Expression Of IFN-related Genes Research Articles

Inflammation Shapes the Transcriptional Landscape of the Bone Marrow Microenvironment in Post-Transplantation Leukemia Relapses

Allogeneic Hematopoietic Cell Transplantation (allo-HCT) represents the most successful therapeutic option for many patients suffering from Acute Myeloid Leukemia (AML). Nevertheless, leukemic cells often find means to evade control from the donor-derived immune system and re-emerge. To date, three alternative and frequent mechanisms by which AML cells modify their features and escape immune control have been described: genetic loss of the mismatched HLA haplotype (HLA loss), downregulation of HLA class II molecules and upregulation of inhibitory ligands, all ultimately leading to abolished leukemia recognition by T lymphocytes. However, increasing evidence suggests that leukemic cells weave a much broader net of interactions, involving several other immune cell types within the bone marrow microenvironment. Still, how this complex crosstalk between malignant cells and the bone marrow niche may shape the features of leukemia post-transplant relapse remains unknown. By exploiting the high resolution provided by single-cell RNA-sequencing (scRNA-seq), we provide a detailed insight of the human bone marrow immune microenvironment and the changes that occur following allo-HCT, both when disease reemergence is prevented, and when it occurs. Using cryopreserved BM aspirates, we profiled a total of 145,420 mononuclear cells from 25 adult AML patients at the time of disease relapse; 56,831 cells from 5 post-transplant patients in complete remission (CR), each tested at two different timepoints (+90 and +365 days) and 45,279 cells from 6 healthy controls (HC). First, scRNA-seq allowed us to recapitulate known leukemia-intrinsic features of each relapse modality, such as HLA loss, down-regulation of HLA class II molecules and upregulation of inhibitory T cell ligands. Moreover, combining genotype and Copy Number Variation (CNV) inference algorithms, we were able to separate malignant cells from their healthy counterparts. Interestingly, HLA loss relapses exhibited a more immature profile, with a significantly higher leukemia stem cell signature (LSC17) (p-value < 0.0001, Wilcoxon rank-sum test) (Ng SW et al., Nature 2016), hinting that the hematopoietic cell of origin impacts on the mechanism of post-transplantation relapse. Leukemic cells also featured a high inflammation-associated gene score (iScore) (Lasry A et al., Nat Cancer 2023), as also evident in non-malignant HSPCs from relapsed patients, which showed an increased IFN-α signature compared to HC and CR. However, AML samples that couldn't be categorized by a known mechanism of relapse displayed a significantly lower iScore, suggesting that leukemia escape in these patients might not have had an immune-related driver (Figure 1a). We next sought to characterize specific BM immune compartments. We overall detected a lower frequency of CD4 T cells in relapsed patients as compared to HC and CR patients (p-value = 0.04, Wilcoxon rank-sum test). We annotated 5 major Natural Killer (NK) cell clusters (immature CD56 dim, mature CD56 dim, CD56 bright, proliferating NK, NKT cells) and a smaller subset of immature CD56 bright NK cells characterized by higher expression of IFN-related genes and NK exhaustion markers, which was defined as inflamed NK cluster. Inflamed NK cells were more represented in patients with upregulation of T cell inhibitory ligands compared to other relapsed patients (5.42% of total NK vs. 0.74%, respectively. p-value = 0.03, Wilcoxon rank-sum test), thus suggesting a shared mechanism of dysfunction signature between T and NK cell that may favor leukemia immune evasion (Figure 1b). In conclusion, we generated a comprehensive atlas of the BM immune microenvironment in AML post-transplantation relapses, showing that inflammation shapes immune subset composition and transcriptional profile in the BM, and that leukemia mechanisms of immune evasion are influenced by the surrounding milieu. Overall, while an in depth understanding of whether leukemia relapse is caused by an inflamed microenvironment, or vice versa, might only be achieved through longitudinal sampling from patients before and after transplant, our results here exemplify how the BM niche could be exploited to find novel vulnerabilities in AML relapses, to be specifically targeted by personalized therapeutic approaches.

