Levels Of Interferon Alpha Research Articles

Acute Effect of MCRC on Selected Blood Parameters - A Placebo-controlled Acute Clinical Study

Acute clinical testing was performed on healthy human subjects to verify whether a single 150mg dose of a proprietary formula marketed under the trade name Mitochroma TM ” (MCRC) can actually increase blood levels of ATP. Sera and blood were collected immediately prior to treatment and at times 30, 60, and 90 minutes after treatment to measure amounts of blood ATP, lactate, ROS, and pO2. Additionally, whole blood was collected at 270 minutes after treatment to measure expression of selected cytokines and chemokines. In comparison to the placebo group, samples collected from subjects treated with MCRC showed increased levels of total blood ATP by 12.5% on average and reduced levels of lactate up to 13%. Blood levels of ROS and pO2 were found unchanged under these experimental conditions. Analyses of blood collected at 270 minutes showed reduced levels of MCP-1 by up to 21%, and increased levels of Interferonalpha up to 16%. In summary, collected data shows that treatment with a single dose of MCRC resulted in an acute increase in blood levels of total blood ATP. These results justify further clinical studies on MCRC in order to determine the effects on a more narrowly selected subject population with reduced blood levels of ATP and increased blood levels of MCP-1.

The NK Cell Response to Mouse Cytomegalovirus Infection Affects the Level and Kinetics of the Early CD8+T-Cell Response

Natural killer (NK) cells and CD8(+) T cells play a prominent role in the clearance of mouse cytomegalovirus (MCMV) infection. The role of NK cells in modulating the CD8(+) T-cell response to MCMV infection is still the subject of intensive research. For analyzing the impact of NK cells on mounting of a CD8(+) T-cell response and the contribution of these cells to virus control during the first days postinfection (p.i.), we used C57BL/6 mice in which NK cells are specifically activated through the Ly49H receptor engaged by the MCMV-encoded ligand m157. Our results indicate that the requirement for CD8(+) T cells in early MCMV control inversely correlates with the engagement of Ly49H. While depletion of CD8(+) T cells has only a minor effect on the early control of wild-type MCMV, CD8(+) T cells are essential in the control of Δm157 virus. The frequencies of virus epitope-specific CD8(+) T cells and their activation status were higher in mice infected with Δm157 virus. In addition, these mice showed elevated levels of alpha interferon (IFN-α) and several other proinflammatory cytokines as early as 1.5 days p.i. Although the numbers of conventional dendritic cells (cDCs) were reduced later during infection, particularly in Δm157-infected mice, they were not significantly affected at the peak of the cytokine response. Altogether, we concluded that increased antigen load, preservation of early cDCs' function, and higher levels of innate cytokines collectively account for an enhanced CD8(+) T-cell response in C57BL/6 mice infected with a virus unable to activate NK cells via the Ly49H-m157 interaction.

Respiratory Syncytial Virus Glycoprotein G Interacts with DC-SIGN and L-SIGN To Activate ERK1 and ERK2

Respiratory syncytial virus (RSV) interaction with epithelial and dendritic cells (DCs) is known to require divalent cations, suggesting involvement of C-type lectins. RSV infection and maturation of primary human DCs are reduced in a dose-dependent manner by EDTA. Therefore, we asked whether RSV infection involves DC-SIGN (CD209) or its isoform L-SIGN (CD299) (DC-SIGN/R). Using surface plasmon resonance analysis, we demonstrated that the attachment G glycoprotein of RSV binds both DC- and L-SIGN. However, neutralization of DC- and L-SIGN on primary human DCs did not inhibit RSV infection, demonstrating that interactions between RSV G and DC- or L-SIGN are not required for productive infection. Thus, neither DC- nor L-SIGN represents a functional receptor for RSV. However, inhibition of these interactions increased DC activation, as evidenced by significantly higher levels of alpha interferon (IFN-α), MIP-1α, and MIP-1β in plasmacytoid DCs (pDCs) exposed to RSV after neutralization of DC-and L-SIGN. To understand the molecular interactions involved, intracellular signaling events triggered by purified RSV G glycoprotein were examined in DC- and L-SIGN-transfected 3T3 cells. RSV G interaction with DC- or L-SIGN was shown to stimulate ERK1 and ERK2 phosphorylation, with statistically significant increases relative to mock-infected cells. Neutralization of DC- and L-SIGN reduced ERK1/2 phosphorylation. With increased DC activation following DC- and L-SIGN neutralization and RSV exposure, these data demonstrate that the signaling events mediated by RSV G interactions with DC/L-SIGN are immunomodulatory and diminish DC activation, which may limit induction of RSV-specific immunity.

