Interferon-α Production Research Articles

Identification of hub-methylated differentially expressed genes in patients with gestational diabetes mellitus by multi-omic WGCNA basing epigenome-wide and transcriptome-wide profiling.

Gestational diabetes mellitus (GDM), defined as dysglycaemia that is detected during pregnancy for the first time, has become a global health burden. GDM was found to be correlated to epigenetic changes, which would cause abnormal expression of placental genes. In the present study, we performed multi-omic weighted gene coexpression network analysis (WGCNA) to systematically identify the hub genes for GDM using both epigenome- and transcriptome-wide microarray data. Two microarray datasets (GSE70493 and GSE70494) were downloaded from the Gene Expression Omnibus (GEO) database. GEO2R was used to screen differentially expressed genes (DEGs) and differentially methylated genes (DMGs) between normal and GDM samples, separately. The results of WGCNA found that 15 modules were identified and the MEblack module had a significantly negative correlation with GDM (r = -.28, P = .03). GO enrichment analysis by BinGO of the MEblack module showed that genes were primarily enriched for the presentation of antigen processing, regulation of interferon-α production and interferon-γ-mediated signaling pathway. By comparing the DEGs, DMGs and hub genes in the coexpression network, we identified five hypermethylated, lowly expressed genes (ABLIM1, GRHL1, HLA-F, NDRG1, and SASH1) and one hypomethylated, highly expressed gene (EIF3F) as GDM-related hub DMGs. Moreover, the expression levels of ABLIM1, GRHL1, HLA-F, NDRG1, and SASH11 in the GDM patients and healthy controls were validated by a real-time quantitative polymerase chain reaction. Finally, gene set enrichment analysis showed that the biological function of cardiac muscle contraction was enriched for four GDM-related hub DMGs (ABLIM1, GRHL1, NDRG1, and SASH1). Analysis of this study revealed that dysmethylated hub genes in GDM placentas might affect the placental function and thus, take part in GDM pathogenesis and fetal cardiac development.

Toll-like receptor 7-adapter complex modulates interferon-α production in HIV-stimulated plasmacytoid dendritic cells.

Plasmacytoid dendritic cells (PDCs) and their production of interferon-alpha (IFN-α) are believed to play an important role in human immunodeficiency virus, type I (HIV-1) pathogenesis. PDCs produce IFN-α and other proinflammatory cytokines through stimulation of Toll-like receptor 7 (TLR7) and TLR9 present in endosomal compartments. TLR7 recognizes single-stranded viral RNA, while TLR9 recognizes unmethylated DNA. In this study, we examined the mechanisms that may underlie variations in IFN-α production in response to HIV, and the impact of these variations on HIV pathogenesis. In four distinct cohorts, we examined PDC production of IFN-α upon stimulation with inactivated HIV-1 particles and unmethylated DNA. The signaling cascade of TLR7 bifurcates at the myeloid differentiation protein 88 (MyD88) adaptor protein to induce expression of either IFN-α or TNF-α. To determine whether variations in IFN-α production are modulated at the level of the receptor complex or downstream of it, we correlated production of IFN-α and TNF-α following stimulation of TLR7 or TLR9 receptors. Flow cytometry detection of intracellular cytokines showed strong, direct correlations between IFN-α and TNF-α expression in all four cohorts, suggesting that variations in IFN-α production are not due to variations downstream of the receptor complex. We then investigated the events upstream of TLR binding by using lipid-like vesicles to deliver TLR ligands directly to the TLR receptors, bypassing the need for CD4 binding and endocytosis. Similar tight correlations were found in IFN-α and TNF-α production in response to the TLR ligands. Taken together, these results strongly suggest that differences in IFN-α production depend on the regulatory processes at the level of the TLR7 receptor complex. Additionally, we found no association between IFN-α production before HIV infection and disease progression.

ATP1B3 cooperates with BST-2 to promote hepatitis B virus restriction.

