Overdose with the anesthetic propofol causes hematological cytotoxicity and immune cell alteration in an experimental ex vivo whole blood culture model

Propofol, an anesthetic characterized by its benefits of rapid induction, maintenance, and recovery times, may cause cytotoxic effects, resulting in propofol infusion syndrome (PRIS). In addition to causing dyslipidemia in PRIS, our previous works showed that propofol overdose induced phagocyte apoptosis. This study, using an experimental ex vivo model of propofol treatment, investigated the possible cytopathology in the blood. A complete blood count examination showed the deregulating effects of propofol overdose 24 h postinoculation, characterized by mononuclear cell increase (lymphocyte and monocyte subsets) and granulocyte decrease. Advanced marker-based flow cytometric analysis confirmed these findings, although there was no change in CD14+ monocytes. Blood smear staining showed the deregulating effects of propofol overdose 24 h postinoculation, characterized by cytosolic vacuolization and cytotoxicity, particularly in neutrophils. Immune cell profiling of caspase-3 activation demonstrated the induction of cell apoptosis following propofol overdose treatment, particularly in granulocytes. Using multiparameter flow cytometry, this study further analyzed the changes in the profile of immune cells, showing a notable increase in CD4 + HLA-DR-CD62L- helper T cells. These studies explored an ex vivo model of cytopathogenic propofol overdose and its special immune-deregulating effects on peripheral blood cells.

Efficacy and Safety of Bruton Tyrosine Kinase Inhibitor Plus Anti-CD20 Antibody Therapy Compared With Chemoimmunotherapy as Front-line Treatment for Chronic Lymphocytic Leukemia: A Systematic Review and Meta-analysis of Randomized Controlled Trials

Treatment with chemoimmunotherapy (CIT) is considered an appropriate front-line treatment option for chronic lymphocytic leukemia (CLL). However, outcomes remain suboptimal. Bruton tyrosine kinase inhibitor (BTKi) combined with anti-CD20 antibody is an effective treatment for treatment-naïve, relapsed/refractory CLL patients. A systematic review and meta-analysis of randomized controlled trials was performed to compare the efficacy and safety of CIT versus BTKi + anti-CD20 antibody as front-line treatment for CLL patients. The endpoints of interest included progression-free survival (PFS), overall survival (OS), overall response rate (ORR), complete response (CR) rate, and safety. Four trials (including 1479 patients) were available as of December 2022 and fulfilled the eligibility criteria. BTKi + anti-CD20 antibody treatment significantly prolonged PFS [hazard ratio (HR), 0.25; 95% confidence interval (CI), 0.15-0.42] compared with CIT, while the combination therapy did not significantly improve OS compared with CIT (HR, 0.73; 95% CI, 0.50-1.06). We observed consistent benefits for PFS among patients with unfavorable features. Although pooled analysis indicated that the addition of BTKi to anti-CD20 antibody led to a higher ORR than CIT [risk ratio (RR), 1.16; 95% CI, 1.13-1.20], there was no difference in CR between the two arms (RR, 1.10; 95% CI, 0.27-4.55). The risk of grade ≥3 adverse effects (AE) was comparable between the two groups (RR, 1.04; 95% CI, 0.92-1.17). The BTKi + anti-CD20 antibody therapy has superior outcomes compared with CIT among patients with treatment-naïve CLL, without excess of toxicity. Future studies should compare next-generation targeted agent combinations versus CIT to determine the optimal management of CLL patients.

Efficacy and safety of add-on anti-CD20 monoclonal antibody to Bruton tyrosine kinase inhibitor treatment for chronic lymphocytic leukemia: a meta-analysis

The efficacy of Bruton tyrosine kinase inhibitors (BTKi) remains suboptimal in chronic lymphocytic leukemia (CLL) treatment. A systematic review and meta-analysis were conducted to compare the outcomes of combining anti-CD20 monoclonal antibodies (mAb) with BTKi therapy versus BTKi monotherapy for patients with CLL. We searched for relevant studies in the Pubmed, Medline, Embase, and Cochrane databases until December 2022. We estimated the effective results using a hazard ratio (HR) for survival outcomes and relative risk (RR) for response outcomes and safety. Four randomized controlled trials (including 1056 patients) were found until November 2022 and fulfilled the inclusion criteria. Progression-free survival was significantly improved with the addition of anti-CD20 mAb to BTKi over BTKi (HR 0.70, 95% confidence interval (CI) 0.51-0.97), whereas pooled analysis of overall survival did not favor combination therapy compared to BTKi monotherapy (HR 0.72, 95% CI 0.50-1.04). Combination therapy was related to a statistically better complete response (RR, 2.03; 95% CI 1.01 to 4.06) and an undetectable minimal residual disease rate (RR, 6.43; 95% CI 3.54 to 11.67). The risk of grade ≥ 3 adverse events was comparable between the two groups (RR, 1.08; (95% CI 0.80 to 1.45). Overall, adding anti-CD20 mAb to BTKi revealed superior efficacy than BTKi alone in untreated or previously treated CLL patients without affecting the safety of single-agent BTKi. Conducting further randomized studies to confirm our results and determine the optimal therapy for managing patients with CLL is essential.

Polypeptide antibiotic actinomycin D induces Mcl-1 uncanonical downregulation in lung cancer cell apoptosis

AIMS

Actinomycin (Act) D, a polypeptide antibiotic, is used clinically to inhibit the growth of malignant tumors. Act D binds to DNA at the transcription initiation complex to prevent the elongation of RNA. Act D causes DNA damage, growth inhibition, and cell death. Myeloid cell leukemia (Mcl-1) is an anti-apoptotic Bcl-2 family member protein, and the present study explored the effects and molecular mechanism of Act D-induced Mcl-1 downregulation.

MAIN METHODS

Human adenocarcinoma A549 cells were used to check the cytotoxic signaling pathways of Act D, particularly in apoptotic mechanism, in a cell-based study approach. Specific blockers targeting the apoptotic factors were examined for their possible roles.

KEY FINDINGS

We found that Act D caused cell growth inhibition and apoptosis. Propidium iodide-based flow cytometric analysis and immunostaining confirmed cell apoptosis. Treatment with Act D caused DNA damage, followed by p53-independent cell death. Western blotting showed a significant decrease in Mcl-1 expression, mitochondrial transmembrane potential loss, and caspase-9/caspase-3 cascade activation. The proteasome inhibitor MG132 reversed Act D-induced Mcl-1 downregulation. However, pharmacological inhibition of glycogen synthase kinase-3, p53 expression, ER stress, autophagy, and vesicle acidification, which are Mcl-1-regulating signaling pathways, did not rescue these effects. Notably, Cullin-Ring E3 ligase partially mediated Mcl-1 downregulation. Administration of transforming growth factor-β induced mesenchymal cell differentiation, but Act D still decreased Mcl-1 and caused cell apoptosis.

SIGNIFICANCE

All of these data show a potential pro-apoptotic effect for Act D by facilitating Mcl-1 uncanonical downregulation.

Measurement of lipid droplets in peripheral immune cells shows an immunomodulatory effect on monocyte polarization in experimental dyslipidaemia

Intracellular lipid droplet (LD) generation is the primary site of energy storage, which is necessary for physiological homeostasis but is related to pathological metabolic disorders. Lipid metabolism is critical for maintaining innate and adaptive immunity; however, it is mainly undefined in peripheral immune cells. Flow cytometry-based immune profiling in healthy peripheral blood cells showed significant original generation of LDs in dendritic cells (DCs, CD3^-CD19^-CD56^-CD11⁺), monocytes (CD3^-CD19^-CD56^-CD14⁺), natural killer cells (NK, CD3^-CD19^-CD56⁺), and B cells (CD3^-CD19⁺). CD36, a common scavenger receptor of lipids, was also highly expressed in LD-accumulated DCs and monocytes. Following short-term treatment with oxidized LDL (oxLDL) in an experimental ex vivo model, CD14⁺ monocytes showed an effective increase in LD generation, but there were no alterations in the immune cell populations. Furthermore, oxLDL-treated CD14⁺ monocytes displayed CD36 expression. However, oxLDL-primed CD14⁺ monocytes showed a blockade in the uptake of extra oxLDL, even while expressing increased CD36, indicating a defect in lipid clearance. Exogenous treatment with oxLDL caused monocyte type 1 polarization accompanied by increased LD accumulation and CD36 expression. This study describes a method to monitor LD generation and CD36 expression in peripheral immune cells and identified an immunomodulatory effect of oxLDL on monocytes by tilting them towards type 1 polarization.

