Unlocking the novel activation mechanism of human IL-18

Interleukin(IL)-18,a member of the IL-1 family,is commonly known as an interferon-γinducer and is expressed in both hematopoietic and non-hematopoietic cells,such as intestinal epithelial cells,keratinocytes,and endothelial cells.In the immune system,the mature IL-18 plays a critical role in eliminating tumors and infectious agents by activating NK cells and T-lymphocytes,and by synergizing with other cytokines like IL-12 and IL-1βto induce inflammation[1-2].

Regulation of activin receptor-interacting protein 2 expression in mouse hepatoma Hepa1-6 cells and its relationship with collagen type Ⅳ

AIM： To investigate the regulation of activin receptor-interacting protein 2 （ARIP2） expression and its possible relationships with collagen type Ⅳ （collagen Ⅳ） in mouse hepatoma cell line Hepal-6 cells. METHODS： The ARIP2 mRNA expression kinetics in Hepal-6 cells was detected by RT-PCR, and its regulation factors were analyzed by treatment with signal transduction activators such as phorbol 12-myristate 13-acetate （PMA）, forskolin and A23187. After pcDNA3- ARIP2 was transfected into Hepal-6 cells, the effects of ARIP2 overexpression on activin type Ⅱ receptor （ActRⅡ） and collagen Ⅳ expression were evaluated. RESULTS： The expression levels of ARIP2 mRNA in Hapel-6 cells were elevated in time-dependent manner 12 h after treatment with activin A and endotoxin LPS, but not changed evidently in the early stage of stimulation （2 or 4 h）. The ARIP2 mRNA expression was increased after stimulated with signal transduction activators such as PMA and forskolin in Hepal-6 cells, whereas decreased after treatment with A23187 （25.3% ± 5.7% vs 48.1% ± 3.6%, P 〈 0.01）. ARIP2 overexpression could remarkably suppress the expression of ActRⅡA mRNA in dose-dependent manner, but has no effect on ActRⅡB in Hepal-6 cells induced by activin A. Furthermore, we have found that overexpression of ARIP2 could inhibit collagen Ⅳ mRNA and protein expressions induced by activin A in Hapel-6 cells. CONCLUSION： These findings suggest that ARIP2 expression can be influenced by various factors. ARIP2 may participate in the negative feedback regulation of signal transduction in the late stage by affecting the expression of ActRIIA and play an important role in regulation of development of liver fibrosis induced by activin.

Biocompatibility and Immunotoxicology of the Preclinical Implantation of a Collagen-based Artificial Dermal Regeneration Matrix

Objective Graft rejection, with the possibility of a violent immune response, may be severe and life threatening. Our aim was to thoroughly investigate the biocompatibility and immunotoxicology of collagen-based dermal matrix(DM) before assessment in clinical trials. Methods DM was subcutaneously implanted in BALB/c mice in two doses to induce a potential immune response. The spleen and lymph nodes were assessed for shape, cell number, cell phenotype via flow cytometry, cell activation via CCK8 kit, Annexin V kit, and Ki67 immunostaining. Serum samples were used to measure antibody concentration by enzyme-linked immunosorbent assay. Local inflammation was analyzed by histology and immunohistochemistry staining. Data analysis was performed by one-way ANOVA and non-parametric tests. Results Our data illustrate that the spleen and lymph node sizes were similar between the negative control mice and mice implanted with DM. However, in the high-dose DM(DM-H) group, the total cell populations in the spleen and lymph nodes, T cells and B cells in the spleen had slight increases in prophase, and the low-dose DM(DM-L) group did not display gross abnormities. Moreover, DM-H initiated moderate cell activation and proliferation in the early phase post-immunization, whereas DM-L did not. Neither DM-H nor DM-L implantation noticeably increased IgM and IgG serum concentrations. Examination of the local cellular response revealed only benign cell infiltration and TNF-α expression in slides of DM in the early phase. Conclusion Overall, DM-H may have induced a benign temporary acute immune response post-implantation, whereas DM-L had quite low immunogenicity. Thus, this DM can be regarded as a safe product.