Increasing evidence indicates ATP1B3, one of the regulatory subunits of Na+/K+‐ATPase, is involved in numerous viral propagations, such as HIV and EV71. However, the function and mechanism of ATP1B3 on hepatitis B virus (HBV) propagation is unknown. Here, we demonstrated that ATP1B3 overexpression reduced the quantity of hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg) in supernatants of HBV expression plasmids cotransfected HepG2 cells. Correspondingly, small interfering RNA and short hairpin RNA mediated ATP1B3 silencing promoted HBsAg and HBeAg expression in the supernatants of HBV expression plasmids transfected HepG2 cells. Mechanically, we reported that ATP1B3 expression could activate nuclear factor‐κB (NF‐κB) pathway by inducing the expression, phosphorylation, and nuclear import of P65 for the first time. And NF‐κB inhibitor (Bay11) impaired the restraint of ATP1B3 on HBV replication. This counteraction effect of Bay11 proved that ATP1B3‐induced NF‐κB activation was crucial for HBV restriction. Accordingly, we observed that anti‐HBV factors interferon‐α (IFN‐α) and interleukin‐6 (IL‐6) production were increased in HepG2 cells after the NF‐κB activation. It suggested that ATP1B3 suppressed HBsAg and HBeAg by NF‐κB/IFN‐α and NF‐κB/IL‐6 axis. Further experiments proved that ATP1B3 overexpression induced anti‐HBV factor BST‐2 expression by NF‐κB/IFN‐α axis in HepG2 cells but not HEK293T cells, and ATP1B3 silencing downregulated BST‐2 messenger RNA level in HepG2 cells. As an HBV restriction factor, BST‐2 cooperated with ATP1B3 to antagonize HBsAg but not HBeAg in HepG2 cells. Our work identified ATP1B3 as a novel candidate of HBV restrictor with unrevealed mechanism and we highlighted it might serve as a potential therapeutic molecule for HBV infection.

C5a/C5aR1 Pathway Is Critical for the Pathogenesis of Psoriasis.

Psoriasis is one of the most common chronic inflammatory skin diseases, affecting ~2% of the population. The lack of characterization of the pathogenesis of psoriasis has hindered efficient clinical treatment of the disease. In our study, we observed that expression of complement component 5a receptor 1(C5aR1) was significantly increased in skin lesions of both imiquimod (IMQ) and IL23-induced psoriatic mice and patients with psoriasis. C5aR1 deficiency or treatment with C5a receptor 1 antagonist (C5aR1a) in mice significantly attenuated psoriasis-like skin lesions and expression of inflammatory cytokines and chemokines. Moreover, C5aR1 deficiency significantly decreased IMQ-induced infiltration of plasmacytoid dendritic cells (pDCs), monocytes and neutrophils in psoriatic skin lesions and functions of pDCs, evidenced by the remarkable reduction in the IMQ-induced production of interferon-α (IFN-α) and tumor necrosis factor α (TNF-α), and FMS-like tyrosine kinase 3 ligand (FLT3L)-dependent pDCs differentiation. Accordingly, in vitro treatment with recombinant C5a accelerated pDCs migration and the differentiation of bone marrow cells into pDCs. Furthermore, biopsies of psoriatic patients showed a dramatic increase of C5aR1+ pDCs infiltration in psoriatic skin lesions, compared to healthy subjects. Our results provide direct evidence that C5a/C5aR1 signaling plays a critical role in the pathogenesis of psoriasis. Inhibition of C5a/C5aR1 pathway is expected to be beneficial in the treatment of patients with psoriasis.

The immunomodulatory-drug, lenalidomide, sustains and enhances interferon-α production by human plasmacytoid dendritic cells.

