Induction and regulation of IFNs during viral infections

Yeast Two-Hybrid Assay for Investigating Antiviral Innate Immunity

Yeast two-hybrid (YTH) technology is a powerful tool for studying protein interactions and has been widely used in various fields of molecular biology, including the study of antiviral innate immunity. This chapter presents detailed information and experimental procedures for identifying virus-host protein interactions involved in immune regulation using yeast two-hybrid technology.

Molecular cloning and functional study of a Rel homologous gene in sea urchin Strongylocentrotus intermedius

NF-κB (Nuclear factor-kappa B) family proteins are versatile transcription factors that play crucial regulatory roles in cell development, growth, apoptosis, inflammation, and immune response. However, there is limited research on the function of these key genes in echinoderms. In this study, an NF-κB family gene (SiRel) was identified in sea urchin Strongylocentrotus intermedius. The gene has an open reading frame length of 1809 bp and encodes for 602 amino acids. Domain prediction results revealed that the N-terminal of SiRel protein encodes a conserved Rel homology domain (RHD), including the RHD-DNA binding domain and the RHD-dimerization domain. Multiple sequence comparison results showed that the protein sequences of these two domains were conserved. Phylogenetic analysis indicated that SiRel clustered with Strongylocentrotus purpuratus p65 protein and Rel protein of other echinoderms. Results from quantitative real-time PCR demonstrated detectable SiRel mRNA expression in all tested sea urchin tissues, with the highest expression level found in the gills. And SiRel mRNA expression levels were significantly induced after LPS (Lipopolysaccharide) and poly(I:C) (Polyinosinic:polycytidylic acid) stimulation. In addition, SiRel protein expression can be found in cytoplasm and nucleus of HEK293T cells. Co-immunoprecipitation results showed that SiRel could interact with sea urchin IκB (Inhibitor of NF-κB) protein. Western blotting and dual-luciferase reporter gene assay results indicated that overexpression of SiRel in HEK293T cells could impact the phosphorylation levels of JNK (c-Jun N-terminal kinase) and Erk1/2 (Extracellular signal-regulated kinases1/2) and activate interleukin-6 (IL-6), activating protein 1 (AP-1), interferon (IFN)α/β/γ, and signal transducer and activator of transcription 3 (STAT3) reporter genes in HEK293T cells. In conclusion, this study reveals that SiRel plays an important role in the innate immune response of sea urchins and enriches our understanding of comparative immunology theory.

Methotrexate, Tofacitinib, and Biologic Disease-Modifying Antirheumatic Drug Safety and Effectiveness Among Patients with Rheumatoid Arthritis in Japan: CorEvitas Registry Observational Study

INTRODUCTION

The evolution of disease-modifying antirheumatic drugs (DMARDs) for the treatment of rheumatoid arthritis (RA) has improved patient prognosis. However, more real-world safety/effectiveness data comparing methotrexate (MTX), tofacitinib, tumor necrosis factor inhibitors (TNFi), and non-TNFi biologic DMARDs (bDMARDs) are warranted.

METHODS

The CorEvitas RA Japan registry was used to identify patients with rheumatologist-diagnosed RA who initiated MTX/tofacitinib/TNFi/non-TNFi bDMARDs. Safety outcomes included incidence of major adverse cardiovascular events (MACE), total cardiovascular disease, total serious infections, total herpes zoster, and total malignancies (excluding non-melanoma skin cancer). Effectiveness outcomes included change from baseline (Δ) in Clinical Disease Activity Index (CDAI) and proportion of patients achieving a minimum clinically important difference (MCID) in CDAI at month 6. Adjusted regression models were fit; marginal means were estimated.

RESULTS

Overall, 1972 patients were included in the safety cohort: MTX (N = 298); tofacitinib (N = 253); TNFi (N = 663); non-TNFi (N = 758). Mean follow-up time was 3.8, 2.9, 3.0, and 2.9 years for MTX, tofacitinib, TNFi, and non-TNFi, respectively. Adjusted incidence rates (IRs, patients with events/100 patient-years [95% confidence intervals]) for MACE and total cardiovascular disease, respectively, were numerically lower for MTX (0.34 [0, 0.83]; 0.42 [0, 0.92]) and TNFi (0.09 [0, 0.27]; 0.61 [0.15, 1.07]) versus tofacitinib (0.48 [0, 1.20]; 2.30 [0.38, 4.22]) and non-TNFi (0.77 [0.35, 1.19]; 1.28 [0.73, 1.82]). Serious infections were numerically higher for non-TNFi (4.47 [3.38, 5.56]); herpes zoster was higher for tofacitinib (7.41 [4.52, 10.29]), versus other groups. IRs for malignancies were comparable between groups. Mean ΔCDAI and rates of achieving MCID in CDAI at month 6 were generally greater with tofacitinib versus other groups.

CONCLUSION

Some variations in incidence of safety outcomes were observed between treatments, while certain effectiveness outcomes favored tofacitinib. Sample size variation between groups and low number of safety events limited the analysis. Further studies are warranted to investigate observed differences.

CLINICALTRIALS

GOV: NCT05572567.

Temporal regulation of MDA5 inactivation by Caspase-3 dependent cleavage of 14-3-3η

The kinetics of type I interferon (IFN) induction versus the virus replication compete, and the result of the competition determines the outcome of the infection. Chaperone proteins that involved in promoting the activation kinetics of PRRs rapidly trigger antiviral innate immunity. We have previously shown that prior to the interaction with MAVS to induce type I IFN, 14-3-3η facilitates the oligomerization and intracellular redistribution of activated MDA5. Here we report that the cleavage of 14-3-3η upon MDA5 activation, and we identified Caspase-3 activated by MDA5-dependent signaling was essential to produce sub-14-3-3η lacking the C-terminal helix (αI) and tail. The cleaved form of 14-3-3η (sub-14-3-3η) could strongly interact with MDA5 but could not support MDA5-dependent type I IFN induction, indicating the opposite functions between the full-length 14-3-3η and sub-14-3-3η. During human coronavirus or enterovirus infections, the accumulation of sub-14-3-3η was observed along with the activation of Caspase-3, suggesting that RNA viruses may antagonize 14-3-3η by promoting the formation of sub-14-3-3η to impair antiviral innate immunity. In conclusion, sub-14-3-3η, which could not promote MDA5 activation, may serve as a negative feedback to return to homeostasis to prevent excessive type I IFN production and unnecessary inflammation.

Cloning and functional characterization of novel human neutralizing anti-interferon-alpha and anti-interferon-beta antibodies

Type I interferons (IFNs) play a pivotal role in immune response modulation, yet dysregulation is implicated in various disorders. Therefore, it is crucial to develop tools that facilitate the understanding of their mechanism of action and enable the development of more effective anti-IFN therapeutic strategies. In this study, we isolated, cloned, and characterized anti-IFN-α and anti-IFN-β antibodies (Abs) from peripheral blood mononuclear cells of individuals treated with IFN-α or IFN-β, harboring confirmed neutralizing Abs. Clones AH07856 and AH07857 were identified as neutralizing anti-IFN-α-specific with inhibition against IFN-α2a, -α2b, and -αK subtypes. Clones AH07859 and AH07866 were identified as neutralizing anti-IFN-β1a-specific signaling, and able to block Lipopolysaccharide or S100 calcium binding protein A14-induced IFN-β signaling effects. Cloned Abs bind rhesus but not murine IFNs. The specificity of inhibition between IFN-α and IFN-β suggests potential for diverse research and clinical applications.

Dietary supplementation of Chinese herbal medicines enhances the immune response and resistance of rainbow trout (Oncorhynchus mykiss) to infectious hematopoietic necrosis virus

Rainbow trout is a widely farmed economical cold-water fish worldwide, but the prevalence of infectious hematopoietic necrosis virus (IHNV) presents a severe risk to the aquaculture industry, resulting in high mortality and huge economic losses. In this study, the impacts of different concentrations (0, 10, 20, and 30 g/kg) of Chinese herbal medicine mixture (CHMM) on the immune response and resistance of rainbow trout to IHNV infection were evaluated. The results show that CHMM noticeably increased (P < 0.05) T-SOD, CAT, AST, ALT, ACP, and AKP activities and decreased MDA content. NF-κB, TNF-α, IFN-β, IL-1β, JAK1, HSP70, and HSP90 expressions were significantly upregulated (P < 0.05) in all CHMMs, while SOCS2 expression was downregulated (P < 0.05). Following infection with IHNV, feeding rainbow trout with varying amounts of CHMM resulted in noticeably increased (P < 0.05) T-SOD, ACP, and AKP activities and significantly decreased (P < 0.05) MDA content and AST and ALT activities. TNF-α, IFN-β, IL-1β, HSP70, and HSP90 expressions were significantly upregulated (P < 0.05) in all CHMMs, while the expressions of JAK1 and SOCS2 were downregulated. The expression level of the IHNV G protein gene at a dosage of 20 g/kg was notably lower than that of the other CHMM feeding groups. This study provides a solid scientific basis for promoting CHMM as an immunostimulant for boosting antiviral immunity in rainbow trout.

