Association between clinical features and course of systemic sclerosis and serum interleukin-8, vascular endothelial growth factor, basic fibroblast growth factor, and interferon alpha

BACKGROUND

Certain mediators, such as soluble growth factors and cytokines, among others, are implicated in the immunopathogenesis of systemic sclerosis (SSc).

OBJECTIVES

This study aimed to examine the association between serum levels of vascular endothelial growth factor (VEGF), interleukin-8 (IL-8), interferon alpha (IFN-α), and basic fibroblast growth factor (bFGF) and the clinical presentation and course of SSc.

MATERIAL AND METHODS

This longitudinal, observational study included 43 patients with SSc and 24 healthy subjects. Serum concentrations of VEGF, IL-8, IFN-α, and bFGF were measured at baseline in patients previously treated for SSc. Medical history of patients was analyzed retrospectively at the time of cytokine measurement to infer clinical correlations, and during follow-up for a median of 5 years, assessing the incidence of death or cancer.

RESULTS

The bFGF and IFN-α concentrations differed between SSc patients and controls (p < 0.01). In turn, organ involvement and SSc phenotypes did not impact studied cytokine concentrations, similar to systemic steroid and/or immunosuppressant use at enrollment. However, we have documented a positive correlation between the current oral steroid dose and serum levels of IL-8 and bFGF. Furthermore, patients with a VEGF level ≥95.7 pg/mL and IFN-α level ≥3.6 pg/mL required cyclophosphamide therapy more often, currently or in the past (approx. 3-fold and 4-fold, respectively). Substantially elevated VEGF and IFN-α concentrations at baseline were associated with higher cancer occurrence (n = 4) during follow-up, while elevated circulating IL-8 level was associated with an increased risk of death (n = 9).

CONCLUSIONS

The SSc group was characterized by higher serum concentrations of bFGF and IFN-α compared to healthy controls. Patients treated with cyclophosphamide or receiving higher systemic steroid doses, thus suffering from a more severe disease type, had increased cytokine levels. Elevated circulating IFN-α and VEGF levels might be correlated with cancer, whereas raised IL-8 levels may be associated with an increased risk of death. However, further research is needed to verify our findings.

The Expression Levels of TREX1 and IFN-α Are Associated with Immune Reconstitution in HIV-1-Infected Individuals

TREX1 acts in the initial prevention of an autoimmune response, but it may contribute to the permissiveness of retrovirus infections. This study investigated the association between the levels of TREX1 gene expression with the polymorphisms TREX1 rs3135941 (T/C) and TREX1 rs3135945 (G/A), and the presence of antinuclear antibodies (ANA) in antiretroviral therapy (ART)-naïve individuals and after 1 year of treatment. Blood samples from 119 individuals with HIV-1 were subjected to genotyping of polymorphisms and quantification of TREX1 gene expression and HIV-1 viral load by qPCR. The concentration of IFN-α and the number of CD4+/CD8+ T lymphocytes were determined by ELISA and flow cytometry, respectively; ANA was investigated by immunofluorescence. A control group of 167 seronegative individuals was used for the comparison of genotypic frequencies. The frequency of the polymorphisms were not associated with HIV infection or with variations in the expression of TREX1 and IFN-α (p > 0.05). ART-naïve individuals exhibited higher TREX1 expression and lower IFN-α expression. After 1 year of ART, TREX1 levels were reduced, while IFN-α and CD4+ T lymphocytes were elevated (p < 0.05). Some individuals on ART presented ANA. These results suggest that ART-mediated restoration of immune competence is associated with a reduction in TREX1 expression, which may induce the development of ANA, regardless of the polymorphism investigated.

Monocytes are the main source of STING-mediated IFN-α production

BACKGROUND

Type I interferon (IFN-I) production by plasmacytoid dendritic cells (pDCs) occurs during viral infection, in response to Toll-like receptor 7 (TLR7) stimulation and is more vigorous in females than in males. Whether this sex bias persists in ageing people is currently unknown. In this study, we investigated the effect of sex and aging on IFN-α production induced by PRR agonist ligands.

METHODS

In a large cohort of individuals from 19 to 97 years old, we measured the production of IFN-α and inflammatory cytokines in whole-blood upon stimulation with either R-848, ODN M362 CpG-C, or cGAMP, which activate the TLR7/8, TLR9 or STING pathways, respectively. We further characterized the cellular sources of IFN-α.

FINDINGS

We observed a female predominance in IFN-α production by pDCs in response to TLR7 or TLR9 ligands. The higher TLR7-driven IFN-α production in females was robustly maintained across ages, including the elderly. The sex-bias in TLR9-driven interferon production was lost after age 60, which correlated with the decline in circulating pDCs. By contrast, STING-driven IFN-α production was similar in both sexes, preserved with aging, and correlated with circulating monocyte numbers. Indeed, monocytes were the primary cellular source of IFN-α in response to cGAMP.

INTERPRETATION

We show that the sex bias in the TLR7-induced IFN-I production is strongly maintained through ages, and identify monocytes as the main source of IFN-I production via STING pathway.

FUNDING

This work was supported by grants from Région Occitanie/Pyrénées-Méditerranée (#12052910, Inspire Program #1901175), University Paul Sabatier, and the European Regional Development Fund (MP0022856).

Effect of pegylated interferon alfa-2a in HBeAg-negative chronic hepatitis B during and 48 weeks after off-treatment follow-up: the limitation of pre-treatment HBsAg load for the seroclearance of HBsAg

Hepatitis B virus (HBV) infection is a major public health problem worldwide. The study aimed to evaluate the efficacy of pegylated interferon (Peg-IFN) alfa-2a treatment for seroclearance of HBs antigen (HBsAg) in HBe antigen (HBeAg)-negative chronic hepatitis B (CHB) patients. This retrospective study investigated 16 HBeAg-negative CHB patients who received Peg-IFN alfa-2a weekly for 48 weeks. Thereafter, the patients were followed-up for 48 weeks after the end of therapy. The following criteria were also used for inclusion: HBV-DNA < 5.0 log copies/mL and without nucleot(s)ide analogs. Four HBsAg-positive cases became HBsAg negative. The HBsAg levels of the 4 patients who achieved HBsAg seroclearance were lower significantly than that of the non-seroclearance group (p = 0.007). The mean HBsAg levels in these 4 cases were 68 IU/mL, while the mean HBsAg levels in the non-seroclearance group were 2,114 IU/mL. The mean HBV-DNA levels in the 4 HBsAg seroclearance cases were 2.8 log copies/mL as compared to 3.6 log copies/mL in HBsAg-non-seroclearance cases (p = 0.01). Cases that are HBeAg negative, with HBV-DNA levels < 5 log copies/mL, and HBsAg titers < 120 IU/mL cases may achieve HBsAg clearance with Peg-IFN therapy.

A selective and sensitive UPLC-ESI-MS/MS method for quantification of Pegylated Interferon Alfa-2b in human serum using signature peptide-based quantitation

A sensitive method for determination of PEG-IFN-α-2b in human serum was developed using ultra performance liquid chromatography aligned with tandem mass spectrometric detection. A two-treatment, two-period, cross over study was conducted to establish bioequivalence between a test and reference formulation and the method was successfully applied to the quantification of PEG-IFN-α-2b in serum samples of this clinical study. The sample concentrations obtained from LC-MS/MS technique were compared with the concentrations obtained from ELISA technique. PEG-IFN-α-2b was isolated from serum using protein precipitation technique with isopropyl alcohol followed by overnight tryptic digestion. The signature peptide formed as result of tryptic digestion was separated on a chromatograph and detected using a mass detector. The mass transition ion-pair of m/z 741.3 → 1047.1 for PEG-IFN-α-2b and m/z 387.4 → 205.2 for internal standard were used for MS/MS detection. The sample extraction involves a simple protein precipitation method followed by tryptic digestion of the supernatant and further sample cleanup was not needed. The method has been validated over a linear range of 1.028-3200 ng/mL with a correlation coefficient ≥ 0.99. The precision (%RSD) was 5.52 to 7.90 and accuracy (%RE) was within -1.80 to 1.68. The total run time was 22.0 min. The sensitivity of LC-MS/MS method was 1.0 ng/ml which was found to be more sensitive than ELISA and resulted in improving the overall study data by being able to quantify all the samples without any below LOQ results helping to further improve the pharmacokinetic modeling. This improved method is a promising anti-body free LC-MS/MS based methodology for estimation of PEG-IFN-α-2b in human serum and may be applied for other such pegylated molecules.

Association of Polymorphisms in C-Reactive Protein (CRP) Promoter -821 A>G, -390 C>A/T, and Plasma Interferon-α (IFN-α) with Plasma CRP Level in Javanese Systemic Lupus Erythematosus (SLE) Patients

BACKGROUND

As an acute-phase reactant, CRP is needed to clear apoptotic cells and immune complexes in SLE. This unresponsive CRP may be caused by genetic variation and abundant IFN-α that might inhibit CRP secretion. This study aims to analyze the association of single nucleotide polymorphisms (SNP) in CRP promoter and plasma IFN-α with CRP level in Javanese SLE patients. We also analyzed the association of these SNPs with SLE.

METHODS

Forty SLE and 40 spondyloarthritis (as control) patients were included. SLE subjects underwent routine laboratory test, CRP level, serum IFN-α, and DNA sequencing to detect SNPs in CRP promoter. The control group only underwent DNA sequencing.