Defects in DNA degradation revealed in crystal structures of TREX1 exonuclease mutations linked to autoimmune disease

Mutations within the human TREX1 3′ exonuclease are associated with Aicardi-Goutières Syndrome (AGS) and familial chilblain lupus (FCL). Both AGS and FCL are autoimmune diseases that result in increased levels of interferon alpha and circulating antibodies to DNA. TREX1 is a member of the endoplasmic reticulum (ER)-associated SET complex and participates in granzyme A-mediated cell death to degrade nicked genomic DNA. The loss of TREX1 activity may result in the accumulation of double-stranded DNA (dsDNA) degradation intermediates that trigger autoimmune activation. The X-ray crystal structures of the TREX1 wt apoprotein, the dominant D200H, D200N and D18N homodimer mutants derived from AGS and FCL patients, as well as the recessive V201D homodimer mutant have been determined. The structures of the D200H and D200N mutant proteins reveal the enzyme has lost coordination of one of the active site metals, and the catalytic histidine (H195) is trapped in a conformation pointing away from the active site. The TREX1 D18N and V201D mutants are able to bind both metals in the active site, but with inter-metal distances that are larger than optimal for catalysis. Additionally, all of the mutant structures reveal a reduced mobility in the catalytic histidine, providing further explanation for the loss of catalytic activity. The structures of the mutant TREX1 proteins provide insight into the dysfunction relating to human disease. Additionally, the TREX1 apoprotein structure together with the previously determined wild type substrate and product structures allow us to propose a distinct mechanism for the TREX1 exonuclease.

Different Mutations inThree Prime Repair Exonuclease 1andRibonuclease H2Genes Affect Clinical Features in Aicardi-Goutières Syndrome

Aicardi-Goutières syndrome is a rare encephalopathy of mutational origin characterized by increased levels of interferon alpha in cerebrospinal fluid. The aim of this study was to explore the influence of different Aicardi-Goutières syndrome genotypes on the clinical course of patients, seeking to identify specific gene expression profiles able to explain Aicardi-Goutières syndrome phenotype differences. We detected the occurrence of Aicardi-Goutières syndrome mutations in 21 patients and compared microarray gene-expression data of cerebrospinal fluid lymphocytes with clinical variables. The levels of interferon alpha in cerebrospinal fluid were high in all patients; we found differences in the expression of genes encoding for Toll-like receptor, endogenous RNases, T lymphocyte activation, angiogenesis inhibition, and peripheral interferon alpha production. These results indicate that further to interferon alpha production in the central nervous system, a variety of other pathogenic mechanisms is activated in Aicardi-Goutières syndrome to various degrees in different patients, thus explaining the interindividual difference in Aicardi-Goutières syndrome course.

Serum interferon-alpha level in first degree relatives of systemic lupus erythematosus patients: Correlation with autoantibodies titers

Background and objectives Interferon-α (IFN-α), a cytokine with both antiviral and immune-regulatory functions, was suggested as a useful tool which can evaluate current systemic lupus erythematosus (SLE) disease activity and identify patients who are at risk of future disease flares. In the current study, serum IFN-α levels and associated demographic, and serological features in Egyptian SLE patients and their first degree relatives (FDRs) in comparison to unrelated healthy controls (UHCs) were examined, in order to identify individuals at the greatest risk for clinical illness. Methods In a cross-sectional study, blood samples were drawn from 54 SLE patients, 93 of their FDRs who consented to enroll into the study and 76 UHCs. Measurement of serum IFN-α by a modified ELISA was carried out. Data were analyzed for associations of serum IFN-α levels with autoantibodies titer. Results Mean serum IFN-α in FDRs was statistically higher than the UHCs and lower than in SLE patients ( P < 0.0001) and it was correlated with ANA titer ( r = 0.6, P < 0.0001) and anti ds DNA titer ( r = 0.62, P < 0.0001). Conclusion IFN-α is a crucial player in the complicated autoimmune changes that occur in SLE and serum IFN-α can be a useful marker identifying persons who are at risk of future disease development.