Efficacy and Safety of Bruton Tyrosine Kinase Inhibitor Monotherapy Compared with Combination Therapy for Chronic Lymphocytic Leukemia and Small Lymphocytic Lymphoma: A Systematic Review and Meta-Analysis

The effectiveness and safety of combination treatments such as chemoimmunotherapies in chronic lymphocytic leukemia and small lymphocytic lymphoma (CLL/SLL) remain controversial. Bruton tyrosine kinase inhibitors (BTKis) are an effective therapy for CLL/SLL patients. This meta-analysis aimed to compare the efficacy and safety of BTKis versus combination therapy in CLL/SLL patients. We searched the PubMed, Cochrane, Medline, and Embase databases through February 2023 for relevant randomized controlled trials (RCTs). Four RCTs (including 1510 patients) were found and met the inclusion criteria. Progression-free survival (PFS) was significantly improved with BTKis when compared to the combination therapy (hazard ratio (HR), 0.30; 95% confidence interval (CI), 0.22–0.40), while a pooled analysis of overall survival did not favor single-agent BTKis over the combination therapy (HR, 0.87; 95% CI, 0.67–1.15). We observed consistent benefits for PFS among patients with high-risk disease characteristics. Although there was no difference in complete response between the two arms (risk ratio (RR), 0.54; 95% CI, 0.20–1.46), BTKi use was related to a better overall response rate (RR, 1.10; 95% CI, 1.04–1.16). The risk of grade ≥3 adverse events (AEs) was comparable between the two arms (RR, 0.82; 95% CI, 0.55–1.23). However, the risk of grade ≥3 AEs was significantly lower in the second-generation BTKi group than in the combination therapy group (RR, 0.73; 95% CI, 0.54–0.98). Overall, BTKis have superior efficacy compared to the combination regimens in patients with untreated or treated CLL/SLL without excess toxicity. Further studies are needed to confirm these results and determine the optimal therapy for managing patients with CLL/SLL.

Negative regulation of type I interferon signaling by integrin-linked kinase permits dengue virus replication

Dengue virus (DENV) infection can induce life-threatening dengue hemorrhagic fever/dengue shock syndrome in infected patients. DENV is a threat to global health due to its growing numbers and incidence of infection in the last 50 years. During infection, DENV expresses ten structural and nonstructural proteins modulating cell responses to benefit viral replication. However, the lack of knowledge regarding the cellular proteins and their functions in enhancing DENV pathogenesis impedes the development of antiviral drugs and therapies against fatal DENV infection. Here, we identified that integrin-linked kinase (ILK) is a novel enhancing factor for DENV infection by suppressing type I interferon (IFN) responses. Mechanistically, ILK binds DENV NS1 and NS3, activates Akt and Erk, and induces NF-κB-driven suppressor of cytokine signaling 3 (SOCS3) expression. Elevated SOCS3 in DENV-infected cells inhibits phosphorylation of STAT1/2 and expression of interferon-stimulated genes (ISGs). Inhibiting ILK, Akt, or Erk activation abrogates SOCS3 expression. In DENV-infected mice, the treatment of an ILK inhibitor significantly reduces viral loads in the brains, disease severity, and mortality rate. Collectively, our results show that ILK is a potential therapeutic target against DENV infection.

Zika virus cleaves GSDMD to disseminate prognosticable and controllable oncolysis in a human glioblastoma cell model

Glioblastoma (GBM) is the most common aggressive malignant brain cancer and is chemo- and radioresistant, with poor therapeutic outcomes. The "double-edged sword" of virus-induced cell death could be a potential solution if the oncolytic virus specifically kills cancer cells but spares normal ones. Zika virus (ZIKV) has been defined as a prospective oncolytic virus by selectively targeting GBM cells, but unclear understanding of how ZIKV kills GBM and the consequences hinders its application. Here, we found that the cellular gasdermin D (GSDMD) is required for the efficient death of a human GBM cell line caused by ZIKV infection. The ZIKV protease specifically cleaves human GSDMD to activate caspase-independent pyroptosis, harming both viral protease-harboring and naive neighboring cells. Analyzing human GSDMD variants showed that most people were susceptible to ZIKV-induced cytotoxicity, except for those with variants that resisted ZIKV cleavage or were defective in oligomerizing the N terminus GSDMD cleavage product. Consistently, ZIKV-induced secretion of the pro-inflammatory cytokine interleukin-1β and cytolytic activity were both stopped by a small-molecule inhibitor targeting GSDMD oligomerization. Thus, potential ZIKV oncolytic therapy for GBM would depend on the patient's GSDMD genetic background and could be abolished by GSDMD inhibitors if required.

Hyperglycemia exacerbates dengue virus infection by facilitating poly(A)-binding protein-mediated viral translation

Diabetes mellitus (DM) is highly comorbid with severe dengue diseases; however, the underlying mechanisms are unclear. Patients with DM have a 1.61-fold increased risk of developing dengue hemorrhagic fever. In search of host factors involved in dengue virus (DENV) infection, we used high-glucose (HG) treatment and showed that HG increased viral protein expression and virion release but had no effects on the early stages of viral infection. After HG stimulation, DENV-firefly luciferase-transfected assay and cellular replicon-based assay indicated increased viral translation, whereas using the glucose uptake inhibitor phloretin blocked this effect. HG treatment increased the translational factor poly(A)-binding protein (PABP) in a glucose transporter-associated, PI3K/AKT-regulated manner. Silencing PABP significantly decreased HG-prompted virion production. HG enhanced the formation of the PABP-eukaryotic translation initiation factor 4G complex, which is regulated by protein-disulfide isomerase. Hyperglycemia increased PABP expression, mortality rate, viral protein expression, and viral loads in streptozotocin-induced DM mice. Overall, hyperglycemic stress facilitates DENV infection by strengthening PABP-mediated viral translation.

Monocyte Distribution Width in Children With Systemic Inflammatory Response: Retrospective Cohort Examining Association With Early Sepsis

OBJECTIVES

To investigate the association between increased monocyte distribution width (MDW) and pediatric sepsis in the emergency department (ED).

DESIGN

Retrospective cohort study.

SETTING

A single academic hospital study.

PATIENTS

Patients from birth to the age of 18 years who presented at the ED of an academic hospital with systemic inflammatory response syndrome (SIRS) were consecutively enrolled. Sepsis was diagnosed using the International Pediatric Surviving Sepsis Campaign criteria.

INTERVENTIONS

Antibiotic treatment was administrated once infection was suspected.

MEASUREMENTS AND MAIN RESULTS

Routine complete blood cell count, neutrophil-to-lymphocyte ratio (NLR), and MDW, a new inflammatory biomarker, were evaluated in the ED. Logistic regression models were used to explore associations with early pediatric sepsis. We included 201 patients with sepsis and 1,050 without sepsis. In the multivariable model, MDW greater than 23 U (odds ratio [OR], 4.97; 95% CI, 3.42-7.22; p < 0.0001), NLR greater than 6 (OR, 2.06; 95% CI, 1.43-2.94; p = 0.0001), WBC greater than 11,000 cells/µL (OR, 6.52; 95% CI, 4.45-9.53; p < 0.0001), and the SIRS score (OR, 3.42; 95% CI, 2.57-4.55; p < 0.0001) were associated with pediatric sepsis. In subgroup analysis, MDW greater than 23 U remained significantly associated with sepsis for children 6-12 years old (OR, 6.76; 95% CI, 2.60-17.57; p = 0.0001) and 13-18 years (OR, 17.49; 95% CI, 7.69-39.76; p = 0.0001) with an area under the receiver operating curve of 0.8-0.9.

CONCLUSIONS

MDW greater than 23 U at presentation is associated with the early diagnosis of sepsis in children greater than or equal to 6 years old. This parameter should be considered as a stratification variable in studies of pediatric sepsis.