RESULTS

The median age of SLE patients was 31.5 years. The median SLAM score was 8.5. The median age of the control group was 39 years. The average CRP was 5.19 SD 2.69 mg/L, median plasma IFN-α was 46.02 pg/ml. There was no significant difference of SNPs in CRP -821 (rs2794521) or -390 (rs3091244) between SLE and control. New SNP was found in CRP -456 A>G in 5 SLE patients, but none in controls. This SNP would increase SLE risk 2.143 times. There was a moderate negative correlation between IFN-α level and plasma CRP. Linear regression only showed IFN-α level (not either SNP) correlated with serum CRP.

CONCLUSION

Plasma IFN-α correlated with CRP level. There was no association of SNPs in CRP -821, -390, and -456 with CRP level. SNP CRP -456 A>G would increase the risk of SLE with an odds ratio of 2.143.

Serum interferon levels associated with the disease activity in women with overt Graves' disease

BACKGROUND

Inflammatory cytokines participate in immune reactions and the pathogenesis of autoimmunity. Herein, we quantified four groups of inflammatory cytokines, including interferons (IFNs), the tumor necrosis factor (TNF) superfamily (TNFSF), interleukin (IL)-related cytokines, and bone and extracellular matrix remodeling-related cytokines to determine their contributions in women with overt Graves' disease (GD).

METHODS

Forty-three women with GD were enrolled in this cross-sectional study. Thirty-seven cytokines, thyroid-stimulating hormone (TSH), free thyroxine, and TSH receptor antibody (TSHRAb) were quantified. GD patients with a low TSH level at the time of sample collection were defined as having active GD.

RESULTS

Patients with active GD had higher IFN-α2, IFN-γ, IFN-λ1, and IFN-λ2 levels than those with inactive GD. In addition, certain TNFSF cytokines, including soluble cluster of differentiation 30 (sCD30), TNFSF member 14 (TNFSF14), pentraxin (PTX)-3, soluble TNF receptor 2 (sTNF-R2), and thymic stromal lymphopoietin (TSLP) were higher in active GD than in inactive GD. Moreover, active GD patients had higher IL-2, IL-12(p40), osteocalcin (OCN), and matrix metalloproteinase (MMP)-3 than inactive GD patients. All IFNs except IFN-λ1 were correlated with TSHRAb titers. Moreover, TNFSF cytokines, consisting of B-cell-activating factor, sCD30, TNFSF14, PTX-3, sTNF-R2, and TSLP, were associated with TSHRAb levels.

CONCLUSIONS

Serum IFNs could be the most remarkable cytokines in modulating the disease severity and TSHRAb titers in women with full-blown GD. Further molecular-based research to clarify the actual role of IFNs in the disease progression of GD is needed.

Factors of Severity in Patients with COVID-19: Cytokine/Chemokine Concentrations, Viral Load, and Antibody Responses

The severity of COVID-19 ranges from mild to critical diseases. However, limited data have been published on the detailed kinetics of viral load and host immune response throughout the disease course depending on disease severity. In this study, we comprehensively analyzed viral load, antibody responses to SARS-CoV-2, and cytokines/chemokines during the disease course, and identified the factors related to severity. Nasopharyngeal (NP) and plasma specimens were obtained from 31 patients with COVID-19 during hospitalization. Viral RNA in NP specimens was quantified by reverse transcription-PCR. Anti-SARS-CoV-2 antibodies and cytokines/chemokines in plasma specimens were analyzed by ELISA and cytometric bead array. The viral load in patients with COVID-19 peaked at the early stage of the disease and continuously decreased. Severe and critical cases showed higher viral load and prolonged viral shedding than asymptomatic and mild cases. Whereas plasma IgG was gradually increased and maintained during hospitalization, plasma IgM peaked at 3 weeks after symptom onset and dissipated. The antibody response in severe and critical cases was slightly delayed but stronger than those in others. High levels of interferon (IFN)-α, IFN-γ-induced protein-10, monokine induced by IFN-γ, and interleukin-6 at 5-10 days from symptom onset were associated with the severity of COVID-19. Our data indicate that high viral load in the respiratory tract and excessive production of cytokines and chemokines between 1 and 2 weeks from the symptom onset were significantly associated with the severity of COVID-19.

Associations of gene polymorphisms in interferon-alpha signature-related genes with autoimmune thyroid diseases

Interferon (IFN)-α treatment predisposes patients to the occurrence of autoimmune thyroid disease (AITD).

METHODS

We investigated associations of single nucleotide polymorphisms (SNPs) of molecules participating in the IFN-α signature, including rs2304204 and rs2304206 of IFN regulatory factor 3 (IRF3), rs1061501 of IRF7, and rs7708392 of TNFA1P3-interacting protein 1 with serum IFN-α levels and AITD in an ethnic Chinese (ie Taiwanese) population. Totally, 319 patients with Graves' disease (GD), 83 patients with Hashimoto's thyroiditis (HT) and 351 healthy controls were recruited.

RESULTS

There were increased percentages of the C allele, and CC and TC + CC genotypes of rs1061501 in GD patients compared to the controls. HT patients had higher serum IFN-α levels compared to the controls, while there was no difference in serum IFN-α levels between patients with GD and controls. However, patients with GD in a remission status had lower serum IFN-α levels than those without remission. On the other hand, the C allele of rs1061501 was only associated with serum IFN-α levels in patients with HT.

CONCLUSIONS

The SNP rs1061501 of IRF7 was associated with the development of GD. Serum IFN-α levels were associated with HT, while they might modify the disease status of GD. Moreover, a genetic effect of rs1061501 on regulating serum IFN-α production was observed in HT.

Comparison of Soybean-based Oil and MCT-olive-fish-soy Oil Intravenous Lipid Emulsions on Soluble Adhesion Markers in Preterm Neonates with Sepsis: A Randomized Controlled Trial

OBJECTIVE

To compare the effects of two different intravenous lipid emulsions on soluble adhesion markers in preterm infants with sepsis.

METHODS

This randomized controlled pilot trial was conducted from February 2016 to February 2017. 40 preterm infants with sepsis were enrolled and assigned to receive either Medium chain triglyceride-Olive-Fish-Soy lipid emulsion (MOFS-LE) or soybean oil-based lipid emulsion (S-LE). Outcomes of the study were changes in sICAM-1 and leukocyte integrin b2 levels, and growth after 7 days of intervention.

RESULTS

Leukocyte integrin b2 was significantly higher in MOFS-LE group. No statistically significant differences were observed for sICAM-1, duration of mechanical ventilation and antibiotics treatment, and mortality rate.

CONCLUSIONS

Leukocyte integrin b2 was significantly higher in preterm septic neonates who received MOFS-LE.

PECULIARITIES OF CLINICAL AND IMMUNOLOGICAL CHARACTERISTICS OF HERPESVIRUS INFECTIONS IN CHILDREN

Aimed at optimization of herpes viral infections diagnosis, 186 babies who had momo-or mixed herpes viral infections were examined. Their blood, liquor, urine, saliva and materials that were scrapped off in the damaged focus (skin, mucous membrane of the mouth) were studied by methods of IFA, RIF,PCR. Clinical and immunologic parallels were studied. Levels of TNF-α, IL-4 and IFN-α in blood serum and in liquor were assessed. Generalized form of mixed infection was characterized by low contents of TNF-α, IL-4 and IFN-α in blood serum and higher of TNF-α in the liquor which in the setting of increased antigen load pointed to the disruption of mechanisms of adaptation and compensation and bad prognosis.

Increased interferon-1α, interleukin-10 and BLyS concentrations as clinical activity biomarkers in systemic lupus erythematosus

BACKGROUND AND OBJECTIVE

to analyse the association between interferon-1α (INF1α), interleukin-10 (IL-10) and BLyS concentrations and clinical activity in systemic lupus erythematosus (SLE).

PATIENTS AND METHODS

A cross-sectional, observational study of 142 SLE patients and 34 healthy controls was performed, through a complete blood and urine test and review of their medical history. Serum concentration of INF1α, IL-10 and BLyS was determined by colorimetric methods. A biostatistical analysis was performed with R (3.3.2.).

RESULTS

69% of our SLE patients showed at least one cytokine increased. INF1α, IL-10 and BLyS are higher in SLE patients than in healthy controls (P<.001, P=.005 and P=.043, respectively), being INF1α the most frequent. Patients were categorised according to low or high concentrations of the three cytokines. We found a significant association between increased IL-10/INF1α concentrations and a higher clinical activity measured by SELENA-SLEDAI (P<.0001) and, to a lesser extent, an association with increased INF1α/IL-10/BLyS concentrations. Elevated levels of IL-10/INF1α and INF1α/IL-10/BLyS related to increased C3-C4 consumption (P<.001 and P=.001 respectively) and anti-dsDNA titres (P=.001 and P=.002 respectively). Elevated INF1α/BLyS related to higher anti-dsDNA titres (P=.004) and ENA positivity (P<.001). Increased levels of INF1α/IL-10/BLyS related to positivity of ANAs (P<.001) and APL (P=.004).

CONCLUSIONS

INF1α, IL-10 and BLyS are higher in SLE patients than in healthy controls. Increased IL-10 levels, regardless of whether or not there were also increased levels of BLyS and/or INF1α, was the cytokine that best fit with clinical activity in SLE measured with classic methods.

