Lack of Evidence for Decreased Protein Stability in the 2397 (Met) Haplotype of the Leucine Rich Repeat Kinase 2 Protein Implicated in Parkinson’s Disease

Missense mutations in the leucine rich repeat kinase 2 (LRRK2) gene are the leading genetic cause of autosomal dominant familial Parkinson’s disease. We previously reported that two mutations within the ROC domain, namely R1441C and A1442P, exhibit increased protein degradation leading to lowered steady state LRRK2 protein levels in HEK293 cells. More recently, the common WD40 domain LRRK2 haplotype, Met2397, which is a risk factor for Crohn’s disease, has been shown to lower steady state protein levels in HEK293 cells. In view of recent evidence implicating LRRK2 and inflamemation in PD, we investigated the effects of Met2397 on LRRK2 expression, and compared them to the Thr2397 variant and other LRRK2 mutants. In this study, we transfected HEK293 cells with plasmid constructs encoding the different LRRK2 variants, and analyzed the resulting protein levels by Western blot and flow cytometry. Here we found that both the Met2397 and Thr2397 haplotypes yield similar levels of LRRK2 protein expression and do not appear to impact cell viability in HEK293 cells, compared to other LRRK mutants. Thus, we have concluded that the Met2397 haplotype is unlikely to play a role in LRRK2 mediated or idiopathic PD.

Activation of leukotriene B_(4)receptor 1 is a prerequisite for complement receptor 3-mediated antifungal responses of neutrophils

Invasive fungal infections are life-threatening,and neutrophils are vital cells of the innate immune system that defend against them.The role of LTA4H-LTB_(4)-BLT1 axis in regulation of neutrophil responses to fungal infection remains poorly understood.Here,we demonstrated that the LTA4H-LTB_(4)-BLT1 axis protects the host against Candida albicans and Aspergillus fumigatus,but not Cryptococcus neoformans infection,by regulating the antifungal activity of neutrophils.Our results show that deleting Lta4h or Blt1 substantially impairs the fungal-specific phagocytic capacity of neutrophils.Moreover,defective activation of the spleen tyrosine kinase(Syk)and extracellular signal-related kinase(ERK1/2)pathways in neutrophils accompanies this impairment.Mechanistically,BLT1 regulates CR3-mediated,β-1,3-glucan-induced neutrophil phagocytosis,while a physical interaction with CR3 with slight influence on its dynamics is observed.Our findings thus demonstrate that the LTA4H-LTB_(4)-BLT1 axis is essential for the phagocytic function of neutrophils in host antifungal immune response against Candida albicans and Aspergillus fumigatus.

Neddylation is a novel therapeutic target for lupus by regulating double negative T cell homeostasis

Systemic lupus erythematosus(SLE),a severe autoimmune disorder,is characterized by systemic inflammatory response,autoantibody accumulation and damage to organs.The dysregulation of double-negative(DN)T cells is considered as a crucial commander during SLE.Neddylation,a significant type of protein post-translational modification(PTM),has been well-proved to regulate T cell-mediated immune response.However,the function of neddylation in SLE is still unknown.Here,we reported that neddylation inactivation with MLN4924,a specific inhibitor of NEDD8-activating enzyme E1(NAE1),or genetic abrogation of Ube2m in T cells decreased DN T cell accumulation and attenuated murine lupus development.Further investigations revealed that inactivation of neddylation blocked Bim ubiquitination degradation and maintained Bim level in DN T cells,contributing to the apoptosis of the accumulated DN T cells in lupus mice.Then double knockout(KO)lupus-prone mice(Ube2m-/-Bim-/-lpr)were generated and results showed that loss of Bim reduced Ube2m deficiency-induced apoptosis in DN T cells and reversed the alleviated lupus progression.Our findings identified that neddylation inactivation promoted Bim-mediated DN T cell apoptosis and attenuated lupus progression.Clinically,we also found that in SLE patients,the proportion of DN T cells was raised and their apoptosis was reduced.Moreover,compared to healthy groups,SLE patients exhibited decreased Bim levels and elevated Cullin1 neddylation levels.Meantime,the inhibition of neddylation induced Bim-dependent apoptosis of DN T cells isolated from SLE patients.Altogether,our findings provide the direct evidence about the function of neddylation during lupus,suggesting a promising therapeutic approach for this disease.