Mycobacterium tuberculosis Culture Filtrate Protein 10-Specific Effector/Memory CD4+and CD8+T Cells in Tubercular Pleural Fluid, with Biased Usage of T Cell Receptor Vβ Chains

T cell-mediated immunity is critical for the control of Mycobacterium tuberculosis infection. Identifying the precise immune mechanisms that lead to control of initial M. tuberculosis infection and preventing reactivation of latent infection are crucial for combating tuberculosis. However, a detailed understanding of the role of T cells in the immune response to infection has been hindered. In addition, there are few flow cytometry studies characterizing the Vβ repertoires of T cell receptors (TCRs) at local sites of M. tuberculosis infection in adult tuberculosis. In this study, we used culture filtrate protein 10 (CFP-10) from M. tuberculosis to characterize T cells at local sites of infection. We simultaneously analyzed the correlation of the production of cytokines with TCR Vβ repertoires in CFP-10-specific CD4(+) and CD8(+) T cell subsets. For the first time, we demonstrate that CFP-10-specific CD4(+) or CD8(+) T cells from tubercular pleural fluid can produce high levels of gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α) and upregulate the expression of CD107a/b on the cell surface. The CFP-10-specific cells were effector/memory cells with a CD45RO(+) CD62L(-) CCR7(-) CD27(-) expression profile. In addition, we found CFP-10-specific CD4(+) and CD8(+) T cells in tubercular pleural fluid, with biased usage of TCR Vβ9, Vβ12, or Vβ7.2. Our findings of CFP-10-specific CD4(+) and CD8(+) T cells in tubercular pleural fluid are critical for understanding the mechanisms of the local cellular immune response and developing more effective therapeutic interventions in cases of M. tuberculosis infection.

The Aicardi–Goutières syndrome. Molecular and clinical features of RNAse deficiency and microRNA overload

Intracellular RNAses are involved in various functions, including microRNA maturation and turnover. Mutations occurring in genes encoding RNAses cause Aicardi–Goutiéres syndrome (AGS). AGS mutations silence RNAse activity, thus inducing accumulation of endogenous RNAs, mainly consisting of short RNAs and microRNAs. Overload of intracellular RNA triggers Toll like receptor-dependent interferon-alpha production in the brain, which in turn activates neurotoxic lymphocytes and inhibits angiogenesis thus inducing the typical clinical phenotype of AGS. However, these pathogenic mechanisms are attenuated after three years of age by the endogenous production of DNAJP58IPK and Cystatin F, which arrest AGS progression. Because RNAses are involved in microRNA turnover, we evaluated the expression of 957 microRNAs in lymphocytes from AGS patients and control patients. Our results indicate that microRNA overload occurs in AGS patients. This upregulation inhibits microRNA turnover impeding the synthesis of the novel microRNAs required for the differentiation and myelination of the brain during the initial period of postnatal life. These pathogenic mechanisms result in AGS, a neurological syndrome characterized by irritability, mild hyperpyrexia, pyramidal and extrapyramidal signs, and spastic-dystonic tetraplegia. Typical cerebrospinal fluid alterations include lymphocytosis and elevated interferon-alpha levels. Brain imaging demonstrates cerebral calcifications, white matter abnormalities, and progressive cerebral atrophy.Thus, evidence exists that mutations silencing intracellular RNases affect microRNA turnover resulting in the severe clinical consequences in the brain characterizing the clinical feature of AGS.

Interferon alpha causes SLE by expanding CD4- CD8- double negative T cell (44.25)