Epithelial-to-mesenchymal transition hinders interferon-γ-dependent immunosurveillance in lung cancer cells

The epithelial-to-mesenchymal transition (EMT) is involved in cancer metastasis; nevertheless, interferon (IFN)-γ induces anticancer activities by causing cell growth suppression, cytotoxicity, and migration inhibition. Regarding the poor response to exogenously administered IFN-γ as anticancer therapy, it was hypothesized that malignant cells may acquire a means of escaping from IFN-γ immunosurveillance, likely through an EMT-related process. A genomic analysis of human lung cancers revealed a negative link between the EMT and IFN-γ signaling, while compared to human lung adenocarcinoma A549 cells, IFN-γ-hyporesponsive AS2 cells exhibited mesenchymal characteristics. Chemically, physically, and genetically engineered EMT attenuated IFN-γ-induced IFN regulatory factor 1 transactivation. Poststimulation of transforming growth factor-β induced the EMT and also selectively retarded IFN-γ-responsive gene expression as well as IFN-γ-induced signal transducer and activator of transcription 1 activation, major histocompatibility complex I, and CD54 expression, cell migration/invasion inhibition, and direct/indirect cytotoxicity. Without changes in IFN-γ receptors, excessive oxidative activation of Src homology-2 containing phosphatase 2 (SHP2) in cells undergoing the EMT primarily caused cellular hyporesponsiveness to IFN-γ signaling and cytotoxicity, while combining an SHP2 inhibitor or antioxidant sensitized EMT-associated AS2 and mesenchymal A549 cells to IFN-γ-induced priming effects on tumor necrosis factor-related apoptosis-inducing ligand cytotoxicity. In cell line-derived xenograft models, combined treatment with IFN-γ and an SHP2 inhibitor induced enhanced anticancer activities. These results imply that EMT-associated SHP2 activation inhibits IFN-γ signaling, facilitating lung cancer cell escape from IFN-γ immunosurveillance.

Role of Glycogen Synthase Kinase-3 in Interferon-γ-Mediated Immune Hepatitis

Glycogen synthase kinase-3 (GSK-3), a serine/threonine kinase, is a vital glycogen synthase regulator controlling glycogen synthesis, glucose metabolism, and insulin signaling. GSK-3 is widely expressed in different types of cells, and its abundant roles in cellular bioregulation have been speculated. Abnormal GSK-3 activation and inactivation may affect its original bioactivity. Moreover, active and inactive GSK-3 can regulate several cytosolic factors and modulate their diverse cellular functional roles. Studies in experimental liver disease models have illustrated the possible pathological role of GSK-3 in facilitating acute hepatic injury. Pharmacologically targeting GSK-3 is therefore suggested as a therapeutic strategy for liver protection. Furthermore, while the signaling transduction of GSK-3 facilitates proinflammatory interferon (IFN)-γ in vitro and in vivo, the blockade of GSK-3 can be protective, as shown by an IFN-γ-induced immune hepatitis model. In this study, we explored the possible regulation of GSK-3 and the potential relevance of GSK-3 blockade in IFN-γ-mediated immune hepatitis.

Elevated TNF-α Induces Thrombophagocytosis by Mononuclear Cells in ex vivo Whole-Blood Co-Culture with Dengue Virus

Background

Infection with dengue virus (DENV) causes hematological complications in dengue diseases characterized by thrombocytopenia accompanied by macrophage activation syndrome and hemophagocytosis in fatal patients.

Methods

In this study, we investigate the undefined mechanisms underlying the progression of thrombocytopenia caused by thrombophagocytosis based on an ex vivo whole-blood co-culture model of DENV infection for mimicking the acute febrile phase of infection.

Results

In this model, complete blood count test showed a decrease in monocytes (p < 0.01), but not neutrophils nor other white blood cells, accompanied by a low thrombocyte count (p < 0.01) in DENV infection with a positive correlation (r = 0.636, p < 0.05). Furthermore, DENV exposure caused significant thrombophagocytosis in mononuclear cells (p < 0.05). Abnormal production of tumor necrosis factor (TNF)-α was highly associated with induction of thrombophagocytosis (r = 0.758, p < 0.01), decreased monocytes (r = −0.758, p < 0.01), and decreased thrombocyte (r = −0.728, p < 0.01). Neutralizing TNF-α considerably (p < 0.05) reversed such DENV-induced effects and was further validated by immunostaining-based flow cytometry analysis on mononuclear CD14 positive monocytes. Exogenous administration of TNF-α effectively caused thrombophagocytosis accompanied by decreased monocytes and thrombocytes, probably causing monocyte activation.

Conclusion

These results demonstrate the potential pathogenesis of thrombocytopenia caused by TNF-α-induced thrombophagocytosis in monocytes during DENV infection.

Polarization of Type 1 Macrophages Is Associated with the Severity of Viral Encephalitis Caused by Japanese Encephalitis Virus and Dengue Virus

Infection with flaviviruses causes mild to severe diseases, including viral hemorrhagic fever, vascular shock syndrome, and viral encephalitis. Several animal models explore the pathogenesis of viral encephalitis, as shown by neuron destruction due to neurotoxicity after viral infection. While neuronal cells are injuries caused by inflammatory cytokine production following microglial/macrophage activation, the blockade of inflammatory cytokines can reduce neurotoxicity to improve the survival rate. This study investigated the involvement of macrophage phenotypes in facilitating CNS inflammation and neurotoxicity during flavivirus infection, including the Japanese encephalitis virus, dengue virus (DENV), and Zika virus. Mice infected with different flaviviruses presented encephalitis-like symptoms, including limbic seizure and paralysis. Histology indicated that brain lesions were identified in the hippocampus and surrounded by mononuclear cells. In those regions, both the infiltrated macrophages and resident microglia were significantly increased. RNA-seq analysis showed the gene profile shifting toward type 1 macrophage (M1) polarization, while M1 markers validated this phenomenon. Pharmacologically blocking C-C chemokine receptor 2 and tumor necrosis factor-α partly retarded DENV-induced M1 polarization. In summary, flavivirus infection, such as JEV and DENV, promoted type 1 macrophage polarization in the brain associated with encephalitic severity.

Serum IL-18 Is a Potential Biomarker for Predicting Severe Dengue Disease Progression

Background. Dengue virus (DENV) infection is the most common arboviral disease that affects tropical and subtropical regions. Based on the clinical hallmarks, the different severities of patients range from mild dengue fever (MDF) to severe dengue diseases (SDDs) and include dengue hemorrhagic fever or dengue shock syndrome. These are commonly associated with cytokine release syndrome (CRS). The types and levels of cytokines/chemokines, which are suppressed or enhanced, are varied, indicating CRS's pathogenic and host defensive effects. Principal Finding. In this study, we created an integrated and precise multiplex panel of cytokine/chemokine assays based on our literature analysis to monitor dengue CRS. A 24-plex panel of cytokines/chemokines was evaluated to measure the plasma levels of targeting factors in dengue patients with an MDF and SDD diagnosis without or with comorbidities. As identified in sixteen kinds of cytokines/chemokines, ten were significantly (P < 0.05) (10/16) increased, one was significantly (P < 0.01) (1/16) decreased, and five were potentially (5/16) altered in all dengue patients (n = 30) in the acute phase of disease onset. Compared to MDF, the levels of IL-8 (CXCL-8) and IL-18 in SDD were markedly (P < 0.05) increased, accompanied by positively increased IL-6 and TNF-α and decreased IFN-γ and RANTES. With comorbidities, SDD significantly (P < 0.01) portrayed elevated IL-18 accompanied by increased IL-6 and decreased IFN-α2 and IL-12. In addition, decreased platelets were significantly (P < 0.05) associated with increased IL-18. Significance. These results demonstrate an efficient panel of dengue cytokine/chemokine assays used to explore the possible level of CRS during the acute phase of disease onset; also, we are the first to report the increase of IL-18 in severe dengue with comorbidity compared to severe dengue without comorbidity and mild dengue.

Different Induction of PD-L1 (CD274) and PD-1 (CD279) Expression in THP-1-Differentiated Types 1 and 2 Macrophages

Background

Phorbol 12-myristate 13-acetate (PMA)-induced differentiation of human monocytic THP-1 cells is an experimental model for preparing resting macrophages (M₀) for cell polarization toward the different functional specializations of macrophages.

Methods

In this study, we examined the expression of immune checkpoints by using flow cytometry following multicolor staining. The blockade of immune checkpoint by using neutralizing antibodies was performed to assess their role in PMA-induced THP-1-differentiated macrophages.

Results

Upon the inducible macrophage differentiation caused by PMA, increased expression levels of CD11b and CD68 were measured and characterized according to their adherent phenotype accompanied by the generation of cellular complexity. While the cell growth rate was abolished post-differentiation, some cells underwent cell death. Notably, we found increases in the expression of programmed cell death protein 1, also known as PD-1 (CD279), and its ligand PD-L1 (CD274), mainly in differentiated M₀ (CD68⁺CD11b⁺) macrophages. However, neutralizing PD-L1/PD-1 neither blocked THP-1 cell differentiation toward macrophages nor inhibited macrophage polarization in M₁ and M₂. In specializing macrophages, a decrease both in CD274 and CD279 was found in M₂.

Conclusion

These results revealed the inducible expression of PD-L1/PD-1 in PMA-induced THP-1-differentiated M₀ macrophages followed by a decrease in M₂ macrophages.

