Nrf2 attenuates the innate immune response after experimental myocardial infarction

Objectives: We aimed to investigate the contribution of the transcription factor nuclear factor erythroid-derived 2-like 2 (Nrf2) to the inflammatory response after experimental myocardial infarction (MI. Background: There is compelling evidence implicating dysregulated inflammation in the mechanism of ventricular remodeling and heart failure (HF) after MI. The transcription factor Nrf2 (encoded by Nfe2l2) is a promising target in this context. It impedes transcriptional upregulation of pro-inflammatory cytokines and is anti-inflammatory in various murine models. Methods: We subjected Nrf2-/- mice and wild type (WT) controls to permanent left coronary artery (LCA) ligation. The inflammatory response was investigated with fluorescence-activated cell sorting (FACS) analysis of peripheral blood and heart cell suspensions, together with qRT-PCR of infarcted tissue for chemokines and their receptors. To investigate whether Nrf2-mediated transcription is a dedicated function of leukocytes, we interrogated publicly available RNA-sequencing (RNA-seq) data from mouse hearts after permanent LCA ligation for Nrf2-regulated gene (NRG) expression. Results: FACS analysis demonstrated a profoundly inflamed phenotype in the hearts of global Nrf2-/- mice as compared to WT mice after MI. Moreover, infarcted tissue from Nrf2-/- mice displayed higher expression of inflammatory cytokines, chemokines, and their receptors, including IL6, Ccl2, and Cxcr4. RNA-seq analysis showed upregulated NRG expression in WT mice after MI compared to untreated mice, which was significantly higher in bioinformatically isolated CCR2+ cells. Conclusions: Taken together, the results suggest that Nrf2 signalling in leukocytes, and possibly CCR2+ monocyte-derived cardiac resident macrophages, may be potential targets to prevent post-MI ventricular remodeling.

TNFRSF11B Suppresses Memory CD4+ T Cell Infiltration in the Colon Cancer Microenvironment: A Multiomics Integrative Analysis

BackgroundColorectal cancer is a lethal cancer worldwide. Due to the low tumor mutation burden and low proportion of tumor-infiltrating lymphocytes in the microenvironment of most patients, innovative immunotherapeutic approaches need to be identified.MethodsUsing the TCGA-COAD dataset (n = 514), we identified TNFRSF11B as a prognostic factor of colon cancer. An immunohistochemistry (IHC) dataset (n = 86), 290 single colorectal cancer cells (GSE81861), and 31 paired colon cancer transcriptional datasets were further applied to validate the function of TNFRSF11B, which was confirmed via fluorescence-activated cell sorting (FACS) analysis.ResultsA risk score system consisting of eight immune-related genes (IRGs) (FGFR2, ZC3HAV1L, TNFRSF11B, CD79A, IGHV3-11, IGHV3-21, IGKV2D-30, and IGKV6D-21) was constructed to predict the prognosis of colon cancer patients. Only TNFRSF11B was closely correlated with late-stage lymph node metastasis and worse survival outcomes (p = 0.010, p = 0.014, and p = 0.0061). In our IHC dataset, 72.09% (62/86) of the colon cancer patients had TNFRSF11B overexpression with significantly shorter overall survival times (p = 0.072). High TNFRSF11B expression typically had a later TNM stage (p = 0.067), a higher frequency of lymph node (p = 0.029) and lymphovascular (p = 0.007) invasion, and a higher incidence of pneumonia (p = 0.056) than their counterparts. The expression of six genes (KRT18, ARPC5L, ACTG1, ARPC2, EZR, and YWHAZ) related to pathogenic E. coli infection was simultaneously increased with TNFRSF11B overexpression via gene set enrichment analysis (GSEA). These genes are involved in the regulation of the actin cytoskeleton, shigellosis, bacterial invasion of epithelial cells, and Salmonella infection. Finally, only activated memory CD4+ T cells (p = 0.017) were significantly decreased in the high TNFRSF11B expression group via CIBERSORT comparison, which was confirmed by TIMER2.0 analysis of the TCGA-COAD dataset. We also performed FACS analysis to show that TNFRSF11B decreased the infiltration of central memory CD4+ T cells and effector memory CD4+ T cells in the colorectal cancer microenvironment (all p <0.001).ConclusionTNFRSF11B acts as a prognostic factor for colon cancer patients and could affect the colon cancer immune response. TNFRSF11B was closely related to lymph node invasion and pathogenic E. coli. infection, which may negatively affect memory-activated CD4+ T cell infiltration in colon cancer.