Abstract Objective: It has been hypothesized that high interferon alpha (IFNα) levels cause systemic lupus erythematosus (SLE), however, the direct proof for this is lacking. We have shown that sole increase of interferon alpha (IFNα) in doxycycline (Dox)-inducible transgenic (IFNα Tg) mice induces production of anti-dsDNA antibody and renal disease akin to human SLE. In this study, we have investigated how IFNα functions and to what extent IFNα operates in the pathogenesis of SLE. Methods: We made C57BL6/FVBN TetOp-mIFNα/EμSR-tTA transgenic female mice in which IFNα was expressed after the cessation of Dox. We transferred CD4+ (5x106), CD8+ (5x106) and CD4- CD8- double negative (DN) T (3x105) subsets derived from 30 weeks Dox-off IFNα Tg mice into naive recipient mice twice. In additional experiment, CD4+ (8x106), CD8+ (8x106) and DN T (9x105) subsets were transferred. Anti-dsDNA antibody, serum IC, proteinuria and renal lesion of recipient mice were evaluated. Results: Transfer of DN T (3x105) subset of Dox-off IFNα Tg mice induced IC-mediated mesangio-proliferative glomerulonephritis. However, there were no increases in anti-dsDNA antibody, serum IC nor proteinuria after the transfer of DN T (9x105) subset. It was, however, noted that alopecia, was developed by transfer of DN T (9x105) subset. Conclusion: DN T cell is responsible for the induction of lupus glomerulonephritis and alopecia.

232 Plasmacytoid Dendritic Cells Accumulate and Secrete Interferon Alpha in Lymph Nodes of Chronically Infected, Treatment-Naïve HIV-1 Patients

During the chronic phase of HIV-1 infection, circulating plasmacytoid dendritic cells (pDC) progressively decline, and express higher interferon alpha (IFNα) levels, which is associated with disease progression. To elucidate the fate and function of pDC during chronic, untreated HIV-1 infection, we analyzed the expression levels and function of several tissue-homing markers on circulating pDC from HIV-1 patients (n = 17) and uninfected controls (n = 11). We also determined pDC frequency, expression levels of activation/maturation markers and IFNα, and the rate of cell death of pDC in lymph nodes untreated HIV-1 patients (n = 18) and healthy controls (n = 11). We found significantly higher CCR7 and CD62L (p<0.05) and CD103 (p<0.01) levels on circulating pDC from HIV-1 patients. All other markers were unchanged. Higher CCR7 levels led to increased migration in response to CCR7 ligands (p<0.01). In addition, higher CCR7 levels and migratory potential correlated directly with HIV-1 viremia (p<0.001, r = 0.79; and p = 0.01, r = 0.7), and inversely with pDC frequency in blood (p = 0.008, r = -0.6; and p = 0.04, r = -0.69). We also found and accumulation of pDC in LN of HIV-1 patients (p = 0.002). LN-homed pDC of HIV-1 patients expressed higher CD40 (p<0.0001), lower BDCA2 (p<0.03), but stable 83 and CD86 levels (p>0.05). Moreover, these cells secreted markedly higher IFNα levels compared to controls (p<0.01), which correlated with higher rates of cell death (p = 0.04, r = 0.48). These results demonstrate that untreated HIV-1 infection is characterized by elevated CCR7 and CD62L expression on circulating pDC, which relocate to lymph nodes, acquire an activated but immature phenotype, and express elevated amounts of IFNα before undergoing cell death. Chronic IFNα expression in lymph nodes of HIV-1 patients may impair differentiation and immune function of bystander CD4+ T cells, contributing to the mechanisms of pathogenesis.

Enhanced in vivo immunity and protection provided by cationic lipid-DNA complex adjuvanted influenza vaccination is independent of Toll-like receptor 9 (106.16)

Abstract As current licensed influenza vaccines provide little or no cross-protective immunity, we have pursued using cationic lipid-DNA complex (CLDC) adjuvant to boost adaptive immunity to inactivated influenza vaccines. CLDC consists of a non-coding plasmid DNA, rich in immunostimulatory CpG motifs, which is encapsulated in cationic lipids. Previous murine and non-human primate studies showed that CLDC adjuvanted influenza vaccination induced more robust immunity and cross-protection. We hypothesized that the CLDC plasmid mediates these effects, at least in part, in a TLR9-dependent manner. Bone-marrow derived dendritic cells (BMDCs) incubated in vitro with CLDC secreted high levels of interferon-alpha (IFN-α), and this induction required CLDC’s DNA component. CLDC-induced IFN-α expression was significantly reduced using TLR9-/- BMDCs. We next vaccinated wildtype and TLR9-/- mice with CLDC-adjuvanted inactivated influenza vaccines. Surprisingly, CLDC’s immunostimulatory responses in vivo were TLR9-independent in that there was no significant difference between wildtype and knockouts for either vaccine immunogenicity (influenza-specific antibody and T-cell responses) or for cross-protection after viral challenge. These studies suggest that the DNA moiety of CLDC enhances immune responses in vivo by a novel, TLR9-independent mechanism. Determining this mechanism will likely be important in the optimal application of CLDC as an adjuvant to human vaccination.