Different profiles of cytokine expression during mild and severe acute pancreatitis

AIM:To study secretion patterns of proand anti-in-flammatory cytokines, and activation of various cellular subsets of leukocytes in peripheral blood.METHODS: We have conducted a prospective obser-vational study. One hundred and eight patients with a diagnosis of acute pancreatitis and onset of the disease within last 72 h were included in this study. The mRNA expression of 25 different types of cytokines in white blood cells was determined by quantitative real time polymerase chain reaction. Levels of 8 different cytokines in blood serum were measured by enzymelinked immunosorbent assay. Clinical data and cytokine expression results were subjected to statistical analysis.RESULTS: Severe and necrotizing acute pancreatitis (AP) is characterized by the significant depletion of circulating lymphocytes. Severe acute pancreatitis is as-sociated with a typical systemic inflammatory response syndrome and over-expression of pro-inflammatory cy-tokines [interleukin (IL)-6, IL-8, macrophage migration inhibitory factor (MIF)]. Serum IL-6 and MIF concentra-tions are the best discriminators of severe and necrotiz-ing AP as well as possible fatal outcome during the early course of the disease. CONCLUSION: Deregulation of cellular immune sys-tem is a key event leading to severe and necrotizing AP. IL-6 and MIF could be used as early predictors of complications.

Viral kinetics of Enterovirus 71 in human habdomyosarcoma cells

AIM:To characterise the viral kinetics of enterovirus 71 (EV71).METHODS:In this study,human rhabdomyosarcoma (RD) cells were infected with EV71 at different multiplicity of infection (MOI).After infection,the cytopathic effect (CPE) was monitored and recorded using a phase contrast microscope associated with a CCD camera at different time points post viral infection (0,6,12,24 h post infection).Cell growth and viability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in both EV71 infected and mock infected cells at each time point.EV71 replication kinet-ics in RD cells was determined by measuring the total intracellular viral RNA with real-time reverse-transcription polymerase chain reaction (qRT-PCR).Also,the intracellular and extracellular virion RNA was isolated and quantified at different time points to analyze the viral package and secretion.The expression of viral protein was determined by analyze the levels of viral structure protein VP1 with Western blotting.RESULTS:EV71 infection induced a significant CPE as early as 6 h post infection (p.i.) in both RD cells infected with high ratio of virus (MOI 10) and low ratio of virus (MOI 1).In EV71 infected cells,the cell growth was inhibited and the number of viable cells was rapidly decreased in the later phase of infection.EV71 virions were uncoated immediately after entry.The intracellular viral RNA began to increase at as early as 3 h p.i.and the exponential increase was found between 3 h to 6 h p.i.in both infected groups.For viral structure protein synthesis,results from western-blot showed that intracellular viral protein VP1 could not be detected until 6 h p.i.in the cells infected at either MOI 1 or MOI 10;and reached the peak at 9 h p.i.in the cells infected with EV71 at both MOI 1 and MOI 10.Simultaneously,the viral package and secretion were also actively processed as the virus underwent rapid replication.The viral package kinetics was comparable for both MOI 1 and MOI 10 infected groups.It was observed that at 3 h p.i,the intracellular virions obviously decreased,thereafter,the intracellular virions began to increase and enter into the exponential phase until 12 h p.i.The total amounts of intracellular virons were decreased from 12 to 24 h p.i.Consistent with this result,the increase of virus secretion occurred during 6 to 12 h p.i.CONCLUSION:The viral kinetics of EV71 were established by analyzing viral replication,package and secretion in RD cells.