Genetic Subtype Driven Changes in Bone Marrow Stromal Cells of Children with B-Cell Precursor Acute Lymphoblastic Leukemia

Introduction We previously showed that B-cell precursor acute lymphoblastic leukemia (BCP-ALL) cells hijack the normal bone marrow microenvironment to create a leukemic niche which facilitates blast cell survival and promotes drug resistance [1-3]. Bone marrow-derived mesenchymal stromal cells (MSCs) are a major component of the bone marrow microenvironment . Ex vivo,these cells provide a survival benefit to co-cultured leukemic cells and induce resistance to chemotherapeutic drugs [1, 2]. We previously showed that leukemic cells re-sensitize to chemotherapeutics ex vivo when the interaction with MSCs is disrupted [2]. Results We here report that patients' BCP-ALL cells induce an Interferon (IFN)-related gene signature in patients'-derived MSCs; a.o. IFI6, MX1, and OAS3 were 4.3 to 7.7-fold upregulated in MSCs flow-sorted after co-culture with BCP-ALL cells compared to the same MSCs flow-sorted after mono-culture . BCP-ALL samples (n=15) with an ETV6-RUNX1 translocation (5 out of 8 samples) were the most potent inducers of the IFN-related gene expression signature in MSCs compared to B-other BCP-ALL (1 out of 6 samples), with IFI6 3.0-fold (p=0.03), MX1 2.6-fold(p=0.05) and OAS3 2.1-fold (p=0.04) higher in MSCs after co-culture with ETV6-RUNX1 BCP-ALL cells. Similarly, an ETV6-RUNX1cell line (REH) also induced this IFN-response more strongly in MSCs compared to cell lines representing other BCP-ALL subtypes (SUPB15, MUTZ5, RCH-ACV and NALM6). Addition of specific inhibitors to these ex vivo BCP-ALL and MSCs cultures, revealed that the ETV6-RUNX1 induced IFN signature was dependent on IFNα/β signaling, whereas no such effect was seen for inhibitors of IFNγ signaling. Additionally, inhibition of direct contact between BCP-ALL cells and MSCs also negatively affected the expression of some IFN responsive genes in MSCs ( CXCL10 3.3-fold, p=0.02, IFI44L 1.57-fold, p=0.01 and IFITM1 1.5-fold, p=0.005) while other genes remained unaltered, suggesting that the transcriptional changes in MSCs are driven by close contact with BCP-ALL cells and not by soluble factors released by these cells or those being part of the culture medium. Normal immune cells including various populations of T-cells, monocytes, NK cells and dendritic cells did not alter the expression levels of the IFN-related genes in MSCs. We also observed that, while MSCs provide a survival benefit to (ETV6-RUNX1) BCP-ALL cells and induce resistance to chemotherapeutic drugs (prednisolone, daunorubicin, L-asparaginase) in these leukemic cells, this was not counteracted by inhibition of IFNα/β signaling. Conclusion Our data show that leukemic cells, more specifically ETV6-RUNX1 positive BCP-ALL cells, induce an IFNα/β signature in MSCs. Activation of this IFNα/β pathway in MSCs does not cause resistance of BCP-ALL cells to chemotherapeutic drugs and hence the IFNα/β activation may serve a different role, e.g., affecting the migration (recruitment and/or repelling) of specific immune cells to the leukemic bone marrow niche. Our findings warrant further studies into the role of the BCP-ALL-induced IFNα/β response in chemotaxis of healthy immune cells to create a beneficial microenvironment for BCP-ALL cells. This knowledge might point to alternative, maybe less intensive ways to eradicate leukemic cells.

ADAM9 drives immunosuppressive environment for lung tumor progression

Abstract Cancer cells develop the immune suppressive tumor environment, but the underlying molecular mechanism for it is still elusive. Here, we demonstrated that ADAM9 contributed to lung tumor progression and promoted IFN-related gene expression in lung cancer cells that participated in immune regulation in the tumor environment. ADAM9 knockout (KO) lung cancer cells reduced lung cancer metastasis with a decrease in neutrophil infiltration and an increase in CD8+ T cell infiltration. By performing the genome-wide approach to explore ADAM9-regulated genes in lung cancer cells, we revealed that ADAM9 regulated cytokine production and lymphocyte activation. It enhanced the master transcription factor of IFN signaling, STAT1 activation in lung cancer cells. Moreover, ADAM9 promoted IL6/IL6 receptor-STAT3 axis signaling that lead to suppression of IL12p40 secretion and MHC class II expression in dendritic cells and macrophages. Notably, we found that type I IFN related-proteins and steroid biosynthesis-related proteins were related to ADAM9-mediated STAT signaling activation by LC-MS/MS analysis. We demonstrated that ADAM9 created an immune suppressive environment by regulating IFN signaling for tumor progression. Supported by grants from NHRI (NHRI-EX112-11219BI)

Anti-G protein antibodies targeting the RSV G protein CX3C chemokine region improve the interferon response.