Pandemic H1N1 influenza virus causes a stronger inflammatory response than seasonal H1N1 influenza virus in ferrets

A 2009 H1N1 influenza virus pandemic, which had its origin in swine, caused severe illness and mortality in humans. Inflammatory responses may be responsible for pathogenesis caused by infection with influenza viruses. To better understand the pathogenic mechanism, clinical signs and inflammatory responses in ferrets infected with the pandemic H1N1 were compared with those caused by seasonal H1N1 influenza virus. Ferrets infected with the 2009 pandemic H1N1 virus displayed higher body temperatures, greater reduction in body weight, and higher viral titers in the tracheae and lungs. Levels of inflammatory cytokines, including interleukin-6, interferon-alpha, and tumor necrosis factor-alpha, were higher in the lungs of ferrets infected with the 2009 pandemic H1N1. The data support the idea that increased pathogenesis caused by the 2009 pandemic H1N1 influenza virus may have been partially mediated by a higher induction of pro-inflammatory cytokines in the lungs of affected humans or animals.

Clinical Utility of Serum Interleukin-8 and Interferon-Alpha in Thyroid Diseases

Serum interleukin-8 (IL-8) and interferon-alpha (IFN-α) levels have been estimated from a total of 88 individuals of which 19 were disease-free healthy individuals, and 69 were patients with thyroid diseases: goitre (N = 21), autoimmune diseases (N = 16), and carcinomas (N = 32). Both IL-8 and IFN-α were significantly higher in all the patients as compared to healthy individuals. Serum IL-8 levels showed significant positive correlation with disease stage in thyroid cancer patients. Higher serum IL-8 levels were associated with advanced disease stage while no significant correlation was observed between serum IFN-α levels and any of the clinicopathological parameters. IL-8 and IFN-α significantly correlated with each other in anaplastic carcinoma patients. Finally concluding, monitoring the serum IL-8 and IFN-α levels can help differentiate patients with thyroid diseases from healthy individuals, and IL-8 seems to have a role in the pathogenesis of thyroid diseases and may represent a target for innovative diagnostic and therapeutic strategies.

Association of Profoundly Impaired Immune Competence in H1N1v‐Infected Patients with a Severe or Fatal Clinical Course

Pandemic A/H1N1v influenza is characterized by a mild clinical course. However, a small subset of patients develops a rapidly progressive course caused by primary viral pneumonia or secondary bacterial infections that, in many cases, lead to death due to respiratory failure. The aim of the present study was to analyze the involvement of the immune response in the clinical presentation of H1N1v influenza. The differentiation and functional capability of T cells from H1N1v-infected patients presenting with either mild disease (n=22) or severe or fatal disease (n=6) were compared. Moreover, plasma cytokines and chemokines were quantified. T cells from H1N1v-infected patients presenting with a severe clinical course resulted in impaired effector cell differentiation and failed to respond to mitogenic stimulation. T cell anergy was strictly associated with a severe acute phase of infection, but T cells could be restored in patients able to recover. Of interest, massive expression of CD95 marker was found on anergic T cells, suggesting an apoptosis-related mechanism. Finally, lower plasma levels of interferon-alpha and monocyte chemoattractant protein-1 were found in patients with a worse clinical course of influenza, suggesting impaired production of these cytokines. Our results show a strict association between host immune competence and the severity of the clinical course of H1N1v infection. By monitoring host functional response, patients with an enhanced risk of developing influenza-associated severe complications could be identified in a timely manner.