Effects of Cd(Ⅱ) and Cu(Ⅱ) on microbial characteristics in 2-chlorophenol-degradation anaerobic bioreactors

The effects of Cd^2＋ and Cu^2＋ at 300 mg/L on anaerobic microbial communities that degrade 2-cholorophenol （2-CP） were examined. Based on the polymerase chain reaction （PCR） of 16S rDNA, bacterial community diversity and archaeal community structure were analyzed with denaturing gradient gel electrophoresis （DGGE） and cloning, respectively. Degradation capabilities of the anaerobic microbial community were drastically abated and the degradation efficiency of 2-CP was reduced to 60% after shock by Cu^2＋ and Cd^2＋, respectively. The bacterial community structure was disturbed and the biodiversity was reduced after shock by Cu^2＋ and Cd^2＋ for 3 d. Some new metal-resistant microbes which could cope with the new condition appeared. The sequence analysis showed that there existed common Archaea species in control sludge and systems when treated with Cu^2＋ and Cd^2＋, such as Methanothrix soehngenii, Methanosaeta concilii, uncultured euryarchaeote, and so on. Both the abundance and diversity of archaeal species were altered with addition of Cd^2＋ and Cu^2＋ at high concentration. Although the abundance of the predominant archaeal species decreased with Cd^2＋ and Cu^2＋ addition for 3 d, they recovered to some extent after 10 d. The diversity of archaeal species was remarkably reduced after recovery for 10 d and the shift in archaeal composition seemed to be irreversible. The 2-CP-degradation anaerobic system was more sensitive to Cu^2＋ than Cd^2＋.

Cryptotanshinone inhibits cytotoxin-associated gene A-associated development of gastric cancer and mucosal erosions

BACKGROUND Approximately 90%of new cases of noncardiac gastric cancer(GC)are related to Helicobacter pylori(H.pylori),and cytotoxin-associated gene A(CagA)is one of the main pathogenic factors.Recent studies have shown that the pharmacological effects of cryptotanshinone(CTS)can be used to treat a variety of tumors.However,the effects of CTS on H.pylori,especially CagA+strain-induced gastric mucosal lesions,on the development of GC is unknown.AIM To assess the role of CTS in CagA-induced proliferation and metastasis of GC cells,and determine if CagA+H.pylori strains causes pathological changes in the gastric mucosa of mice.METHODS The effects of CTS on the proliferation of GC cells were assessed using the Cell Counting Kit-8(CCK-8)assay,and the abnormal growth,migration and invasion caused by CagA were detected by CCK-8 and transwell assays.After transfection with pSR-HA-CagA and treatment with CTS,proliferation and metastasis were evaluated by CCK-8 and transwell assays,respectively,and the expression of Src homology 2(SH2)domain–containing phosphatase 2(SHP2)and phosphorylated SHP2(p-SHP2)was detected using western blotting in AGS cells.The enzymelinked immunosorbent assay was used to determine the immunoglobulin G(IgG)level against CagA in patient serum.Mice were divided into four groups and administered H.pylori strains(CagA+or CagA-)and CTS(or PBS)intragastrically,and establishment of the chronic infection model was verified using polymerase chain reaction and sequencing of isolated strains.Hematoxylin and eosin staining was used to assess mucosal erosion in the stomach and toxicity to the liver and kidney.RESULTS CTS inhibited the growth of GC cells in dose-and time-dependent manners.Overexpression of CagA promoted the growth,migration,and invasion of GC cells.Importantly,we demonstrated that CTS significantly inhibited the CagAinduced abnormal proliferation,migration,and invasion of GC cells.Moreover,the expression of p-SHP2 protein in tumor tissue was related to the expression of IgG against CagA in the serum of GC patients.Additionally,CTS suppressed the protein expression levels of both SHP2 and p-SHP2 in GC cells.CTS suppressed CagA+H.pylori strain-induced mucosal erosion in the stomach of mice but had no obvious effects on the CagA-H.pylori strain group.CONCLUSION CTS inhibited CagA-induced proliferation and the epithelial-mesenchymal transition of GC cells in vitro,and CagA+H.pylori strains caused mucosal erosions of the stomach in vivo by decreasing the protein expression of SHP2.