Internalization and Transport of PEGylated Lipid-Based Mixed Micelles across Caco-2 Cells Mediated by Scavenger Receptor B1

The aim of this study was to get insight into the internalization and transport of PEGylat-ed mixed micelles loaded by vitamin K, as mediated by Scavenger Receptor B1 (SR-B1) that is abundantly expressed by intestinal epithelium cells as well as by differentiated Caco-2 cells. Inhibition of SR-B1 reduced endocytosis and transport of vitamin-K-loaded 0%, 30% and 50% PEGylated mixed micelles and decreased colocalization of the micelles with SR-B1. Confocal fluorescence microscopy, fluorescence-activated cell sorting (FACS) analysis, and surface plasmon resonance (SPR) were used to study the interaction between the mixed micelles of different compositions (varying vitamin K loading and PEG content) and SR-B1. Interaction of PEGylated micelles was independent of the vitamin K content, indicating that the PEG shell prevented vitamin K exposure at the surface of the micelles and binding with the receptor and that the PEG took over the micelles’ ability to bind to the receptor. Molecular docking calculations corroborated the dual binding of both vita-min K and PEG with the binding domain of SR-B1. In conclusion, the improved colloidal stability of PEGylated mixed micelles did not compromise their cellular uptake and transport due to the affinity of PEG for SR-B1. SR-B1 is able to interact with PEGylated nanoparticles and mediates their subsequent internalization and transport.

Enhanced Stimulation of Antigen-Specific Immune Responses Against NPM1-Mutated AML

Nucleophosmin1 (NPM1) is one of the most frequently mutated genes in AML, is often associated with a favorable prognosis and seems to be a suitable target structure for immunotherapeutic approaches. Other groups and ours described specific immune responses of CD8-positive T cells against immunogenic epitopes derived from the mutational region of NPM1 in AML patients (pts). In this extended immunological study, we investigated immune responses against the mutational epitope of NPM1 but also against other LAA in NPM1 mut compared to NPM1 wt pts. 30 AML pts were analyzed using FACS analysis, tetramer staining and colony forming immunoassays (CFI). 15 NPM1 mut and 15 NPM1 wt pts were investigated in CFI to detect CTL mediated immune responses against leukemic progenitor/stem cells (LPC/LSC). We also added immune checkpoint inhibitors to investigate whether these immune responses could be enhanced. Against the LAA PRAME-P3, WT1 and RHAMM-R3 we detected similar frequencies of T cell responses in CFI in NPM1 mut compared to NPM1 wt pts. Antigen specific immune responses were detected in CFI by comparing growth of patient cells alone with growth by addition of antigen specific CTL and calculating colony reduction. Comparing NPM1 mut/NPM1 wt pts many had an immune response to LAA, more than 50% of the pts in both cohorts exhibited an immune response against all epitopes. In NPM1 wt pts no responses were found against the NPM1 epitope as expected, whereas NPM1 mut patients showed a high frequency of immune responses in 10/15 NPM1 mut AML pts (67%) in CFI a reduction of colonies was detected. With the addition of anti-PD1 antibody to CFI we detected an increase of immune responses. For the LAA responses were similar comparing NPM1 mut/NPM1 wt. Compared to LAA, the epitope NPM1 showed a particularly strong immune response when the antibody anti-PD1 was added. All 15 NPM1 mut pts showed an immune response with anti-PD1, with a median reduction of colonies of 47%. 7 of 15 NPM1 mut pts showed a strong immune response against LPC/LSC in CFI with more than 50% reduction of colonies. The data suggest that especially NPM1 mut patients are suitable candidates for antibody therapy with the PD1 antibody. Combination with another immunotherapy such as an NPM1 specific vaccine would be a possibility. Even though no advantage in therapy with the anti-PD1 antibody has yet been shown in the overall AML collective, this therapy could be an option for patients with NPM1 mutated AML. Disclosures Greiner: Bristol Myers Squibb: Other: Unspecified Relationship. Schneider: AbbVie: Current Employment. Schrezenmeier: Novartis: Honoraria; Apellis: Honoraria; Sanofi: Honoraria; Alexion, AstraZeneca Rare Disease: Honoraria, Other: Travel support, Research Funding; Roche: Honoraria.