Plasmacytoid Dendritic Cells Accumulate and Secrete Interferon Alpha in Lymph Nodes of HIV-1 Patients

Circulating plasmacytoid dendritic cells (pDC) decline during HIV-1 infection, but at the same time they express markedly higher levels of interferon alpha (IFNα), which is associated with HIV-1 disease progression. Here we show an accumulation of pDC in lymph nodes (LN) of treatment-naïve HIV-1 patients. This phenomenon was associated with elevated expression of the LN homing marker, CCR7, on pDC in peripheral blood of HIV-1 patients, which conferred increased migratory capacity in response to CCR7 ligands in ex vivo functional assays. LN-homed pDC of HIV-1 patients presented higher CD40 and lower BDCA2 levels, but unchanged CD83 and CD86 expression. In addition, these cells expressed markedly higher amounts of IFNα compared to uninfected individuals, and were undergoing faster rates of cell death. These results demonstrate for the first time that in asymptomatic, untreated HIV-1 patients circulating pDC up-regulate CCR7 expression, accumulate in lymph nodes, and express high amounts of IFNα before undergoing cell death. Since IFNα inhibits cell proliferation and modulates immune responses, chronically high levels of this cytokine in LN of HIV-1 patients may impair differentiation and immune function of bystander CD4+ T cells, thus playing into the mechanisms of AIDS immunopathogenesis.

Gene-Gene-Sex Interaction in Cytokine Gene Polymorphisms Revealed by Serum Interferon Alpha Phenotype in Juvenile Dermatomyositis

To detect genetic polymorphisms associated with high serum interferon alpha (IFN-alpha) levels in juvenile dermatomyositis (JDM) and explore interactions in associated polymorphisms. Eighty-five children of European ancestry with definite/probable JDM were studied. Selected genetic polymorphisms that were associated with high IFN-alpha levels in 12 untreated patients with newly diagnosed JDM were genotyped in a validation cohort of 73 children with JDM and analyzed for gene-gene and gene-sex interactions. Untreated children with newly diagnosed JDM carrying both the osteopontin (OPN) rs28357094G and tumor necrosis factor alpha (TNF-alpha)-308 A alleles had significantly increased serum IFN-alpha levels. These 2 polymorphisms were genotyped in the validation cohort, and the OPN rs28357094G allele was more common in female subjects with JDM (odds ratio=3.97, P=.012). This OPN allele was most strongly enriched in female carriers of TNF-alpha-308A as compared with male carriers of TNF-alpha-308A (odds ratio>9.0; P=7.2x10(-3)). These data support a complex gene-gene-sex interaction between the OPN and TNF-alpha promoter regions in JDM, defining a high serum IFN-alpha subgroup within JDM. This suggests pathogenic synergy between the OPN and TNF-alpha loci in female subjects with JDM, which may underlie some of the increased incidence of this condition in girls.

Epstein‐Barr virus promotes interferon‐α production by plasmacytoid dendritic cells

Epstein-Barr virus (EBV) infection has been linked to systemic lupus erythematosus (SLE), as demonstrated by the presence of increased seroprevalence and elevated viral loads, but the mechanism of this linkage has not been elucidated. Increased interferon-alpha (IFNalpha) levels and signatures, which are associated with innate immune responses, have been found in patients with SLE. Plasmacytoid dendritic cells (PDCs) are innate immune cells that mediate viral immunity by producing large quantities of IFNalpha, but the role they play during infection with EBV remains unclear. To address this issue, we investigated the ability of EBV to promote IFNalpha production by PDCs in healthy subjects. Human PDCs were sorted and cultured in the presence of EBV, EBV-encoded RNA, and EBV double-stranded DNA. IFNalpha production by PDCs was measured by enzyme-linked immunosorbent assay, with the activation of these cells measured by flow cytometry. We found that EBV DNA and RNA promoted IFNalpha production by human PDCs through engagement of Toll-like receptor 9 (TLR-9) and TLR-7, respectively, with the initial viral recognition by PDCs mediated by binding to class II major histocompatibility complex (MHC) molecules. These data demonstrate that class II MHC-specific engagement by virus, with subsequent viral nucleic acid recognition, mediates IFNalpha production by PDCs. Our results suggest that elevated levels of IFNalpha found in SLE patients may be a result of aberrantly controlled chronic viral infection.