Antisense RNA of Survivin Gene Inhibits the Proliferation of Leukemia Cells and Sensitizes Leukemia Cell Line to Taxol-induced Apoptosis

The effects of survivin antisense RNA on proliferation of leukemia cell line HL-60 and taxol-induced chemotherapy was explored. A cDNA fragment of survivin obtained by RT-PCR was inserted into a plamid vector named pcDNA3 in the reverse direction. The vector encoding antisense RNA of survivin was confirmed by restriction enzyme digestion and DNA sequencing. The recombinant plasmid was delivered into HL-60 cells by electroporation. Growth curves were plotted based on cell counting. Trypan blue dye exclusion assay and MTT assay were carried out after the cells were incubated with taxol. DNA gel electrophoresis and nuclear staining were performed for cell apoptosis assay. The correct construction of the recombinant plasmid has been identified by restriction enzyme digestion and DNA sequencing. A stable down-regulation has been achieved in HL-60 SVVas cells after G418 selection. Compared to HL-60 cells, the proliferation of HL-60 SVVas cells was significantly inhibited （P〈0.05）. Cytotoxicity assays indicated that IC50 of HL-60 SVVas for taxol was relatively lower than controls （P〈0.01）. Apoptosis assays revealed that taxol-induced apoptosis was detected in HL-60 SVVas cells incubated with 50 ng/ml taxol for 12 h, while in HL-60 cells incubated with 100 ng/ml taxol for 72 h. It was suggested that Survivin antisense RNA could inhibit the proliferation of HL-60 cells and enhance taxol-induced apoptosis in HL-60 cells, which may lay an experimental foundation for further research on gene therapy in leukemia.

Triclosan inhibits the activation of human periodontal ligament fibroblasts induced by lipopolysaccharide from Porphyromonas gingivalis

Periodontitis is a highly prevalent,chronic,non-specific,and immunologically devastating disease of periodontal tissues,caused by microbial infection.This study aims to examine the efficacy and protective mechanism of triclosan(TCS),a bisphenolic,non-cationic component of oral care products,against periodontal inflammation induced by lipopolysaccharide purified from Porphyromonas gingivalis(LPS-PG).TCS markedly downregulated interleukin-6(IL-6),IL-8,and IL-15 in human periodontal ligament fibroblasts(HPDLFs)treated with LPS-PG.By using a liquid chromatography-tandem mass spectrometry(LC-MS/MS)approach,318 differentially expressed proteins(161 upregulated and 157 downregulated)were identified in TCS-pretreated HPDLFs.TCS upregulated HSPA5 and HSP90B1 but downregulated HSPA2.Besides,TCS upregulated miR-548i in HPDLFs,which downregulated IL-15.These results indicate that TCS attenuates the activation of HPDLFs and downregulates the inflammatory cytokines through various mechanisms,thus highlighting its protective role in periodontal inflammation.

Common mtDNA variations at C5178a and A249d/T6392C/G10310A decrease the risk of severe COVID-19 in a Han Chinese population from Central China

Background:Mitochondria have been shown to play vital roles during severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection and coronavirus disease 2019(COVID-19)development.Currently,it is unclear whether mitochondrial DNA(mtDNA)variants,which define mtDNA haplogroups and determine oxidative phosphorylation performance and reactive oxygen species production,are associated with COVID-19 risk.Methods:A population-based case-control study was conducted to compare the distribution of mtDNA variations defining mtDNA haplogroups between healthy controls(n=615)and COVID-19 patients(n=536).COVID-19 patients were diagnosed based on molecular diagnostics of the viral genome by qPCR and chest X-ray or computed tomography scanning.The exclusion criteria for the healthy controls were any history of disease in the month preceding the study assessment.MtDNA variants defining mtDNA haplogroups were identified by PCR-RFLPs and HVS-I sequencing and determined based on mtDNA phylogenetic analysis using Mitomap Phylogeny.Student’s t-test was used for continuous variables,and Pearson’s chi-squared test or Fisher’s exact test was used for categorical variables.To assess the independent effect of each mtDNA variant defining mtDNA haplogroups,multivariate logistic regression analyses were performed to calculate the odds ratios(OR)and 95%confidence intervals(CI)with adjustments for possible confounding factors of age,sex,smoking and diseases(including cardiopulmonary diseases,diabetes,obesity and hypertension)as determined through clinical and radiographic examinations.Results:Multivariate logistic regression analyses revealed that the most common investigated mtDNA variations(>10%in the control population)at C5178 a(in NADH dehydrogenase subunit 2 gene,ND2)and A249 d(in the displacement loop region,D-loop)/T6392 C(in cytochrome c oxidase I gene,CO1)/G10310 A(in ND3)were associated with a reduced risk of severe COVID-19(OR=0.590,95%CI 0.428–0.814,P=0.001;and OR=0.654,95%CI 0.457–0.936,P=0.020,respectively),while A4833 G(ND2),A4715 G(ND2),T3394 C(ND1)and G5417 A(ND2)/C16257 a(D-loop)/C16261 T(D-loop)were related to an increased risk of severe COVID-19(OR=2.336,95%CI 1.179–4.608,P=0.015;OR=2.033,95%CI 1.242–3.322,P=0.005;OR=3.040,95%CI 1.522–6.061,P=0.002;and OR=2.890,95%CI 1.199–6.993,P=0.018,respectively).Conclusions:This is the first study to explore the association of mtDNA variants with individual’s risk of developing severe COVID-19.Based on the case–control study,we concluded that the common mtDNA variants at C5178 a and A249 d/T6392 C/G10310 A might contribute to an individual’s resistance to developing severe COVID-19,whereas A4833 G,A4715 G,T3394 C and G5417 A/C16257 a/C16261 T might increase an individual’s risk of developing severe COVID-19.