Respiratory syncytial virus (RSV) is a poor inducer of antiviral interferon (IFN) responses which result in incomplete immunity and RSV disease. Several RSV proteins alter antiviral responses, including the non-structural proteins (NS1, NS2) and the major viral surface proteins, that is, fusion (F) and attachment (G) proteins. The G protein modifies the host immune response to infection linked in part through a CX3 C chemokine motif. Anti-G protein monoclonal antibodies (mAbs), that is, clones 3D3 and 2D10 that target the G protein CX3C chemokine motif can neutralize RSV and inhibit G protein-CX3CR1 mediated chemotaxis. Determine how monoclonal antibodies against the RSV F and G proteins modify the type I and III IFN responses to RSV infection. As the G protein CX3 C motif is implicated in IFN antagonism, we evaluated two mAbs that block G protein CX3C-CX3CR1 interaction and compared responses to isotype mAb control using a functional cellular assay and mouse model. Mouse lung epithelial cells (MLE-15 cells) and BALB/c mice were infected with RSV Line19 F following prophylactic mAb treatment. Cell supernatant or bronchoalveolar lavage fluid (BALF) were assayed for types I and III IFNs. Cells were interrogated for changes in IFN-related gene expression. Treatment with an anti-G protein mAb (3D3) resulted in improved IFN responses compared with isotype control following infection with RSV, partially independently of neutralization, and this was linked to upregulated SOCS1 expression. These findings show that anti-G protein antibodies improve the protective early antiviral response, which has important implications for vaccine and therapeutic design. RSV is a leading cause of respiratory disease in infants and the elderly. The only Food and Drug Administration-approved prophylactic treatment is limited to an anti-F protein monoclonal antibody (mAb), that is, palivizumab which has modest efficacy against RSV disease. Accumulating evidence suggests that targeting the RSV attachment (G) protein may provide improved protection from RSV disease. It is known that the G protein is an IFN antagonist, and IFN has been shown to be protective against RSV disease. In this study, we compared IFN responses in mouse lung epithelial (MLE-15) cells and in mice infected with RSV Line19 F treated with anti-G protein or anti-F protein mAbs. The levels of type I and III IFNs were determined. Anti-G protein mAbs improved the levels of IFNs compared with isotype-treated controls. These findings support the concept that anti-G protein mAbs mediate improved IFN responses against RSV disease, which may enable improved treatment of RSV infections.

Effects of Some Interferon-Related Proteins on Influenza A Viruse RNA Polymerase Activity

Interferons (IFNs) are one of the most important components of innate immunity against viruses, especially those carrying the RNA genomes such as influenza viruses. Upon viral infection, the IFNs are rapidly secreted, inducing the expression of several genes in the target cells and establishing an antiviral state. In this study, the effects of proteins encoded by some IFN-related genes on influenza A virus RNA-dependent RNA polymerase enzyme were investigated. We evaluated the importance of these proteins in the pathogenesis of different influenza A virus types. The IFN-related genes were amplified by polymerase chain reaction from the HEK293 cDNA library and cloned into pCHA expression vector. The expression of genes and subcellular localizations of the proteins were determined by Western blotting and immunofluorescence staining, respectively. The effects of IFNs-related proteins on virus RdRP enzyme were determined by influenza A virus mini-replicons. The study revealed that the influenza A virus infections significantly altered the transcript level of the IFN-related CCL5, IFIT1, IFIT3, IFITM3, and OAS1 genes in HEK293 cells. It was determined that the alteration of the gene expression was also related to the virus type. The mini-replicon assays showed that the transient expression of CCL5, IFI27, OAS1, IFITM3, IFIT1, and IFIT3 have inhibitory effects on WSN and/or DkPen type virus RdRP enzymes. We observed that the proteins except OAS1 inhibited WSN type RdRP enzyme at a higher level than that of DkPen enzyme. It was concluded that influenza A virus infection significantly alters the IFN-related gene expression in the cells. Most of the proteins encoded from these genes showed an inhibitory effect on the virus RdRP enzymes in the HEK293 cells. The inhibition of the influenza virus RdRP with IFN-related proteins may be the result of direct or indirect interactions between the host proteins and the viral enzyme subunits.