Individual liver plasmacytoid dendritic cells are capable of producing IFNα and multiple additional cytokines during chronic HCV infection

Plasmacytoid dendritic cells (pDCs) are "natural" interferon α (IFNα)-producing cells. Despite their importance to antiviral defense, autoimmunity, and ischemic liver graft injury, because DC subsets are rare and heterogeneous, basic questions about liver pDC function and capacity to make cytokines remain unanswered. Previous investigations failed to consistently detect IFNα mRNA in HCV-infected livers, suggesting that pDCs may be incapable of producing IFNα. We used a combination of molecular, biochemical, cytometric, and high-dimensional techniques to analyze DC frequencies/functions in liver and peripheral blood mononuclear cells (PBMCs) of hepatitis C virus (HCV)-infected patients, to examine correlations between DC function and gene expression of matched whole liver tissue and liver mononuclear cells (LMCs), and to determine if pDCs can produce multiple cytokines. T cells often produce multiple cytokines/chemokines but until recently technical limitations have precluded tests of polyfunctionality in individual pDCs. Mass cytometry (CyTOF) revealed that liver pDCs are the only LMC that produces detectable amounts of IFNα in response TLR-7/8 stimulation. Liver pDCs secreted large quantities of IFNα (~2 million molecules of IFNα/cell/hour) and produced more IFNα than PBMCs after stimulation, p = 0.0001. LMCs secreted >14-fold more IFNα than IFNλ in 4 hours. Liver pDC frequency positively correlated with whole liver expression of "IFNα-response" pathway (R2 = 0.58, p = 0.007) and "monocyte surface" signature (R2 = 0.54, p = 0.01). Mass cytometry revealed that IFNα-producing pDCs were highly polyfunctional; >90% also made 2-4 additional cytokines/chemokines of our test set of 10. Liver BDCA1 DCs, but not BDCA3 DCs, were similarly polyfunctional. pDCs from a healthy liver were also polyfunctional. Our data show that liver pDCs retain the ability to make abundant IFNα during chronic HCV infection and produce many other immune modulators. Polyfunctional liver pDCs are likely to be key drivers of inflammation and immune activation during chronic HCV infection.

BN nanospheres functionalized with mesoporous silica for enhancing CpG oligodeoxynucleotide-mediated cancer immunotherapy

CpG oligodeoxynucleotides (CpG ODNs) possess strong immunostimulatory activity, which hold great promise in cancer immunotherapy. However, their therapeutic efficacy is largely limited due to nuclease degradation and poor cellular internalization. Efficiently delivering CpG ODNs into target cells is crucial to improve their therapeutic efficacy. Boron nitride nanospheres (BNNS) possess advantage as carriers for CpG ODNs. However, their poor aqueous dispersity and low CpG ODN loading capacity became a big obstacle for further applications. Herein, we develop amino group grafted, mesoporous silica (MS)-functionalized BNNS as novel nanovectors for CpG ODN delivery. Modification of BNNS with MS significantly improved the dispersity of BNNS and CpG ODN loading. BNNS@MS-NH2 exhibited no cytotoxicity and enhanced the delivery of CpG ODNs into macrophages. BNNS@MS-NH2/CpG ODN complexes triggered enhanced immunostimulation and induced higher amounts of cytokines. Most importantly, BNNS@MS-NH2/CpG ODN complexes induced bifurcated cytokines, which simultaneously simulated the secretion of IL-6, TNF-α and IFN-α. In contrast, CpG ODN and BNNS/CpG ODN complexes could not. The result of the Transwell plate assay suggested that BNNS@MS-NH2/CpG ODN complexes were more effective in inhibiting cancer cell growth. Taken together, our findings provide a promising strategy for enhancing CpG ODN-mediated cancer immunotherapy.

Pharmacokinetics comparison of two pegylated interferon alfa formulations in healthy volunteers

BACKGROUND

Several countries have used pegylation technology to improve the pharmacokinetic properties of essential drugs. Recently, a novel interferon alfa-2b protein conjugated to four-branched 12 kDa polyethylene glycol molecules was developed jointly between Cuba and Brazil. The aim of this study was to compare the pharmacokinetic properties of BIP48 (pegylated interferon alfa-2b from Bio-Manguinhos/Fiocruz, Brazil) to those of PEGASYS® (commercially available pegylated interferon alfa-2a from Roche Pharmaceutical).

METHODS

This phase I, single-centre, randomized, double-blind crossover trial enrolled 31 healthy male volunteers aged 19 to 35 who were allocated to two stages, either side of a 5-week wash-out period, with each arm lasting 14 consecutive days after subcutaneous administration of 180 μg of one formulation or the other (study or comparator). The main outcome variable was serum pegylated interferon concentrations in 15 samples collected during the course of the study and tested using an enzyme immunoassay.

RESULTS

There were no differences between formulations in terms of magnitude or absorption parameters. Analysis of time parameters revealed that BIP48 remained in the body significantly longer than PEGASYS® (Tmax: 73 vs. 54 h [p = 0.0010]; MRT: 133 vs. 115 h [p = 0.0324]; ke: 0.011 vs. 0.013 h(-1) [p = 0.0153]; t1/2: 192 vs. 108 h [p = 0.0218]).

CONCLUSION

BIP48 showed the expected pharmacokinetic profile for a pegylated product with a branched molecular structure. Compared to PEGASYS®, the magnitude absorption was similar, but time parameters were consistent with slower elimination. Further studies should be conducted to evaluate the clinical implications of these findings. A phase II-III repeated-dose clinical trial is ongoing to study these findings in patients with chronic hepatitis C virus infection.

TRIAL REGISTRATION

This study is registered on the ClinicalTrials.gov platform (accession number NCT01889849 ). This trial was retrospectively registered in June 2013.

Serum IFN-λ3 Levels Correlate with Serum Hepatitis C Virus RNA Levels in Symptomatic Patients with Acute Hepatitis C

BACKGROUND

Recent genome-wide association studies demonstrated that 2 single nucleotide polymorphisms (SNPs), upstream of the interferon-λ (IFNL) 3 gene, are associated with the spontaneous clearance of hepatitis C virus (HCV) in symptomatic patients with acute hepatitis C (AHC). Although these 2 SNPs, rs8099917 and rs12979860, have established their significant roles in the innate immunity response to spontaneously clear HCV in patients with AHC, the detailed mechanisms of their roles remain largely unknown.

AIM

This study is aimed at clarifying the factors affecting IFNL3 production and assessing the roles of IFNL3 in AHC.

MATERIALS AND METHODS

A total of 21 AHC patients who visited the hospital within 10 days after symptom onset were assessed. As controls, 23 healthy volunteers (HVs) were examined. Serum IFNL3 levels were quantified using an in-house, IFNL3-specific chemiluminescence enzyme immunoassay (CLEIA) kit. Serum IFNL1, IFN-α, IFN-β, and IFN-γ induced protein-10 (IP-10) levels were assayed using commercial enzyme-linked immunosorbent assay (ELISA) kits.

RESULTS

At baseline, serum IFNL3 levels were higher in AHC patients than in HVs (p < 0.0001). The higher levels in AHC patients did not differ between patients with the rs8099917 TT genotype and those with the non-TT (TG/GG) genotype (p = 0.546). Serial measurement of serum IFNL3 levels did not predict the outcome of conventional AHC. However, serum IFNL3 levels at baseline correlated positively with the HCV RNA levels (p = 0.005). Following HCV eradication, serum IFNL3 levels reduced to within the range obtained for HVs. Baseline serum IFNL1 levels did not differ significantly between AHC patients and HVs (p = 0.284). Serum levels of IFNL1 and IFNL3 at baseline also showed no correlative power (p = 0.288). Serum IFN-α and IFN-β were detected together with remarkably high serum IFNL3 levels in only one patient who progressed to acute liver failure (ALF).

CONCLUSION

These findings indicate that serum IFNL3 levels at baseline are higher in AHC patients regardless of the rs8099917 polymorphism, and primary HCV infection triggers the production of IFNL3. As a first line of defense in the innate immune system against invading HCV, increased IFNL3 levels play an important role, but serum IFNL3 levels are not the principal determinant of the clinical course of conventional AHC.

Polyunsaturated fatty acids levels and initial presentation of somatic symptoms induced by interferon-alpha therapy in patients with chronic hepatitis C viral infection

OBJECTIVES

Somatic symptoms are common in depressive disorder and are similar to sickness behaviors due to inflammatory activation after cytokine administration. Omega-3 polyunsaturated fatty acids (PUFAs) are natural anti-inflammatory agents and may reduce inflammation-induced behavioral changes. The aim of this study was to investigate the role of PUFAs on the development of somatic symptoms and depression in patients of hepatitis C virus infection (HCV) receiving interferon-alpha therapy (IFN-α) in a prospective manner.

METHODS

In this 24-week, prospective cohort study, 43 patients with chronic HCV ongoing IFN-α therapy were assessed with the mini-international neuropsychiatric interview for major depressive episodes and neurotoxicity rating scale (NRS) for somatic symptoms.

RESULTS

One-third later developed IFN-α-induced depression (depression (DEP) group). As compared to subjects without depression, DEP group had higher NRS scores (P < 0.001), lower eicosapentaenoic acid (EPA) levels (P = 0.038) at week 2. Somatic symptoms, regardless of painful/non-painful characteristics, had positive association with arachidonic acid (P < 0.05), and negative association with EPA (P < 0.05).

CONCLUSION

This study implies that early intervention with omega-3 PUFAs might be a promising strategy to prevent depression and somatic symptoms in patients receiving cytokine therapy.