The Autophagosomes Containing Dengue Virus Proteins and Full-Length Genomic RNA Are Infectious

Autophagic machinery is involved in selective and non-selective recruitment as well as degradation or exocytosis of cargoes, including pathogens. Dengue virus (DENV) infection induces autophagy that enhances virus replication and vesicle release to evade immune system surveillance. This study reveals that DENV2 induces autophagy in lung and liver cancer cells and showed that DENV2 capsid, envelope, NS1, NS3, NS4B and host cell proinflammatory high mobility group box 1 (HMGB1) proteins associated with autophagosomes which were purified by gradient centrifugation. Capsid, NS1 and NS3 proteins showing high colocalization with LC3 protein in the cytoplasm of the infected cells were detected in the purified double-membrane autophagosome by immunogold labeling under transmission electron microscopy. In DENV infected cells, the levels of capsid, envelope, NS1 and HMGB1 proteins are not significantly changed compared to the dramatic accumulation of LC3-II and p62/SQSTM1 proteins when autophagic degradation was blocked by chloroquine, indicating that these proteins are not regulated by autophagic degradation machinery. We further demonstrated that purified autophagosomes were infectious when co-cultured with uninfected cells. Notably, these infectious autophagosomes contain DENV2 proteins, negative-strand and full-length genomic RNAs, but no viral particles. It is possible that the infectivity of the autophagosome originates from the full-length DENV RNA. Moreover, we reveal that DENV2 promotes HMGB1 exocytosis partially through secretory autophagy. In conclusion, we are the first to report that DENV2-induced double-membrane autophagosomes containing viral proteins and full-length RNAs are infectious and not undergoing autophagic degradation. Our novel finding warrants further validation of whether these intracellular vesicles undergo exocytosis to become infectious autophagic vesicles.

SHP2: The protein tyrosine phosphatase involved in chronic pulmonary inflammation and fibrosis

Chronic respiratory diseases (CRDs), including pulmonary fibrosis, chronic obstructive pulmonary disease (COPD), lung cancer, and asthma, are significant global health problems due to their prevalence and rising incidence. The roles of protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPs) in controlling tyrosine phosphorylation of targeting proteins modulate multiple physiological cellular responses and contribute to the pathogenesis of CRDs. Src homology-2 domain-containing PTP2 (SHP2) plays a pivotal role in modulating downstream growth factor receptor signaling and cytoplasmic PTKs, including MAPK/ERK, PI3K/AKT, and JAK/STAT pathways, to regulate cell survival and proliferation. In addition, SHP2 mutation and activation are commonly implicated in tumorigenesis. However, little is known about SHP2 in chronic pulmonary inflammation and fibrosis. This review discusses the potential involvement of SHP2 deregulation in chronic pulmonary inflammation and fibrosis, as well as the therapeutic effects of targeting SHP2 in CRDs.

Pharmacologically Inhibiting Glycogen Synthase Kinase-3β Ameliorates Renal Inflammation and Nephrotoxicity in an Animal Model of Cisplatin-Induced Acute Kidney Injury

The adverse effect of cisplatin administration causes acute kidney injury (AKI) following renal inflammation and nephrotoxicity, characterized by proximal tubular cell apoptosis and necrosis. Pro-apoptotic and pro-inflammatory roles of glycogen synthase kinase (GSK)-3β have been reported. This study investigated the therapeutic blockade of GSK-3β in cisplatin-induced AKI. A renal cisplatin nephrotoxicity model showed activation of GSK-3β in vivo, particularly in proximal tubular epithelial cells. Pharmacologically inhibiting GSK-3β abolished cisplatin nephrotoxicity, including proximal tubular injury, cell cytotoxicity, and biochemical dysfunction. Additionally, GSK-3β inhibitor treatment ameliorated renal inflammation by reducing immune cell infiltration, cell adhesion molecule expression, and pro-inflammatory cytokine/chemokine production. Cisplatin treatment caused GSK-3β activation in vitro in the human renal proximal tubular epithelial cell line HK-2, whereas either pharmacological administration of GSK-3β inhibitors or genetic transduction of GSK-3β short-hairpin RNA impeded cisplatin-induced cytotoxicity. These results indicate that cisplatin activates GSK-3β followed by GSK-3β-mediated renal inflammation and nephrotoxicity, contributing to AKI.

Hemodialysis acutely altered interferon-gamma release assay test result and immune cell profile

Patients receiving hemodialysis (HD) are at risk of TB development. IGRA-positive patients showed significant decrease in quantitative IGRA result with alterations in CD3⁺CD4⁺CD45RO⁺, NK cell, and monocyte subsets immediately upon HD procedure. Our result suggested that the timing of IGRA testing is crucial in end-stage renal disease population.

Profiles of Peripheral Immune Cells of Uncomplicated COVID-19 Cases with Distinct Viral RNA Shedding Periods

The heterogeneity of immune response to COVID-19 has been reported to correlate with disease severity and prognosis. While so, how the immune response progress along the period of viral RNA-shedding (VRS), which determines the infectiousness of disease, is yet to be elucidated. We aim to exhaustively evaluate the peripheral immune cells to expose the interplay of the immune system in uncomplicated COVID-19 cases with different VRS periods and dynamic changes of the immune cell profile in the prolonged cases. We prospectively recruited four uncomplicated COVID-19 patients and four healthy controls (HCs) and evaluated the immune cell profile throughout the disease course. Peripheral blood mononuclear cells (PBMCs) were collected and submitted to a multi-panel flowcytometric assay. CD19⁺-B cells were upregulated, while CD4, CD8, and NK cells were downregulated in prolonged VRS patients. Additionally, the pro-inflammatory-Th1 population showed downregulation, followed by improvement along the disease course, while the immunoregulatory cells showed upregulation with subsequent decline. COVID-19 patients with longer VRS expressed an immune profile comparable to those with severe disease, although they remained clinically stable. Further studies of immune signature in a larger cohort are warranted.

Repurposing the Antiemetic Metoclopramide as an Antiviral Against Dengue Virus Infection in Neuronal Cells

Dengue virus (DENV) is transmitted by Aedes mosquitoes to humans and is a threat worldwide. No effective new drugs have been used for anti-dengue treatment, and repurposing drugs is an alternative approach to treat this condition. Dopamine 2 receptor (D2R) is a host receptor positively associated with DENV infection. Metoclopramide (MCP), a D2R antagonist clinically used to control vomiting and nausea in patients with DENV infection, was putatively examined for inhibition of DENV infection by targeting D2R. In the mouse neural cell line Neuro-2a with D2R expression, a plaque assay demonstrated the antiviral efficacy of MCP treatment. However, in the cell line BHK-21, which did not express D2R, MCP treatment caused no further inhibition of DENV infection. Either MCP treatment or exogenous administration of a neutralizing D2R antibody blocked DENV binding. Treatment with MCP also reduced DENV dsRNA replication and DENV-induced neuronal cell cytotoxicity in vitro. An in vivo study demonstrated the antiviral effect of MCP against DENV-induced CNS neuropathy and mortality. These results showed that repurposing the D2R-targeting antiemetic MCP is a potential therapeutic strategy against DENV infection.

Overcoming interferon (IFN)-γ resistance ameliorates transforming growth factor (TGF)-β-mediated lung fibroblast-to-myofibroblast transition and bleomycin-induced pulmonary fibrosis

Abnormal activation of transforming growth factor (TGF)-β is a common cause of fibroblast activation and fibrosis. In bleomycin (BLM)-induced lung fibrosis, the marked expression of phospho-Src homology-2 domain-containing phosphatase (SHP) 2, phospho-signal transducer and activator of transcription (STAT) 3, and suppressor of cytokine signaling (SOCS) 3 was highly associated with pulmonary parenchymal lesions and collagen deposition. Human pulmonary fibroblasts differentiated into myofibroblasts exhibited activation of SHP2, SOCS3, protein inhibitor of activated STAT1, STAT3, interleukin (IL)-6, and IL-10. The significant retardation of interferon (IFN)-γ signaling in myofibroblasts was revealed by the decreased expression of phospho-STAT1, IFN-γ-associated genes, and IFN-γ-inducible protein (IP) 10. Microarray analysis showed an induction of fibrotic genes in TGF-β1-differentiated myofibroblasts, whereas IFN-γ-regulated anti-fibrotic genes were suppressed. Interestingly, BIBF 1120 treatment effectively inhibited both STAT3 and SHP2 phosphorylation in TGF-β1-differentiated myofibroblasts and BLM fibrotic lung tissues, which was accompanied by suppression of fibroblast-myofibroblast transition. Moreover, the combined treatment of BIBF 1120 plus IFN-γ or SHP2 inhibitor PHPS1 plus IFN-γ markedly reduced TGF-β1-induced α-smooth muscle actin and further ameliorated BLM lung fibrosis. Accordingly, myofibroblasts were hyporesponsiveness to IFN-γ, while blockade of SHP2 contributed to the anti-fibrotic efficacy of IFN-γ.