Metastatic Breast Carcinoma-Associated Fibroblasts Have Enhanced Protumorigenic Properties Related to Increased IGF2 Expression.

The microenvironment of metastatic breast cancer is incompletely characterized, despite prior evidence that it plays a key role in the biology of metastasis. A major component of the tumor stroma is the carcinoma-associated fibroblast (CAF), which has been shown to communicate with other stromal and cancer cells to create a protumorigenic milieu. Our study was designed to characterize human CAFs from different metastatic sites. We collected eight carcinoma-associated fibroblasts (mCAFs) from different metastatic sites and compared them with CAFs from primary tumors (pCAFs) and with normal breast fibroblasts (NFs). Molecular profiles and effects on breast cancer cell growth, on response to doxorubicin and on T-cell proliferation were compared. We observed marked differences in mCAFs compared with pCAFs and NFs with respect to in vitro proliferation and effects on breast cancer cell migration, spheroid growth, invasion, response to doxorubicin, and in vivo tumor growth. We found marked transcriptomic differences between mCAFs and pCAFs, including increased expression of IFN-related genes and IGF2 in the former. Cluster analysis revealed two groups of mCAFs, with the liver mCAFs clustering together, with increased PDGFA expression. Treatment with an antibody against insulin-like growth factors (BI836845) inhibited growth of mixed mCAF-tumor cell xenografts in vivo. Also, mCAFs had a suppressive effect on T-cell proliferation. This is the first comparative analysis of a set of CAFs from metastatic sites in breast cancer. It revealed a marked protumorigenic effect in these mCAFs, which occurs in part through increased expression of IGF2.

Screening for Antiviral Medaka Haploid Embryonic Stem Cells by Genome Wide Mutagenesis.

Nervous necrosis virus (NNV), one of the most prevalent fish pathogens, has caused significant losses in both yield and economy to the aquaculture. Host factors involved in NNV infection remain to be identified due to the lack of ideal model for the study of NNV and host interaction. Haploid stem cells have proven to be ideal materials in genetic screens. Here, we generated a cell line HX1G1 (simply named G1) with the activity against red-spotted grouper nervous necrosis virus (RGNNV) by N-ethyl-N-nitrosourea (ENU)-mediated whole genome random mutagenesis from the haploid embryonic stem cell HX1a, a cell clone from haploid cell line HX1 that we previously derived from the medaka fish. G1 cells retained the characteristics of haploidy and pluripotency as indicated by the EBs differentiation ability after genetic mutagenesis. Compared with HX1a cells, no typical cytopathic effects were observed, and the expression of RNA-dependent RNA polymerase (RDRP) was significantly reduced in G1 cells post RGNNV infection, indicating the enhanced anti-RGNNV activity of G1. Furthermore, we demonstrated that RGNNV entry into G1 cells was partially inhibited, and this inhibition might be relevant to the induced mutation of heat shock cognate protein 70 (HSC70) which was decisive for NNV entry. Interestingly, G1 cells were to some extent permissive to RGNNV infection, but RGNNV was spontaneously cleared in G1 cells during serial passage. In addition, we also found that the expression levels of interferon (IFN)-related genes were higher in G1 cells than those in HX1a cells, suggesting that viral clearance might be associated with the elevated expression of IFN-related genes in G1 cells.

The β4 subunit of Cav1.2 channels is required for an optimal interferon response in cardiac muscle cells.

The auxiliary β4 subunit of the cardiac Cav1.2 channel plays a poorly understood role in gene transcription. Here, we characterized the regulatory effects of the β4 subunit in H9c2 rat cardiac cells on the abundances of Ifnb mRNA [which encodes interferon-β (IFN-β)] and of the IFN-β-related genes Ddx58, Ifitm3, Irf7, Stat2, Ifih1, and Mx1, as well as on the abundances of the antiviral proteins DDX58, IRF7, STAT2, and IFITM3. Knocking down the β4 subunit in H9c2 cells reduced the expression of IFN-β-stimulated genes. In response to inhibition of the kinase JAK1, the abundances of β4 subunit mRNA and protein were decreased. β4 subunit abundance was increased, and it translocated to the nucleus, in cells treated with IFN-β, infected with dengue virus (DENV), or transfected with poly(I:C), a synthetic analog of double-stranded RNA. Cells that surrounded the virus-infected cells showed translocation of β4 subunit proteins to nuclei in response to spreading infection. We showed that the β4 subunit interacted with the transcriptional regulator IRF7 and that the activity of an Irf7 promoter-driven reporter was increased in cells overexpressing the β4 subunit. Last, overexpressing β4 in undifferentiated and differentiated H9c2 cells reduced DENV infection and decreased the abundance of the viral proteins NS1, NS3, and E-protein. DENV infection and poly(I:C) also increased the concentration of intracellular Ca2+ in these cells. These findings suggest that the β4 subunit plays a role in promoting the expression of IFN-related genes, thereby reducing viral infection.