Early protection events in swine immunized with an experimental live attenuated classical swine fever marker vaccine, FlagT4G

Prophylactic vaccination using live attenuated classical swine fever (CSF) vaccines has been a very effective method to control the disease in endemic regions and during outbreaks in previously disease-free areas. These vaccines confer effective protection against the disease at early times post-vaccination although the mechanisms mediating the protection are poorly characterized. Here we present the events occurring after the administration of our in-house developed live attenuated marker vaccine, FlagT4Gv. We previously reported that FlagT4Gv intramuscular (IM) administered conferred effective protection against intranasal challenge with virulent CSFV (BICv) as early as 7 days post-vaccination. Here we report that FlagT4Gv is able to induce protection against disease as early as three days post-vaccination. Immunohistochemical testing of tissues from FlagT4Gv-inoculated animals showed that tonsils were colonized by the vaccine virus by day 3 post-inoculation. There was a complete absence of BICv in tonsils of FlagT4Gv-inoculated animals which had been intranasal (IN) challenged with BICv 3 days after FlagT4Gv infection, confirming that FlagT4Gv inoculation confers sterile immunity. Analysis of systemic levels of 19 different cytokines in vaccinated animals demonstrated an increase of IFN-α three days after FlagT4Gv inoculation compared with mock infected controls.

Detection of interferon alpha protein reveals differential levels and cellular sources in disease

Type I interferons (IFNs) are essential mediators of antiviral responses. These cytokines have been implicated in the pathogenesis of autoimmunity, most notably systemic lupus erythematosus (SLE), diabetes mellitus, and dermatomyositis, as well as monogenic type I interferonopathies. Despite a fundamental role in health and disease, the direct quantification of type I IFNs has been challenging. Using single-molecule array (Simoa) digital ELISA technology, we recorded attomolar concentrations of IFNα in healthy donors, viral infection, and complex and monogenic interferonopathies. IFNα protein correlated well with functional activity and IFN-stimulated gene expression. High circulating IFNα levels were associated with increased clinical severity in SLE patients, and a study of the cellular source of IFNα protein indicated disease-specific mechanisms. Measurement of IFNα attomolar concentrations by digital ELISA will enhance our understanding of IFN biology and potentially improve the diagnosis and stratification of pathologies associated with IFN dysregulation.

[Correlations between serum 25-hydroxyvitamin D and cytokines in patients newly diagnosed with systemic lupus erythematosus]

Objective To investigate the correlations between serum 25-hydroxyvitamin D (25-OH-VitD) and serum cytokines of interferon (IFN)-α2, interleukin(IL)-6, IL-10, and IL-17A in Chinese Han patients newly diagnosed with systemic lupus erythematosus (SLE). Methods This study recruited 86 Chinese patients newly diagnosed with SLE and 73 healthy volunteers. The serum 25-OH-VitD was detected using ELISA. The serum levels of IFN-α2, IL-6, IL-10 and IL-17A were detected using Luminex liquichip. The associations between serum 25-OH-VitD and serum cytokines, clinical manifestations and laboratory findings were analyzed using Spearman linear correlation analysis. Results The serum 25-OH-VitD was significantly lower in SLE patients than in healthy controls. The serum 25-OH-VitD was positively correlated with serum C3, negatively correlated with serum IL-17A and 24 hour urine protein excretion, but not obviously correlated with serum IFN-α2, IL-6 and IL-10. Conclusion The serum 25-OH-VitD decreases in Chinese patients newly diagnosed with SLE and it is negatively correlated with serum IL-17A.

Altered type II interferon precedes autoantibody accrual and elevated type I interferon activity prior to systemic lupus erythematosus classification

OBJECTIVES

The relationship of immune dysregulation and autoantibody production that may contribute to systemic lupus erythematosus (SLE) pathogenesis is unknown. This study evaluates the individual and combined contributions of autoantibodies, type I interferon (IFN-α) activity, and IFN-associated soluble mediators to disease development leading to SLE.

METHODS

Serial serum specimens from 55 individuals collected prior to SLE classification (average timespan=4.3 years) and unaffected healthy controls matched by age (±5 years), gender, race and time of sample procurement were obtained from the Department of Defense Serum Repository. Levels of serum IFN-α activity, IFN-associated mediators and autoantibodies were evaluated and temporal relationships assessed by growth curve modelling, path analysis, analysis of covariance and random forest models.

RESULTS

In cases, but not matched controls, autoantibody specificities and IFN-associated mediators accumulated over a period of years, plateauing near the time of disease classification (p<0.001). Autoantibody positivity coincided with or followed type II IFN dysregulation, preceding IFN-α activity in growth curve models, with elevated IFN-α activity and B-lymphocyte stimulator levels occurring shortly before SLE classification (p≤0.005). Cases were distinguished by multivariate random forest models incorporating IFN-γ, macrophage chemoattractant protein (MCP)-3, anti-chromatin and anti-spliceosome antibodies (accuracy 93% >4 years pre-classification; 97% within 2 years of SLE classification).

CONCLUSIONS

Years before SLE classification, enhancement of the type II IFN pathway allows for accumulation of autoantibodies and subsequent elevations in IFN-α activity immediately preceding SLE classification. Perturbations in select immunological processes may help identify at-risk individuals for further clinical evaluation or participation in prospective intervention trials.

Intestinal-borne dermatoses significantly improved by oral application of Escherichia coli Nissle 1917

AIM: To evaluate the effect of oral Escherichia coli (E. coli) Nissle application on the outcome of intestinal-borne dermatoses.

METHODS: In a randomized, controlled, non-blinded prospective clinical trial 82 patients with intestinal-borne facial dermatoses characterized by an erythematous papular-pustular rash were screened. At the initiation visit 37 patients entered the experimental arm and 20 patients constituted the control arm. All 57 patients were treated with a vegetarian diet and conventional topical therapy of the dermatoses with ointments containing tetracycline, steroids and retinoids. In the experimental arm patients received a one month therapy with oral E. coli Nissle at a maintenance dose of 2 capsules daily. The experimental group was compared to a non-treatment group only receiving the diet and topical therapy. The primary outcome parameter was improvement of the dermatoses, secondary parameters included life quality and adverse events. In addition the immunological reaction profile (IgA, interleucin-8 and interferon-α) was determined. Furthermore the changes of stool consistency and the microbiota composition over the time of intervention were recorded.

RESULTS: Eighty-nine percent of the patients with acne, papular-pustular rosacea and seborrhoic dermatitis responded to E. coli Nissle therapy with significant amelioration or complete recovery in contrast to 56% in the control arm (P < 0.01). Accordingly, in the E. coli Nissle treated patients life quality improved significantly (P < 0.01), and adverse events were not recorded. The clinical improvement was associated with a significant increase of IgA levels to normal values in serum as well as suppression of the proinflammatory cytokine IL-8 (P < 0.01 for both parameters). In the E. coli Nissle treated group a shift towards a protective microbiota with predominance of bifidobacteria and lactobacteria (> 10⁷ CFU/g stool) was observed in 79% and 63% of the patients, respectively (P < 0.01), compared to no change in the control group without E. coli Nissle. Moreover, the detection rate of a pathogenic flora dropped from 73% to 14 % of the patients in the experimental arm (P < 0.01) with no significant change in the control arm (accounting 80% before and 70% after the observation period, P > 0.05). Accordingly, stool consistency, color and smell normalized in the E. coli Nissle treated patients.

CONCLUSION: E. coli Nissle protects the mucus barrier by overgrowth of a favorable gut microbiota with less immunoreactive potential which finally leads to clinical improvement of intestinal borne dermatoses.

Type I and III IFNs Produced by Plasmacytoid Dendritic Cells in Response to a Member of the Flaviviridae Suppress Cellular Immune Responses

The pestivirus noncytopathic bovine viral diarrhea virus (BVDV) can suppress IFN production in the majority of cell types in vitro. However, IFN is detectable in serum during acute infection in vivo for ∼5-7 d, which correlates with a period of leucopoenia and immunosuppression. In this study, we demonstrate that a highly enriched population of bovine plasmacytoid dendritic cells (DCs) produced IFN in response to BVDV in vitro. We further show that the majority of the IFN produced in response to infection both in vitro and in vivo is type III IFN and acid labile. Further, we show IL-28B (IFN-λ3) mRNA is induced in this cell population in vitro. Supernatant from plasmacytoid DCs harvested postinfection with BVDV or recombinant bovine IFN-α or human IL-28B significantly reduced CD4(+) T cell proliferation induced by tubercle bacillus Ag 85-stimulated monocyte-derived DCs. Furthermore, these IFNs induced IFN-stimulated gene expression predominantly in monocyte-derived DCs. IFN-treated immature DCs derived from murine bone marrow also had a reduced capacity to stimulate T cell proliferative responses to tubercle bacillus Ag 85. Immature DCs derived from either source had a reduced capacity for Ag uptake following IFN treatment that is dose dependent. Immunosuppression is a feature of a number of pestivirus infections; our studies suggest type III IFN production plays a key role in the pathogenesis of this family of viruses. Overall, in a natural host, we have demonstrated a link between the induction of type I and III IFN after acute viral infection and transient immunosuppression.