CNS Immune Profiling in a Dengue Virus-Infected Immunocompetent Outbred ICR Mice Strain

Dengue virus (DENV) infection in the brain causes severe dengue disease with neuropathic complications. In addition to viral effects, immunogenic or pathogenic central nervous system (CNS) inflammation can be induced during DENV infection. By using an immunocompetent outbred ICR (Institute of Cancer Research) mouse model for investigating CNS immunity upon DENV infection, we conducted single-panel immune cell profiling and a multiplex cytokine assay. The ICR mice infected with DENV presented with progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality. When the virions were released, the viral non-structural protein 1 was expressed in the brain in a time-dependent manner. Isolated brain CD45-positive cells revealed a significant population of resident CD14-positive cells, which was considerably decreased 8 days post-infection. We found an unexpected time-kinetic decrease in CD19-positive cells and CD11c/MHC II-positive cells and an increase in NK1.1-positive cells. Further assays showed the time-dependent induction of proinflammatory and NK1.1-associated cytokines in the DENV-infected brains. These results indicate a CNS immune profile of DENV infection and hypothetical CNS immunity in response to DENV infection.

Senescence in Monocytes Facilitates Dengue Virus Infection by Increasing Infectivity

Aging and chronic condition increase the incidence of dengue virus (DENV) infection, generally through a mechanism involving immunosenescence; however, the alternative effects of cellular senescence, which alters cell susceptibility to viral infection, remain unknown. Human monocytic THP-1 cells (ATCC TIB-202) treated with D-galactose to induce cellular senescence were susceptible to DENV infection. These senescent cells showed increased viral entry/binding, gene/protein expression, and dsRNA replication. The use of a replicon system showed that pharmacologically induced senescence did not enhance the effects on viral protein translation. By examining viral receptor expression, we found increased expression of CD209 (DC-SIGN) in the senescent cells. Interleukin (IL)-10 was aberrantly produced at high levels by the senescent cells, and the expression of the DENV receptor DC-SIGN was increased in these senescent cells, partially via IL-10-mediated regulation of the JAK2-STAT3 signaling pathway. The results demonstrate that a senescent phenotype facilitates DENV infection, probably by increasing DC-SIGN expression.

Lower risk of primary Sjogren's syndrome in patients with dengue virus infection: a nationwide cohort study in Taiwan

The data concerning the association between dengue viruses (DV) infection and autoimmune diseases (ADs) remain unclear and are scarce. This nationwide population-based cohort study assessed the risk of ADs among patients with DV infection. We analyzed Taiwanese medical data from the Registry of the National Notifiable Disease Reporting System of Taiwan’s Centers for Disease Control between 1998 and 2015 and identified patients with DV infection. From the entire general population data in the National Health Insurance Research Database, we randomly selected a comparison cohort that was individual matching by age, sex, residence, and index date. We analyzed the risk of ADs using a Cox proportional hazards regression model stratified by sex, age, and residence. We enrolled 29,365 patients with DV infection (50.68% men; mean age, 44.13 years) and 117,460 age-, sex-, and residence-matched controls in the present study. The incidence rates of organ-specific ADs were nonsignificantly higher in the DV cohort than in the non-DV control cohort. An approximately 70% lower risk of primary Sjogren syndrome (pSS) was evident in the DV cohort than in the non-DV control cohort with an adjusted hazard ratio of 0.30 (95% confidence interval 0.13–0.67) after adjusting for comorbidities in matched design. By contrast, the other systemic ADs were nonsignificantly lower in the DV cohort than in the non-DV control cohort. This nationwide long-term cohort study demonstrated that patients with DV infection had a lower risk of primary Sjogren syndrome than those without DV infection.

Key Points • This retrospective, longitudinal cohort observational study shows that patients with DV infection had a lower risk of pSS than those without DV infection. • The DV cohort had an approximately 70% lower risk of pSS than the control group, with a multivariate-adjusted HR of 0.30. • On the basis of this result, we contended that DV infection has a protective effect that reduces the risk of pSS.

TGF-beta-mediated lung fibroblast-to-myofibroblast transition exhibits IFN-γ resistance via SHP2/SOCS3 activation

Idiopathic pulmonary fibrosis is a lethal disease of unknown etiology. Abnormal activation of TGF-β is a common cause in developing fibrotic lesions, where Src homology-2 domain-containing phosphatase 2 (SHP2) plays a critical regulator in fibroblast activation and fibrosis. We found that a marked expression of phospho-SHP2, phospho-STAT3 and the suppressor of cytokine signaling 3 (SOCS3) were detected in bleomycin-induced rat lung fibrosis, which was highly association with pulmonary parenchymal lesions and collagen deposition. Human pulmonary fibroblasts differentiated into myofibroblasts via TGF-β1 treatment were characterized with the increased bundles of F-actin, enhanced expression of α-smooth muscle actin (α-SMA), fibronectin and collagen, which also exhibited the activation of SHP2, SOCS1/3, PIAS1, STAT3, IL-6 and IL-10. An AKT-regulated glycogen synthase kinase (GSK)-3β/SHP2 axis was induced in ROS-dependent regulation during myofibroblast differentiation. The significant retardation of interferon (IFN)-γ signaling in myofibroblasts was revealed by the decrease expression of phospho-STAT1 and IFN-γ-associated genes along with IFN-γ-inducible protein 10 (IP-10) reduction. Treatment of nintedanib (bibf1120) in myofibroblasts effectively inhibits both SHP2 and SOCS3 activation accompanying by a suppression of fibroblast-to-myofibroblast transition (FMT). Moreover, synergistic treatment of nintedanib and IFN-γ markedly ameliorated TGF-β1-mediated FMT. Accordingly, we speculate that the activation of both ROS/AKT/GSK-3β/SHP2 and IL-6/STAT3/SOCS3 axis signaling causes myofibroblasts hyposensitivity to IFN-γ whereby escaping from IFN-γ immune-surveillance during FMT.

A trichlorobenzene-substituted azaaryl compound MTP0L145 blocks endosomal acidification to inhibit dengue virus infection

Blocking endosomal acidification retards dengue virus (DENV) infection. A trichlorobenzene-substituted azaaryl compound MTP0L145, originally designed as a novel fibroblast growth factor receptor (FGFR) inhibitor, confers an unexpected inhibition on endosomal acidification. Here, we examined for the blockade of DENV infection by MTP0L145. As similar to Bafilomycin A1, treatment of FGFR inhibitors MTP0L145 and BGJ39 all cause a blocking effect on endosomal acidification in cells with DENV infection. Inhibiting FGFR significantly causes inhibition on DENV infection, including dsRNA replication, protein expression, and virus release, but not viral entry as well as translation directly. FGFR antagonist NSC12, a blocker of FGF and FGFR interaction, neither inhibits viral entry nor causes blocking effects on endosomal acidification and viral replication, indicating a ligand-independent involvement. MTP0L145 and BGJ-398 inhibit receptor tyrosine kinase activity in FGFRs following DENV infection. Activation of vacuolar-type H+-ATPase for endosomal activation requires FGFR-mediated PI3-kinase/Akt and MAPK activation. Inhibiting the FGFR signaling pathway effectively retards DENV infection and mortality. These results demonstrate that MTP0L145 treatment reduces DENV infection principally by retarding FGFR-regulated endosomal acidification.

This study was supported by grants from the Ministry of Science and Technology (MOST108-2320-B-038-026), Taipei, Taiwan.

HECT E3 Ubiquitin Ligase-Regulated Txnip Degradation Facilitates TLR2-Mediated Inflammation During Group A Streptococcal Infection

Thioredoxin-interacting protein (Txnip) inhibits the activity of thioredoxin (Trx) to modulate inflammatory responses. The burden of inflammation caused by microbial infection is strongly associated with disease severity; however, the role of Txnip in bacterial infection remains unclear. In Group A Streptococcus (GAS)-infected macrophages, Txnip was degraded independent of glucose consumption and streptococcal cysteine protease expression. Treatment with proteasome inhibitors reversed GAS-induced Txnip degradation. The activation of Toll-like receptor 2 (TLR2) initiated Txnip degradation, while no further Txnip degradation was observed in TLR2-deficient bone marrow-derived macrophages. NADPH oxidase-regulated NF-κB activation and pro-inflammatory activation were induced and accompanied by Txnip degradation during GAS infection. Silencing Txnip prompted TLR2-mediated inducible nitric oxide synthase (iNOS)/NO, TNF-α, and IL-6 production whereas the blockage of Txnip degradation by pharmacologically inhibiting the HECT E3 ubiquitin ligase with heclin and AMP-dependent protein kinase with dorsomorphin effectively reduced such effects. Our findings reveal that TLR2/NADPH oxidase-mediated Txnip proteasomal degradation facilitates pro-inflammatory cytokine production during GAS infection.