Mutually Positive Regulatory Feedback Loop between Interferons and Estrogen Receptor-α in Mice: Implications for Sex Bias in Autoimmunity

BackgroundSystemic lupus erythematosus (SLE), an autoimmune disease, predominantly affects women of childbearing age. Moreover, increased serum levels of interferon-α (IFN-α) are associated with the disease. Although, the female sex hormone estrogen (E2) is implicated in sex bias in SLE through up-regulation of IFN-γ expression, the molecular mechanisms remain unknown. Here we report that activation of IFN (α or γ)-signaling in immune cells up-regulates expression of estrogen receptor-α (ERα; encoded by the Esr1 gene) and stimulates expression of target genes.Methodology/Principal FindingsWe found that treatment of mouse splenic cells and mouse cell lines with IFN (α or γ) increased steady-state levels of ERα mRNA and protein. The increase in the ERα mRNA levels was primarily due to the transcriptional mechanisms and it was dependent upon the activation of signal transducer and activator of transcription-1 (STAT1) factor by IFN. Moreover, the IFN-treatment of cells also stimulated transcription of a reporter gene, expression of which was driven by the promoter region of the murine Esr1 gene. Notably, splenic cells from pre-autoimmune lupus-prone (NZB × NZW)F1 female mice had relatively higher steady-state levels of mRNAs encoded by the IFN and ERα-responsive genes as compared to the age-matched males.Conclusions/SignificanceOur observations identify a novel mutually positive regulatory feedback loop between IFNs and ERα in immune cells in mice and support the idea that activation of this regulatory loop contributes to sex bias in SLE.

Interacting Roles of Immune Mechanisms and Viral Load in the Pathogenesis of Crimean-Congo Hemorrhagic Fever

Until now, the pathogenesis of Crimean-Congo hemorrhagic fever (CCHF) has not been well described. However, it has been hypothesized that it could be a result of the direct injury of virus-infected tissues in combination with the indirect effects of host immune responses, including cytokines. To shed more light on the role of viral load and cytokines, differential influences of CCHF virus (CCHFV) RNA load, antibody response, and cytokine production on severity and outcome of the disease were studied in sera of 46 patients with confirmed acute CCHF from Kosovo. In this study, viral load proved to be strongly related to the severity and outcome of the disease, with higher viral loads detected in patients with fatal outcomes than in surviving patients. Also, patients with fatal outcome had on average a weaker antibody response, if one was present at all. High levels of interleukin-10 (IL-10), gamma interferon (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha) were associated with poor outcome, since detected concentrations were highest in patients with fatal outcome and lowest in patients with moderate disease course. Additionally, a positive linear dependence between viral load and these cytokines was observed. Interestingly, reduced levels of IL-12 were detected in all CCHF patients. Our study favors the hypothesis that CCHF could be a result of a delayed and downregulated immune response caused by IL-10, which leads to an increased replication and spread of CCHFV throughout the body. This consequently triggers increased production of IFN-gamma and TNF-alpha, cytokines mediating vascular dysfunction, disseminated intravascular coagulation, organ failure, and shock.

Expanding the phenotypic spectrum of lupus erythematosus in Aicardi‐Goutières syndrome

Aicardi-Goutières syndrome (AGS) is an early-onset encephalopathy resembling congenital viral infection that is characterized by basal ganglia calcifications, loss of white matter, cerebrospinal fluid (CSF) lymphocytosis, and elevated interferon-alpha levels in the CSF. Studies have shown that AGS is an autosomal-recessive disease linked to mutations in 5 genes, encoding the 3'-repair DNA exonuclease 1 (TREX1), the 3 subunits of ribonuclease H2 (RNASEH2A-C), and sterile alpha motif domain and HD domain-containing protein 1 (SAMHD1). In this study we further characterized the phenotypic spectrum of this disease. Clinical and laboratory data were obtained from 26 patients fulfilling the clinical diagnostic criteria for AGS. Genomic DNA was screened for mutations in all 5 AGS genes by direct sequencing, and sera were analyzed for autoantibodies. In 20 patients with AGS, 20 mutations, 12 of which were novel, were identified in all 5 AGS genes. Clinical and laboratory investigations revealed a high prevalence of features (some not previously described in patients with AGS) that are commonly seen in patients with systemic lupus erythematosus (SLE), such as thrombocytopenia, leukocytopenia, antinuclear antibodies, erythematous lesions, oral ulcers, and arthritis, which were observed in 12 (60%) of 20 patients with AGS. Moreover, the coexistence of AGS and SLE, was for the first time, demonstrated in 2 patients with molecularly proven AGS. These findings expand the phenotypic spectrum of lupus erythematosus in AGS and provide further insight into its disease mechanisms by showing that activation of the innate immune system as a result of inherited defects in nucleic acid metabolism could lead to systemic autoimmunity.