Background: Lenalidomide (LEN), an immunomodulatory drug (IMiD), is currently used for treatment of multiple myeloma (MM). LEN potentiates T cell and natural killer cell functions. However, the cellular and molecular mechanisms underlying the immunomodulatory effects of LEN remain unclear. We focused on the effects of LEN on human plasmacytoid dendritic cells (pDCs), which are the major source of interferon (IFN)-α in the blood and play a central role in innate immune responses.Results: We found that bortezomib, a proteasome inhibitor used to treat MM, killed pDCs but that 0.1–3 μM LEN (covering clinical plasma concentration range) did not affect pDC survival or CD86 expression. Bortezomib inhibited pDC-derived IFN-α production in a dose-dependent fashion, but 0.1–3 µM LEN sustained pDC-derived IFN-α production when stimulated with an optimal concentration of CpG-ODN 2216 (3 μM). In pDCs stimulated with a low concentration of CpG-ODN (0.1 μM), LEN enhanced IFN-α production. These results indicated that LEN, when used at a clinically relevant concentration, can potentially enhance IFN-α production by pDCs.Conclusion: Collectively, our findings unveiled a novel target of LEN and extend the repertoire of the drug’s known immunomodulatory effects. These effects may explain the low incidence of herpes zoster viral infection observed during LEN treatment compared with bortezomib treatment. LEN may function as an IMiD affecting a wide array of immune cells, including pDCs, leading to amplification of a positive immune axis able to eliminate MM cells.

Disturbed Transcription of TLRs’ Negative Regulators and Cytokines Secretion among TLR4- and 9-Activated PBMCs of Agammaglobulinemic Patients

ABSTRACTToll-like receptors (TLRs) are inevitable elements for immunity development and antibody production. TLRs are in close interaction with Bruton’s tyrosine kinase which has been found mutated and malfunctioned in the prototype antibody deficiency disease named X-linked agammaglobulinemia (XLA). TLRs’ ability was evaluated to induce transcription of TLR-negative regulators, including suppressor of cytokine signaling 1 (SOCS1), interleukin-1 receptor-associated kinase 3 (IRAK-M), tumor necrosis factor alpha-induced protein 3 (TNFAIP3, A20), and Ring finger protein 216 (RNF216), and Tumor necrosis factor-α (TNF-α) and Interferon-α (IFN-α) production via Lipopolysaccharides (LPS) and CpG-A oligodeoxynucleotides (CpG-A ODN). Measured by TaqMan real-time polymerase chain reaction (PCR), meaningfully increased transcripts of SOCS1 and RNF216 were found in XLA peripheral blood mononuclear cells (PBMCs). Also, TLR inductions of XLA have led to similar downregulations in the regulator’s transcription which was different from that in healthy donors. Cytokine measurement by enzyme-linked immunosorbent assay (ELISA) revealed a significant lower TNF-α production both before and after LPS. By selected molecules in this study, TLRs’ potential defectiveness range expands TLRs expression, downstream signaling, and cytokine production. The results show new potential elements that could play a part in TLRs defect and pathogenesis of agammaglobulinemia as well.

Short-Term Probiotic Administration Increases Fecal-Anti Candida Activity in Healthy Subjects.

Background: Candida albicans’ ability to evade host immune responses represents a serious threat for vulnerable patients. Objectives: To investigate if (1) feces from healthy subjects exert anti-Candida activity; (2) fecal anti-Candida activity is modified by probiotic administration and (3) different probiotic differently modulate anti-Candida activity. Patients and methods: Feces from healthy donors were analyzed before and after seven days of dietary supplementation with two different probiotic formulations (VSL#3®; Vivomixx®). Candida albicans was cultured with decreasing concentrations of diluted feces, obtained before and after the treatment period. The relationship between anti-Candida activity of feces, interferon-α, anti-interferon-α antibodies and the expression of MxA, ISG15 and IFNAR1 was also evaluated. Results: Feces obtained prior to probiotic intake and feces collected after supplementation with VSL#3® did not affect Candida albicans growth. On the contrary, a 3log10 inhibition of Candida development was observed after Vivomixx® intake. Interferon-α played a role in the inhibition of Candida growth. Conclusion: Fecal anti-Candida activity was not observed prior to probiotic supplementation. Seven days of administration of Vivomixx® increased fecal anti-Candida activity, the same effect was not observed after intake of VSL#3®. The probiotic-induced anti-Candida activity seems to be related to an increased local production and release of interferon-α. Clinical trials are needed to determine if a short pretreatment with specific probiotic formulations may increase anti-Candida defenses in patients at risk.