A cytotoxic anti-IL-3Rα antibody targets key cells and cytokines implicated in systemic lupus erythematosus

To date, the major target of biologic therapeutics in systemic lupus erythematosus (SLE) has been the B cell, which produces pathogenic autoantibodies. Recently, targeting type I IFN, which is elaborated by plasmacytoid dendritic cells (pDCs) in response to endosomal TLR7 and TLR9 stimulation by SLE immune complexes, has shown promising results. pDCs express high levels of the IL-3Rα chain (CD123), suggesting an alternative potential targeting strategy. We have developed an anti-CD123 monoclonal antibody, CSL362, and show here that it affects key cell types and cytokines that contribute to SLE. CSL362 potently depletes pDCs via antibody-dependent cell-mediated cytotoxicity, markedly reducing TLR7, TLR9, and SLE serum-induced IFN-α production and IFN-α-upregulated gene expression. The antibody also inhibits TLR7- and TLR9-induced plasmablast expansion by reducing IFN-α and IL-6 production. These effects are more pronounced than with IFN-α blockade alone, possibly because pDC depletion reduces production of other IFN subtypes, such as type III, as well as non-IFN proinflammatory cytokines, such as IL-6. In addition, CSL362 depletes basophils and inhibits IL-3 signaling. These effects were confirmed in cells derived from a heterogeneous population of SLE donors, various IFN-dependent autoimmune diseases, and healthy controls. We also demonstrate in vivo activity of CSL362 following its s.c. administration to cynomolgus monkeys. This spectrum of effects provides a preclinical rationale for the therapeutic evaluation of CSL362 in SLE.

Classical Swine Fever Virus vs. Classical Swine Fever Virus: The Superinfection Exclusion Phenomenon in Experimentally Infected Wild Boar

Two groups with three wild boars each were used: Group A (animals 1 to 3) served as the control, and Group B (animals 4 to 6) was postnatally persistently infected with the Cat01 strain of CSFV (primary virus). The animals, six weeks old and clinically healthy, were inoculated with the virulent strain Margarita (secondary virus). For exclusive detection of the Margarita strain, a specific qRT-PCR assay was designed, which proved not to have cross-reactivity with the Cat01 strain. The wild boars persistently infected with CSFV were protected from superinfection by the virulent CSFV Margarita strain, as evidenced by the absence of clinical signs and the absence of Margarita RNA detection in serum, swabs and tissue samples. Additionally, in PBMCs, a well-known target for CSFV viral replication, only the primary infecting virus RNA (Cat01 strain) could be detected, even after the isolation in ST cells, demonstrating SIE at the tissue level in vivo. Furthermore, the data analysis of the Margarita qRT-PCR, by means of calculated ΔCt values, supported that PBMCs from persistently infected animals were substantially protected from superinfection after in vitro inoculation with the Margarita virus strain, while this virus was able to infect naive PBMCs efficiently. In parallel, IFN-α values were undetectable in the sera from animals in Group B after inoculation with the CSFV Margarita strain. Furthermore, these animals were unable to elicit adaptive humoral (no E2-specific or neutralising antibodies) or cellular immune responses (in terms of IFN-γ-producing cells) after inoculation with the second virus. Finally, a sequence analysis could not detect CSFV Margarita RNA in the samples tested from Group B. Our results suggested that the SIE phenomenon might be involved in the evolution and phylogeny of the virus, as well as in CSFV control by vaccination. To the best of our knowledge, this study was one of the first showing efficient suppression of superinfection in animals, especially in the absence of IFN-α, which might be associated with the lack of innate immune mechanisms.

Th17 Cytokines Disrupt the Airway Mucosal Barrier in Chronic Rhinosinusitis

Cytokine mediated changes in paracellular permeability contribute to a multitude of pathological conditions including chronic rhinosinusitis (CRS). The purpose of this study was to investigate the effect of interferons and of Th1, Th2, and Th17 cytokines on respiratory epithelium barrier function. Cytokines and interferons were applied to the basolateral side of air-liquid interface (ALI) cultures of primary human nasal epithelial cells (HNECs) from CRS with nasal polyp patients. Transepithelial electrical resistance (TEER) and permeability of FITC-conjugated dextrans were measured over time. Additionally, the expression of the tight junction protein Zona Occludens-1 (ZO-1) was examined via immunofluorescence. Data was analysed using ANOVA, followed by Tukey HSD post hoc test. Our results showed that application of interferons and of Th1 or Th2 cytokines did not affect the mucosal barrier function. In contrast, the Th17 cytokines IL-17, IL-22, and IL-26 showed a significant disruption of the epithelial barrier, evidenced by a loss of TEER, increased paracellular permeability of FITC-dextrans, and discontinuous ZO-1 immunolocalisation. These results indicate that Th17 cytokines may contribute to the development of CRSwNP by promoting a leaky mucosal barrier.

ALTERATION OF OXIDATIVE METABOLISM AND IMMUNOLOGICAL PARAMETERS UNDER THE INFLUENCE OF UVA RADIATION IN WOMEN OF DIFFERENT AGES

Purpose of study was to investigate the alteration of oxidative and immunological metabolism in blood of reproductive and menopausal age women after UVA irradiation. Women of two groups (1 - menopausal, 2 - reproductive age) were exposed to radiation with wave length 320-400 nm for 5-10 minutes per session in the solarium for the period of 3 months (6 days per month).. Parameters of oxidative metabolism - activity of red blood cells (RBC), antioxidant enzymes catalase (CAT) and superoxiddismutase (SOD) were studied by spectrophotometric method; reactive oxygen (O2-) and lipid (LOO/) free radicals content in whole blood were studied by Electron Paramagnetic Resonance (EPR) methods with use of specific spin-traps - 5,5-Dimethyl-1-Pyrroline-N-Oxide (DMPO) and α-phenyl-N-tert-butylnitrone (PBN) (SIGMA). Parameters of immunological metabolism - IFN-α, IL-2, IL-10 cytokines content in blood were studied by immunoenzymatic assay ELISA. The study protocol has been approved by the Ethical Committee of the Tbilisi State Medical University. After the course of UVA irradiation in menopausal women CAT activity increased by 20%, SOD - by 24%, and EPR signal of spin trapped lipoperoxide radicals was detected. No alterations in blood redox-balance were detected in women of reproductive age. Values of blood immunological parameters in menopausal women were not changed under the influence of UV radiation; in women of reproductive age IL-10 content increase by 93% (within a normal value range) was revealed. Research results have shown that UVA rays cause a particularly significant influence on the oxidative metabolism in the women of menopausal age. Increase of IL-10 blood levels in women of reproductive age (considering its imunosupressing activity) represents an additional risk of cancerogenesis. Based on the study results, we recommend avoiding UV (including UVA) radiation procedures to women of both reproductive and menopausal ages.

Enhancing Pharmacokinetics, Tumor Accumulation, and Antitumor Efficacy by Elastin-Like Polypeptide Fusion of Interferon Alpha

Genetic fusion of elastin-like polypeptide (ELP) to the C-terminus of interferon alpha (IFN) generates a well-defined IFN-ELP fusion protein with high yield and well-retained bioactivity. The fusion protein significantly enhances pharmacokinetics, tumor accumulation, and antitumor efficacy of interferon alpha in a murine cancer model.

Osteoclast Differentiation Is Impaired in a Subgroup of SLE Patients and Correlates Inversely with Mycophenolate Mofetil Treatment

Osteoporosis can arise in systemic lupus erythematosus (SLE) patients secondary to medication and/or chronic inflammation. To analyze if patients with SLE have phenotypically-impaired osteoclastogenesis, we differentiated ex vivo monocytes from 72 SLE patients and 15 healthy individuals into osteoclasts followed by TRAP staining and counting. We identified a subgroup of SLE patients (45%) with a significantly impaired osteoclast differentiation, relative to the other SLE patients or healthy individuals (OR 11.2; 95% CI 1.4–89.9). A review of medication indicated that patients with osteoclast counts equal to healthy donors were significantly more likely to be treated with mycophenolate mofetil (MMF) compared to patients with impaired osteoclastogenesis. We analyzed expression of RANKL and the MMF target genes IMPDH1 and IMPDH2 in osteoclasts by qPCR, but detected no difference. Since MMF might influence interferon-α (IFNα) and -γ (IFNγ) we measured serum IFNα and IFNγ levels. Patients with very low osteoclast counts also had comparably higher IFNα serum levels than patients with normal osteoclast counts. We conclude that in vitro osteoclastogenesis is impaired in a subgroup of SLE patients. This correlates inversely with MMF treatment and high IFNα serum levels. Further observational study will be required to determine whether this translates into a clinically meaningful effect.

Almond Skin Inhibits HSV-2 Replication in Peripheral Blood Mononuclear Cells by Modulating the Cytokine Network

We have investigated the effect of almond skin extracts on the production of pro-inflammatory and anti-inflammatory cytokines in human peripheral blood mononuclear cells (PBMCs). PBMCs were either infected or not by herpes simplex virus type 2 (HSV-2), with and without prior treatment with almond skin extracts. Production of IL-17 induced by HSV-2 was inhibited by natural skins (NS) treatment. NS triggered PBMC in releasing IFN-α, IFN-γ and IL-4 in cellular supernatants. These results may explain the antiviral potential of almond skins.

Induction dosing of peginterferon alfa-2a (40 KD) and/or high-dose ribavirin in genotype 1 CHC patients with difficult-to-treat characteristics: pharmacokinetic and viral kinetic (PK/VK) assessment from PROGRESS

BACKGROUND/AIMS

PROGRESS randomized chronic hepatitis C genotype 1 patients with a baseline viral load ≥400,000 IU/mL weighing ≥85 kg to regimens of 180 μg/week for 48 weeks or 360 μg/week for 12 weeks followed by 180 μg/week for 36 weeks peginterferon alfa-2a plus ribavirin. This analysis explored pharmacokinetics and early viral kinetics (VK) and evaluates differences between groups.

METHODOLOGY

Blood samples for pharmacokinetic and VK analyses were collected from 51 patients enrolled in the PROGRESS study.