Regarding “Transcriptional and Cytokine Profiles Identify CXCL9 as a Biomarker of Disease Activity in Morphea”

IFN-related pathways have not been studied in morphea, and biomarkers are needed. We sought to characterize morphea serum cytokine imbalance and IFN-related gene expression in blood and skin to address this gap by performing a case-control study of 87 participants with morphea and 26 healthy control subjects. We used multiplexed immunoassays to determine serum cytokine concentrations, performed transcriptional profiling of whole blood and lesional morphea skin, and used double-staining immunohistochemistry to determine the cutaneous cellular source of CXCL9. We found that CXCL9 was present at increased concentrations in morphea serum ( P r = 0.44, P = 0.0001), a validated measure of disease activity. CXCL9 gene expression was also increased in inflammatory lesional morphea skin (fold change = 30.6, P = 0.006), and preliminary transcriptional profiling showed little evidence for IFN signature in whole blood. Double-staining immunohistochemistry showed CXCL9 co-localized with CD68 + dermal macrophages. In summary, inflammatory morphea is characterized by T helper type 1 cytokine imbalance in serum, particularly CXCL9, which is associated with disease activity. CXCL9 expression in lesional macrophages implicates the skin as the source of circulating cytokines. CXCL9 is a promising biomarker of disease activity in morphea.

Transcriptional and Cytokine Profiles Identify CXCL9 as a Biomarker of Disease Activity in Morphea

IFN-related pathways have not been studied in morphea, and biomarkers are needed. We sought to characterize morphea serum cytokine imbalance and IFN-related gene expression in blood and skin to address this gap by performing a case-control study of 87 participants with morphea and 26 healthy control subjects. We used multiplexed immunoassays to determine serum cytokine concentrations, performed transcriptional profiling of whole blood and lesional morphea skin, and used double-staining immunohistochemistry to determine the cutaneous cellular source of CXCL9. We found that CXCL9 was present at increased concentrations in morphea serum (P < 0.0001), as were other T helper type 1 cytokines. CXCL9 serum concentration correlated with the modified Localized Scleroderma Skin Severity Index (r= 0.44, P= 0.0001), a validated measure of disease activity. CXCL9 gene expression was also increased in inflammatory lesional morphea skin (fold change= 30.6, P= 0.006), and preliminary transcriptional profiling showed little evidence for IFN signature in whole blood. Double-staining immunohistochemistry showed CXCL9 co-localized with CD68+ dermal macrophages. In summary, inflammatory morphea is characterized by T helper type 1 cytokine imbalance in serum, particularly CXCL9, which is associated with disease activity. CXCL9 expression in lesional macrophages implicates the skin as the source of circulating cytokines. CXCL9 is a promising biomarker of disease activity in morphea.

Dietary phytochemicals modulate skin gene expression profiles and result in reduced lice counts after experimental infection in Atlantic salmon.