Liquid crystal immune sensing

Immunology Systemic scleroderma (SSc) is an autoimmune disease of the connective tissue thought to be the result of aberrant innate immune signaling. CXCL4, a platelet-derived chemoattractant for neutrophils, monocytes, and fibroblasts, can serve as a biomarker for this disease. Lande et al. report that high CXCL4 levels found in SSc patients correlates with plasmacytoid dendritic cell (pDC) activation and interferon-α production. They show that CXCL4 organizes both “self” and foreign DNA into liquid-crystalline supramolecular complexes in a DNA size–dependent manner. These complexes chaperone nucleic acids into pDCs and allow for optimal clustering and activation of the innate immune sensor Toll-like receptor 9. Beyond SSc pathogenesis, these findings may illuminate the role of platelets in wound healing and tissue repair. Nat. Commun. 10 , 1731 (2019).

CXCL4 assembles DNA into liquid crystalline complexes to amplify TLR9-mediated interferon-\u03b1 production in systemic sclerosis

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis and vasculopathy. CXCL4 represents an early serum biomarker of severe SSc and likely contributes to inflammation via chemokine signaling pathways, but the exact role of CXCL4 in SSc pathogenesis is unclear. Here, we elucidate an unanticipated mechanism for CXCL4-mediated immune amplification in SSc, in which CXCL4 organizes “self” and microbial DNA into liquid crystalline immune complexes that amplify TLR9-mediated plasmacytoid dendritic cell (pDC)-hyperactivation and interferon-α production. Surprisingly, this activity does not require CXCR3, the CXCL4 receptor. Importantly, we find that CXCL4-DNA complexes are present in vivo and correlate with type I interferon (IFN-I) in SSc blood, and that CXCL4-positive skin pDCs coexpress IFN-I-related genes. Thus, we establish a direct link between CXCL4 overexpression and the IFN-I-gene signature in SSc and outline a paradigm in which chemokines can drastically modulate innate immune receptors without being direct agonists.

Antiviral Activity of Graphene Oxide-Silver Nanocomposites by Preventing Viral Entry and Activation of the Antiviral Innate Immune Response.

Developing nanomaterials-based antimicrobial agents has shown a widespread promise. In this study, silver nanoparticle-modified graphene oxide (GO-AgNPs) nanocomposites were self-assembled via interfacial electrostatic force. By using the porcine reproductive and respiratory syndrome virus (PRRSV) as a pattern, the antiviral effect of the as-prepared GO-AgNPs nanocomposites on the replication of virus was investigated. The results indicated that exposure with GO-AgNPs nanocomposites could obviously suppress PRRSV infection. It was found that GO-AgNPs nanocomposites exhibited a better inhibitory effect compared with AgNPs and GO. By selecting the porcine epidemic diarrhea virus (PEDV) as a contrast virus, GO-AgNPs nanocomposites were proven to have a broad antiviral activity. Mechanism studies showed that GO-AgNPs nanocomposites might prevent PRRSV from entering the host cells, with 59.2% inhibition efficiency. Meanwhile, GO-AgNPs nanocomposite treatment enhances the production of interferon-α (IFN-α) and IFN-stimulating genes (ISGs), which can directly inhibit the proliferation of virus. Taken together, this study reports a new type of antiviral agent and provides a promising pharmaceutical agent for treating infection by the highly pathogenic PRRSV. Moreover, it may provide novel ideas for the research and development of antiviral formulations based on nanocomposites and extend their applications in biological systems.

Immune function of plasmacytoid dendritic cells, natural killer cells, and their crosstalk in HBV infection.

