-γ in GVHD and GVL

Interferon （IFN）-γ, a potent proinflammatory cytokine produced by multiple types of cells （e.g., activated T, NK and NKT cells）, plays important and complex roles in both innate and adaptive immune responses. There may be a correlation between the IFN-γ level and GVHD severity in patients receiving allogeneic hematopoietic cell transplantation. However, such a correlation may just reflect the presence of large numbers of activated T cells, and does not necessarily imply a harmful role of IFN-γ in the pathogenesis of GVHD. There has been increasing experimental evidence that IFN-γ is not required and may even inhibit GVHD. Paradoxically, IFN-γ facilitates graft-versus-leukemic （GVL） effects. Thus, IFN-γ blockade is likely deleterious in patients after allogeneic hematopoietic cell transplantation, and not beneficial as previously suggested.     

Dynamic Changes of NCR− Type 3 Innate Lymphoid Cells and Their Role in Mice with Bronchopulmonary Dysplasia

Inflammation - Inflammation is one of the important pathogenesis of bronchopulmonary dysplasia (BPD). Type 3 innate lymphoid cells (ILC3) play a role in a variety of inflammatory lung...     

Interferon-γ release assay in people infected with immunodeficiency virus

The present study aimed to use QuantiFERON TB Gold in tube (Cellestis Limited, Carnegie, Victoria, Australia) as a tool for the screening for tubercular infection in HIV-positive patients. Seventy-three HIV-positive subjects were tested. For each individual, QuantiFERON TB in tube was performed. The immunoassay was negative in 53 subjects, positive in eight and indeterminate in 12. The data obtained indicate that factors such as the CD4 cell count and their percentage, as well as the stage of the disease, could affect the performance of the interferon-γ release assay in populations at risk such as HIV-positive subjects.     

Upregulation of IFN-γ and IL-12 is associated with a milder form of hantavirus hemorrhagic fever with renal syndrome

Hantavirus hemorrhagic fever with renal syndrome (HFRS) is a zoonotic disease characterized by acute onset, fever, malaise, and back pain. As the disease progresses, hemorrhagic disturbances and kidney dysfunctions predominate. The examination of tissue collected postmortem supports the premise that virus replication is not responsible for this pathology; therefore, it is widely believed that virus-induced immune responses lead to the clinical manifestations associated with HFRS. The overproduction of inflammatory cytokines is commonly reported in subjects with HFRS and has given rise to the hypothesis that a so-called “cytokine storm” may play a pivotal role in the pathogenesis of this disease. Currently, supportive care remains the only effective treatment for HFRS. Our data show that serum levels of interferon (IFN)-γ, interleukin (IL)-10, CCL2, and IL-12 are upregulated in HFRS cases when compared to healthy controls and the level of upregulation is dependent on the phase and severity of the disease. Furthermore, we observed an association between the mild form of the disease and elevated serum levels of IFN-γ and IL-12. Collectively, these observations suggest that the administration of exogenous IFN-γ and IL-12 may provide antiviral benefits for the treatment of HFRS and, thus, warrants further investigations.     

Inhibition of PI3Kδ Improves Systemic Lupus in Mice

Systemic lupus erythematosus (SLE) is an autoimmune disease accompanying excessive inflammatory responses. Phosphoinositide 3-kinase p110δ (PI3Kδ) is reported to associate with autoimmune conditions. We here aimed to determine whether selective inhibition of PI3Kδ is effective in a lupus model of BXSB mice, using the selective PI3Kδ inhibitor IC87114, which was intraperitoneally administrated to BXSB mice aged from 14 to 22 weeks. We showed that IC87114 improved renal function by decreasing the levels of proteinuria and serum creatinine, ameliorating the pathologic changes of kidneys and IgG and C3 deposition. Serum anti-autoantibody to nuclear antigen, anti-dsDNA, IL-1β, and IL-17 were markedly reduced by IC87114 therapy. Hepatic damage was also inhibited by administration of IC87114. Expression of phosphorylated AKT (p-AKT) and monocyte chemoattractant protein-1 was inhibited and mouse survival improved. In sum, PI3Kδ activation may be a critical factor for escalating autoimmune renal and hepatic damage, and its inhibition may alleviate the autoimmune damage. Our study reveals that the selective blockade of PI3Kδ is effective for mouse SLE.     