BackgroundThe use of phytochemicals is a promising solution in biological control against salmon louse (Lepeophtheirus salmonis). Glucosinolates belong to a diverse group of compounds used as protection against herbivores by plants in the family Brassicaceae, while in vertebrates, ingested glucosinolates exert health-promoting effects due to their antioxidant and detoxifying properties as well as effects on cell proliferation and growth. The aim of this study was to investigate if Atlantic salmon fed two different doses of glucosinolate-enriched feeds would be protected against lice infection. The effects of feeding high dose of glucosinolates before the infection, and of high and low doses five weeks into the infection were studied.MethodsSkin was screened by 15 k oligonucleotide microarray and qPCR.ResultsA 25 % reduction (P < 0.05) in lice counts was obtained in the low dose group and a 17 % reduction in the high dose group compared to fish fed control feed. Microarray analysis revealed induction of over 50 interferon (IFN)-related genes prior to lice infection. Genes upregulated five weeks into the infection in glucosinolate-enriched dietary groups included Type 1 pro-inflammatory factors, antimicrobial and acute phase proteins, extracellular matrix remodeling proteases and iron homeostasis regulators. In contrast, genes involved in muscle contraction, lipid and glucose metabolism were found more highly expressed in the skin of infected control fish.ConclusionsAtlantic salmon fed glucosinolates had a significantly lower number of sea lice at the end of the experimental challenge. Feeding glucosinolates coincided with increased expression of IFN-related genes, and higher expression profiles of Type 1 immune genes late into the infection. In addition, regulation of genes involved in the metabolism of iron, lipid and sugar suggested an interplay between metabolism of nutrients and mechanisms of resistance.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1537-y) contains supplementary material, which is available to authorized users.

Apolipoprotein E genotype status affects habitual human blood mononuclear cell gene expression and its response to fish oil intervention.

People who carry the apolipoprotein E4 (APOE4) single nucleotide polymorphism have an increased risk of cardiovascular disease (CVD). Fish-oil supplementation may help in the prevention of CVD, though interindividual differences in the response to n-3 PUFAs have been observed. We aimed to assess the impact of APOE genotype on peripheral blood mononuclear cell whole genome gene expression at baseline and following a fish-oil intervention. Participants received 6 months of fish-oil supplementation containing 1800 mg of eicosapentaenoic acid and docosahexaenoic acid per day. APOE genotype and peripheral blood mononuclear cell whole genome gene expression before and after supplementation were measured. We characterized the differences in gene expression profiles in carriers of APOE4 (N = 8) compared to noncarriers (N = 15). At baseline, 1320 genes were differentially expressed and the fish-oil supplementation differentially regulated 866 genes between APOE4 carriers and noncarriers. Gene set enrichment analysis showed that carriers had a higher gene expression of cholesterol biosynthesis and IFN signaling pathways. Fish-oil supplementation reduced expression of IFN-related genes in carriers only. The increased expression of IFN signaling and cholesterol biosynthesis pathways might explain part of the association between APOE4 and CVD. Fish-oil supplementation may particularly benefit APOE4 carriers by decreasing expression of IFN-related genes.

Up-regulation of the interferon-related genes in BRCA2 knockout epithelial cells.

BRCA2 mutations are significantly associated with early-onset breast cancer, and the tumour-suppressing function of BRCA2 has been attributed to its involvement in homologous recombination (HR)-mediated DNA repair. In order to identify additional functions of BRCA2, we generated BRCA2-knockout HCT116 human colorectal carcinoma cells. Using genome-wide microarray analyses, we have discovered a link between the loss of BRCA2 and the up-regulation of a subset of interferon (IFN)-related genes, including APOBEC3F and APOBEC3G. The over-expression of IFN-related genes was confirmed in different human BRCA2(-/-) and mouse Brca2(-/-) tumour cell lines, and was independent of senescence and apoptosis. In isogenic wild-type BRCA2 cells, we observed over-expression of IFN-related genes after treatment with DNA-damaging agents, and following ionizing radiation. Cells with endogenous DNA damage because of defective BRCA1 or RAD51 also exhibited over-expression of IFN-related genes. Transcriptional activity of the IFN-stimulated response element (ISRE) was increased in BRCA2 knockout cells, and the expression of BRCA2 greatly decreased IFNα-stimulated ISRE reporter activity, suggesting that BRCA2 directly represses the expression of IFN-related genes through the ISRE. Finally, the colony-forming capacity of BRCA2 knockout cells was significantly reduced in the presence of either IFNβ or IFNγ, suggesting that IFNs may have potential as therapeutic agents in cancer cells with BRCA2 mutations. The GEO Accession No. for microarray analysis is GSE54830.