Chronic hepatitis B virus infection is a major health problem, with over 245 million chronic carriers worldwide. This persistent infection is thought to be associated with inefficient innate and adaptive immune responses. Natural killer cells (NK cells) and plasmacytoid dendritic cells (pDCs) are the major innate immune cells which respond to viral infection at the early phase and are considered major components of the antiviral immune response. In this review, we summarize recent findings regarding the role of NK cells, pDCs, and their cross-talk in HBV infection and its chronicity. Although the data regarding the biological function of pDCs and NK cells in HBV infection is still controversial, many studies show that in chronic HBV infection, the cytotoxicity of NK cells is retained, while their capacity to secrete cytokines is strongly impaired. In addition, interferon-α production by pDCs is impaired during chronic HBV infection, and the virus interferes with pDC-NK cell interaction.

Alcohol enhances type 1 interferon-α production and mortality in young mice infected with Mycobacterium tuberculosis.

In the current study, we used a mouse model and human blood samples to determine the effects of chronic alcohol consumption on immune responses during Mycobacterium tuberculosis (Mtb) infection. Alcohol increased the mortality of young mice but not old mice with Mtb infection. CD11b+Ly6G+ cells are the major source of IFN-α in the lungs of Mtb-infected alcohol-fed young mice, and IFN-α enhances macrophage necroptosis in the lungs. Treatment with an anti-IFNAR-1 antibody enhanced the survival of Mtb-infected alcohol-fed young mice. In response to Mtb, peripheral blood mononuclear cells (PBMCs) from alcoholic young healthy individuals with latent tuberculosis infection (LTBI) produced significantly higher amounts of IFN-α than those from non-alcoholic young healthy LTBI+ individuals and alcoholic and non-alcoholic old healthy LTBI+ individuals. Our study demonstrates that alcohol enhances IFN-α production by CD11b+Ly6G+ cells in the lungs of young Mtb-infected mice, which leads to macrophage necroptosis and increased mortality. Our findings also suggest that young alcoholic LTBI+ individuals have a higher risk of developing active TB infection.

Excessive interferon-α signaling in autoimmunity alters glycosphingolipid processing in B cells

Excessive interferon-α (IFN-α) production by innate immune cells is a hallmark of autoimmune diseases. What other cell type secretes IFN-α and how IFN-α affects immune cell metabolism and homeostasis in autoimmunity are largely unclear. Here, we report that autoimmune B cells, arising from two different B cell-specific genetic lesions in mice, secrete IFN-α. In addition, IFN-α, found in abundance in autoimmunity, elicited profound changes in the B cell lipidome, increasing their expression of glycosphingolipids (GSLs) and leading to their CD1d-mediated depletion of iNKT cells in vitro and in vivo. IFN-α receptor blockade could reverse the loss of iNKT cells. Excessive stimulation of B cells with IFN-α altered the expression of enzymes that catalyze critical steps in GSL processing, increasing the expressions of glucosylceramide synthase (GCS) and globotrihexosylceramide synthase (Gb3S) but decreasing that of α-galactosidase A (α-galA). Inhibiting GCS or restoring α-galA expression prevented iNKT depletion by IFN-α-activated B cells. Taken together, our work indicated that excessive IFN-α perturbs GSL metabolism in B cells which in turn adversely affects iNKT homeostasis.