RESULTS

Mean peginterferon alfa-2a trough concentration at week 12 was 11.7±4.3 ng/mL for 180 μg and 23.4±11.3 ng/mL for 360 μg. Early VK profiles suggested a trend towards an enhanced viral decline in the 360 μg groups with a mean decrease in HCV RNA at 48 hours post first dose of 1.04 log10 (IU/mL) compared with 0.76 log10 (IU/mL) in the 180 μg groups. Mean beta slope increased with dose, ranging from 0.38±0.26 log10 IU/week at 180 μg to 0.52±0.32 log10 IU/week at 360 μg.

CONCLUSIONS

Early viral de clines may be enhanced with the 360 μg dose. These data may suggest the utility of high-dose peginterfer on alfa-2a plus direct-acting antivirals (DAA) in select difficult-to-treat populations.

microRNA146a expression in lupus patients with and without renal complications

microRNA146a (miRNA) expression profiles are likely to become important diagnostic and prognostic tools in many disease aspects. This work aimed to study the expression of miRNA146a in lupus patients with and without renal complications and to assess its association with disease activity. Patients enrolled in the study included 52 females affected by systemic lupus erythematosus (SLE) and another 60 females with lupus nephritis (LN). Forty-eight age-matched healthy females were enrolled as a control group. miRNA146a expression was assessed using real-time PCR. In SLE patients, miRNA146a was underexpressed as compared to healthy controls and lower levels were detected among lupus patients with renal affection. In addition, miRNA146a expression was low and serum Interferon-α (IFN-α) level was high in patients with active lupus as compared to those with inactive disease. miRNA146a expression was inversely correlated to serum IFN-α level and to anti ds-DNA titer in the three studied groups. In conclusion, miRNA146a might be implicated in lupus pathogenesis. Moreover, miRNA146a expression correlates negatively to lupus activity and LN, whereas serum IFN-α has a direct correlation to both disease activity and nephritis; hence, both miRNA146a expression and serum IFN-α could be potentially important diagnostic biomarkers and potential novel strategies for therapeutic interventions, which may possibly be implied to enhance the sensitivity and specificity for the prediction of flares and prognosis in SLE patients.

The preventive effects of natural adjuvants, G2 and G2F on tracheal responsiveness and serum IL-4 and IFN-γ (th1/th2 balance) in sensitized guinea pigs

OBJECTIVE

The effects of natural adjuvants on lung inflammation and tracheal responsiveness were examined in sensitized guinea pigs.

METHODS

The responses of guinea pig tracheal chains and the serum levels of interleukin-4 and interferon-gamma were examined in control pigs and three other groups of guinea pigs: the sensitized group and two other sensitized groups treated with either adjuvant G2 or adjuvant G2F (n=7 for each group). Sensitization of the animals was achieved by injection and inhalation of ovalbumin.

RESULTS

The results showed that sensitized animals had increased tracheal responsiveness and increased serum levels of interleukin-4 and interferon-gamma compared to controls (p<0.05 to p<0.001). Treatments with either G2 or G2F prevented the increase in tracheal responsiveness and serum interleukin-4 (p<0.01 to p<0.001). However, the serum levels of interferon-gamma and the interleukin-4-to-interferon-gamma ratio was increased in the treated groups (p<0.001 for all cases).

CONCLUSIONS

These results indicate important preventive effects of two natural adjuvants, particularly G2, on the changes in tracheal responsiveness, serum cytokines and the interleukin-4-to-interferon-gamma ratio (T helper 1/T helper 2 balance) in sensitized guinea pigs.

c-FLIP-Short reduces type I interferon production and increases viremia with coxsackievirus B3

Cellular FLIP (c-FLIP) is an enzymatically inactive paralogue of caspase-8 and as such can block death receptor-induced apoptosis. However, independent of death receptors, c-FLIP-Long (c-FLIP_L) can heterodimerize with and activate caspase-8. This is critical for promoting the growth and survival of T lymphocytes as well as the regulation of the RIG-I helicase pathway for type I interferon production in response to viral infections. Truncated forms of FLIP also exist in mammalian cells (c-FLIP_S) and certain viruses (v-FLIP), which lack the C-terminal domain that activates caspase-8. Thus, the ratio of c-FLIP_L to these short forms of FLIP may greatly influence the outcome of an immune response. We examined this model in mice transgenically expressing c-FLIP_S in T cells during infection with Coxsackievirus B3 (CVB3). In contrast to our earlier findings of reduced myocarditis and mortality with CVB3 infection of c-FLIP_L-transgenic mice, c-FLIP_S-transgenic mice were highly sensitive to CVB3 infection as manifested by increased cardiac virus titers, myocarditis score, and mortality compared to wild-type C57BL/6 mice. This observation was paralleled by a reduction in serum levels of IL-10 and IFN-α in CVB3-infected c-FLIP_S mice. In vitro infection of c-FLIP_S T cells with CVB3 confirmed these results. Furthermore, molecular studies revealed that following infection of cells with CVB3, c-FLIP_L associates with mitochondrial antiviral signaling protein (MAVS), increases caspase-8 activity and type I IFN production, and reduces viral replication, whereas c-FLIP_S promotes the opposite phenotype.

A strong interferon response correlates with a milder dengue clinical condition

BACKGROUND

Type 1 interferon (IFNα/β) has a significant role in establishing protection against virus infections. It has been well documented by in vitro studies that dengue virus (DENV) activates a robust IFNα/β response. However, DENV also induces a down-regulation of the JAK/STAT pathway, inhibiting the induction of interferon regulated genes. As a consequence, the role played by the IFN type 1 response in the protection of dengue patients is not fully understood.

OBJECTIVE

To compare IFN-α levels in dengue patients with dengue fever (DF) or dengue hemorrhagic fever (DHF) undergoing primary or secondary infections.

STUDY DESIGN

Two hundred and four serum samples were analyzed for IFN-α level by cytometric bead array. Patients' clinical condition was assigned following the WHO 1997 criteria and specific IgG and IgM antibodies were measured using commercial assays to determine primary and secondary infections. The infecting serotype was determined by qRT-PCR.

RESULTS AND CONCLUSION

The IFN-α levels were found significantly higher in DF than DHF patients irrespective of the infecting serotype (DENV1 or 2), and were found to decline rapidly at day 3 after fever onset. For DENV2 infections, higher IFN-α level was found during primary than secondary infections. These results suggest that an early strong interferon response correlates with a better clinical condition.

IFNα serum levels are associated with endothelial progenitor cells imbalance and disease features in rheumatoid arthritis patients

Introduction

IFNα has been largely implicated in the ethiopathogenesis of autoimmune diseases but only recently it has been linked to endothelial damage and accelerated atherosclerosis in autoimmunity. In addition, proinflammatory conditions are supposed to be implicated in the cardiovascular status of these patients. Since a role for IFNα in endothelial damage and impaired Endothelial Progenitor Cell (EPC) number and function has been reported in other diseases, we aimed to evaluate the potential associations of IFNα serum levels on EPC populations and cytokine profiles in Rheumatoid Arthritis (RA) patients.

Methods

pre-EPC, EPC and mature EPC (mEPC) populations were quantified by flow cytometry analyzing their differential CD34, CD133 and VEGFR2 expression in blood samples from 120 RA patients, 52 healthy controls (HC), and 83 systemic lupus erythematosus (SLE) patients as disease control. Cytokine serum levels were measured by immunoassays and clinical and immunological data, including cardiovascular (CV) events and CV risk factors, were retrospectively obtained by reviewing clinical records.

Results

Long-standing, but not recent onset RA patients displayed a significant depletion of all endothelial progenitor populations, unless high IFNα levels were present. In fact, the IFN^high RA patient group (n = 40, 33%), showed increased EPC levels, comparable to SLE patients. In addition, high IFNα serum levels were associated with higher disease activity (DAS28), presence of autoantibodies, higher levels of IL-1β, IL-6, IL-10 and MIP-1α, lower amounts of TGF-β, and increased mEPC/EPC ratio, thus suggesting higher rates of endothelial damage and an endothelial repair failure. Finally, the relationship between high IFNα levels and occurrence of CV events observed in RA patients seems to support this hypothesis.

Conclusions

IFNα serum marker could be used to identify a group of RA patients with increased disease activity, EPC imbalance, enhanced proinflammatory profile and higher cardiovascular risk, probably due, at least in part, to an impaired endothelial repair.

Measuring interferon alpha and other cytokines in SLE

The progression of disease in patients with systemic lupus erythematosus (SLE) is affected by production, accumulation, and actions of cytokines. Type I interferon (IFN), specifically IFN-α, is recognized as a central mediator of disease pathogenesis in SLE. We describe a functional assay to measure type I IFN activity in SLE plasma and have also measured the response of peripheral blood cells to that cytokine family. This method can be scaled to assess IFN functional activity, as well as activity and cellular response to other cytokines, in relation to cellular and serologic parameters relevant to SLE.

[Interferon inductor activity and interferon production under the action of acridonacetic acid salts]

Peculiarities of the kinetics of accumulation and duration of circulation of three types of interferon under the action of acridonacetic acid salts have been studied. Optimum doses of meglumine salt of acridonacetic acid are established, which ensure efficient and consistent induction of three interferon types, ensuring their prolonged circulation in the blood.