Intracellular Distributing and Interferon-γ Secretion of Human Interleukin-18 in BxPC-3 Cells

Objective: To investigate the characteristics of interleukin-18 (IL-18) in vitro, explore IL-18, interferon-γ (IFN-γ) and interleukin-2 (IL-2) secretive activity in BxPC-3 line cells with interleukin-18 mutants.Methods: Human IL-18 full-length gene (hIL-18-F) and the hIL-18 presumed mature protein gene (hIL-18-M) were inserted into the expression vector pEGFP-N1, to construct recombinant plasmids as Mu0, Mu1, Mu2, Mu3, and Mu4, and the recombinant plasmids were then transferred into BxPC-3 line cells. There are significant differences between Mu1, Mu2 and the pEGFP-C1 control group (P<0.05) by 3-(4,5-dimethiazol- 2-yl)- 2,5-diphenyltetrazolium bromide (MTT) for a proliferation assay, and the fluorescence of the Mu1 and Mu 2 appeared targeted to the membranous region in the BxPC-3 cells after transfected 24h by confocal laser scanning microscope (OLSM).To characterize the intracellular distribution of hIL-18, recombinant IL-18 were each fused to the enhanced green fluorescent protein gene, and expressed in BxPC-3 cells.Results: Results showed that the Mu1 tended to the membranous region in BxPC-3 cells, this indicates that the N-terminal former amino acid peptide helped ChIL-18 target to BxPC-3 cellS membranes. ELISA results demonstrated that IFN-γ and IL-18 secreted levels of BxPC-3 cells transfecting with recombinant plasmid showed an significant difference (P<0.01); refers to IL-2 expression, the two BxPC-3 cells groups transfecting with recombinant plasmid have no significant function (P>0.05).Conclusions: The results showed that hIL-18 and hIL-18 presumed mature protein can induce the secretion of IFN-γ in BxPC-3 cells, and increase the expression of IL-18, but they have no effects on IL-2.     

Interferon-γ for treatment of severe atopic eczema in two children

Two 4- and 5-year-old children suffering from refractory atopic dermatitis were treated with recombinant interferon- (rIFN-). rIFN- was injected at 50 g subcutaneously three times a week in the first child for 3 weeks, followed by three times 25 g in week 4. In the other child two treatment courses of 4 weeks were given after a break of 2 weeks. Therapy was well tolerated. In child one reductions in eczematous body surface and severity of lesions were observed, while no beneficial effect was seen in the other. Clinical chemistry data remained unchanged. Immunological studies performed in parallel showed a decrease in total serum IgE of 50% in child 1, a decrease in spontaneous in vitro IgE production, an increase in in vitro production of interleukin-6, and a normalization of previously decreased in vitro lymphocyte responses to several mitogens. While marked immunological changes were noted during IFN- treatment, clinical benefits were not encouraging. Diminished IFN- production has been claimed to be a major pathogenic factor in atopic eczema. Our results indicate that the pathogenesis is more complex. Clinically, we were unable to confirm previous observations in adults. Further studies are needed before IFN- can be recommended for therapy of pediatric atopic eczema.Abbreviations IFN- interferon- - IL interleukin     

Pineal Germinoma in a Child with Interferon-γ Receptor 1 Deficiency. Case Report and Literature Review

Interferon-γ receptor 1 (IFN-γR1) deficiency is one of the primary immunodeficiencies conferring Mendelian Susceptibility to Mycobacterial Disease (MSMD). Some cases of neoplasms have been recently reported in patients with MSMD, underlying the already known link between immunodeficiency and carcinogenesis. We report the first case of intracranial tumour, i.e. pineal germinoma, in a 11-year-old patient with complete IFN-γR1 deficiency. The first clinical presentation of the genetic immunodeficiency dates back to when the child was aged 2 y and 10 mo, when he presented a multi-focal osteomyelitis caused by Mycobacterium scrofulaceum. The diagnosis of IFN-γR1 deficiency (523delT/523delT in IFNGR1 gene) was subsequently made. The child responded to antibiotic therapy and remained in stable clinical condition until the age of 11 years, when he started complaining of frontal, chronic headache. MRI revealed a solid pineal region mass lesion measuring 20 × 29 × 36 mm. Histological findings revealed a diagnosis of pineal germinoma. The patient received chemotherapy followed by local whole ventricular irradiation with boost on pineal site, experiencing complete remission, and to date he is tumor-free at four years follow-up. Four other cases of tumors have been reported in patients affected by MSMD in our knowledge: a case of Kaposi sarcoma, a case of B-cell lymphoma, a case of cutaneous squamous cell carcinoma and a case of oesophageal squamous cell carcinoma. In conclusion, in patients with MSMD, not only the surveillance of infectious diseases, but also that of tumors is important.     