Anti-TNF Alpha-Induced Psoriasis: A Rare Paradoxical Side Effect

Introduction: TNF-α inhibitors are widely used in the management of Crohn's disease (CD) and psoriasis. These agents can paradoxically cause psoriasis. We present a case report of Crohn's disease patient on infliximab therapy who developed psoriasis. Case report: A 45 year old man with a history of Crohn's colitis, well controlled on infliximab, came to clinic for evaluation of pruritic rash for 2-3 weeks that started on his legs initially and spread to involve his arms, chest, and back. He denied systemic symptoms, use of new medications or skin products, sick contact and recent travel. His CD was in remission for more than 1 year, and the last dose of infliximab was given 4 weeks ago. Skin exam revealed well-demarcated, erythematous plaques with overlying adherent scales involving chest, abdomen, back, legs and extensor surfaces of both arms. The patient was referred to dermatology for further evaluation. Punch skin biopsy revealed psoriasis. It was attributed to the use of infliximab. He was treated with topical steroids and UVB phototherapy with minimal improvement. Infliximab was held and planned to switch to other biologic agents for maintenance of CD. Discussion: CD is characterized by transmural inflammation of the gastrointestinal tract due to inflammatory cytokines such as interleukin (IL)-12 and TNF-α, resulting in symptoms of CD. TNF-α inhibitors, e.g., infliximab are effective in inducing and maintaining remission in moderate to severe CD patients. Plaque-type psoriasis, guttate psoriasis, palmoplantar pustulosis, psoriasis of the nail and scalp have been described in the literature with the use of these agents. Estimated prevalence is 0.6% to 5.3%. Previously reported cases have a wide diversity as far as agent types, gender and age of patients, treatment duration, type of eruption, and presence or absence of personal or family history of psoriasis are concerned. Pustular eruption resembling palmoplantar pustulosis is the most characteristic pattern, and it has been reported in about one-third of all reported cases. Pathogenesis of TNF-α inhibitors induced psoriasis involves a disruption in cytokine balance allowing unopposed interferon-α production by dendritic cells. In most cases, topical steroid therapy is enough. UVB phototherapy or discontinuation of TNF-α inhibitor or switching to an alternative anti-TNF agent is required in severe cases.Figure: Rash on back.Figure: Rash on elbow.

Repetitive extragenic palindromic DNA sequences from Brucella melitensis stimulate Toll-like receptor 9 signaling in macrophages

Brucella DNA activates the host innate immune system via the intracellular Toll-like receptor 9 (TLR9). However, the Brucella DNA sequences which are responsible for these immunostimulatory effects remain to be elucidated. The present study demonstrated that repetitive extragenic palindromic (REPs) sequences present in Brucella DNA were able to stimulate macrophages through TLR9. The induction of interferon-α (IFN-α) production by Brucella REPs was detected in cultured RAW264.7 mouse macrophages as well as in Wistar rats. Knockdown of TLR9 expression by siRNA in macrophages led to a reduction in IFN-α production following REPs stimulation. In addition, it was confirmed that the activating capacity of Brucella REPs is CpG dependent. Induction of IFN-α by Brucella REPs was completely abrogated when REP sequences were transformed into non-CpG sequences or by C-methylated modifications. Furthermore, it was observed that REPs-initiated TLR9/NF-κB and TLR9/MAPK signaling pathways contributed to the production of IFN-α. The identification of Brucella REPs as natural TLR9 agonists may be useful for the development of novel therapeutic applications.

Carbon dots as inhibitors of virus by activation of type I interferon response

Carbon dots (CDs) has shown exciting potential in the field of bioscience and biotechnology due to their low toxicity, biological and ecological friendliness and desirable performance characteristics of quantum dots (QDs). However, the effects of CDs on viruses are still largely unknown. In this study, we investigate the effect of CDs on the replication of virus by using pseudorabies virus (PRV) and porcine reproductive and respiratory syndrome virus (PRRSV) as the models of DNA virus and RNA virus, respectively. Analyses of virus titers and the expression of viral proteins demonstrate that cells treated with CDs can significantly inhibit the multiplication of PRV and PRRSV. In mechanism, CDs treatment dramatically induces interferon-α (IFN-α) production and the expression of IFN-stimulating genes (ISGs) which in turn inhibits virus replication. Taken together, these results reveal a previously undefined role of CDs and provide a new strategy to develop antiviral agents.

Sex differences in HIV-1-mediated immunopathology.

The article reviews our current knowledge regarding the role of sex and sex hormones in regulating innate immune responses to viral infections, which may account for the described sex differences in immunity to HIV-1. Prominent sex differences exist in various infectious and autoimmune diseases. Biological mechanisms underlying these differences include the modulation of immunological pathways by sex hormones and gene dosage effects of immunomodulatory genes encoded by the X chromosome. During HIV-1 infections, women have been shown to present with lower viral load levels in primary infection, although their progression to AIDS is faster in comparison with men when accounting for viral load levels in chronic infection. HIV-1-infected women furthermore tend to have higher levels of immune activation and interferon-stimulated gene expression in comparison with men for the same viral load, which has been associated to innate sensing of HIV-1 by Toll-like receptor 7 and the consequent interferon-α production by plasmacytoid dendritic cells. Improvement in understanding the mechanisms associated with sex differences in HIV-1-mediated immunopathology will be critical to take sex differences into consideration when designing experimental and clinical studies in HIV-1-infected populations.