Interaction of IFNL3 with insulin resistance,steatosis and lipid metabolism in chronic hepatitis C virus infection

Metabolic changes are inextricably linked to chronic hepatitis C(CHC).Recently polymorphisms in the IFNL3(IL28B)region have been shown to be strongly associated with spontaneous and treatment induced recovery from hepatitis C virus(HCV)infection.Further,circumstantial evidence suggests a link between IFNL3single nucleotide polymorphisms and lipid metabolism,steatosis and insulin resistance in CHC.The emerging picture suggests that the responder genotypes of IFNL3polymorphisms are associated with a higher serum lipid profile,and less frequent steatosis and insulin resistance.This review analyzes the current data regarding this interaction and its meaning for HCV pathogenesis and disease progression.

Dendritic cells in hepatitis C virus infection:Key players in the IFNL3-genotype response

Recently,single nucleotide polymorphisms,in the vicinity of the interferon lambda 3(IFNL3)gene have been identified as the strongest predictor of spontaneous and treatment induced clearance of hepatitis C virus(HCV)infection.Since then,increasing evidence has implicated the innate immune response in mediating the IFNL3 genotype effect.Dendritic cells(DCs)are key to the host immune response in HCV infection and their vital role in the IFNL3 genotype effect is emerging.Reports have identified subclasses of DCs,particularly myeloid DC2s and potentially plasmacytoid DCs as the major producers of IFNL3 in the setting of HCV infection.Given the complexities of dendritic cell biology and the conflicting current available data,this review aims to summarize what is currently known regarding the role of dendritic cells in HCV infection and to placeit into context of what is know about lambda interferons and dendritic cells in general.

Doxorubicin-conjugated siRNA lipid nanoparticles for combination cancer therapy

Evasion of apoptosis is a hallmark of cancer,attributed in part to overexpression of the antiapoptotic protein B-cell lymphoma 2(Bcl-2).In a variety of cancer types,including lymphoma,Bcl-2 is overexpressed.Therapeutic targeting of Bcl-2 has demonstrated efficacy in the clinic and is the subject of extensive clinical testing in combination with chemotherapy.Therefore,the development of co-delivery systems for Bcl-2 targeting agents,such as small interfering RNA(siRNA),and chemotherapeutics,such as doxorubicin(DOX),holds promise for enabling combination cancer therapies.Lipid nanoparticles(LNPs)are a clinically advanced nucleic acid delivery system with a compact structure suitable for siRNA encapsulation and delivery.Inspired by ongoing clinical trials of albumin-hitchhiking doxorubicin prodrugs,here we developed a DOX-siRNA co-delivery strategy via conjugation of doxorubicin to the surface of siRNAloaded LNPs.Our optimized LNPs enabled potent knockdown of Bcl-2 and efficient delivery of DOX into the nucleus of Burkitts'lymphoma(Raji)cells,leading to effective inhibition of tumor growth in a mouse model of lymphoma.Based on these results,our LNPs may provide a platform for the co-delivery of various nucleic acids and DOX for the development of new combination cancer therapies.

Microenvironment and cell mechanics

Microenvironment contains biophysical and biochemical elements to maintain survival,growth,proliferation,and differentiation of cells.Any change can lead to cell response to the mechanical forces,which can be described by elasticity.It is an indicator of a cell’s state since it plays an important role in many cellular processes.In many cases,cell elasticity is measured by using discontinuous manner,which may not allow elucidating real-time activity of individual live cells in physiological condition or cell response against microenvironmental changes.I argue that measuring cell elasticity using continuously repetitive nanoindentation technique is important that should be considered.As an example,I discuss mechanics of human embryonic kidney(HEK)cells in various conditions.In resting cells,there is an activity of the cytoskeleton whose oscillation amplitude is strongly affected by the intracellular calcium,and the collective activity of myosin motor proteins induces elasticity oscillation.Experimental results also reveal that actin cytoskeleton and cell membrane determine cell mechanics.