[Induction of type 1, 2 and 3 interferons by acridone acetates]

The induction profile of endogenous interferons of three types under the action of meglumine acridone acetate and sodium acridone acetate, as well as the characteristics of the kinetics of their accumulation and circulation in the blood of experimental animals are described. Meglumine acridone acetate provided balance in induction, production and circulation of the interferons in the blood vs. sodium aeridone acetate under the same conditions. The optimal dose of meglumine acridone acetate (2.0-3.5 mg/mouse) with effective, consecutive and overlapping induction-production of the interferons ensured their prolonged (for 72 hours) circulation in the blood after a single administration.

[Activation of hypomethylated DNA on plasmacytoid dendritic cells in patients with systemic lupus erythematosus]

OBJECTIVE

To explore the activation of hypomethylated DNA on plasmacytoid dendritic cells (pDC) in patients with systemic lupus erythematosus (SLE).

METHODS

Peripheral blood mononuclear cells (PBMC) were isolated from whole blood of SLE patients and healthy controls. The methylation level of DNA and the expression of DNA methyltransferase 1 (DNMT1) mRNA were detected. Flow cytometry was used to detect the expression of CD32 on pDC and the serum concentration of interferon-alpha (IFN-α) measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The DNA methylation level from SLE patients (1.4 ± 0.6) % was lower than that of controls (1.8 ± 0.7) % (P < 0.01). The expression of DNMT1 mRNA significantly decreased in SLE patients (0.06 ± 0.03) versus the controls (0.09 ± 0.02) (P < 0.01). The CD32 expression on pDC from SLE patients (29 ± 19)% was higher than that from controls (18.02 ± 7.80)% (P < 0.01). The serum level of IFN-α in SLE patients (4.5 ± 6.7) ng/L was significantly higher than that of controls (2.1 ± 2.0) ng/L (P < 0.01). The methylation level of DNA in SLE patients was positively correlated with the expression of DNMT1 mRNA (r = 0.257, P < 0.05) and negatively with the expression of CD32 (r = -0.358, P < 0.01) and IFN-α (r = -0.280, P < 0.05).

CONCLUSIONS

The methylation level of genomic DNA decreases in SLE patients due to the down-regulated expression of DNMT1 gene. Hypomethylated DNA may be translocated intracellularly via endocytic receptor (CD32) on pDC. And the activation of pDC is induced to produce IFN-α so as to participate in the onset of SLE.

Influence of Atg5 mutation in SLE depends on functional IL-10 genotype

Increasing evidence supports the involvement of autophagy in the etiopathology of autoimmune diseases. Despite the identification of autophagy-related protein (Atg)-5 as one of the susceptibility loci in systemic Lupus erythematosus (SLE), the consequences of the carriage of these mutations for patients remain unclear. The present work analyzed the association of Atg5 rs573775 single nucleotide polymorphism (SNP) with SLE susceptibility, IFNα, TNFα and IL-10 serum levels, and clinical features, in 115 patients and 170 healthy individuals. Patients who where carriers of the rs573775 T* minor allele presented lower IFNα levels than those with the wild genotype, whereas the opposite result was detected for IL-10. Thus, since IL-10 production was regulated by rs1800896 polymorphisms, we evaluated the effect of this Atg5 mutation in genetically high and low IL-10 producers. Interestingly, we found that the rs573775 T* allele was a risk factor for SLE in carriers of the high IL-10 producer genotype, but not among genetically low producers. Moreover, IL-10 genotype influences SLE features in patients presenting the Atg5 mutated allele. Specifically, carriage of the rs573775 T* allele led to IL-10 upregulation, reduced IFNα and TNFα production and a low frequency of cytopenia in patients with the high IL-10 producer genotype, whereas patients with the same Atg5 allele that were low IL-10 producers presented reduced amounts of all these cytokines, had a lower prevalence of anti-dsDNA antibodies and the latest onset age. In conclusion, the Atg5 rs573775 T* allele seems to influence SLE susceptibility, cytokine production and disease features depending on other factors such as functional IL-10 genotype.

Anti-NKG2A autoantibodies in a patient with systemic lupus erythematosus

OBJECTIVES

To characterize a novel anti-NKG2A autoantibody detected in a patient with SLE during a severe flare, and in a cross-sectional study investigate the occurrence of such autoantibodies in patients with SLE and primary SS (pSS).

METHODS

Serum or IgG from patients with SLE, pSS and healthy volunteers were assayed for blocking of anti-NKG2A or HLA-E binding to peripheral blood mononuclear cells or CD94/NKG2A- and CD94/NKG2C-transfected Ba/F3 cells. The anti-NKG2A autoantibodies were evaluated for effect on NK cell degranulation in response to HLA-E-transfected K562 cells. IFN-α was determined by an immunoassay and disease activity by the SLEDAI score.

RESULTS

Anti-NKG2A autoantibodies, which blocked binding of HLA-E tetramers to CD94/NKG2A-transfected cells and impaired NKG2A-mediated inhibition of NK cell activation, were observed in a patient with SLE. The presence of anti-NKG2A autoantibodies was associated with high SLE disease activity (SLEDAI score 14 and 16) and increased serum IFN-α. Of 94 SLE, 60 pSS and 30 healthy donor sera, only the index patient serum contained anti-NKG2A autoantibodies.

CONCLUSION

The presence of autoantibodies targeting NKG2A is a rare event, but when such autoantibodies occur they may promote excessive NK cell function. This can contribute to the pathogenesis by increasing the killing of cells and the release of autoantigens. Our findings highlight the possible importance of NK cells in the SLE disease process.

Interferon-α induction and detection of anti-ro, anti-la, anti-sm, and anti-rnp autoantibodies by autoantigen microarray analysis in juvenile dermatomyositis

OBJECTIVE

To evaluate serum interferon-α (IFNα) activity in the context of autoantibody profiles in patients with juvenile dermatomyositis (JDM).

METHODS

Sera from 36 patients with JDM were analyzed. Autoantibody profiles were determined by probing microarrays, which were fabricated with ∼80 distinct autoantigens, with serum and a Cy3-conjugated secondary antibody. Arrays were scanned and analyzed to determine antigen reactivity. Serum IFNα activity was measured using a functional reporter cell assay. Sera were assayed alone or in combination with cellular material released from necrotic U937 cells to stimulate peripheral blood mononuclear cells from healthy donors in vitro, and IFNα production in culture was measured by a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA).

RESULTS

Reactivity against at least 1 of 41 autoantigens on the microarray, including Ro 52, Ro 60, La, Sm, and RNP, was observed in 75% of the serum samples from patients with JDM. IFNα activity was detected in 7 samples by reporter cell assay. The reporter cell assay showed a significant association of reactivity against Ro, La, Sm, and proliferating cell nuclear antigen with serum IFNα activity (P = 0.005). Significance Analysis of Microarrays (SAM) identified increased reactivity against Sm, RNP, Ro 52, U1-C, and Mi-2 in these sera. Sixteen samples induced IFNα production as measured by DELFIA, and there was a significant association of reactivity against Ro, La, Sm, and RNP with the induction of IFNα by serum and necrotic cell material (P = 0.034). SAM identified increased reactivity against Ro 60 in these sera.

CONCLUSION

These data support the hypothesis that nucleic acid-associated autoantibodies, including the Ro/La and Sm/RNP complexes, may stimulate the production of active IFNα in children with JDM.

Blocking TLR7- and TLR9-mediated IFN-α production by plasmacytoid dendritic cells does not diminish immune activation in early SIV infection

Persistent production of type I interferon (IFN) by activated plasmacytoid dendritic cells (pDC) is a leading model to explain chronic immune activation in human immunodeficiency virus (HIV) infection but direct evidence for this is lacking. We used a dual antagonist of Toll-like receptor (TLR) 7 and TLR9 to selectively inhibit responses of pDC but not other mononuclear phagocytes to viral RNA prior to and for 8 weeks following pathogenic simian immunodeficiency virus (SIV) infection of rhesus macaques. We show that pDC are major but not exclusive producers of IFN-α that rapidly become unresponsive to virus stimulation following SIV infection, whereas myeloid DC gain the capacity to produce IFN-α, albeit at low levels. pDC mediate a marked but transient IFN-α response in lymph nodes during the acute phase that is blocked by administration of TLR7 and TLR9 antagonist without impacting pDC recruitment. TLR7 and TLR9 blockade did not impact virus load or the acute IFN-α response in plasma and had minimal effect on expression of IFN-stimulated genes in both blood and lymph node. TLR7 and TLR9 blockade did not prevent activation of memory CD4+ and CD8+ T cells in blood or lymph node but led to significant increases in proliferation of both subsets in blood following SIV infection. Our findings reveal that virus-mediated activation of pDC through TLR7 and TLR9 contributes to substantial but transient IFN-α production following pathogenic SIV infection. However, the data indicate that pDC activation and IFN-α production are unlikely to be major factors in driving immune activation in early infection. Based on these findings therapeutic strategies aimed at blocking pDC function and IFN-α production may not reduce HIV-associated immunopathology.

A persistent type I interferon (IFN) response is thought to be important in driving immune activation and progression to AIDS in human immunodeficiency virus (HIV)-infected individuals. Plasmacytoid dendritic cells (pDC) produce copious amounts of type I IFN upon virus exposure through engagement of Toll-like receptor (TLR) 7 and TLR9 and thus may be central players in the etiology of immune activation. We used a dual antagonist of TLR7 and TLR9 to selectively block the response of pDC but not other mononuclear phagocytes prior to and for 8 weeks following simian immunodeficiency virus (SIV) infection of rhesus macaques. We show that pDC are major, but not exclusive, producers of IFN-α that mediate a marked but transient IFN-α response in lymph nodes in the acute phase of infection. TLR7 and TLR9 antagonist prevented this IFN-α production without suppressing pDC recruitment. Nevertheless, TLR7 and TLR9 blockade did not impact expression of IFN-stimulated genes or decrease the activation of T cells, the hallmarks of immune activation. The findings indicate that TLR7 and TLR9-driven activation of pDC is unlikely to be a major contributor to immune activation in the early stages of immunodeficiency virus infections and suggest that therapeutic strategies aimed at targeting pDC and IFN-α production may not reduce HIV-associated immunopathology.