Decreased invasion ability of hypotaurine synthesis deficient glioma cells was partially due to hypomethylation of Wnt5a promoter

Glioma is one of the lethal central nervous system tumors.The infiltrative and invasive growth nature makes it difficult to identify the boundary between glioma and the normal tissues,resulting in inevitable recurrence after surgery operation.Gliomas do not metastasize,so to prevent the residual tumor from proliferating or invading is a key challenge.Previous report indicated that hypotaurine could facilitate glioma invasion and suppress demethylases’activities.Using a hypotaurine synthesis deficient U251 cell line,we proved that the cells invasion ability was impaired.Gene expression profile analysis exhibited that knocking down one of the key enzymes of hypotaurine synthesis,2-aminoethanethiol dioxygenase(ADO),significantly affected the extracellular matrix-receptor process.Of that process,Wnt5a expression was severely upregulated by decreased intracellular ADO expression.Cells cultured at the presence of hypotaurine showed a decrease in intracellular Wnt5a protein and mRNA levels.This phenotype was due to hypermethylation of Wnt5a promoter,which was most likely the result of hypotaurine’s inhibiting demethylases activities.Collectively,this study demonstrated that hypotaurine synthesis deficient U251 cells were prone to epigenetic modification and Wnt5a seemed to be a tumor suppressor under that circumstance.This tumor suppression effect is warranted to be reevaluated in real tumor samples and the relevant evidence might contribute to develop new glioma interference strategies.

Current State of Monoclonal Antibody Therapy for Allergic Diseases

Allergic disease is one of the most common chronic diseases,which can affect both children and adults,be often caused by allergen-induced unfavorable immune responses,and initiate various symptoms in different organs,including up-/low-airways and skin,such as asthma,atopic dermatitis,and rhinosinusitis.With increasing prevalence of allergic disease worldwide and their impact on the quality of life,new biological therapeutic approaches for these disorders become hot areas of intensive research.Multiple factors are involved and play important role in the pathogenesis of allergic disease,which can promote or trigger T helper 2(Th2)-type immune responses,leading to production of the type 2 cytokines and immunoglobulin E(IgE),the two critical events in the allergic diseases.Using monoclonal antibodies to target these molecules,therefore,might provide possible benefits for the patients suffered from these diseases.Apart of those having approved biologics for allergic diseases,some potential targets such as epithelial-derived alarmins thymic stromal lymphopoietin(TSLP)and interleukin 33(IL-33)have been also described and proposed to develop monoclonal antibodies against either these cytokines,their receptors,or both.These new and potential targets have substantially enriched the therapeutic opportunities in the field of allergic diseases.The present review aims to briefly outline the role of monoclonal antibodies targeting the cytokines and immunoglobulin involved in the development of allergic diseases,and to discuss the clinical effects of these antibodies.