Newly Developed Oncolytic Herpes Simplex Viruses Expressing Multiple Immunomodulatory Transgenes Effectively Target AML Cells

Acute myeloid leukemia (AML) is the most common human leukemia and is a major area of unmet medical need among hematologic malignancies. Progress has been made in identifying therapeutic targets and several approved therapies, but resistance to frontline chemotherapy remains a major cause of treatment failure, highlighting the need for new therapies. Oncolytic viruses (OV) are a promising new class of therapeutics that rely on tumor specific oncolysis and the generation of a potent adaptive anti-tumor immune response for efficacy. To investigate if our newly developed oncolytic herpes simplex viruses (oHSVs), designed to potentiate anti-leukemia immunity, effectively target primitive AML cells, we evaluated oHSV-VG161, which is engineered to express IL-12, IL-15 and the IL-15 receptor alpha subunit, along with a peptide fusion protein capable of disrupting PD-1/PD-L1 interaction. After screening several AML cell lines that expressed relatively high levels of a HSV entry receptor (HVEM), we demonstrated that VG161-infected OCIAML3 and MOLM13 cells significantly enhanced cell killing (IC 50: 0.4 & 1.8 multiplicity of infection (MOI) as compared to MV4-11 and U973 cells (IC 50: 3.0 & 9.5 MOI). These effects were 2-3 folds lower in control VG160-infected cells. We also observed that VG161-infected AML cells induced apoptosis in a dose-dependent manner (~50%) after 48 hours and cleaved PARP, Caspase-3 and Caspase-8 were increased in these cells, and to a lesser extent in control VG160-infected cells. Both VG160 and VG161 viruses replicated efficiently in OCIAML3 and MOLM13 cells in a timely, dose-dependent manner, evidenced by qPCR detection of HSV-1 ICP27 DNA copy numbers (>500-fold increase) over 48 hours of treatment. This result was supported by detection of protein expression of HSV-1 glycoprotein D in VG160 and VG161-infected cells (up to 40% of protein detected) by FACS analysis. Interestingly, IL-12 but not IL-15 protein expression was found in intracellular-stained VG161-infected OCIAML3 and MOLM13 cells in a dose-dependent manner (up to 13% of protein detected, P<0.01) but not in VG160-infected cells, as assessed by FACS analysis. Production of IL-12 was also detected in cultured media obtained from VG161-infected AML cells (up to 150 pg/mL) by ELISA. To investigate potential molecular mechanisms of VG161-mediated anti-leukemia response and specific signalling pathways, we have screened several potential candidates and found immune regulating genes, such as IRF3, IRF7, IRF9, NFkB and ISGs, as well as type I IFN to be highly increased in VG161-infected cells as compared to VG160-infected cells (2-4-folds, P<0.001) in a dose dependent manner over 48 hours of treatment, assayed by qRT-PCR. Western blot analysis demonstrated increased phosphorylation of p-STAT1 and its protein expression in VG161-infected cells compared to VG160 control cells (~2-fold). These results suggest that VG161 viruses expressing several engineered immunomodulatory transgenes, particularly IL-12, contribute to anti-leukemia responses by activating specific immune regulating pathways such as the JAK/STAT pathway. In addition, we detected an increase in both RNA and protein levels of PD-L1 in VG161-infected AML cells, suggesting the necessity of PD-L1 blocking peptide in the viral construct. To further investigate VG161's role in regulating innate and adaptive immune responses, we have examined the biological effects of VG160/VG161 in the presence of healthy peripheral blood mononuclear cells (PBMC) in both AML cell lines and primary AML patient cells in vitro. Most interestingly, VG160 or VG161-infected OCIAML3 and MOLM13 cells show enhanced cell killing when co-cultured with PBMC and this cell killing effect was greatly enhanced in VG161-infected cells as compared to VG160-infected cells, especially in the MOLM13 cell line (up to 90% killing). This observation was further supported when primitive AML patient cells were co-cultured with VG161 and PBMC as compared to VG160 control cells. Moreover, PD-L1 expression was highly increased in AML patient cells when cultured with VG161 as compared to VG160 (2.7-fold) and this was further enhanced when co-cultured with VG161 and PBMC. Thus, we have demonstrated that newly developed oHSVs engineered with several immunomodulatory transgenes effectively target primitive AML cells, suggesting a potential treatment strategy for AML. Disclosures No relevant conflicts of interest to declare.