Fractionated ionizing radiation facilitates interferon-γ signaling and anticancer activity in lung adenocarcinoma cells

Fractionated ionizing radiation (FIR) is a radiotherapy regimen that is regularly performed as part of lung cancer treatment. In contrast to the growth inhibition caused by DNA damage, immunomodulation in post-irradiated cancer cells is not well documented. Interferon (IFN)-γ confers anticancer activity by triggering both growth inhibition and cytotoxicity. This study investigated the priming effects of FIR with immunomodulation on the anticancer IFN-γ. Cell morphology, cell growth, and cytotoxicity were observed in FIR-treated A549 lung adenocarcinoma. Induction of p53 and epithelial-mesenchymal transition (EMT) were monitored. Following FIR, activation of IFN-γ signaling pathways were detected. FIR caused changes in cell morphology, inhibited cell growth, and induced cytotoxicity. While p53 was induced by FIR, no epithelial-mesenchymal transition could be found. Following IFN-γ stimulation, FIR-induced p53-associated cell cytotoxicity was significantly enhanced. Additionally, FIR increased the downstream response to IFN-γ by facilitating IFN-γ-induced signal transducer and activator of transcription 1 (STAT1) signaling without affecting the receptor expression. FIR-facilitated STAT1 activation through the mechanism involving mitogen-activated protein kinase activation and Src-homology 2 domain-containing tyrosine phosphatase 2 inactivation. These results demonstrate the FIR-facilitated IFN-γ signaling and its anticancer activity.

A Murine Model of Dengue Virus-induced Acute Viral Encephalitis-like Disease

Dengue virus (DENV), an arthropod-borne virus transmitted by mosquitoes, may cause the severe disease known as dengue hemorrhagic fever, which is characterized by lethal complications due to plasma leakage, ascites, pleural effusion, respiratory distress, severe bleeding, and organ impairment. A few cases of DENV infection present neurological manifestations; however, studies have not explored DENV-induced neuropathogenesis further. In this study, we present a protocol to use an immunocompetent outbred ICR (Institute of Cancer Research) mouse for investigating the induction of central nervous system (CNS) infection with DENV, followed by the progression of acute viral encephalitis-like disease.

Functional neutralization of anti-IFN-γ autoantibody in patients with nontuberculous mycobacteria infection

Interferon (IFN)-γ is crucial for normal immune surveillance and exhibits immunomodulatory, antimicrobial, and anticancer activity. Patients with nontuberculous mycobacteria (NTM) infection commonly express high levels of anti-IFN-γ autoantibodies (autoAbs) and suffer from recurrent infections due to adult-onset immunodeficiency with defects in IFN-γ immune surveillance. In this study, we developed the methods for determination of anti-IFN-γ autoAbs and then characterized their neutralizing activity in patients with NTM infection. A modified sandwich ELISA-based colorimetric assay followed by immunoblot analysis detected the presence of autoAbs in three out of five serum samples. Serum levels of IFN-γ were decreased. Synthetic peptide binding assay showed variable patterns of epitope recognition in patients positive for anti-IFN-γ autoAbs. Functional tests confirmed that patient serum blocked IFN-γ-activated STAT1 activation and IRF1 transactivation. Furthermore, IFN-γ-regulated inflammation, chemokine production and cytokine production were also blocked. These results provide potentially useful methods to assay anti-IFN-γ autoAbs and to characterize the effects of neutralizing autoAbs on IFN-γ signaling and bioactivity.

Autophagy regulates vinorelbine sensitivity due to continued Keap1-mediated ROS generation in lung adenocarcinoma cells

Autophagy is one of the induced mechanisms in metastatic cancer to escape death due to starvation, hypoxia, metabolic stresses, chemotherapy, and radiation. Some publications have revealed that chemotherapy combined with autophagy inhibitor will overcome drug resistance. We modified AS2 cells with PTEN overexpression, mTOR knockdown, or Keap1 knockdown, and made modification of A549 cells with PTEN knockdown, Atg5 knockdown, and Keap1 overexpression. Our study was aimed toward an exploration of how autophagy modulates Keap1, ROS generation, and vinorelbine-induced apoptosis in these cell lines. We found that lung cancer PC14PE6/AS2 (AS2) had higher mTOR and Akt and also lower PTEN expression than A549 cells. Descended autophagy was demonstrated with more decreased p62 accumulation and LC3 II conversion in AS2 cells as compared to A549 cells. The A549 cells had lower Keap1/Nrf2 and more active anti-oxidant response element (ARE) activity than the AS2 cells. We modified AS2 cells with PTEN overexpression, mTOR knockdown, Keap1 knockdown, and revealed amplified p62 and LC3 expression accompanied with decreased Akt, Keap1, ROS, and vinorelbine-induced apoptosis. Declined p62, LC3 expression were accompanied with increased Akt, Keap1, ROS, and vinorelbine-induced apoptosis after modification of A549 cells with PTEN knockdown, Atg5 knockdown, and Keap1 overexpression. Keap1 overexpression lowered ARE levels in A549 cells, and ARE level exhibited up-growth in Keap1 knockdown AS2 cells. The autophagy inhibitor caused more ROS generation and vinorelbine-induced apoptosis in the A549 and CL1-5 cells. According to these findings, autophagy regulates vinorelbine sensitivity by continuing Keap1-mediated ROS generation in lung adenocarcinoma cells.

It needs more evidence to prove that chemotherapy combined with autophagy inhibitor will overcome drug resistance. The pilot study demonstrated a VNR-sensitive strategy in lung adenocarcinoma cells, by which regulators of autophagy modulated Keap1-mediated ROS generation and VNR-induced apoptosis.

The antiparasitic drug niclosamide inhibits dengue virus infection by interfering with endosomal acidification independent of mTOR

Background

The antiparasitic agent niclosamide has been demonstrated to inhibit the arthropod-borne Zika virus. Here, we investigated the antiviral capacity of niclosamide against dengue virus (DENV) serotype 2 infection in vitro and in vivo.

Principle finding

Niclosamide effectively retarded DENV-induced infection in vitro in human adenocarcinoma cells (A549), mouse neuroblastoma cells (Neuro-2a), and baby hamster kidney fibroblasts (BHK-21). Treatment with niclosamide did not retard the endocytosis of DENV while niclosamide was unable to enhance the antiviral type I interferon response. Furthermore, niclosamide did not cause a direct effect on viral replicon-based expression. Niclosamide has been reported to competitively inhibit the mTOR (mammalian target of rapamycin), STAT3 (signal transducer and activator of transcription 3), and NF-κB (nuclear factor kappa-light-chain-enhancer of activated B cells) signaling pathways; however, selective inhibitors of those pathways did not reduce DENV infection. Similar to the vacuolar-type H⁺-ATPase inhibitor bafilomycin A1, both niclosamide and other protonophores, such as CCCP (carbonyl cyanide m-chlorophenyl hydrazone), and FCCP (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone), effectively reduced endosomal acidification and viral dsRNA replication. Co-administration of a single dose of niclosamide partially decreased viral replication, viral encephalitis, and mortality in DENV-infected ICR suckling mice.

Significance

These results demonstrate that niclosamide diminishes viral infection by hindering endosomal acidification.

Dengue and severe dengue cause global health concerns annually. Without antiviral drugs, supportive care is the only treatment option for patients with DENV infection. A current vaccine has been approved for protection against DENV infection; however, the potential risks and challenges associated with the immunopathogenesis of DENV remain unresolved. For anti-dengue therapy, the repurposing of drugs with antimicrobial and anticancer properties is a possible pharmacological strategy. In this study, we evaluated the potential antiviral effects of the antiparasitic drug niclosamide, considering its current pharmacological efficacy against arthropod-borne Zika virus infection. Using in vitro and in vivo models of DENV infection, we demonstrated that one of the therapeutic effects of niclosamide is to significantly target endosomal acidification. Following safety screening, repurposing niclosamide treatment may facilitate the development of anti-dengue drugs in the near future.