Correlation of Cytotoxic Effect of Transmembrane and Secretory TNF-α to Cell Cycle

This study was aimed to examine the correlation of the cytotoxic effects induced by two types of TNF-α to cell cycle. Hoechst 33342 and PI were used to detect the morphological changes in the cell death induced by the two types of TNF-α. TdT and PI co-staining was performed to determine the phase of cell cycle of apoptotic cells. L929 cells in different phases of cell cycle were further synchronized and their sensitivity to the two types of TNF-α was observed. Our results showed that the apoptosis of HepG2 cells triggered by tm-TNF-α mainly occurred in G1 phase while in HL-60, Raji and K562 cell lines it mainly took place in S phase. The apoptosis of L929 cells induced by tm-TNF-α mainly occurred in S phase while the apoptosis induced by s-TNF-α mainly appeared in G1 phase. L929 cells were sensitive to s-TNF-α when synchronized in G1 phase (cytotoxicity 49.8%) while their sensi-tivity to tm-TNF-α was highest in S phase (45.7%) and G1/S phase (cytotoxicity 40.6%). It was concluded that tm-TNF-α-induced apoptosis of different target cells took place in different phases of cell cycle. The apoptosis of the specific cell line induced by the two types of TNF-α occurred in different phases of cell cycle. The sensitivity of the specific cell line to the two types of TNF-α was correlated with the phase of cell cycle.

ISOLATION AND CULTURE OF TUMOR-INFILTRATING LYMPHOCYTES FROM MOUSE HEPATOMA

By uaing enzyme digestion and Flcoll- Hypaque or Percoll discontinuous density methods, we have successfully obtained tumor-infiltrating lymphocytes (TIL) from mouse hepatoma. When analyzing the purity of TIL after separation. It was found that Percoll was more effective than Flcoll (P<0. 01). TIL could be activated In the presence of recombinant lL-2 (rIL-2) and begin to expand after culturing for 5-7 days, the tumor cells tend to decrease and disappeared after 14 days or so. TIL increased 105-fold over 40 days. Conditioned medium containing supernatant of PHA and rIL- 2 stimulated syngeneic spleen cell culture could promote the expansion of TIL.

Studies on Activity of NK Cells in Preeclampsia Patients

The activity of the NK cells in patients with preeclampsia was studied to investigate the pathogenesis of preeclampsia. By using MTT and 51Cr releasing technique, the proliferation and killing ability of the NK cells in maternal and umbilical blood from preeclampsia patients (n=18) and normal third trimester pregnant women (n=18) were detected. The NK-92 cell line was as the positive control. The results showed that the NK cell counts of umbilical blood in preeclampsia patients and normal third trimester pregnant women were significantly greater than those of maternal blood (both P<0.05). Compared with that in normal third trimester pregnant women, the proliferative ability of the NK cells in preeclampsia patients was apparently increased (P<0.05). Compared with that in maternal blood, the proliferative ability of the NK cells in umbilical blood from both preeclampsia patients and normal third trimester pregnant women was dramatically increased. The killing ability of the NK cells in preeclampsia patients was significantly higher than that in normal third trimester pregnant women (P <0.05). It was suggested that both number and function of the NK cells in preeclampsia women were increased, and that in umbilical blood was greater than that in maternal blood, speculating that the function of the NK cells may affect the maintenance of the maternal and fetal immune tolerance during pregnancy.

Construction,Expression and In Vitro Biological Behaviors of Ig scFv Fragment in Patients with Chronic B Cell Leukemia

The expression vector of SmIg scFv fragment was constructed in patient with B cell chronic lymphocyte leukemia （B-CLL） and expressed in E. coli to obtain scFv fragment, and the effect of the protein on the proliferation of stimulated peripheral blood mononuclear cells （PBMC） was investigated in vitro. Two pairs of primers were designed, and variable region genes of light chain and heavy chain were amplified by PCR respectively from the pGEM-T vectors previously constructed in our laboratory which containing light chain gene or Fd fragment of heavy chain gene. The PCR product was digested, purified and inserted into pHEN2 vector to construct the soluble expression vector pHEN2-scFv. After the induction by IPTG, the scFv protein was identified by SDS- PAGE electrophoresis and purified by Ni-NTA-Chromatography. MTT was used to determine the effect of purified protein on the proliferation of stimulated PBMC in vitro. Plasmid PCR and restriction enzyme digestion of pHEN2-scFv revealed the pHEN2-scFv vector was constructed successfully. Id-scFv protein was expressed in positive clone after induced by IPTG. SDS-PAGE analysis showed that the relative molecular weight of fusion protein was about 30 kD （1 kD= 0. 9921 ku）, which was consistent with the theoretically predicted value. Proliferation of PBMC could be induced by purified Id-scFv. It was suggested that the expression vector of SmIg scFv fragment was constructed successfully, and scFv protein was expressed and secreted from E. coil, which could induce proliferation of PBMC. This may lay an experimental foundation for further research of Id- HSP complex vaccine for B-CLL.