Dengue virus activates membrane TRAIL relocalization and IFN-α production by human plasmacytoid dendritic cells in vitro and in vivo

Background

Dengue displays a broad spectrum of clinical manifestations that may vary from asymptomatic to severe and even fatal features. Plasma leakage/hemorrhages can be caused by a cytokine storm induced by monocytes and dendritic cells during dengue virus (DENV) replication. Plasmacytoid dendritic cells (pDCs) are innate immune cells and in response to virus exposure secrete IFN-α and express membrane TRAIL (mTRAIL). We aimed to characterize pDC activation in dengue patients and their function under DENV-2 stimulation in vitro.

Methods & Findings

Flow cytometry analysis (FCA) revealed that pDCs of mild dengue patients exhibit significantly higher frequencies of mTRAIL compared to severe cases or healthy controls. Plasma levels of IFN-α and soluble TRAIL are increased in mild compared to severe dengue patients, positively correlating with pDC activation. FCA experiments showed that in vitro exposure to DENV-2 induced mTRAIL expression on pDC. Furthermore, three dimension microscopy highlighted that TRAIL was relocalized from intracellular compartment to plasma membrane. Chloroquine treatment inhibited DENV-2-induced mTRAIL relocalization and IFN-α production by pDC. Endosomal viral degradation blockade by chloroquine allowed viral antigens detection inside pDCs. All those data are in favor of endocytosis pathway activation by DENV-2 in pDC. Coculture of pDC/DENV-2-infected monocytes revealed a dramatic decrease of antigen detection by FCA. This viral antigens reduction in monocytes was also observed after exogenous IFN-α treatment. Thus, pDC effect on viral load reduction was mainly dependent on IFN-α production

Conclusions

This investigation characterizes, during DENV-2 infection, activation of pDCs in vivo and their antiviral role in vitro. Thus, we propose TRAIL-expressing pDCs may have an important role in the outcome of disease.

Dengue is an important endemic tropical disease to which there are no specific therapeutics or approved vaccines. Currently several aspects of pathophysiology remain incompletely understood. A crucial cellular population for viral infections, the plasmacytoid dendritic cells (pDCs) was analyzed in this study. The authors found an in vivo association between the activation state of pDCs and the disease outcome. Membrane TNF-related apoptosis inducing ligand (TRAIL) expressing pDCs, representing activated pDCs, were found in higher frequency in milder cases of dengue than severe cases or healthy individuals. Detection of antiviral cytokine interferon-alpha (IFN-α) and soluble TRAIL positively correlated with pDC activation. Dengue virus (DENV) serotype-2 was able to directly activate pDCs in vitro. Under DENV stimulation TRAIL was relocalized from intracellular to pDC plasma membrane and IFN-α was highly produced. The authors suggest an endocytosis-dependent pathway for DENV-induced pDC activation. It is also highlighted here a role for exogenous IFN-α and pDCs in reducing viral replication in monocytes, one of DENV main target cells. These findings may contribute in the future to the establishment of good prognostic immune responses together with clinical manifestations/warning signs.

The role of innate versus adaptive immune responses in a mouse model of O'nyong-nyong virus infection

O'nyong-nyong virus (ONNV), an alphavirus closely related to chikungunya virus (CHIKV), has caused three major epidemics in Africa since 1959. Both ONNV and CHIKV produce similar syndromes with fever, rash, and debilitating arthralgia. To determine the roles of the innate and adaptive immune responses, we infected different knockout mice with two strains of ONNV (SG650 and MP30). Wild-type, RAG1 KO, and IFNγR KO mice showed no signs of illness or viremia. The STAT1 KO and A129 mice exhibited 50-55% mortality when infected with SG650. Strain SG650 was more virulent in the STAT1 KO and A129 than MP30. Deficiency in interferon α/β signaling (A129 and STAT1 KO) leaves mice susceptible to lethal disease; whereas a deficiency of interferon γ signaling alone had no effect on survival. Our findings highlight the importance of type I interferon in protection against ONNV infection, whereas the adaptive immune system is relatively unimportant in the acute infection.

The expression of transmembrane and soluble CXCL16 and the relation with interferon-alpha secretion in patients with Behçet's disease

OBJECTIVES

CXCL16 is a member of CXC chemokine, which is synthesised in plasmacytoid dendritic cell as a transmembrane molecule. Transmembrane CXCL16 on plasmacytoid dendritic cell plays a role in binding, uptaking and accumulation of CpG D ODN in early endosomes rather then lysosomal vesicles, thereby causing a high level of interferon-alpha secretion. Previously, we disclosed pronounced interferon-alpha production from these cells in patients with Behçet's disease. The aim of this study was to investigate the relation between the secretion of IFN-α and the expression of CXCL16 on surface of plasmacytoid dendritic cell from patients with Behçet's disease, and compare it with patients with ankylosing spondylitis and healthy controls.

METHODS

The study population consisted of 73 cases (35 with Behçet's disease, 19 with ankylosing spondylitis and 19 controls). We investigated the expression of CXCL16 on surface of plasmacytoid dendritic cells by flow cytometry, and the serum levels of IFN-α and CXCL16 with ELISA.

RESULTS

Serum levels of IFN-α in patients with Behçet's disease were significantly higher than the controls (p=0.009), and than patients with ankylosing spondylitis, but not statistically significant (p=0.124). Serum levels of CXCL16 in patients with Behçet's disease and patients with ankylosing spondylitis were significantly higher than controls (p=0.009, p=0.003, respectively). We found no difference in the percentage and MFI of plasmacytoid dendritic cells and CD123+CXCL16+ cells determined by flow cytometry among the study and control groups. In patients with Behçet's disease, a positive correlation was found between the percentage of plasmacytoid dendritic cells and CD123+CXCL16+ cells (p<0.001). Furthermore, there was also a positive correlation between the percentage of plasmacytoid dendritic cells and serum levels of CXCL16 in patients with ankylosing spondylitis (p=0.001). In addition, there was a positive correlation between the percentage of CD123+CXCL16+ cells and serum levels of IFN-α in Behçet's disease group (p=0.034). We could not find any significant difference in other comparisons.

CONCLUSIONS

We suggested that the expression of transmembrane CXCL16 on surface of plasmacytoid dendritic cell might contribute to high serum IFN-α levels seen in patients with BD.

Interferon regulatory factor 7 (IRF7) is required for the optimal initial control but not subsequent clearance of lymphocytic choriomeningitis virus infection in mice

The role of IRF7 in the host response to lymphocytic choriomeningitis virus (LCMV) Armstrong 53b infection of mice was investigated. Intracranial infection of IRF7 KO mice was associated with delayed onset of LCM, increased survival and significantly reduced expression of the Ifng gene in the brain but not in the periphery. IRF7 KO mice showed impaired control of LCMV replication and delayed clearance of LCMV. Similar numbers of activated anti-LCMV-GP(33-41) CD8+ T cells were present in the brain and spleens of infected WT and IRF7 KO mice. While plasma IFN-β was increased to similar levels, IFN-α was markedly reduced in IRF7 KO compared with WT mice. Compared with IFN-β, IFN-α was a less potent inhibitor of LCMV infection in vitro. In conclusion, IRF7 (1) is required for the early innate control of LCMV infection, likely through the regulation of the appropriate type I IFN response, and (2) is not required for the antiviral CD8+ T cell-dependent clearance of LCMV from infected tissues.

Interferon-α is the primary plasma type-I IFN in HIV-1 infection and correlates with immune activation and disease markers

Type-I interferon (IFN-I) has been increasingly implicated in HIV-1 pathogenesis. Various studies have shown elevated IFN-I and an IFN-I-induced gene and protein expression signature in HIV-1 infection, yet the elevated IFN-I species has not been conclusively identified, its source remains obscure and its role in driving HIV-1 pathogenesis is controversial. We assessed IFN-I species in plasma by ELISAs and bioassay, and we investigated potential sources of IFN-I in blood and lymph node tissue by qRT-PCR. Furthermore, we measured the effect of therapeutic administration of IFNα in HCV-infected subjects to model the effect of IFNα on chronic immune activation. IFN-I bioactivity was significantly increased in plasma of untreated HIV-1-infected subjects relative to uninfected subjects (p = 0.012), and IFNα was the predominant IFN-I subtype correlating with IFN-I bioactivity (r = 0.658, p<0.001). IFNα was not detectable in plasma of subjects receiving anti-retroviral therapy. Elevated expression of IFNα mRNA was limited to lymph node tissue cells, suggesting that peripheral blood leukocytes are not a major source of IFNα in untreated chronic HIV-1 infection. Plasma IFN-I levels correlated inversely with CD4 T cell count (p = 0.003) and positively with levels of plasma HIV-1 RNA and CD38 expression on CD8 T cells (p = 0.009). In hepatitis C virus-infected subjects, treatment with IFN-I and ribavirin increased expression of CD38 on CD8 T cells (p = 0.003). These studies identify IFNα derived from lymph nodes, rather than blood leukocytes, as a possible source of the IFN-I signature that contributes to immune activation in HIV-1 infection.