Interferon-γ in the tumor microenvironment promotes the expression of B7H4 in colorectal cancer cells, thereby inhibiting cytotoxic T cells

The bioactivity of interferon-γ (IFN-γ) in cancer cells in the tumor microenvironment (TME) is not well understood in the current immunotherapy era. We found that IFN-γ has an immunosuppressive effect on colorectal cancer (CRC) cells. The tumor volume in immunocompetent mice was significantly increased after subcutaneous implantation of murine CRC cells followed by IFN-γ stimulation, and RNA sequencing showed high expression of B7 homologous protein 4 (B7H4) in these tumors. B7H4 promotes CRC cell growth by inhibiting the release of granzyme B (GzmB) from CD8+ T cells and accelerating apoptosis in CD8+ T cells. Furthermore, interferon regulatory factor 1 (IRF1), which binds to the B7H4 promoter, is positively associated with IFN-γ stimulation-induced expression of B7H4. The clinical outcome of patients with CRC was negatively related to the high expression of B7H4 in cancer cells or low expression of CD8 in the microenvironment. Therefore, B7H4 is a biomarker of poor prognosis in CRC patients, and interference with the IFN-γ/IRF1/B7H4 axis might be a novel immunotherapeutic method to restore the cytotoxic killing of CRC cells.

GSTP1 is a negative regulator of MAVS in the antiviral signaling against SVCV infection

Glutathione S-transferase P1 (GSTP1), the most ubiquitous member of the GST superfamily, plays vital roles in the detoxification, antioxidant defense, and modulation of inflammatory responses. However, limited studies have been conducted on the function of GSTP1 in antiviral innate immunity. In this study, we have cloned the homolog of GSTP1 in triploid hybrid crucian carp (3nGSTP1) and investigated its regulatory role in the interferon signaling pathway. The open reading frame of 3nGSTP1 is composed of 627 nucleotides, encoding 209 amino acids. In response to spring viremia of carp virus (SVCV) infection, the mRNA level of 3nGSTP1 was up-regulated in the liver, kidney, and caudal fin cell lines (3 nF C) of triploid fish. The knockdown of 3nGSTP1 in 3 nF C improved host cell's antiviral capacity and attenuated SVCV replication. Additionally, overexpression of 3nGSTP1 inhibited the activation of IFN promoters induced by SVCV infection, poly (I:C) stimulation, or the RLR signaling factors. The co-immunoprecipitation assays further revealed that 3nGSTP1 interacts with 3nMAVS. In addition, 3nGSTP1 dose-dependently inhibited 3nMAVS-mediated antiviral activity and reduced 3nMAVS protein level. Mechanistically, 3nGSTP1 promoted ubiquitin-proteasome degradation of MAVS by promoting its K48-linked polyubiquitination. To conclude, our results indicate that GSTP1 acts as a novel inhibitor of MAVS, which negatively regulates the IFN signaling.

Advances in the understanding of circRNAs that influence viral replication in host cells

Circular RNAs (circRNAs) are non-coding RNAs discovered in recent years, which are produced by back-splicing involving the 3' and 5' ends of RNA molecules. There is increasing evidence that circRNAs have important roles in cancer, neurological diseases, cardiovascular and cerebrovascular diseases, and other diseases. In addition, host circRNAs and virus-encoded circRNAs participate in the body's immune response, with antiviral roles. This review summarizes the mechanisms by which host and viral circRNAs interact during the host immune response. Comprehensive investigations have revealed that host circRNAs function as miRNA sponges in a particular manner, primarily by inhibiting viral replication. Viral circRNAs have more diverse functions, which generally involve promoting viral replication. In addition, in contrast to circRNAs from RNA viruses, circRNAs from DNA viruses can influence host cell migration, proliferation, and apoptosis, along with their effects on viral replication. In summary, circRNAs have potential as diagnostic and therapeutic targets, offering a foundation for the diagnosis and treatment of viral diseases.

STAT4 Phosphorylation of T-helper Cells predicts surgical outcomes in Refractory Chronic Rhinosinusitis

Objective

Chronic rhinosinusitis (CRS) impacts an estimated 5% to 15% of people worldwide, incurring significant economic healthcare burden. There is a urgent need for the discovery of predictive biomarkers to improve treatment strategies and outcomes for CRS patients.

Study design

Cohort study of CRS patients and healthy controls using blood samples.

Setting

Out-patient clinics.

Methods

Whole blood samples were collected for flow cytometric analysis. Mechanistic studies involved the transfection of human primary T cells and Jurkat cells.

Results

Our analysis began with a 63-69 year-old female patient diagnosed with refractory CRS,. Despite undergoing multiple surgeries, she continually faced sinus infections. Whole exome sequencing pinpointed a heterozygous IL-12Rb1 mutation situated in the linker region adjacent to the cytokine binding domain. When subjected to IL-12 stimulation, the patient's CD4 T-cells exhibited diminished STAT4 phosphorylation. However, computer modeling or T-cell lines harboring the same IL-12 receptor mutation did not corroborate the hypothesis that IL-12Rb could be responsible for the reduced phosphorylation of STAT4 by IL-12 stimulation. Upon expanding our investigation to a broader CRS patient group using the pSTAT4 assay, we discerned a subset of refractory CRS patients with abnormally low STAT4 phosphorylation. The deficiency showed improvement both in-vitro and in-vivo after exposure to Latilactobacillus sakei (aka Lactobacillus sakei), an effect at least partially dependent on IL-12.

Conclusion

In refractory CRS patients, an identified STAT4 defect correlates with poor clinical outcomes after sinus surgery, which can be therapeutically targeted by Latilactobacillus sakei treatment. Prospective double-blind placebo-controlled trials are needed to validate our findings.

Interleukin-36γ is causative for liver damage upon infection with Rift Valley fever virus in type I interferon receptor-deficient mice

Type I interferons (IFN) are pro-inflammatory cytokines which can also exert anti-inflammatory effects via the regulation of interleukin (IL)-1 family members. Several studies showed that interferon receptor (IFNAR)-deficient mice develop severe liver damage upon treatment with artificial agonists such as acetaminophen or polyinosinic:polycytidylic acid. In order to investigate if these mechanisms also play a role in an acute viral infection, experiments with the Bunyaviridae family member Rift Valley fever virus (RVFV) were performed. Upon RVFV clone (cl)13 infection, IFNAR-deficient mice develop a severe liver injury as indicated by high activity of serum alanine aminotransferase (ALT) and histological analyses. Infected IFNAR-/- mice expressed high amounts of IL-36γ within the liver, which was not observed in infected wildtype (WT) animals. In line with this, treatment of WT mice with recombinant IL-36γ induced ALT activity. Furthermore, administration of an IL-36 receptor antagonist prior to infection prevented the formation of liver injury in IFNAR-/- mice, indicating that IL-36γ is causative for the observed liver damage. Mice deficient for adaptor molecules of certain pattern recognition receptors indicated that IL-36γ induction was dependent on mitochondrial antiviral-signaling protein and the retinoic acid-inducible gene-I-like receptor. Consequently, cell type-specific IFNAR knockouts revealed that type I IFN signaling in myeloid cells is critical in order to prevent IL-36γ expression and liver injury upon viral infection. Our data demonstrate an anti-inflammatory role of type I IFN in a model for virus-induced hepatitis by preventing the expression of the novel IL-1 family member IL-36γ.

mRNA COVID-19 vaccine elicits potent adaptive immune response without the persistent inflammation seen in SARS-CoV-2 infection

SARS-CoV-2 infection and vaccination elicit potent immune responses. Our study presents a comprehensive multimodal single-cell dataset of peripheral blood of patients with acute COVID-19 and of healthy volunteers before and after receiving the SARS-CoV-2 mRNA vaccine and booster. We compared host immune responses to the virus and vaccine using transcriptional profiling, coupled with B/T cell receptor repertoire reconstruction. COVID-19 patients displayed an enhanced interferon signature and cytotoxic gene upregulation, absent in vaccine recipients. These findings were validated in an independent dataset. Analysis of B and T cell repertoires revealed that, while the majority of clonal lymphocytes in COVID-19 patients were effector cells, clonal expansion was more evident among circulating memory cells in vaccine recipients. Furthermore, while clonal αβ T cell responses were observed in both COVID-19 patients and vaccine recipients, dramatic expansion of clonal γδT cells was found only in infected individuals. Our dataset enables comparative analyses of immune responses to infection versus vaccination, including clonal B and T cell responses. Integrating our data with publicly available datasets allowed us to validate our findings in larger cohorts. To our knowledge, this is the first dataset to include comprehensive profiling of longitudinal samples from healthy volunteers pre/post SARS-CoV-2 vaccine and booster.