Expression of Cytokines in Mouse Hepatitis B Virus X Gene-transfected Model

The expression profile in the mouse hepatitis B virus X （HBx）-transfected model was investigated in order to lay a foundation for further study on the implication of cytokines expression in hepa- titis B virus （HBV） infection. Hydrodynamic injection method via the tail vein was used to establish the animal HBx-transfected model. By using microassay, the differential expression of gene in each group was analyzed, which was further confirmed by using real-time PCR and semi-quantitative PCR. Most of chemokine genes such as Cc12, Cc15, Cc19, MIG and IP-10 were up-regulated in the HBx-transfected mouse model versus the control mice, which was coincided with the microarray results. Western blotting and immunohistochemistry were applied to detect the expression of MIG and IP-10 in the liver tissues. Simultaneously, ELISA was adopted to measure the content of IFN-y in the liver tissues. DNA mi- croassay revealed that the expression of 611 genes changed in HBx-transfected mice as compared with that in pCMV-tag2B-transfected mice, and most of the screened chemokines were up-regulated （includ- ing MIG and IP-10）. Additionally, IFN-y protein levels were increased by 20.7% （P〈0.05） in pCMV-tag2B-HBx-transfected mice as compared with the untreated mice. IFN-7 protein levels were reduced by 53.9% （P〈0.05） in pCMV-tag2B-transfected mice as compared with the untreated mice, which was consistent with the up-regulation of MIG and IP-10. It was suggested HBx transfection could induce the expression of MIG and IP-10 in the liver tissues, which might play the roles in HBV-related liver immunity and cytokines-mediated antiviral effect.

Establishment of Stable High Expression Cell Line with Green Fluorescent Protein and Resistance Genes

In order to establish stable high expression cell lines, the eukaryotic expression vector pIRES2EGFP and recombinant plasmid pIRES2EGFP-TIM-3 were transfected into mammalian cells CHO by Lipofectamine. The transfected cells were cultivated under selective growth medium including G418 and green fluorescent protein （GFP） positive cells were sorted by FACS. Simultaneously, growing transfectants were selected only by G418 in the medium. The GFP expression in stably transfected cells was detected by FACS. Under selective growth conditions with G418, the percentage of GFP positive cells was reduced rapidly and GFP induction was low. In contrast, the percentages of GFP positive cells were increased gradually after FACS. By 3 rounds of GFP selection, the stable high expression cell lines were established. Furthermore, using FACS analysis GFP and the target protein TIM-3 co-expression in the stable transfectants cultured in nonselective medium was detected. Theses results demonstrated that the stably transfected cell lines that express high titer of recombinant protein can be simply and fleetly obtained by using GFP and selective growth medium.

Study of the Effects of LPSon the TACE Gene Expression and Its Function

In order to investigate the effects of LPS on the TACE gene transcription and expression and its regulating effect on the TM TNF secretion, in vitro studies were carried out on HL 60 cells stimulated by LPS. TACE, TNF α mRNA levels were detected by Dot Elisa and the distribution of membrane molecules determined by flow cytometry assay and indirect immunofluorescence. The results showed that: (1) TACE was detected in or on HL 60 cells and it is predominantly localized on cell surface and to a perinuclear compartment. (2) LPS induced a time dependent increasement of TNF α mRNA and enhanced TNF conversion with decreasing distribution of TNF in cell surface and increasing secretion of TNF protein. Such conversion could be inhibited by TACE ODN. (3) LPS also induced time dependently increased expression of TACE gene and activation of its function. On the other hand, TACE protein in cell lysate and on cell surface was decreased. It was suggested that TACE molecular structure might change following its mediating membrane anchored molecular secretion.