Interferon-γ deficiency reduces neointimal formation in a model of endoluminal endothelial injury combined with atherogenic diet

Interferon (IFN)-γ has been implicated in restenosis, however its precise role in the pathophysiology of neointimal formation following angioplasty is unclear, as it has been shown to both promote and inhibit neointimal formation. Dietary-induced hypercholesterolemia enhances injury-mediated neointimal formation, associated with increased systemic inflammation and serum IFN-γ. This study examined the effect of IFN-γ gene deficiency ((-/-)) on neointimal formation in a mouse model of endothelial injury combined with an atherogenic diet. Neointimal formation was induced via endoluminal endothelial injury of the common iliac arteries of IFN-γ(-/-) and wild-type (WT) C57Bl/6 mice. Histopathological analysis of the arteries was performed at 3 and 6 weeks post-surgery. IFN-γ(-/-) mice demonstrated a significant reduction in neointimal formation at the 3-week time point, compared to their WT counterpart. No significant differences in plasma lipid profile and the extent of re-endothelialization were detected between IFN-γ(-/-) and WT mice, suggesting that the effect of IFN-γ on neointimal formation is due to injury-mediated vessel neointimal responses. In support of the histopathological findings, immunohistochemical analysis revealed a significant reduction in vessel infiltrating macrophages, and neointimal PDGF-B expression, vascular smooth muscle cell composition and cellular proliferation in the IFN-γ(-/-) mice, in comparison to their corresponding WT group at the 3-week time point. In conclusion, the IFN-γ-mediated pathway plays an important role in inflammatory responses and proliferative effects following injury, suggesting that modulation of the IFN-γ pathway would be beneficial in controlling neointimal formation and restenosis.     

Interferon-α induces altered transitional B cell signaling and function in Systemic Lupus Erythematosus

Previous studies suggest that the B cells of patients with Systemic Lupus Erythematosus (SLE) are hyper-responsive to BCR crosslinking; however, it has been unclear whether this is the result of altered B cell signaling or differences in various B cell subpopulations in SLE patients as compared to healthy controls. Here we have developed a novel Phosflow technique that permits examination of cell signaling in distinct B cell subpopulations stratified based upon developmental stage and cell surface IgM levels, which we use to show that the naïve B cells of SLE patients are hyper-responsive to IgM receptor crosslinking, resulting in increased SYK phosphorylation. We further demonstrate that this hyper-responsiveness is most marked in the transitional B cell subset and that it is associated with altered function, resulting in decreased apoptosis and increased proliferation of these cells. Examination of repeated samples from the same patients revealed that the hyper-responsiveness fluctuated over time, suggesting that it may be mediated by pro-inflammatory factors rather than genetic variations between patients. In support of this concept, incubation of healthy control B cells with IFN-α or SLE plasma induced the hyper-responsive phenotype, which was blocked by anti-IFN-α antibody. Furthermore, no obvious correlation was seen between genetic variants that are proposed to alter BCR signaling and the increased SYK phosphorylation. The findings suggest that pro-inflammatory factors, in particular Type I IFNs, modulate B cell function in SLE in a way that could contribute to the breach of tolerance in this condition.     

Transgenic Expression of Interferon-γ in Mouse Stomach Leads to Inflammation,Metaplasia, and Dysplasia