Systemic aspergillosis in a patient with interferon gamma receptor 1 deficiency; a case report

BACKGROUND

Interferon-gamma receptor deficiency is a heterogeneous spectrum of disease which involves mutations in IFNGR1, IFNGR2 genes, and the downstream signaling proteins such as STAT1. These mutations are associated with immunodeficiency 27 A and 27B, making the patient prone to mycobacterial infections. Patients with this condition are also at increased risk for affliction with viral and bacterial infections, such as with the Herpesviridae family, Listeria, and Salmonella. Moreover, SH2B3 mutation is associated with autoimmune and lymphoproliferative conditions.

CASE PRESENTATION

the patient was a 19-month-old infant girl who presented with a two-week history of fever. She had near-normal flowcytometry with high IgM and IgE. She had pneumonic infiltration in her chest and right hilar and para-aortic lymphadenopathy. PCR of whole blood for Aspergillus fumigatus came back positive. In her Whole Exome Sequencing she had IFNGR1 and SH2B3 mutations.

CONCLUSION

systemic fungal infections such as Aspergillosis can occur in patients with interferon-gamma receptor one deficiency. This type of immunodeficiency should be considered in treating patients with systemic Aspergillosis.

Antiviral Therapy of COVID-19

Since the beginning of the COVID-19 pandemic, the scientific community has focused on prophylactic vaccine development. In parallel, the experience of the pharmacotherapy of this disease has increased. Due to the declining protective capacity of vaccines against new strains, as well as increased knowledge about the structure and biology of the pathogen, control of the disease has shifted to the focus of antiviral drug development over the past year. Clinical data on safety and efficacy of antivirals acting at various stages of the virus life cycle has been published. In this review, we summarize mechanisms and clinical efficacy of antiviral therapy of COVID-19 with drugs based on plasma of convalescents, monoclonal antibodies, interferons, fusion inhibitors, nucleoside analogs, and protease inhibitors. The current status of the drugs described is also summarized in relation to the official clinical guidelines for the treatment of COVID-19. In addition, here we describe innovative drugs whose antiviral effect is provided by antisense oligonucleotides targeting the SARS-CoV-2 genome. Analysis of laboratory and clinical data suggests that current antivirals successfully combat broad spectra of emerging strains of SARS-CoV-2 providing reliable defense against COVID-19.

Characterization of the induction kinetics and antiviral functions of IRF1, ISG15 and ISG20 in cells infected with gammacoronavirus avian infectious bronchitis virus

Coronavirus infection induces a variety of cellular antiviral responses either dependent on or independent of type I interferons (IFNs). Our previous studies using Affymetrix microarray and transcriptomic analysis revealed the differential induction of three IFN-stimulated genes (ISGs), IRF1, ISG15 and ISG20, by gammacoronavirus infectious bronchitis virus (IBV) infection of IFN-deficient Vero cells and IFN-competent, p53-defcient H1299 cells, respectively. In this report, the induction kinetics and anti-IBV functions of these ISGs as well as mechanisms underlying their differential induction are characterized. The results confirmed that these three ISGs were indeed differentially induced in H1299 and Vero cells infected with IBV, significantly more upregulation of IRF1, ISG15 and ISG20 was elicited in IBV-infected Vero cells than that in H1299 cells. Induction of these ISGs was also detected in cells infected with human coronavirus-OC43 (HCoV-OC43) and porcine epidemic diarrhea virus (PEDV), respectively. Manipulation of their expression by overexpression, knockdown and/or knockout demonstrated that IRF1 played an active role in suppressing IBV replication, mainly through the activation of the IFN pathway. However, a minor, if any, role in inhibiting IBV replication was played by ISG15 and ISG20. Furthermore, p53, but not IRF1, was implicated in regulating the IBV infection-induced upregulation of ISG15 and ISG20. This study provides new information on the mechanisms underlying the induction of these ISGs and their contributions to the host cell antiviral response during IBV infection.

The Cell-Mediated Immune Response against Bovine alphaherpesvirus 1 (BoHV-1) Infection and Vaccination

Bovine Alphaherpesvirus 1 (BoHV-1) is one of the major respiratory pathogens in cattle worldwide. Infection often leads to a compromised host immune response that contributes to the development of the polymicrobial disease known as “bovine respiratory disease”. After an initial transient phase of immunosuppression, cattle recover from the disease. This is due to the development of both innate and adaptive immune responses. With respect to adaptive immunity, both humoral and cell-mediated immunity are required to control infection. Thus, several BoHV-1 vaccines are designed to trigger both branches of the adaptive immune system. In this review, we summarize the current knowledge on cell-mediated immune responses directed against BoHV-1 infection and vaccination.

Susceptibilidad genética y aclaramiento viral de la infección por Virus de la Hepatitis C

El virus de la hepatitis C (VHC) sigue siendo una de las principales causas de hepatitis crónica en el mundo occidental. Del 15 % al 40 % de los individuos con infección aguda por VHC logran el aclaramiento viral espontáneo; sin embargo, los factores y variables asociadas a este fenómeno no están completamente descritas. El análisis de los mecanismos de patogénesis de la infección por VHC es indispensable para identificar los factores y variables implicadas en el aclaramiento espontáneo o en la persistencia de la infección. En algunos estudios se han documentado los factores del huésped asociados al aclaramiento viral espontáneo durante la infección aguda, entre ellos el polimorfismo del gen de la interleucina -28 (IL28B) que codifica para el interferón lambda 3 (IFNL3). El objetivo de este artículo es realizar una revisión de la literatura sobre la fisiopatología de la infección por el VHC y describir la evidencia acerca del papel de los polimorfismos en el gen IL28B y su impacto en el proceso de aclaramiento viral espontáneo, así como en otros aspectos de la historia natural y el tratamiento de la infección.

Differential expression of interferon inducible protein: Guanylate binding protein (GBP1 & GBP2) in severe dengue

Dengue virus is reported to activate endothelial cells (EC), but the precise cause for severe dengue (SD) is not known. Guanylate binding proteins (GBPs) are IFN-inducible proteins secreted by ECs and are involved in the anti-oxidant and anti-viral response. The involvement of GBPs in the pathogenesis of dengue remains under explored. In the present study, we quantified the mRNA and protein levels of GBP1 and 2 during acute, defervescence and convalescent phase in SD-10, dengue without warning sign-15 and dengue with warning sign-25 compared to other febrile illnesses-10 and healthy controls-8 using RT-PCR and ELISA respectively. Lipid peroxidation in plasma samples were measured using the Kei Satoh method. Protein and DNA oxidation were determined by ELISA. The efficacy of the proteins in predicting disease severity was done by Support Vector Machine (SVM) model. A significant (P ≤ 0.01) decrease in the levels of mRNA and protein of both GBP1 and GBP2 was observed during defervescence in both SD and DWW cases. The levels were significantly (P ≤ 0.05) tapered off in SD cases from acute till critical phases compared to other study groups. DNA, protein and lipid oxidation markers showed an increasing trend in SD (P ≤ 0.01). Both GBP1 & 2 were found to be negatively associated plasma leakage and oxidative stress markers. EC's activated with SD serum showed a reduced expression of GBP 1 and 2. Nevertheless, the SVM model revealed that plasma levels of proteins along with clinical symptoms could predict the disease outcomes with higher precision. This is the first study reporting a downregulated expression of GBP1 & 2 and their association with oxidative stress and plasma leakage in dengue cases. This suggests the importance of GBPs in regulating disease manifestation. However, further investigations are required to ascertain its role as a biomarker or therapeutic target in dengue infection.

Rhinovirus Infection and Virus-Induced Asthma

While the aetiology of asthma is unclear, the onset and/or exacerbation of asthma may be associated with respiratory infections. Virus-induced asthma is also known as virus-associated/triggered asthma, and the reported main causative agent is rhinovirus (RV). Understanding the relationship between viral infections and asthma may overcome the gaps in deferential immunity between viral infections and allergies. Moreover, understanding the complicated cytokine networks involved in RV infection may be necessary. Therefore, the complexity of RV-induced asthma is not only owing to the response of airway and immune cells against viral infection, but also to allergic immune responses caused by the wide variety of cytokines produced by these cells. To better understand RV-induced asthma, it is necessary to elucidate the nature RV infections and the corresponding host defence mechanisms. In this review, we attempt to organise the complexity of RV-induced asthma to make it easily understandable for readers.