Oxidative stress-initiated one-carbon metabolism drives the generation of interleukin-10-producing B cells to resolve pneumonia

The metabolic reprogramming underlying the generation of regulatory B cells during infectious diseases remains unknown.Using a Pseudomonas aeruginosa-induced pneumonia model,we reported that IL-10-producing B cells(IL-10+B cells)play a key role in spontaneously resolving infection-mediated inflammation.Accumulated cytosolic reactive oxygen species(ROS)during inflammation were shown to drive IL-10+B-cell generation by remodeling one-carbon metabolism.Depletion of the enzyme serine hydroxymethyltransferase 1(Shmt1)led to inadequate one-carbon metabolism and decreased IL-10+B-cell production.Furthermore,increased one-carbon flux elevated the levels of the methyl donor S-adenosylmethionine(SAM),altering histone H3 lysine 4 methylation(H3K4me)at the Il10 gene to promote chromatin accessibility and upregulate Il10 expression in B cells.Therefore,the one-carbon metabolism-associated compound ethacrynic acid(EA)was screened and found to potentially treat infectious pneumonia by boosting IL-10+B-cell generation.Overall,these findings reveal that ROS serve as modulators to resolve inflammation by reprogramming one-carbon metabolism pathways in B cells.

Decreased LDHB expression in breast tumor cells causes NK cell activation and promotes tumor progression

Objective: Abnormal metabolism is the underlying reason for breast cancer progression. Decreased lactate dehydrogenase B(LDHB) has been detected in breast cancer but the function of LDHB remains unknown.Methods: Western blot was used to analyze LDHB expression in breast cancer cells. The impact of LDHB on tumor cell migration and invasion was determined using Transwell assays, wound healing assays, and a mouse lung metastasis model. Subcutaneous tumor formation, a natural killer(NK) cell cytotoxicity assay, and flow cytometry evaluated NK cell activation. Immunofluorescence and quantitative real-time PCR detected NK cell activation markers. Kaplan-Meier analysis evaluated the effect of immune cell infiltration on prognosis. Single-sample gene set enrichment analysis determined NK cell activation scores. A support vector machine predicted the role of LDHB in NK cell activation.Results: In this study we showed that LDHB inhibits the breast cancer cell metastasis and orchestrates metabolic reprogramming within tumor cells. Our results revealed that LDHB-mediated lactic acid clearance in breast cancer cells triggers NK cell activation within the tumor microenvironment. Our findings, which were confirmed in a murine model, demonstrated that LDHB in tumor cells promotes NK cell activation and ultimately results in the eradication of malignant cells. Clinically, our study further validated that LDHB affects immune cell infiltration and function. Specifically, its expression has been linked to enhanced NK cell-mediated cytotoxicity and improved patient survival. Furthermore, we identified LDHB expression in tumors as an important predictor of NK cell activation, with strong predictive ability in some cancers.Conclusions: Our results suggest that LDHB is a promising target for activating the tumor immune microenvironment in breast cancer, where LDHB-associated lactic acid clearance leads to increased NK cell activity. This study highlights the critical role of LDHB in regulating immune responses and its potential as a therapeutic target for breast cancer.

The nuclear cytokine IL-37a controls lethal cytokine storms primarily via IL-1R8-independent transcriptional upregulation of PPARγ

Cytokine storms are crucial in the development of various inflammatory diseases,including sepsis and autoimmune disorders.The immunosuppressive cytokine INTERLEUKIN(IL)-37 consists of five isoforms(IL-37a-e).We identified IL-37a as a nuclear cytokine for the first time.Compared to IL-37b,IL-37a demonstrated greater efficacy in protecting against Toll-like receptor-induced cytokine hypersecretion and lethal endotoxic shock.The full-length(FL)form of IL-37a and the N-terminal fragment,which is processed by elastase,could translocate into cell nuclei through a distinctive nuclear localization sequence(NLS)/importin nuclear transport pathway.These forms exerted their regulatory effects independent of the IL-1R8 receptor by transcriptionally upregulating the nuclear receptor peroxisome proliferator-activated receptor(PPARγ).This process involved the recruitment of the H3K4 methyltransferase complex WDR5/MLL4/C/EBPβand H3K4me1/2 to the enhancer/promoter of Pparg.The receptor-independent regulatory pathway of the nuclear IL-37a–PPARγaxis and receptor-dependent signaling by secreted IL-37a maintain homeostasis and are potential therapeutic targets for various inflammatory diseases,including sepsis.