Cyclic Peptide-Gadolinium Nanocomplexes as siRNA Delivery Tools

We have recently reported that a cyclic peptide containing five tryptophan, five arginine, and one cysteine amino acids [(WR)5C], was able to produce peptide-capped gadolinium nanoparticles, [(WR)5C]-GdNPs, in the range of 240 to 260 nm upon mixing with an aqueous solution of GdCl3. Herein, we report [(WR)5C]-GdNPs as an efficient siRNA delivery system. The peptide-based gadolinium nanoparticles (50 µM) did not exhibit significant cytotoxicity (~93% cell viability at 50 µM) in human leukemia T lymphoblast cells (CCRF-CEM) and triple-negative breast cancer cells (MDA-MB-231) after 48 h. Fluorescence-activated cell sorting (FACS) analysis indicated that the cellular uptakes of Alexa-488-labeled siRNA were found to be enhanced by more than 10 folds in the presence of [(WR)5C]-GdNPs compared with siRNA alone in CCRF-CEM and MDA-MB-231 cells after 6 h of incubation at 37 °C. The gene silencing efficacy of the nanoparticles was determined via the western blot technique using an over-expressed gene, STAT-3 protein, in MDA-MB-231 cells. The results showed ~62% reduction of STAT-3 was observed in MDA-MB-231 with [(WR)5C]-GdNPs at N/P 40. The integrity of the cellular membrane of CCRF-CEM cells was found to be intact when incubated with [(WR)5C]-Gd nanoparticles (50 µM) for 2 h. Confocal microscopy reveals higher internalization of siRNA in MDA-MB-231 cells using [(WR)5C]-GdNPs at N/P 40. These results provided insight about the use of the [(WR)5C]-GdNPs complex as a potent intracellular siRNA transporter that could be a nontoxic choice to be used as a transfection agent for nucleic-acid-based therapeutics.

Increased mortality and altered local immune response in secondary peritonitis after previous visceral operations in mice

Postoperative peritonitis is characterized by a more severe clinical course than other forms of secondary peritonitis. The pathophysiological mechanisms behind this phenomenon are incompletely understood. This study used an innovative model to investigate these mechanisms, combining the models of murine Colon Ascendens Stent Peritonitis (CASP) and Surgically induced Immune Dysfunction (SID). Moreover, the influence of the previously described anti-inflammatory reflex transmitted by the vagal nerve was characterized. SID alone, or 3 days before CASP were performed in female C57BL/6 N mice. Subdiaphragmatic vagotomy was performed six days before SID with following CASP. The immune status was assessed by FACS analysis and measurement of cytokines. Local intestinal inflammatory changes were characterized by immunohistochemistry. Mortality was increased in CASP animals previously subjected to SID. Subclinical bacteremia occurred after SID, and an immunosuppressive milieu occurred secondary to SID just before the induction of CASP. Previous SID modified the pattern of intestinal inflammation induced by CASP. Subdiaphragmatic vagotomy had no influence on sepsis mortality in our model of postoperative peritonitis. Our results indicate a surgery-induced inflammation of the small intestine and the peritoneal cavity with bacterial translocation, which led to immune dysfunction and consequently to a more severe peritonitis.