Real-world effectiveness and safety of tofacitinib and abatacept in patients with rheumatoid arthritis

OBJECTIVE

We compared the 52-week effectiveness and safety of tofacitinib (TOF) and abatacept (ABT) in patients with RA in a real-world setting and investigated a role of human leucocyte antigens (HLA)-DRB1 shared epitope (SE) in the effectiveness.

METHODS

RA patients starting TOF (n = 187) and ABT (n = 183) were enrolled. Effectiveness was compared after reducing the selection bias to a minimum using the inverse probability of treatment weighting (IPTW) based on propensity scores. The influence of SE alleles on effectiveness was compared within each treatment group. A treatment group comparison was also performed within SE-positive and SE-negative groups.

RESULTS

Herpes zoster and some laboratory abnormalities were more frequent in the TOF group than in the ABT group. Patient characteristics did not differ significantly between treatment groups after adjustments with IPTW. The TOF group had a significantly higher proportion of DAS in 28 joints using ESR (DAS28-ESR) remission at week 52 than the ABT group. The DAS28-ESR at week 12 and thereafter was not affected by the copy number of SE alleles in the TOF group, but decreased significantly as the copy number increased in the ABT group. In SE-positive patients, remission and drug retention rates did not differ significantly between the two treatment groups. In SE-negative patients, the TOF group showed significantly higher remission and drug retention rates than the ABT group.

CONCLUSION

The present results suggest that TOF is more effective with regard to remission at week 52 based on treatment responses in SE-negative RA patients.

Comparative transcriptome analysis of MDBK cells reveals that BoIFN-γ augmented host immune responses to bovine herpesvirus 1 infection

Bovine herpesvirus 1 (BoHV-1) is an alphaherpesvirus that causes infectious bovine rhinotracheitis and infectious pustular vulvovaginitis in cattle. Ιnterferon-gamma (IFN-γ) is a pleiotropic cytokine with antiviral activity that modulates the innate and adaptive immune responses. In this study, we prepared high-purity bovine interferon gamma (BoIFN-γ) dimer protein using prokaryotic expression system and affinity chromatography. We subsequently investigated the effect of BoIFN-γ on BoHV-1 infection in Madin-Darby bovine kidney (MDBK) cells. The results showed that BoIFN-γ pre-treament not only decreased the production of BoHV-1 but also reduced the cytopathic effect of the virus. Differential gene expression profiles of BoHV-1 infected MDBK cells were then analysed through high-throughput RNA sequencing. The data showed that BoIFN-γ pre-treatment reduced lipid metabolism disorder and DNA damage caused by BoHV-1 infection. Furthermore, BoIFN-γ treatment upregulated the transcription of interferon regulatory transcription factors (IRF1 and GBP5) and interferon-stimulated genes (ISGs) of MDBK cells. Additionally, BoIFN-γ promotes expression of cellular protein involved in complement activation and coagulation cascades response as well as antigen processing and presentation process, while BoHV-1 infection dramatically downregulates transcription of these immune components including C3, C1r, C1s, PLAT, ITGB2, PROCR, BoLA, CD74, B2M, PA28, BoLA-DRA, and TAPBP. Collectively, our findings revealed that BoIFN-γ pre-treatment can improve host resistance to BoHV-1 infection and regulate transcription or expression of host protein associated with cellular metabolism and innate immune response. This provides insights into the development of prophylactic agents for prevention and control of BoHV-1 infection.

Incident and recurrent herpes zoster for first-line bDMARD and tsDMARD users in seropositive rheumatoid arthritis patients: a nationwide cohort study

BACKGROUND

There is limited information regarding disease-modifying antirheumatic drug (DMARD)-dependent risks of overall, incident, and recurrent herpes zoster (HZ) during first-line biologic DMARD (bDMARD) or targeted synthetic DMARD (tsDMARD) treatment among patients with seropositive rheumatoid arthritis (RA) in terms of HZ risk.

METHODS

A total of 11,720 patients with seropositive RA who were prescribed bDMARD or tofacitinib between January 2011 and January 2019 from the Korean Health Insurance Review & Assessment Service database were studied. A multivariate Cox proportional hazards regression model was adopted to evaluate the adjusted hazard ratio (aHR) with 95% confidence interval (CI) for the risk of HZ dependent on the choice of first-line bDMARDs or tsDMARD, including etanercept, infliximab, adalimumab, golimumab, tocilizumab, rituximab, tofacitinib, and abatacept.

RESULTS

During the 34,702 person-years of follow-up, 1686 cases (14.4%) of HZ were identified, including 1372 (11.7%) incident and 314 (2.7%) recurrent HZs. Compared with that of the abatacept group, tofacitinib increased the overall risk (aHR, 2.46; 95% CI, 1.61-3.76; P<0.001), incidence (aHR, 1.99; 95% CI, 1.18-3.37; P=0.011), and recurrence (aHR, 3.69; 95% CI, 1.77-7.69; P<0.001) of HZ. Infliximab (aHR, 1.36; 95% CI, 1.06-1.74; P=0.017) and adalimumab (aHR, 1.29; 95% CI, 1.02-1.64; P=0.032) also increased the overall HZ risk. Moreover, a history of HZ was found to be an independent risk factor for HZ (aHR, 1.54; 95% CI, 1.33-1.78; P<0.001).

CONCLUSIONS

HZ risk is significantly increased in RA patients with a history of HZ after the initiation of bDMARDs or tsDMARD. The risk of incident and recurrent HZ was higher after tofacitinib treatment in patients with RA than that after treatment with bDMARDs. Individualized characteristics and history of HZ should be considered when selecting bDMARDs or tsDMARD for RA patients considering HZ risks.

Distinct Immunological Profiles Help in the Maintenance of Salivary Secretory IgA Production in Mild Symptoms COVID-19 Patients

Background

Relevant aspects regarding the SARS-CoV-2 pathogenesis and the systemic immune response to this infection have been reported. However, the mucosal immune response of the upper airways two months after SARS-CoV-2 infection in patients with mild/moderate symptoms is still not completely described. Therefore, we investigated the immune/inflammatory responses of the mucosa of the upper airways of mild/moderate symptom COVID-19 patients two months after the SARS-CoV-2 infection in comparison to a control group composed of non-COVID-19 healthy individuals.

Methods

A cohort of 80 volunteers (age 37.2 ± 8.2), including non-COVID-19 healthy individuals (n=24) and COVID-19 patients (n=56) who presented mild/moderate symptoms during a COVID-19 outbreak in Brazil in November and December of 2020. Saliva samples were obtained two months after the COVID-19 diagnosis to assess the levels of SIgA by ELISA and the cytokines by multiplex analysis.

Results

Salivary levels of SIgA were detected in 39 volunteers into the COVID-19 group and, unexpectedly, in 14 volunteers in the control group. Based on this observation, we distributed the volunteers of the control group into without SIgA or with SIgA sub-groups, and COVID-19 group into without SIgA or with SIgA sub-groups. Individuals with SIgA showed higher levels of IL-10, IL-17A, IFN-γ, IL-12p70, IL-13, and IFN-α than those without SIgA. In intergroup analysis, the COVID-19 groups showed higher salivary levels of IL-10, IL-13, IL-17A, and IFN-α than the control group. No statistical differences were verified in the salivary levels of IL-6 and IFN-β. Lower IL-12p70/IL-10 and IFN-γ/IL-10 ratios were found in the control group without SIgA than the control group with SIgA and the COVID-19 group with SIgA.

Conclusion

We were able to present, for the first time, that associations between distinct immunological profiles can help the mucosal immunity to maintain the salivary levels of SIgA in COVID-19 patients two months after the SARS-CoV-2 infection.

Development of epitope-based chimeric protein as a vaccine against Lujo virus by utilizing immunoinformatic tools

Aim: Lujo is a modern zoonotic virus that is potentially fatal and spreads by bodily fluids. In this research, immunoinformatic tools are used to build a vaccine. Methodology: The epitopes of cytotoxic T-lymphocytes, helper T-lymphocytes and linear B-lymphocytes were predicted from the most antigenic protein. The designed vaccine's physiochemical properties and 3D structure have been forecasted. Low free energy and strong binding affinity estimated in molecular docking against toll-like receptor 4 (TLR4) and dynamic simulation. Furthermore, in silico cloning in the Escherichia coli K12 host system was performed for high level of expression. Conclusion: Finally, immune simulation was used to determine immune responses to the vaccine that was formulated confirming the developed vaccine as a good candidate against Lujo virus.