Anti-TNF-α restricts dengue virus-induced neuropathy

Proinflammatory TNF-α facilitates dengue virus (DENV) infection in endovascular dysfunction and neurotoxicity. The introduction of TNF-α blocking therapy with Abs is performed to test its therapeutic effect in this study. In DENV-infected mice, TNF-α production in the brain accompanied the progression of neurotoxicity and encephalitis. DENV infection caused the loss of hippocampal neurons with TNF-α expression around damaged regions, and immunostaining showed the induction of apoptosis in hippocampal neurons. TNF-α was expressed in active microglia and astrocytes in DENV-infected mice. TNF-α facilitated DENV-induced neurotoxicity in vitro in murine Neuro-2a cells. Using a currently established encephalitic mouse model in which DENV infection causes progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days postinfection, we showed that TNF-α transgenic mice represented the progressive disease development and administration of neutralizing TNF-α Ab reduced dengue encephalitis and mortality. These results demonstrate an immunopathogenesis of TNF-α for mediating DENV-induced encephalitis-associated neurotoxicity and that targeting TNF-α can be used as a strategy against dengue encephalitis.

Targeting TNF-α against dengue virus-induced neurotoxicity and acute viral encephalitis-like symptoms

Pro-inflammatory tumor necrosis factor α (TNF-α) facilitates dengue virus (DENV) infection in endovascular dysfunction and neurotoxicity. The introduction of TNF-α blocking therapy with antibodies and antagonists is performed for testing its therapeutic effects in this study. In DENV-infected mice, TNF-α was produced in the brains accompanied by the progression of neurotoxicity and encephalitis. DENV infection caused loss in hippocampal neurons with TNF-α expression around the damaged regions. Additionally, immunostaining showed the induction of apoptosis in hippocampal neurons. TNF-α was expressed in active microglia as well as astrocytes of DENV-infected mice. TNF-α facilitated DENV-induced neurotoxicity in vitro in murine Neuro-2a cells. By using a currently established encephalitic mice model that DENV infection caused progressive hunchback posture, limbic seizures, limbic weakness, paralysis, and lethality 7 days post-infection, TNF-α transgenic mice represented the progressive disease development while administration of neutralizing TNF-α antibody reduced dengue encephalitis and mortality. These results demonstrate an immunopathogenesis of TNF-α for mediating DENV-induced encephalitis-associated neurotoxicity and targeting TNF-α can be used as a strategy against dengue encephalitis.

Bevacizumab Reduces S100A9-Positive MDSCs Linked to Intracranial Control in Patients with EGFR-Mutant Lung Adenocarcinoma

INTRODUCTION

In vitro models have demonstrated immune-modulating effects of bevacizumab (BEV). Combinations of an EGFR tyrosine kinase inhibitor (TKI) with BEV improve progression-free survival (PFS) in patients with EGFR-mutated lung adenocarcinoma. How BEV confers this clinical effect and the underlying mechanisms of its effect are not clear.

METHODS

A total of 55 patients with stage 4 EGFR-mutated lung adenocarcinoma were enrolled. Myeloid-derived suppressor cells (MDSCs), type 1 and type 2 helper T cells, and cytotoxic T lymphocytes were analyzed by flow cytometry. Clinical data were collected for analysis.

RESULT

In all, 25 patients received EGFR TKI and BEV combination therapy (the BEV/TKI group) and 30 patients received EGFR TKI monotherapy (the TKI-only group). The BEV/TKI group had longer PFS (23.0 versus 8.6 months [p = 0.001]) and, in particular, better intracranial control rates (80.0% versus 43.0% [p = 0.03]), a longer time to intracranial progression (49.1 versus 12.9 months [p = 0.002]), and fewer new brain metastases (38.0% versus 71.0% [p = 0.03]) than the TKI-only group did. The BEV/TKI group had a lower percentage of circulating MDSCs (20.4% ± 6.5% before treatment versus 12.8% ± 6.6% after treatment, respectively [p = 0.02]), and higher percentages of type 1 helper T cells (22.9% ± 15.3% versus 33.2% ± 15.6% [p < 0.01]) and cytotoxic T lymphocytes (15.5% ± 7.2% versus 21.2% ± 5.6% [p < 0.01]) after treatment, changes that were not seen in the TKI-only group. Pretreatment percentage of MDSCs was correlated with PFS, with this correlation attenuated after BEV/TKI treatment. Percentage of MDSCs was also associated with shorter time to intracranial progression.

CONCLUSION

Combining a EGFR TKI with BEV extended PFS and protected against brain metastasis. Those effects were probably due to the reduction of circulating S100A9-positive MDSCs by BEV, which leads to restoration of effective antitumor immunity. Our data also support the rationale for a BEV-immune checkpoint inhibitor combination.

S100A9+ MDSC and TAM-mediated EGFR-TKI resistance in lung adenocarcinoma: the role of RELB

Background

Monocytic myeloid-derived suppressor cells (MDSCs), particularly the S100A9+ subset, has been shown initial clinical relevance. However, its role in EGFR-mutated lung adenocarcinoma, especially to EGFR-tyrosine kinase inhibitor (EGFR-TKI) is not clear. In a clinical setting of EGFR mutated lung adenocarcinoma, a role of the MDSC apart from T cell suppression was also investigated.

Results

Blood monocytic S100A9⁺ MDSC counts were higher in lung cancer patients than healthy donors, and were associated with poor treatment response and shorter progression-free survival (PFS). S100A9⁺ MDSCs in PBMC were well correlated to tumor infiltrating CD68⁺ and S100A9⁺ cells, suggesting an origin of TAMs. Patient’s MDMs, mostly from S100A9⁺ MDSC, similar to primary alveolar macrophages from patients, both expressed S100A9 and CD206, attenuated EGFR-TKI cytotoxicity. Microarray analysis identified up-regulation of the RELB signaling genes, confirmed by Western blotting and functionally by RELB knockdown.

Conclusions

In conclusion, blood S100A9⁺ MDSC is a predictor of poor treatment response to EGFR-TKI, possibly via its derived TAMs through activation of the non-canonical NF-κB RELB pathway.

Methods

Patients with activating EGFR mutation lung adenocarcinoma receiving first line EGFR TKIs were prospectively enrolled. Peripheral blood mononuclear cells (PBMCs) were collected for MDSCs analysis and for monocyte-derived macrophages (MDMs) and stored tissue for TAM analysis by IHC. A transwell co-culture system of MDMs/macrophages and H827 cells was used to detect the effect of macrophages on H827 and microarray analysis to explore the underlying molecular mechanisms, functionally confirmed by RNA interference.

An increase in galectin-3 causes cellular unresponsiveness to IFN-γ-induced signal transduction and growth inhibition in gastric cancer cells

Glycogen synthase kinase (GSK)-3β facilitates interferon (IFN)-γ signaling by inhibiting Src homology-2 domain-containing phosphatase (SHP) 2. Mutated phosphoinositide 3-kinase (PI3K) and phosphatase and tensin homolog (PTEN) cause AKT activation and GSK-3β inactivation to induce SHP2-activated cellular unresponsiveness to IFN-γ in human gastric cancer AGS cells. This study investigated the potential role of galectin-3, which acts upstream of AKT/GSK-3β/SHP2, in gastric cancer cells. Increasing or decreasing galectin-3 altered IFN-γ signaling. Following cisplatin-induced galectin-3 upregulation, surviving cells showed cellular unresponsiveness to IFN-γ. Galectin-3 induced IFN-γ resistance independent of its extracellular β-galactoside-binding activity. Galectin-3 expression was not regulated by PI3K activation or by a decrease in PTEN. Increased galectin-3 may cause GSK-3β inactivation and SHP2 activation by promoting PDK1-induced AKT phosphorylation at a threonine residue. Overexpression of AKT, inactive GSK-3β^R96A, SHP2, or active SHP2^D61A caused cellular unresponsiveness to IFN-γ in IFN-γ-sensitive MKN45 cells. IFN-γ-induced growth inhibition and apoptosis in AGS cells were observed until galectin-3 expression was downregulated. These results demonstrate that an increase in galectin-3 facilitates AKT/GSK-3β/SHP2 signaling, causing cellular unresponsiveness to IFN-γ.