Adeno-associated virus mediated delivery of Tregitope 167 ameliorates experimental colitis

AIM:To explore the anti-inflammatory potential of adeno-associated virus-mediated delivery of Tregitope 167 in an experimental colitis model.METHODS:The trinitrobenzene sulfonate(TNBS) model of induced colitis was used in Balb/c mice.Subsequently after intravenous adeno-associated virusmediated regulatory T-cell epitopes(Tregitope) delivery,acute colitis was initiated by intra-rectal administration of 1.5 mg TNBS in 40% ethanol followed by a second treatment with TNBS(0.75 mg in 20% ethanol) 8 d later.Control groups included mice not treated with TNBS(healthy control group) and mice treated by TNBS only(diseased group).At the time of sacrifice colon weight,the disease activity index and histology damage score were determined.Immunohistochemical staining of the colonic tissues was performed to asses the cellular infiltrate and the presence of transcription factor forkhead Box-P3(Foxp3).Thymus,mesenteric lymph nodes,liver and spleen tissue were collected and the corresponding lymphocyte populations were further assessed by flow cytometry analysis for the expression of CD4+ T cell and regulatory T cell associated markers.RESULTS:The Tregitope 167 treated mice gained an average of 4% over their initial body weight at the time of sacrifice.In contrast,the mice treated with TNBS alone(no Tregitope) developed colitis,and lost 4% of their initial body weight at the time of sacrifice(P < 0.01).The body weight increase that had been observed in the mice pre-treated with Tregitope 167 was substantiated by a lower disease activity index and a decreased colon weight as compared to the diseased control group(P < 0.01 and P < 0.001,respectively).Immunohistochemical staining of the colonic tissues for CD4+ showed that inflammatory cell infiltrates were present in TNBS treated mice with or without administration with tregitope 167 and that these cellular infiltrates consisted mainly of CD4+ cells.For both TNBS treated groups CD4+ T cell infiltrates were observed in the sub-epithelial layer and the lamina propria.CD4+ T cell infiltrates were also present in the muscularis mucosa layer of the diseased control mice,but were absent in the Tregitope 167 treated group.Numerous Foxp3 positive cells were detected in the lamina propria and sub-epithelium of the colon sections from mice treated with Tregitope 167.Furthermore,the Foxp3 and glycoprotein A repetitions predominant markers were significantly increased in the CD4+ T lymphocyte population in the thymus of the mice pre-treated with adeno-associated virus serotype 5(cytomegalovirus promoter-Tregitope 167),as cytomegalovirus promoter compared to lymphocyte populations in the thymus of diseased and the healthy control mice(P < 0.05 and P < 0.001,respectively).CONCLUSION:This study identifies adeno-associated virus-mediated delivery of regulatory T-cell epitope 167 as a novel anti-inflammatory approach with the capacity to decrease intestinal inflammation and induce longterm remission in inflammatory bowel disease.

Cell-type specific and non-redundant anti-proliferative effects of shRNA-mediated Galpha12- and Galpha13 knockdown in lung cancer cell lines

In small cell lung cancer cells, various autocrine stimuli lead to the parallel activation of Gq/11 and G12/13 proteins. The contribution of the Gq/11-PLC-β cascade to the mitogenic effects in SCLC cells is well established, but the relevance of G12/13 signaling is less explored. While in prostate and breast cancer, G12/13 activation has been shown previously to promote invasiveness without being involved in cellular proliferation, previous data from our group indicate anti-proliferative effects of G12/13 knockdown in small cell lung cancer (SCLC) cells. To further investigate the role of G12/13-dependent signaling in lung tumor cells, we employed shRNA-mediated targeting of Gα12, Gα13, or both, in SCLC and NSCLC cell lines. Lentiviral expression of shRNAs resulted in specific Gα12 and Gα13 knockdown. Of note, upon single knockdown of one family member, no counter-upregulation of the other one was observed. Interestingly, inhibition of proliferation was cell line dependent. In cell lines where knock-down led to antiproliferation, single knockdown of either Gα12 or Gα13 was sufficient to impair proliferation and double knockdown of Gα12 and Gα13 tended not to further increase anti-proliferative effects. Likewise, when single knockdown was insufficient for an inhibition of proliferation, no effects were observed in double knockdowns. Taken together, these findings indicate that both Gα12 and Gα13 affect cellular proliferation individually and interference with one family member is sufficient for anti-tumor effects.