HMGB1: A Potential Target of Nervus Vagus Stimulation in Pediatric SARS-CoV-2-Induced ALI/ARDS

From the start of pandemics, children were described as the ones who were less affected by SARS-Cov-2 or COVID-19, which was mild in most of the cases. However, with the growing vaccination rate of the adult population, children became more exposed to the virus and more cases of severe SARS-CoV-2-induced ARDS are being diagnosed with the disabling consequences or lethal outcomes associated with the cytokine storm. Thus, we do hypothesize that some of the children could benefit from nervus vagus stimulation during COVID-19 ARDS through the inhibition of HMGB1 release and interaction with the receptor, resulting in decreased neutrophil accumulation, oxidative stress, and coagulopathy as well as lung vascular permeability. Moreover, stimulation through alpha-7 nicotinic acetylcholine receptors could boost macrophage phagocytosis and increase the clearance of DAMPs and PAMPs. Further rise of FGF10 could contribute to lung stem cell proliferation and potential regeneration of the injured lung. However, this stimulation should be very specific, timely, and of proper duration, as it could lead to such adverse effects as increased viral spread and systemic infection, especially in small children or infants due to specific pediatric immunity state and anatomical features of the respiratory system.

Anti-rheumatic drug-induced hepatitis B virus reactivation and preventive strategies for hepatocellular carcinoma

To date, an estimated 3 million people worldwide have been infected with chronic hepatitis B virus (HBV). Although anti-HBV therapies have improved the long-term survival profile of chronic carriers, viral reactivation still poses a significant challenge for preventing HBV-related hepatitis, hepatocellular carcinoma (HCC), and death. Immuno-modulating drugs, which are widely applied in managing rheumatic conditions, are commonly associated with HBV reactivation (HBVr) as a result of drug-induced immune suppression. However, there are few reports on the risk of HBVr and the medication management plan for HBV carriers, especially rheumatic patients. In this review, we summarize immuno-modulating drug-induced HBVr during rheumatoid therapy and its preventive strategies for HBVr-induced liver diseases, especially cirrhosis and HCC. These findings will assist with developing treatments for rheumatic patients, and prevent HBV-related cirrhosis and HCC.

Pharmacological perturbation of CXCL1 signaling alleviates neuropathogenesis in a model of HEVA71 infection

Hand, foot and mouth disease (HFMD) caused by Human Enterovirus A71 (HEVA71) infection is typically a benign infection. However, in minority of cases, children can develop severe neuropathology that culminate in fatality. Approximately 36.9% of HEVA71-related hospitalizations develop neurological complications, of which 10.5% are fatal. Yet, the mechanism by which HEVA71 induces these neurological deficits remain unclear. Here, we show that HEVA71-infected astrocytes release CXCL1 which supports viral replication in neurons by activating the CXCR2 receptor-associated ERK1/2 signaling pathway. Elevated CXCL1 levels correlates with disease severity in a HEVA71-infected mice model. In humans infected with HEVA71, high CXCL1 levels are only present in patients presenting neurological complications. CXCL1 release is specifically triggered by VP4 synthesis in HEVA71-infected astrocytes, which then acts via its receptor CXCR2 to enhance viral replication in neurons. Perturbing CXCL1 signaling or VP4 myristylation strongly attenuates viral replication. Treatment with AZD5069, a CXCL1-specific competitor, improves survival and lessens disease severity in infected animals. Collectively, these results highlight the CXCL1-CXCR2 signaling pathway as a potential target against HFMD neuropathogenesis.

The Impact of Rubella Virus Infection on a Secondary Inflammatory Response in Polarized Human Macrophages

Macrophages (MΦ) are known to exhibit distinct responses to viral and bacterial infection, but how they react when exposed to the pathogens in succession is less well understood. Accordingly, we determined the effect of a rubella virus (RV)-induced infection followed by an LPS-induced challenge on cytokine production, signal transduction and metabolic pathways in human GM (M1-like)- and M (M2-like)-MΦ. We found that infection of both subsets with RV resulted in a low TNF-α and a high interferon (IFN, type I and type III) release whereby M-MΦ produced far more IFNs than GM-MΦ. Thus, TNF-α production in contrast to IFN production is not a dominant feature of RV infection in these cells. Upon addition of LPS to RV-infected MΦ compared to the addition of LPS to the uninfected cells the TNF-α response only slightly increased, whereas the IFN-response of both subtypes was greatly enhanced. The subset specific cytokine expression pattern remained unchanged under these assay conditions. The priming effect of RV was also observed when replacing RV by IFN-β one putative priming stimulus induced by RV. Small amounts of IFN-β were sufficient for phosphorylation of Stat1 and to induce IFN-production in response to LPS. Analysis of signal transduction pathways activated by successive exposure of MΦ to RV and LPS revealed an increased phosphorylation of NFκB (M-MΦ), but different to uninfected MΦ a reduced phosphorylation of ERK1/2 (both subtypes). Furthermore, metabolic pathways were affected; the LPS-induced increase in glycolysis was dampened in both subtypes after RV infection. In conclusion, we show that RV infection and exogenously added IFN-β can prime MΦ to produce high amounts of IFNs in response to LPS and that changes in glycolysis and signal transduction are associated with the priming effect. These findings will help to understand to what extent MΦ defense to viral infection is modulated by a following exposure to a bacterial infection.

Sex differences in innate anti-viral immune responses to respiratory viruses and in their clinical outcomes in a birth cohort study

The mechanisms explaining excess morbidity and mortality in respiratory infections among males are poorly understood. Innate immune responses are critical in protection against respiratory virus infections. We hypothesised that innate immune responses to respiratory viruses may be deficient in males. We stimulated peripheral blood mononuclear cells from 345 participants at age 16 years in a population-based birth cohort with three live respiratory viruses (rhinoviruses A16 and A1, and respiratory syncytial virus) and two viral mimics (R848 and CpG-A, to mimic responses to SARS-CoV-2) and investigated sex differences in interferon (IFN) responses. IFN-α responses to all viruses and stimuli were 1.34-2.06-fold lower in males than females (P = 0.018 -  < 0.001). IFN-β, IFN-γ and IFN-induced chemokines were also deficient in males across all stimuli/viruses. Healthcare records revealed 12.1% of males and 6.6% of females were hospitalized with respiratory infections in infancy (P = 0.017). In conclusion, impaired innate anti-viral immunity in males likely results in high male morbidity and mortality from respiratory virus infections.

Inhaled interferons beta and SARS-COV2 infection: a preliminary therapeutic perspective

Introduction

SARS-COV2 infection represents a therapeutic challenge due to the limited number of effective therapies available and due to the fact that it is not clear which host response in terms of inflammation pattern is the most predictive for an optimal (and rapid) recovery. Interferon β pathway is impaired in SARS-COV2 infection and this is associated with a bigger disease burden. Exogenous inhaled interferon might be beneficial in this setting.

Areas covered

Nebulized interferon-β is currently investigated as a potential therapy for SARS-COV2 because the available data from a phase II study demonstrate that this medication is able to accelerate the recovery from disease.

Expert opinion

Further clinical studies are needed in order to better document the efficacy of this therapy especially in severe forms of COVID-19, the optimal duration of therapy and if such a medication is appropriate for domiciliary use. Also combined regimens with antivirals or with compounds which are able to enhance the endogenous production of interferon might be of promise.

Adipocyte inflammation and pathogenesis of viral pneumonias: an overlooked contribution

Epidemiological evidence establishes obesity as an independent risk factor for increased susceptibility and severity to viral respiratory pneumonias associated with H1N1 influenza and SARS-CoV-2 pandemics. Given the global obesity prevalence, a better understanding of the mechanisms behind obese susceptibility to infection is imperative. Altered immune cell metabolism and function are often perceived as a key causative factor of dysregulated inflammation. However, the contribution of adipocytes, the dominantly altered cell type in obesity with broad inflammatory properties, to infectious disease pathogenesis remains largely ignored. Thus, skewing of adipocyte-intrinsic cellular metabolism may lead to the development of pathogenic inflammatory adipocytes, which shape the overall immune responses by contributing to either premature immunosenescence, delayed hyperinflammation, or cytokine storm in infections. In this review, we discuss the underappreciated contribution of adipocyte cellular metabolism and adipocyte-produced mediators on immune system modulation and how such interplay may modify disease susceptibility and pathogenesis of influenza and SARS-CoV-2 infections in obese individuals.