Therapeutic Effects of Monoclonal Antibody against Dengue Virus NS1 in a STAT1 Knockout Mouse Model of Dengue Infection

Dengue virus (DENV) is the causative agent of dengue fever, dengue hemorrhagic fever, and dengue shock syndrome and is endemic to tropical and subtropical regions of the world. Our previous studies showed the existence of epitopes in the C-terminal region of DENV nonstructural protein 1 (NS1) which are cross-reactive with host Ags and trigger anti-DENV NS1 Ab-mediated endothelial cell damage and platelet dysfunction. To circumvent these potentially harmful events, we replaced the C-terminal region of DENV NS1 with the corresponding region from Japanese encephalitis virus NS1 to create chimeric DJ NS1 protein. Passive immunization of DENV-infected mice with polyclonal anti-DJ NS1 Abs reduced viral Ag expression at skin inoculation sites and shortened DENV-induced prolonged bleeding time. We also investigated the therapeutic effects of anti-NS1 mAb. One mAb designated 2E8 does not recognize the C-terminal region of DENV NS1 in which host-cross-reactive epitopes reside. Moreover, mAb 2E8 recognizes NS1 of all four DENV serotypes. We also found that mAb 2E8 caused complement-mediated lysis in DENV-infected cells. In mouse model studies, treatment with mAb 2E8 shortened DENV-induced prolonged bleeding time and reduced viral Ag expression in the skin. Importantly, mAb 2E8 provided therapeutic effects against all four serotypes of DENV. We further found that mAb administration to mice as late as 1 d prior to severe bleeding still reduced prolonged bleeding time and hemorrhage. Therefore, administration with a single dose of mAb 2E8 can protect mice against DENV infection and pathological effects, suggesting that NS1-specific mAb may be a therapeutic option against dengue disease.

Disseminated cutaneous Mycobacterium kansasii infection presenting with Rosai-Dorfman disease-like histological features in a patient carrying anti-interferon-γ autoantibodies

Typical cutaneous non-tuberculous mycobacteria (NTM) infections show a histopathology pattern of granulomas with admixed Langhans giant cells, and abscesses may be observed in acute lesions. Herein, we describe a patient carrying a high titer of autoantibodies to interferon (IFN)-γ with disseminated Mycobacterium kansasii infection presenting with emperipolesis and Rosai-Dorfman disease (RDD)-like histopathological features characterized by remarkable, large, pale-staining "RD cells", which were CD68 and S100 positive and CD1a negative. The patient was misdiagnosed with RDD initially, but exhibited a poor response to all interventions. A re-biopsy revealed Langhans-type multinucleated giant cells; multiple definite acid-fast bacilli were also found. M. kansasii was isolated from cultured tissues. Anti-NTM treatment was initiated. After treatment, all lesions resolved almost completely within the following month. High-titer anti-IFN-γ autoantibodies were detected during follow up, leading to the diagnosis of adult-onset immunodeficiency syndrome. In conclusion, patients carrying high-titer autoantibodies to IFN-γ who also have a disseminated cutaneous M. kansasii infection may present with RDD-like histopathological features, which may be a pitfall in the diagnosis of disseminated cutaneous NTM infections.

Blockade of dengue virus infection and viral cytotoxicity in neuronal cells in vitro and in vivo by targeting endocytic pathways

Dengue virus (DENV) infection in neuronal cells was speculated to trigger neuropathy. Herein, we determined the blockade of DENV infection by targeting endocytic pathways in vitro and in vivo. In DENV-infected mouse brains, we previously showed that viral proteins are expressed in neuronal cells around the hippocampus with accompanying neurotoxicity. DENV caused infection, including entry, double-stranded (ds)RNA replication, protein expression, and virus release, followed by cytotoxicity in the mouse neuronal Neuro-2a cell line. Pharmacologically blocking clathrin-mediated endocytosis of the DENV retarded viral replication. Targeting vacuolar-type H⁺-ATPase (V-ATPase)-based endosomal acidification effectively blocked the DENV replication process, but had no direct effect on viral translation. Blockade of the clathrin- and V-ATPase-based endocytic pathways also attenuated DENV-induced neurotoxicity. Inhibiting endosomal acidification effectively retarded DENV infection, acute viral encephalitis, and mortality. These results demonstrate that clathrin mediated endocytosis of DENV followed by endosomal acidification-dependent viral replication in neuronal cells, which can lead to neurotoxicity.

Exophagy of annexin A2 via RAB11, RAB8A and RAB27A in IFN-γ-stimulated lung epithelial cells

Annexin A2 (ANXA2), a phospholipid-binding protein, has multiple biological functions depending on its cellular localization. We previously demonstrated that IFN-γ-triggered ANXA2 secretion is associated with exosomal release. Here, we show that IFN-γ-induced autophagy is essential for the extracellular secretion of ANXA2 in lung epithelial cells. We observed colocalization of ANXA2-containing autophagosomes with multivesicular bodies (MVBs) after IFN-γ stimulation, followed by exosomal release. IFN-γ-induced exophagic release of ANXA2 could not be observed in ATG5-silenced or mutant RAB11-expressing cells. Furthermore, knockdown of RAB8A and RAB27A, but not RAB27B, reduced IFN-γ-triggered ANXA2 secretion. Surface translocation of ANXA2 enhanced efferocytosis by epithelial cells, and inhibition of different exophagic steps, including autophagosome formation, fusion of autophagosomes with MVBs, and fusion of amphisomes with plasma membrane, reduced ANXA2-mediated efferocytosis. Our data reveal a novel route of IFN-γ-induced exophagy of ANXA2.

Reactive oxygen species are required for zoledronic acid-induced apoptosis in osteoclast precursors and mature osteoclast-like cells

Inhibiting osteoclasts and osteoclast precursors to reduce bone resorption is an important strategy to treat osteoclast-related diseases, such as osteoporosis, inflammatory bone loss, and malignant bone metastasis. However, the mechanism by which apoptosis is induced in the osteoclasts and their precursors are not completely understood. Here, we used nitrogen-containing bisphosphonate zoledronic acid (ZA) to induce cell apoptosis in human and murine osteoclast precursors and mature osteoclast-like cells. Caspase-3-mediated cell apoptosis occurred following the ZA (100 μM) treatment. Reactive oxygen species (ROS) were also generated in a time-dependent manner. Following knock-down of the p47^phox expression, which is required for ROS activation, or co-treatment with the ROS inhibitor, N-acetyl-L-cysteine, ZA-induced apoptosis was significantly suppressed in both osteoclast precursors and mature osteoclast-like cells. The ROS-activated mitogen-activated protein kinases pathways did not trigger cell apoptosis. However, a ROS-regulated Mcl-1 decrease simultaneously with glycogen synthase kinase (GSK)-3β promoted cell apoptosis. These findings show that ZA induces apoptosis in osteoclast precursors and mature osteoclast-like cells by triggering ROS- and GSK-3β-mediated Mcl-1 down-regulation.

Escape from IFN-γ-dependent immunosurveillance in tumorigenesis

Immune interferon (IFN), also known as IFN-γ, promotes not only immunomodulation but also antimicrobial and anticancer activity. After IFN-γ binds to the complex of IFN-γ receptor (IFNGR) 1-IFNGR2 and subsequently activates its downstream signaling pathways, IFN-γ immediately causes transcriptional stimulation of a variety of genes that are principally involved in its biological activities. Regarding IFN-γ-dependent immunosurveillance, IFN-γ can directly suppress tumorigenesis and infection and/or can modulate the immunological status in both cancer cells and infected cells. Regarding the anticancer effects of IFN-γ, cancer cells develop strategies to escape from IFN-γ-dependent cancer immunosurveillance. Immune evasion, including the recruitment of immunosuppressive cells, secretion of immunosuppressive factors, and suppression of cytotoxic T lymphocyte responses, is speculated to be elicited by the oncogenic microenvironment. All of these events effectively downregulate IFN-γ-expressing cells and IFN-γ production. In addition to these extrinsic pathways, cancer cells may develop cellular tolerance that manifests as hyporesponsiveness to IFN-γ stimulation. This review discusses the potential escape mechanisms from IFN-γ-dependent immunosurveillance in tumorigenesis.

S100A10 Regulates ULK1 Localization to ER-Mitochondria Contact Sites in IFN-γ-Triggered Autophagy

During the process of autophagy, the autophagy-related proteins are translocated to autophagosome formation sites. Here, we demonstrate that S100A10 is required for ULK1 localization to autophagosome formation sites. Silencing of S100A10 reduces IFN-γ-induced autophagosome formation. We also determined the role of annexin A2 (ANXA2), a binding partner of S100A10, which has been reported to promote phagophore assembly. Silencing of ANXA2 reduced S100A10 expression. However, overexpression of S100A10 in ANXA2-silenced cells was still able to enhance autophagosome formation, suggesting that ANXA2 regulates IFN-γ-induced autophagy through S100A10. We also observed that S100A10 interacted with ULK1 after IFN-γ stimulation, and S100A10 knockdown prevented ULK1 localization to autophagosome formation sites. Finally, the release of high mobility group protein B1, one of the functions mediated by IFN-γ-induced autophagy, was inhibited in S100A10 knockdown cells. These results elucidate the importance of S100A10 in autophagosome formation and reveal the relationship between S100A10 and ULK1 in IFN-γ-induced autophagy.