Major pathogenic steps in human lupus can be effectively suppressed by nucleosomal histone peptide epitope-induced regulatory immunity

Low-dose tolerance therapy with nucleosomal histone peptide epitopes blocks lupus disease in mouse models, but effect in humans is unknown. Herein, we found that CD4(+)CD25(high)FoxP3(+) or CD4(+)CD45RA(+)FoxP3(low) T-cells, and CD8(+)CD25(+)FoxP3(+) T-cells were all induced durably in PBMCs from inactive lupus patients and healthy subjects by the histone peptide/s themselves, but in active lupus, dexamethasone or hydroxychloroquine unmasked Treg-induction by the peptides. The peptide-induced Treg depended on TGFβ/ALK-5/pSmad 2/3 signaling, and they expressed TGF-β precursor LAP. Lupus patients' sera did not inhibit Treg induction. The peptide epitope-induced T cells markedly suppressed type I IFN related gene expression in lupus PBMC. Finally, the peptide epitopes suppressed pathogenic autoantibody production by PBMC from active lupus patients to baseline levels by additional mechanisms besides Treg induction, and as potently as anti-IL6 antibody. Thus, low-dose histone peptide epitopes block pathogenic autoimmune response in human lupus by multiple mechanisms to restore a stable immunoregulatory state.

FRI0263 Activation of the interferon pathway is dependent upon autoantibodies in african american sle patients, but not in european-american sle patients

BackgroundLupus is a heterogeneous autoimmune disease characterized by anti-RNA-binding protein autoantibodies and high circulating levels of interferon. The disease is more prevalent and more severe in African-Americans as compared to...

Expression of interferon-induced antiviral genes is delayed in a STAT1 knockout mouse model of Crimean-Congo hemorrhagic fever

BackgroundCrimean Congo hemorrhagic fever (CCHF) is a tick-borne hemorrhagic zoonosis associated with high mortality. Pathogenesis studies and the development of vaccines and antivirals against CCHF have been severely hampered by the lack of suitable animal model. We recently developed and characterized a mature mouse model for CCHF using mice carrying STAT1 knockout (KO).FindingsGiven the importance of interferons in controlling viral infections, we investigated the expression of interferon pathway-associated genes in KO and wild-type (WT) mice challenged with CCHF virus. We expected that the absence of the STAT1 protein would result in minimal expression of IFN-related genes. Surprisingly, the KO mice showed high levels of IFN-stimulated gene expression, beginning on day 2 post-infection, while in WT mice challenged with virus the same genes were expressed at similar levels on day 1.ConclusionsWe conclude that CCHF virus induces similar type I IFN responses in STAT1 KO and WT mice, but the delayed response in the KO mice permits rapid viral dissemination and fatal illness.

Microarray analysis on germfree mice elucidates the primary target of a traditional Japanese medicine juzentaihoto: acceleration of IFN-α response via affecting the ISGF3-IRF7 signaling cascade

BackgroundThe traditional Japanese medicine juzentaihoto (JTX) is a pharmaceutical grade multi-herbal medicine widely used for the prevention of cancer metastasis and infection in immuno-compromized patients in Japan. The effect of JTX has been supposed to be intimately affected by the immunological properties of host and enteric microflora. The influence of JTX on the gene expression profile in the large and small intestines was investigated by microarray analyses using mice of different strains with or without enteric microflora.ResultsIn all types of mice, including germfree (GF) animals, the genes most affected by two-week oral JTX treatment were the type 1 interferon (IFN)-related genes including Stat1, Isgf3g and Irf7, which play a critical role in the feedback loop of IFN-α production cascade. In IQI specific pathogen free (SPF) mice JTX increased the steady state level of the expression of IFN-related genes, but had the opposite effect in IQI GF and BALB/c SPF mice. Promoter analysis suggests that tandem repeated $IRFF (the promoter sequences for interferon regulatory factors) may be a primary target for JTX action. Pre-treatment of JTX accelerated the effects of an oral IFN "inducer" 2-amino-5-bromo-6-methyl-4-pyrimidinol (ABMP) (up-regulation of IFN-α production in IQI strain and down-regulation in BALB/c mice), which is in good accordance with the effect of JTX on gene expression of type 1 IFN-related genes.ConclusionsMicroarray analysis revealed that the target of JTX might be the transcription machinery regulating the steady-state level of genes involved in the ISGF3-IRF7 cascade, whose effect is bi-directional in a strain- and microbiota-dependent manner.