UMP-CMP kinase 2 gene expression in macrophages is dependent on the IRF3-IFNAR signaling axis

Toll-like receptors (TLRs) are highly-conserved pattern recognition receptors that mediate innate immune responses to invading pathogens and endogenous danger signals released from damaged and dying cells. Activation of TLRs trigger downstream signaling cascades, that culminate in the activation of interferon regulatory factors (IRFs), which subsequently leads to type I interferon (IFN) response. In the current study, we sought to expand the scope of gene expression changes in THP1-derived macrophages upon TLR4 activation and to identify interferon-stimulated genes. RNA-seq analysis led to the identification of several known and novel differentially expressed genes, including CMPK2, particularly in association with type I IFN signaling. We performed an in-depth characterization of CMPK2 expression, a nucleoside monophosphate kinase that supplies intracellular UTP/CTP for nucleic acid synthesis in response to type I IFN signaling in macrophages. CMPK2 was significantly induced at both RNA and protein levels upon stimulation with TLR4 ligand-LPS and TLR3 ligand-Poly (I:C). Confocal microscopy and subcellular fractionation indicated CMPK2 localization in both cytoplasm and mitochondria of THP-1 macrophages. Furthermore, neutralizing antibody-based inhibition of IFNAR receptor in THP-1 cells and BMDMs derived from IFNAR KO and IRF3 KO knockout mice further revealed that CMPK2 expression is dependent on LPS/Poly (I:C) mediated IRF3- type I interferon signaling. In summary, our findings suggest that CMPK2 is a potential interferon-stimulated gene in THP-1 macrophages and that CMPK2 may facilitate IRF3- type I IFN-dependent anti-bacterial and anti-viral roles.

Proteomic Characterization of the Cellular Effects of AhR Activation by Microbial Tryptophan Catabolites in Endotoxin-Activated Human Macrophages

Sensing microbial tryptophan catabolites by the aryl hydrocarbon receptor (AhR) plays a pivotal role in host-microbiome homeostasis by modulating the host immune response. Nevertheless, the involved cellular processes triggered by the metabolites are mainly unknown. Here, we analyzed proteomic changes in macrophages after treatment with the tryptophan metabolites indole-3-acetic acid (I3AA) or indole-3-aldehyde (IAld), as well as the prototypic exogenous AhR-ligand benzo(a)pyrene (BaP) in the absence and presence of lipopolysaccharide (LPS) to identify affected cellular processes and pathways. The AhR-ligands regulated metabolic and immunologic processes in dependency of LPS co-stimulation. All investigated ligands time-dependently enhanced fatty acid β-oxidation. Differences due to the combination with LPS were observed for all three ligands. Additionally, oxidative phosphorylation was significantly increased by IAld and I3AA in a time and LPS-dependent manner. Immunoregulatory processes were affected in distinct ways. While BaP and I3AA up-regulated IL-8 signaling, IL-6 signaling was decreased by IAld. BaP decreased the inflammasome pathway. Thus, AhR-ligand-dependent regulations were identified, which may modulate the response of macrophages to bacterial infections, but also the commensal microbiota through changes in immune cell signaling and metabolic pathways that may also alter functionality. These findings highlight the relevance of AhR for maintaining microbial homeostasis and, consequently, host health.

Progress in Traditional Chinese Medicine Against Respiratory Viruses: A Review

Respiratory viruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV)-1, SARS-CoV-2, influenza A viruses, and respiratory syncytial virus, pose a serious threat to society. Based on the guiding principles of “holism” and “syndrome differentiation and treatment”, traditional Chinese medicine (TCM) has unique advantages in the treatment of respiratory virus diseases owing to the synergistic effect of multiple components and targets, which prevents drug resistance from arising. According to TCM theory, there are two main strategies in antiviral treatments, namely “dispelling evil” and “fu zheng”. Dispelling evil corresponds to the direct inhibition of virus growth and fu zheng corresponds to immune regulation, inflammation control, and tissue protection in the host. In this review, current progress in using TCMs against respiratory viruses is summarized according to modern biological theories. The prospects for developing TCMs against respiratory viruses is discussed to provide a reference for the research and development of innovative TCMs with multiple components, multiple targets, and low toxicity.

A Role of Variance in Interferon Genes to Disease Severity in COVID-19 Patients

The rapid rise and global consequences of the novel coronavirus disease 19 (COVID-19) have again brought the focus of the scientific community on the possible host factors involved in patient response and outcome to exposure to the virus. The disease severity remains highly unpredictable, and individuals with none of the aforementioned risk factors may still develop severe COVID-19. It was shown that genotype-related factors like an ABO Blood Group affect COVID-19 severity, and the risk of infection with SARS-CoV-2 was higher for patients with blood type A and lower for patients with blood type O. Currently it is not clear which specific genes are associated with COVID-19 severity. The comparative analysis of COVID-19 and other viral infections allows us to predict that the variants within the interferon pathway genes may serve as markers of the magnitude of immune response to specific pathogens. In particular, various members of Class III interferons (lambda) are reviewed in detail.

African swine fever virus protein MGF-505-7R promotes virulence and pathogenesis by inhibiting JAK1- and JAK2-mediated signaling

African swine fever virus (ASFV) is a large DNA virus that is highly contagious and pathogenic in domestic pigs with a mortality rate up to 100%. However, how ASFV suppresses JAK-STAT1 signaling to evade the immune response remains unclear. In this study, we found that the ASFV-encoded protein MGF-505-7R inhibited proinflammatory IFN-γ-mediated JAK-STAT1 signaling. Mechanistically, MGF-505-7R was found to interact with JAK1 and JAK2 and mediate their degradation. Further study indicated that MGF-505-7R promoted degradation of JAK1 and JAK2 by upregulating the E3 ubiquitin ligase RNF125 expression and inhibiting expression of Hes5, respectively. Consistently, MGF-505-7R-deficient ASFV induced high levels of IRF1 expression and displayed compromised replication both in primary porcine alveolar macrophages and pigs compared with wild-type ASFV. Furthermore, MGF-505-7R deficiency attenuated the virulence of the ASFV and pathogenesis of ASF in pigs. These findings suggest that the JAK-STAT1 axis mediates the innate immune response to the ASFV and that MGF-505-7R plays a critical role in the virulence of the ASFV and pathogenesis of ASF by antagonizing this axis. Thus, we conclude that deletion of MGF-505-7R may serve as a strategy to develop attenuated vaccines against the ASFV.

The Impact of Human Herpesviruses in Clinical Practice of Inflammatory Bowel Disease in the Era of COVID-19

Human herpesviruses (HHVs): herpes simplex virus (HSV) types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), HHV-6, HHV-7, and HHV-8, are known to be part of a family of DNA viruses that cause several diseases in humans. In clinical practice of inflammatory bowel disease (IBD), the complication of CMV enterocolitis, which is caused by CMV reactivation under disruption of intestinal barrier function, inflammation, or strong immunosuppressive therapy, is well known to affect the prognosis of disease. However, the relationship between other HHVs and IBD remains unclear. In the transplantation field, reactivation of other viruses, such as HHV-6, could cause colitis under immunosuppressed condition. Recent research revealed that combined infection of some HHVs could be a risk factor for colectomy in patients with ulcerative colitis. This suggests that it would be important to clarify HHV behavior in the treatment for patients with IBD, especially in those under immunosuppressive therapies. Looking at the relationship with recently emerged novel coronaviruses (SARS-CoV-2), there are reports describe that SARS-CoV-2 might induce reactivation of HSV-1, EBV, VZV (herpes zoster), and HHV-6/7. If SARS-CoV-2 infection becomes common, vigilance against HHV reactivation may become more crucial. In this review, we discuss the impact of HHVs in clinical practice of inflammatory bowel diseases, especially during the SARS-CoV-2 pandemic.