Gastric adenocarcinoma is one of the leading causes of cancer mortality worldwide. It arises through a stepwise process that includes prominent inflammation with expression of interferon-γ (IFN-γ) and multiple other pro-inflammatory cytokines. We engineered mice expressing IFN-γ under the control of the stomach-specific H⁺/K⁺ ATPase β promoter to test the potential role of this cytokine in gastric tumorigenesis. Stomachs of H/K-IFN-γ transgenic mice exhibited inflammation, expansion of myofibroblasts, loss of parietal and chief cells, spasmolytic polypeptide expressing metaplasia, and dysplasia. Proliferation was elevated in undifferentiated and metaplastic epithelial cells in H/K-IFN-γ transgenic mice, and there was increased apoptosis. H/K-IFN-γ mice had elevated levels of mRNA for IFN-γ target genes and the pro-inflammatory cytokines IL-6, IL-1β, and tumor necrosis factor-α. Intracellular mediators of IFN-γ and IL-6 signaling, pSTAT1 and pSTAT3, respectively, were detected in multiple cell types within stomach. H/K-IFN-γ mice developed dysplasia as early as 3 months of age, and 4 of 39 mice over 1 year of age developed antral polyps or tumors, including one adenoma and one adenocarcinoma, which expressed high levels of nuclear β-catenin. Our data identified IFN-γ as a pivotal secreted factor that orchestrates complex changes in inflammatory, epithelial, and mesenchymal cell populations to drive pre-neoplastic progression in stomach; however, additional alterations appear to be required for malignant conversion.Gastric adenocarcinoma is one of the most common causes of cancer-related deaths worldwide,¹ and although the incidence of these cancers in the United States is decreasing, the 5-year survival rate is a dismal 27%.² Gastric cancer in humans develops through a series of stages, first defined by Correa and Piazuelo, which includes gastritis, atrophy, intestinal metaplasia, dysplasia, and carcinoma.³ Infection with Helicobacter pylori is the greatest single risk factor for the development of gastric cancer.⁴ The gastritis that accompanies Helicobacter infection plays a major role in gastric cancer development⁵; however, the key inflammatory mediators driving this process have not been fully defined. Data from several types of malignancy point to critical functions for inflammation in cancer,⁶ with an interplay between extrinsic factors (infection/inflammation) and intrinsic factors (oncogenes/tumor suppressor genes) driving neoplastic progression.⁷ Targeting pivotal pro-tumorigenic cytokines may thus be useful for the treatment or prevention of certain types of cancer.⁸Interaction of Helicobacter with epithelial cells in the gastric corpus triggers an immune response that leads to the production of multiple cytokines and the establishment of chronic inflammation. Polymorphisms in the IL-1β gene predispose to gastric cancer development in humans,^9,10 and overexpression of IL1β in the corpus of transgenic mice leads to gastric dysplasia and cancer,¹¹ pointing to an important role for this cytokine in gastric tumorigenesis. A Th1-polarized immune response, characterized by elevated expression of interferon-γ (IFN-γ), is activated in Helicobacter-infected stomach and appears to be required for preneoplastic changes, including parietal cell atrophy and the development of gastric metaplasia known as spasmolytic peptide-expressing metaplasia (SPEM),^12–14 which may be a precursor to gastric cancer.¹⁵In mice, transgene-driven expression of IFN-γ in the brain leads to robust induction of the Hh pathway ligand/activator Sonic hedgehog (Shh). This deregulated activation of the Hh signaling pathway in turn leads to the development of medulloblastoma,^16,17 an Hh pathway–driven brain tumor. Because elevated activity of the Hedgehog (Hh) signaling pathway has also been linked to gastric cancer,^18,19 these results raised the interesting possibility that IFN-γ may contribute to inflammation-associated gastric neoplasia in part through induction of Shh expression and oncogenic signaling activity.We tested the potential role of IFN-γ as a pivotal cytokine driving neoplastic progression in stomach by generating transgenic mice, designated H/K-IFN-γ, which overexpress murine IFN-γ driven by an H/K ATPase β promoter, which targets transgene expression to the gastric corpus. We show that IFN-γ overexpression leads to inflammation, increased proliferation, parietal cell and chief cell atrophy, SPEM, an increased number of myofibroblasts, dysplasia, and, in a subset of mice, tumor development. Interestingly, while this work was underway, another group produced mice with stomach-targeted overexpression of IFN-γ. Those mice, in which IFN-γ signaling was activated at lower levels than the mice described here, did not exhibit gastritis and SPEM. Indeed, these processes, as well as neoplasia driven by Helicobacter infection or IL-1β overexpression, were blocked.²⁰ In striking contrast, we show that robust expression of IFN-γ in our model is sufficient to orchestrate multiple changes in inflammatory, epithelial, and mesenchymal cell populations to drive premalignant progression in stomach, though additional alterations appear to be required for the development of full-blown neoplasia.     