Rheumatoid arthritis subgroup with type I interferon signature: Comment on the article by Thurlings et al

To the Editor: Thurlings and colleagues recently reported that the presence of a type I interferon (IFN) signature in patients with rheumatoid arthritis (RA) is predictive of a decreased clinical response to rituximab treatment (1). Similarly, Sekiguchi et al reported that the emergence of IFN-related gene expression in RA patients is associated with a dampened response to the tumor necrosis factor (TNF) inhibitor infliximab (2). There is thus an emerging body of evidence highlighting the important role of IFN in the determination of clinical response to certain therapeutic agents in RA. A hallmark of RA is juxtaarticular bone erosion mediated by stimulated osteoclasts. The development of osteoclasts requires the presence of RANKL and macrophage colonystimulating factor, and is enhanced by interleukin-1 (IL-1), IL-6, and TNF (3). Interestingly, IFN inhibits osteoclast formation (4,5), raising the possibility that the joint erosive process might be retarded in the RA subgroup with a type I IFN signature. This hypothesis is supported by observations in systemic lupus erythematosus, a disease in which IFN is a key cytokine and the associated polyarthritis is typically nonerosive (6). Further, in the study by Thurlings et al, patients with the type I IFN signature had lower baseline disease activity, despite a dampened response to treatment as measured by the 28-joint Disease Activity Score (7). Although it is not entirely clear if the type I IFN signature emerges as a result of treatment with biologic agents or if it represents an additional immunologic event in this RA subset, the presence of type I IFN might contribute, in part, to the difference in disease activity between responders and nonresponders in both studies. Therefore, this RA subgroup with the type I IFN signature might benefit from additional antimalarial treatment, as this decreases IFN production (8). It would be crucial to investigate both the progression of the joint destruction and the responsiveness to antimalarial treatment in this RA subgroup with a type I IFN signature. The answer would provide a biologic rationale for the use of antimalarial drugs in RA as well.

Host immune-related gene responses against highly pathogenic avian influenza virus infection in vitro differ among chicken cell lines established from different organs

Highly pathogenic avian influenza virus (HPAIV) induces acute disease in chickens causing high mortality and morbidity and is a major threat to poultry industries in Southeast Asian countries. The mechanisms of disease manifestation and host innate immune responses against HAPIV in chickens are not well understood. In this study, we examined virus replication and host gene expressions in four chicken cell lines in vitro to elucidate the impact of host innate immune responses against viral replication. It was demonstrated that viral replication efficiencies were different depending on the cell line. The viral replication appeared to be affected by the basal expression of IFN related genes. The expression of immune-related genes against the viral infection also varied in a cell line dependent manner. In non-immune derived cell lines, but not in immune derived cell lines, the expression of the CCL5 and CCL20 genes were induced by HPAIV infection. Reverse genetics HPAIV, with internal genes from avirulent avian influenza, reduced virus replication and affected immune-related gene expression in a cell line dependent manner. These results suggest the possibility that differential immune responses in different cell types in local tissues could modulate the consequences of HPAIV infection in chickens.

Mycobacterium tuberculosis Triggers Host Type I IFN Signaling To Regulate IL-1β Production in Human Macrophages

Mycobacterium tuberculosis is a virulent intracellular pathogen that survives in macrophages even in the presence of an intact adaptive immune response. Type I IFNs have been shown to exacerbate tuberculosis in mice and to be associated with disease progression in infected humans. Nevertheless, the mechanisms by which type I IFNs regulate the host response to M. tuberculosis infection are poorly understood. In this study, we show that M. tuberculosis induces an IFN-related gene expression signature in infected primary human macrophages, which is dependent on host type I IFN signaling as well as the mycobacterial virulence factor, region of difference-1. We further demonstrate that type I IFNs selectively limit the production of IL-1β, a critical mediator of immunity to M. tuberculosis. This regulation occurs at the level of IL1B mRNA expression, rather than caspase-1 activation or autocrine IL-1 amplification and appears to be preferentially used by virulent mycobacteria since avirulent M. bovis bacillus Calmette-Guérin (BCG) fails to trigger significant expression of type I IFNs or release of mature IL-1β protein. The latter property is associated with decreased caspase-1-dependent IL-1β maturation in the BCG-infected macrophages. Interestingly, human monocytes in contrast to macrophages produce comparable levels of IL-1β in response to either M. tuberculosis or BCG. Taken together, these findings demonstrate that virulent and avirulent mycobacteria employ distinct pathways for regulating IL-1β production in human macrophages and reveal that in the case of M. tuberculosis infection the induction of type I IFNs is a major mechanism used for this purpose.