Virus-like vesicles based on SFV-containing rabies virus glycoprotein make a safe and efficacious rabies vaccine candidate in a mouse model

Rabies is a fatal zoonosis causing encephalitis in mammals, and vaccination is the most effective method to control and eliminate rabies. Virus-like vesicles (VLVs), which are characterized as infectious, self-propagating membrane-enveloped particles composed of only Semliki Forest virus (SFV) replicase and vesicular stomatitis virus glycoprotein (VSV-G), have been proven safe and efficient as vaccine candidates. However, previous studies showed that VLVs containing rabies virus glycoprotein (RABV-G) grew at relatively low titers in cells, impeding their potential use as a rabies vaccine. In this study, we constructed novel VLVs by transfection of a mutant SFV RNA replicon encoding RABV-G. We found these VLVs could self-propagate efficiently in cell culture and could evolve to high titers (approximately 10⁸ FFU/ml) by extensive passaging 25 times in BHK-21 cells. Furthermore, we found that the evolved amino acid change in SFV nsP1 at positions 470 and 482 was critical for this high-titer phenotype. Remarkably, VLVs could induce robust type I IFN expression in BV2 cells and were highly sensitive to IFN-α. We found that direct inoculation of VLVs into the mouse brain caused lesser body weight loss, mortality and neuroinflammation compared with RABV vaccine strain. Finally, it could induce increased generation of germinal centre (GC) B cells, plasma cells (PCs) and virus-neutralizing antibodies (VNAs), as well as provide protection against virulent RABV challenge in immunized mice. This study demonstrated that VLVs containing RABV-G could proliferate in cells and were highly evolvable, revealing the feasibility of developing an economic, safe and efficacious rabies vaccine. IMPORTANCE VLVs have been shown to represent a more versatile and superior vaccine platform. In previous studies, VLVs containing the Semliki Forest Virus replicase (SFV nsP1-4) and rabies virus glycoprotein (RABV-G) grew to relatively low titers in cells. In our study, we not only succeeded in generating VLVs that proliferate in cells and stably express RABV-G, the VLVs that evolved grew to higher titers reaching 10⁸ FFU/ml. We also found that nucleic acid changes at positions 470 and 482 in nsP1 were vital for this high-titer phenotype. Moreover, the VLVs that evolved in our studies were highly attenuated in mice, induced potent immunity and protected mice from lethal RABV infection. Collectively, our study showed that high titers of VLVs containing RABV-G were achieved demonstrating that these VLVs could be an economical, safe, and efficacious rabies vaccine candidate.

Immunity and Viral Infections: Modulating Antiviral Response via CRISPR-Cas Systems

Viral infections cause a variety of acute and chronic human diseases, sometimes resulting in small local outbreaks, or in some cases spreading across the globe and leading to global pandemics. Understanding and exploiting virus-host interactions is instrumental for identifying host factors involved in viral replication, developing effective antiviral agents, and mitigating the severity of virus-borne infectious diseases. The diversity of CRISPR systems and CRISPR-based tools enables the specific modulation of innate immune responses and has contributed impressively to the fields of virology and immunology in a very short time. In this review, we describe the most recent advances in the use of CRISPR systems for basic and translational studies of virus-host interactions.

Between immunomodulation and immunotolerance: The role of IFNγ in SARS-CoV-2 disease

Interferons have prominent roles in various pathophysiological conditions, mostly related to inflammation. Interferon-gamma (IFNγ) was, initially discovered as a potent antiviral agent, over 50 years ago, and has recently garnered renewed interest as a promising factor involved in both innate and adaptive immunity. When new disease epidemics appear such as SARS-CoV (severe acute respiratory syndrome coronavirus), MERS-CoV (Middle East respiratory syndrome coronavirus), IAV (Influenza A virus), and in particular the current SARS-CoV-2 pandemic, it is especially timely to review the complexity of immune system responses to viral infections. Here we consider the controversial roles of effectors like IFNγ, discussing its actions in immunomodulation and immunotolerance. We explore the possibility that modulation of IFNγ could be used to influence the course of such infections. Importantly, not only could endogenous expression of IFNγ influence the outcome, there are existing IFNγ therapeutics that can readily be applied in the clinic. However, our understanding of the molecular mechanisms controlled by IFNγ suggests that the exact timing for application of IFNγ-based therapeutics could be crucial: it should be earlier to significantly reduce the viral load and thus decrease the overall severity of the disease.

Double-edged effects of interferons on the regulation of cancer-immunity cycle

Interferons (IFNs) are a large family of pleiotropic cytokines that regulate both innate and adaptive immunity and show anti-cancer effects in various cancer types. Moreover, it was revealed that IFN signaling plays critical roles in the success of cancer therapy strategies, thereby enhancing their therapeutic effects. However, IFNs have minimal or even adverse effects on cancer eradication, and mediate cancer immune escape in some instances. Thus, IFNs have a double-edged effect on the cancer immune response. Recent studies suggest that IFNs regulate each step of the cancer immunity-cycle, consisting of cancer antigen release, presentation of antigens and activation of T cells, trafficking and infiltration of effector T cells into the tumor microenvironment, and recognition and killing of cancer cells, which contributes to our understanding of the mechanisms of IFNs in regulating cancer immunity. In this review, we focus on IFNs and cancer immunity and elaborate on the roles of IFNs in regulating the cancer-immunity cycle.

Interferon α2-Thymosin α1 Fusion Protein (IFNα2-Tα1): A Genetically Engineered Fusion Protein with Enhanced Anticancer and Antiviral Effect

Human interferon α2 (IFNα2) and thymosin α1 (Tα1) are therapeutic proteins used for the treatment of viral infections and different types of cancer. Both IFNα2 and Tα1 show a synergic effect in their activities when used in combination. Furthermore, the therapeutic fusion proteins produced through the genetic fusion of two genes can exhibit several therapeutic functions in one molecule. In this study, we determined the anticancer and antiviral effect of human interferon α2-thymosin α1 fusion protein (IFNα2-Tα1) produced in our laboratory for the first time. The cytotoxic and genotoxic effect of IFNα2-Tα1 was evaluated in HepG2 and MDA-MB-231 cells. The in vitro assays confirmed that IFNα2-Tα1 inhibited the growth of cells more effectively than IFNα2 alone and showed an elevated genotoxic effect. The expression of proapoptotic genes was also significantly enhanced in IFNα2-Tα1-treated cells compared to IFNα2-treated cells. Furthermore, the HCV RNA level was significantly reduced in IFNα2-Tα1-treated HCV-infected Huh7 cells compared to IFNα2-treated cells. The quantitative PCR analysis showed that the expression of various genes, the products of which inhibit HCV replication, was significantly enhanced in IFNα2-Tα1-treated cells compared to IFNα2-treated cells. Our findings demonstrate that IFNα2-Tα1 is more effective than single IFNα2 as an anticancer and antiviral agent.

The inhibitory receptor Tim-3 fails to suppress IFN-γ production via the NFAT pathway in NK-cell, unlike that in CD4+ T cells

Background

T cell immunoglobulin and mucin domain-containing-3 (Tim-3) is a negative regulator expressed on T cells, and is also expressed on natural killer (NK) cells. The function of Tim-3 chiefly restricts IFNγ-production in T cells, however, the impact of Tim-3 on NK cell function has not been clearly elucidated.

Results

In this study, we demonstrated down-regulation of Tim-3 expression on NK cells while Tim-3 is upregulated on CD4⁺ T cells during HIV infection. Functional assays indicated that Tim-3 mediates suppression of CD107a degranulation in NK cells and CD4⁺ T cells, while it fails to inhibit the production of IFN-γ by NK cells. Analyses of downstream pathways using an antibody to block Tim-3 function demonstrated that Tim-3 can inhibit ERK and NFκB p65 signaling; however, it failed to suppress the NFAT pathway. Further, we found that the NFAT activity in NK cells was much higher than that in CD4⁺ T cells, indicating that NFAT pathway is important for promotion of IFN-γ production by NK cells.

Conclusions

Thus, our data show that the expression of Tim-3 on NK cells is insufficient to inhibit IFN-γ production. Collectively, our findings demonstrate a potential mechanism of Tim-3 regulation of NK cells and a target for HIV infection immunotherapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12865-021-00417-9.

Tofacitinib-induced Ramsay- Hunt Syndrome in a Patient with Rheumatoid Arthritis

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by joint and systemic involvement. Tofacitinib is a JAK- inhibitor that is an effective agent in the treatment of active RA. Varicella zoster virus(VZV) reactivation is among the most important adverse effects of tofacitinib. Ramsay-Hunt syndrome(RHS) is a rare clinical condition that develops as a result of VZV reactivation and progresses with hearing loss, dizziness, and facial nerve paralysis.

OBJECTIVE

To present a case of Ramsay-Hunt syndrome due to varicella zoster reactivation in a RA patient using tofacitinib.

CASE REPORT

A 63-year-old female RA patient under tofacitinib treatment was admitted to the rheumatology outpatient clinic due to widespread skin rashes on her face and ear, and hearing loss. On inspection widespread erythematous, vesicular rashes on the left side of the face, lips, around the eye and in the ear, and mild facial paralysis on the left side were detected. On laboratory investigations, acute phase reactants were increased. Serological study for specific antibodies against varicella zoster virus showed higher titers. Dermatology and ear nose throat specialist consultations were performed, and varicella zoster lesions on the left inner ear, face, and mild facial paresis were considered. According to clinical and laboratory findings, the patient was diagnosed with RHS triggered by tofacitinib. Tofacitinib and methotrexate were discontinued, and intravenous acyclovir was started. On the control examination, the patient's skin lesions and facial nerve paralysis regressed.

CONCLUSION

Herein, we reported the fırst case of tofacitinib-induced RHS in a patient with RA. This may be another side effect of biologic treatment. New studies are needed on this subject.