Interferon-γ influences the composition of leukocytic infiltrates in murine lyme carditis

Interferon (IFN)-γ is present in lesions of patients with Lyme disease and positively correlates with the severity of manifestations. To investigate the role of IFNγ in the development of Lyme carditis, wild-type and IFNγ-deficient C57BL/6 mice were infected with the causative bacterium, Borrelia burgdorferi. Histological analysis revealed no change in the severity of carditis between wild-type and IFNγ-deficient mice at 14, 21, 25, and 28 days after infection. However, a distinct shift in the types of leukocytes within the hearts of IFNγ-deficient mice was observed at 25 days. In the absence of IFNγ, the number of neutrophils in the heart was increased, whereas the number of T lymphocytes was decreased. Bacterial loads within hearts were the same as in wild-type mice. Macrophages secrete chemokines that recruit immune cells, which could contribute to the accumulation of leukocytes in murine Lyme carditis. The ability of IFNγ and B. burgdorferi to activate murine macrophages was examined, and the two stimuli synergistically induced chemoattractants for mononuclear cells (ie, CXCL9, CXCL10, CXCL11, CXCL16, and CCL12) and decreased those for neutrophils (ie, CXCL1, CXCL2, and CXCL3). IFNγ and B. burgdorferi also synergistically enhanced secretion of CXCL9 and CXCL10 by murine cardiac endothelial cells. These results indicate that IFNγ influences the composition of inflammatory infiltrates in Lyme carditis by promoting the accumulation of leukocytes associated with chronic inflammation and suppressing that of cells that typify acute inflammation.     

Application of Ultralow Doses of Antibodies to Interferon-γ in Complex Therapy of Bacterial Infections and Prophylaxis of Bacterial Complications

Comparative placebo-controlled clinical trials on the efficiency and safety of ultralow doses of antibodies to human IFN-γ (anaferon pediatric formulation and anaferon) and prophylaxis of bacterial complication showed that administration of these preparations in complex therapy of bacterial infection reduced the incidence of bacterial complications of viral infections and considerably decreased the duration of the main clinical symptoms of the disease.     

Serum Neopterin as a Parameter for Monitoring the Course of Renal Cell Carcinoma during Interferon-γ Therapy

Serum analyses were performed regularly over 1 year of therapy with bioactive doses of recombinant interferon-γ (mean 200 μg) in eight patients with advanced renal cell carcinoma in order to assess the usefulness of neopterin in monitoring the course of disease. The baseline level calculated from repeated measurements before treatment (2.87 + 0.59 nmol/liter) did not correlate with the extent of metastatic spread. All patients did show significant increases in serum neopterin concentrations 48 hr after IFN application (7.09 ± 1.99 nmol/liter, P < 0.05, t test) in accordance with a temporary IFN-γ-induced reinforcement of macrophage activity. However, no difference was observable when comparing the baseline values to those obtained 1 week after the last IFN application (3.05 ± 1.16 nmol/liter). There was no correlation with the course of disease, i.e., neither with response (n = 1) nor with progression (n = 7). in contrast to previous studies, the present report shows that although serum neopterin is an appropriate marker for IFN-γ-induced reinforcement of monocyte/macrophage activity, it is not suitable for monitoring the course of metastatic renal cell carcinoma.     

The PPARγ Agonist Rosiglitazone Impairs Colonic Inflammation in Mice with Experimental Colitis

Various animal models showed that peroxisome proliferator-activated receptor (PPAR)γ agonists, when given as a gavage shortly preceding colitis induction, protect against inflammatory bowel disease (IBD). We have examined the effects of 16 days rosiglitazone treatment via the diet prior to dextran sodium sulphate (DSS)-induced colitis in mice. After 7 days DSS in the drinking water, rosiglitazone-fed mice had lost significantly more weight than control mice. Rosiglitazone-treated mice had more diarrhea, weight of colon and spleen were increased, and length of colon was decreased. Histology showed that rosiglitazone-treated mice had more severe colitis, mainly caused by more ulceration, crypt loss, and edema. Immunofluorescence showed a loss of tight junction structure Zonula Occludens protein 1 (ZO-1) in colons of rosiglitazone-treated mice as compared to control mice. Also, serum amyloid P component (SAP) concentrations in plasma were increased. However, concentrations of tumor necrosis factor (TNF)-α and interferon (IFN)-γ in colon homogenates, and TNF-α in spleen homogenates were significantly decreased, whereas interleukin (IL)-10 in spleen homogenates was increased. Other cytokines (IL-2, IL-4, IL-6, IL-12p70 and monocyte chemotactic protein (MCP)-1) and myeloperoxidase (MPO) concentrations showed no differences. In conclusion, 16 days pretreatment with rosiglitazone impaired DSS-induced colitis in mice.