Proton Pump Inhibitor and Tacrolimus Uses are Associated With Hypomagnesemia in Connective Tissue Disease: a Potential Link With Renal Dysfunction and Recurrent Infection

Background: Low levels of serum magnesium perturb renal tubular cell function and lymphocytes, resulting in renal deterioration and an imbalance in mononuclear cells. This study investigated the mechanism and influence of hypomagnesemia in patients with connective tissue disease.Methods: We retrospectively evaluated patients with connective tissue disease and available serum magnesium data who visited Keio University Hospital in 2019. Patients were divided into two groups: those with (serum magnesium < 1.8 mg/dl) and those without hypomagnesemia; their rates of hospitalization for severe infection and cumulative renal deterioration were compared. Patients’ fractions of lymphocytes and natural killer and dendritic cell subsets, as measured by fluorescence-activated cell sorting (FACS) analysis, were also compared.Results: Among 284 patients, hypomagnesemia was detected in 63 (22.2%). Multivariate analysis revealed that the use of proton pump inhibitors [odds ratio (OR), 1.48; p = 0.01] and tacrolimus (OR, 6.14; p < 0.01) was independently associated with hypomagnesemia. In addition, the renal deterioration rate was significantly higher in tacrolimus and/or proton pump inhibitor users with hypomagnesemia (p = 0.01). The hospitalization rate for severe infection was also higher in patients with hypomagnesemia (p = 0.04). FACS analysis showed lower CD8+ T cell, CD19+ B cell, natural killer cell, and dendritic cell counts in patients with hypomagnesemia (p = 0.03, p = 0.02, p = 0.02, and p = 0.03, respectively).Conclusion: The use of tacrolimus and proton pump inhibitors may be associated with hypomagnesemia and lead to poor renal outcomes and severe infection in patients with connective tissue disease.

Performance Evaluation of Biozentech Malaria Scanner in Plasmodium knowlesi and P. falciparum as a New Diagnostic Tool

The computer vision diagnostic approach currently generates several malaria diagnostic tools. It enhances the accessible and straightforward diagnostics that necessary for clinics and health centers in malaria-endemic areas. A new computer malaria diagnostics tool called the malaria scanner was used to investigate living malaria parasites with easy sample preparation, fast and user-friendly. The cultured <i>Plasmodium</i> parasites were used to confirm the sensitivity of this technique then compared to fluorescence-activated cell sorting (FACS) analysis and light microscopic examination. The measured percentage of parasitemia by the malaria scanner revealed higher precision than microscopy and was similar to FACS. The coefficients of variation of this technique were 1.2-6.7% for <i>Plasmodium knowlesi</i> and 0.3-4.8% for <i>P. falciparum</i>. It allowed determining parasitemia levels of 0.1% or higher, with coefficient of variation smaller than 10%. In terms of the precision range of parasitemia, both high and low ranges showed similar precision results. Pearson’s correlation test was used to evaluate the correlation data coming from all methods. A strong correlation of measured parasitemia (<i>r²</i>=0.99, <i>P</i><0.05) was observed between each method. The parasitemia analysis using this new diagnostic tool needs technical improvement, particularly in the differentiation of malaria species.

Abatacept enhances blood regulatory B cells of rheumatoid arthritis patients to a level that associates with disease remittance

Abatacept, an inhibitor of CD28 mediated T-cell activation, has been shown to be effective in controlling inflammation during rheumatoid arthritis (RA). However, its effects on immune regulatory B and T cells (Bregs and Tregs) has not been fully explored. Thirty-one RA patients treated with abatacept for ≥ 6 months along with 31 RA patients treated with other modalities as well as 30 healthy controls were recruited. Of these 62 RA patient, 49 (79%) were females with a mean age of 54 ± 12 years and disease duration of 10 ± 6 years. The blood levels of Tregs and Bregs and their production of immunosuppressive cytokines, were determined using FACS analysis and Luminex Multiplex assay. Treatment with abatacept significantly enhanced the blood level of IL-35+ IL-10+ Bregs (P = 0.0007). Their levels were higher in the blood of remitted patients (DAS28-CRP < 2.6) compared to the unremitted ones (P = 0.0173), 6 months following abatacept treatment initiation. Moreover, abatacept treatment significantly enhanced the blood levels of LAG3+ conventional and unconventional Tregs of RA patients. This increase in the blood levels of Bregs and Tregs was accompanied with an elevated serum level of IL-35 and IFN-β in abatacept-treated patients. Therefore, Abatacept efficiency to achieve remittance in RA could be attributed, in part, to its ability to enhance immune regulatory cells, especially IL-35+ IL-10+ Bregs.