Genetic Delivery and Gene Therapy in Pulmonary Hypertension

Pulmonary hypertension (PH) is a progressive complex fatal disease of multiple etiologies. Hyperproliferation and resistance to apoptosis of vascular cells of intimal, medial, and adventitial layers of pulmonary vessels trigger excessive pulmonary vascular remodeling and vasoconstriction in the course of pulmonary arterial hypertension (PAH), a subgroup of PH. Multiple gene mutation/s or dysregulated gene expression contribute to the pathogenesis of PAH by endorsing the proliferation and promoting the resistance to apoptosis of pulmonary vascular cells. Given the vital role of these cells in PAH progression, the development of safe and efficient-gene therapeutic approaches that lead to restoration or down-regulation of gene expression, generally involved in the etiology of the disease is the need of the hour. Currently, none of the FDA-approved drugs provides a cure against PH, hence innovative tools may offer a novel treatment paradigm for this progressive and lethal disorder by silencing pathological genes, expressing therapeutic proteins, or through gene-editing applications. Here, we review the effectiveness and limitations of the presently available gene therapy approaches for PH. We provide a brief survey of commonly existing and currently applicable gene transfer methods for pulmonary vascular cells in vitro and describe some more recent developments for gene delivery existing in the field of PH in vivo.

Direct Evidence of Abortive Lytic Infection-Mediated Establishment of Epstein-Barr Virus Latency During B-Cell Infection

Viral infection induces dynamic changes in transcriptional profiles. Virus-induced and antiviral responses are intertwined during the infection. Epstein-Barr virus (EBV) is a human gammaherpesvirus that provides a model of herpesvirus latency. To measure the transcriptome changes during the establishment of EBV latency, we infected EBV-negative Akata cells with EBV-EGFP and performed transcriptome sequencing (RNA-seq) at 0, 2, 4, 7, 10, and 14 days after infection. We found transient downregulation of mitotic division-related genes, reflecting reprogramming of cell growth by EBV, and a burst of viral lytic gene expression in the early phase of infection. Experimental and mathematical investigations demonstrate that infectious virions were not produced in the pre-latent phase, suggesting the presence of an abortive lytic infection. Fate mapping using recombinant EBV provided direct evidence that the abortive lytic infection in the pre-latent phase converges to latent infection during EBV infection of B-cells, shedding light on novel roles of viral lytic gene(s) in establishing latency. Furthermore, we find that the BZLF1 protein, which is a key regulator of reactivation, was dispensable for abortive lytic infection in the pre-latent phase, suggesting the divergent regulation of viral gene expressions from a productive lytic infection.

Testicular Atrophy and Hypothalamic Pathology in COVID-19: Possibility of the Incidence of Male Infertility and HPG Axis Abnormalities

Coronavirus disease 2019 (COVID-19), which resulted from the pandemic outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a massive inflammatory cytokine storm leading to multi-organ damage including that of the brain and testes. While the lungs, heart, and brain are identified as the main targets of SARS-CoV-2-mediated pathogenesis, reports on its testicular infections have been a subject of debate. The brain and testes are physiologically synchronized by the action of gonadotropins and sex steroid hormones. Though the evidence for the presence of the viral particles in the testicular biopsies and semen samples from COVID-19 patients are highly limited, the occurrence of testicular pathology due to abrupt inflammatory responses and hyperthermia has incresingly been evident. The reduced level of testosterone production in COVID-19 is associated with altered secretion of gonadotropins. Moreover, hypothalamic pathology which results from SARS-CoV-2 infection of the brain is also evident in COVID-19 cases. This article revisits and supports the key reports on testicular abnormalities and pathological signatures in the hypothalamus of COVID-19 patients and emphasizes that testicular pathology resulting from inflammation and oxidative stress might lead to infertility in a significant portion of COVID-19 survivors. Further investigations are required to monitor the reproductive health parameters and HPG axis abnormalities related to secondary pathological complications in COVID-19 patients and survivors.

Exploring the Pivotal Immunomodulatory and Anti-Inflammatory Potentials of Glycyrrhizic and Glycyrrhetinic Acids

Licorice extract is a Chinese herbal medication most often used as a demulcent or elixir. The extract usually consists of many components but the key ingredients are glycyrrhizic (GL) and glycyrrhetinic acid (GA). GL and GA function as potent antioxidants, anti-inflammatory, antiviral, antitumor agents, and immuneregulators. GL and GA have potent activities against hepatitis A, B, and C viruses, human immunodeficiency virus type 1, vesicular stomatitis virus, herpes simplex virus, influenza A, severe acute respiratory syndrome-related coronavirus, respiratory syncytial virus, vaccinia virus, and arboviruses. Also, GA was observed to be of therapeutic valve in human enterovirus 71, which was recognized as the utmost regular virus responsible for hand, foot, and mouth disease. The anti-inflammatory mechanism of GL and GA is realized via cytokines like interferon-γ, tumor necrotizing factor-α, interleukin- (IL-) 1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, and IL-17. They also modulate anti-inflammatory mechanisms like intercellular cell adhesion molecule 1 and P-selectin, enzymes like inducible nitric oxide synthase (iNOS), and transcription factors such as nuclear factor-kappa B, signal transducer and activator of transcription- (STAT-) 3, and STAT-6. Furthermore, DCs treated with GL were capable of influencing T-cell differentiation toward Th1 subset. Moreover, GA is capable of blocking prostaglandin-E2 synthesis via blockade of cyclooxygenase- (COX-) 2 resulting in concurrent augmentation nitric oxide production through the enhancement of iNOS2 mRNA secretion in Leishmania-infected macrophages. GA is capable of inhibiting toll-like receptors as well as high-mobility group box 1.

Type I Interferons and Malaria: A Double-Edge Sword Against a Complex Parasitic Disease

Type I interferons (IFN-Is) are important cytokines playing critical roles in various infections, autoimmune diseases, and cancer. Studies have also shown that IFN-Is exhibit 'conflicting' roles in malaria parasite infections. Malaria parasites have a complex life cycle with multiple developing stages in two hosts. Both the liver and blood stages of malaria parasites in a vertebrate host stimulate IFN-I responses. IFN-Is have been shown to inhibit liver and blood stage development, to suppress T cell activation and adaptive immune response, and to promote production of proinflammatory cytokines and chemokines in animal models. Different parasite species or strains trigger distinct IFN-I responses. For example, a Plasmodium yoelii strain can stimulate a strong IFN-I response during early infection, whereas its isogenetic strain does not. Host genetic background also greatly influences IFN-I production during malaria infections. Consequently, the effects of IFN-Is on parasitemia and disease symptoms are highly variable depending on the combination of parasite and host species or strains. Toll-like receptor (TLR) 7, TLR9, melanoma differentiation-associated protein 5 (MDA5), and cyclic GMP-AMP synthase (cGAS) coupled with stimulator of interferon genes (STING) are the major receptors for recognizing parasite nucleic acids (RNA/DNA) to trigger IFN-I responses. IFN-I levels in vivo are tightly regulated, and various novel molecules have been identified to regulate IFN-I responses during malaria infections. Here we review the major findings and progress in ligand recognition, signaling pathways, functions, and regulation of IFN-I responses during malaria infections.

Expression of porcine interferon-α and its bioactivity analysis in vitro and in vivo

Interferon α (IFN-α) plays a crucial role in the host's immune response. In this study, the amino acid sequence of porcine interferon α (PoIFN-α) was analyzed. Seven substitutions, S38F, H40Q, F43L, N78D, Y86C, S151A, and R156T, were mutated and obtained by aligning the sequences of PoIFN-α subtypes. The PoIFN-α mutants were designed, expressed, and purified in E. coli. The antiviral activities of these PoIFN-αs were measured in Vero and swine testis cells against vesicular stomatitis virus (VSV). Their inhibitory abilities on pseudorabies virus (PRV) were also examined. Commercial PoIFN-α was used as a control. We found the ideal inducer concentration of isopropyl β-D-thiogalactoside was 1 mM, and the best time-point for induction was 8 h. The PoIFN-α mutant named PoIFN-α-156s had the highest antiviral activity, which was about 200-fold more than that of PoIFN-α. PoIFN-α-156s could inhibit VSV and PRV replication in a dose-dependent manner in vitro. The half-life of PoIFN-α-156s was longer than that of PoIFN-α in mice, and the effective antiviral action was higher than PoIFN-α. Animal experiments showed that PoIFN-α-156s could decrease the viral load after infection with VSV. Overall, these results suggest that recombinant PoIFN-α-156s has the ability of antivirus, and is feasible for veterinary clinical applications and fundamental research.