The effects of repetitive extragenic palindromic sequences from Brucella melitensis DNA on the toll-like receptor 9-mediated interferon-α production

To screen the repetitive extragenic palindromic sequences with activation of toll-like receptor 9 (TLR9) activity from Brucella melitensis DNA, providing new ideas and new targets for prevention and treatment of brucellosis. Bioinformatics methods were used to detect repetitive extragenic palindromic (REP) sequences from Brucella melitensis DNA. The studied REPs were selected and synthesized. RAW264.7 was cultured and transfected with REPs mediated by lipofectamine 3000. Additionally, TLR9-siRNA was used to downregulate TLR9 expression. The content of interferon-α (IFN-α) in the supernatant was then measured by ELISA. A total of 2 200 REP sequences in Brucella melitensis DNA were identified. Twelve REP sequences were synthesized for further detecting of the TLR9 agonistic activity. IFN-α expression in RAW264.7 treated with M2, M3, M4, M5, M6, M7, M9, M12 were (26.944 ± 1.868), (46.461 ± 2.562), (34.980 ± 2.055), (43.016 ± 2.162), (62.533 ± 4.031), (67.125 ± 5.069), (18.908 ± 1.633), (39.572 ± 2.465) pg/ml respectively, which significantly increased when compared with the negative control group [(12.594 ± 1.338) pg/ml, t=10.817, 20.295, 15.812, 20.724, 20.365, 18.016, 5.180, 16.660, all P<0.05]. Additionally, TLR9-siRNA can significantly decrease the levels of IFN-α in RAW264.7 treated with M6. REP sequences presented in Brucella melitensis DNA are able to induce IFN-α expression through TLR9, which can be helpful for the understanding of pathogenesis and immunity of Brucella melitensis.

Activated T cells enhance interferon-α production by plasmacytoid dendritic cells stimulated with RNA-containing immune complexes

ObjectivesPatients with systemic lupus erythematosus (SLE) have an ongoing interferon-α (IFN-α) production by plasmacytoid dendritic cells (pDCs). We investigated whether T cells can promote IFN-α production by pDCs.MethodsHuman pDCs were...

Inherited DOCK2 Deficiency in Patients with Early-Onset Invasive Infections

BackgroundCombined immunodeficiencies are marked by inborn errors of T-cell immunity in which the T cells that are present are quantitatively or functionally deficient. Impaired humoral immunity is also common. Patients have severe infections, autoimmunity, or both. The specific molecular, cellular, and clinical features of many types of combined immunodeficiencies remain unknown.MethodsWe performed genetic and cellular immunologic studies involving five unrelated children with early-onset invasive bacterial and viral infections, lymphopenia, and defective T-cell, B-cell, and natural killer (NK)–cell responses. Two patients died early in childhood; after allogeneic hematopoietic stem-cell transplantation, the other three had normalization of T-cell function and clinical improvement.ResultsWe identified biallelic mutations in the dedicator of cytokinesis 2 gene (DOCK2) in these five patients. RAC1 activation was impaired in the T cells. Chemokine-induced migration and actin polymerization were defective in the T cells, B cells, and NK cells. NK-cell degranulation was also affected. Interferon-α and interferon-λ production by peripheral-blood mononuclear cells was diminished after viral infection. Moreover, in DOCK2-deficient fibroblasts, viral replication was increased and virus-induced cell death was enhanced; these conditions were normalized by treatment with interferon alfa-2b or after expression of wild-type DOCK2.ConclusionsAutosomal recessive DOCK2 deficiency is a new mendelian disorder with pleiotropic defects of hematopoietic and nonhematopoietic immunity. Children with clinical features of combined immunodeficiencies, especially with early-onset, invasive infections, may have this condition. (Supported by the National Institutes of Health and others.)