Correlative CD4 and CD8 T-cell immunodominance in humans and mice:Implications for preclinical testing

Antigen-specific T-cell recognition is restricted by Major Histocompatibility Complex(MHC)molecules,and differences between CD4 and CD8 immunogenicity in humans and animal species used in preclinical vaccine testing are yet to be fully understood.In this study,we addressed this matter by analyzing experimentally identified epitopes based on published data curated in the Immune Epitopes DataBase(IEDB)database.We first analyzed SARS-CoV-2 spike(S)and nucleoprotein(N),which are two common targets of the immune response and well studied in both human and mouse systems.We observed a weak but statistically significant correlation between human and H-2^(b)mouse T-cell responses(CD8 S specific(r=0.206,p=1.37×10^(−13));CD4 S specific(r=0.118,p=2.63×10^(−5))and N specific(r=0.179,p=2.55×10^(−4))).Due to intrinsic differences in MHC molecules across species,we also investigated the association between the immunodominance of common Human Leukocyte Antigen(HLA)alleles for which HLA transgenic mice are available,namely,A*02:01,B*07:02,DRB1*01:01,and DRB1*04:01,and found higher significant correlations for both CD8 and CD4(maximum r=0.702,p=1.36×10^(−31)and r=0.594,p=3.04−122,respectively).Our results further indicated that some regions are commonly immunogenic between humans and mice(either H-2^(b)or HLA transgenic)but that others are human specific.Finally,we noted a significant correlation between CD8 and CD4 S-(r=0.258,p=7.33×10^(21))and N-specific(r=0.369,p=2.43×10^(14))responses,suggesting that discrete protein subregions can be simultaneously recognized by T cells.These findings were confirmed in other viral systems,providing general guidance for the use of murine models to test T-cell immunogenicity of viral antigens destined for human use.

Neuroimmunology:reviews and perspectives on recent advances

In an abstract sense,the immune system is tasked to monitor and interpret insults and potential threats from the external world and mount appropriate defensive actions accordingly.At the same time,it also monitors states of internal organs and facilitates resistance to perturbation and maintenance of homeostasis.

Neuroimmune regulation in the pancreas

The pancreas exerts endocrine and exocrine functions in energy balance.The neural innervation and immune milieu are both crucial in supporting pancreatic homeostasis.The neuronal network connects the pancreas with the central nervous system(CNS)and the enteric nervous system(ENS)and sustains metabolic activities.The nerves in the pancreas are categorized as spinal sensory afferent fibers,vagal sensory afferent nerves,autonomic fibers of both sympathetic and parasympathetic divisions,and fibers from the ENS and intrapancreatic ganglia.They innervate different regions and various cell types,which collectively determine physiological functions.Studies have established that the diverse pathological conditions,including pancreatitis,diabetes,and pancreatic tumor,are attributed to aberrant immune reactions;however,it is largely not clear how the neuronal network may influence the disease conditions.Enlightened by the recent advances illuminating the organ-wide neuronal architecture and the dysfunctions in pancreatic disorders,this review will highlight emerging opportunities to explore the cellular interrelationship,particularly the neuroimmune components in pancreatic health and diseases.

Not to be and how not to be:the questions of Tregs controlled by RIPK1

Millions of cells undergo daily cell death,a process essential for maintaining physiological homeostasis and pathogenesis.Various forms of cell death,such as apoptosis,necroptosis,ferroptosis and pyroptosis,have been extensively studied for their distinct biological functions[1,2].Generally,programmed cell death,like apoptosis,is considered physiological and results in little to no inflammatory response.

Glioma-derived ANXA1 suppresses the immune response to TLR3 ligands by promoting an anti-inflammatory tumor microenvironment

A highly immunosuppressive tumor microenvironment(TME)and the presence of the blood‒brain barrier are the two major obstacles to eliciting an effective immune response in patients with high-grade glioma(HGG).Here,we tried to enhance the local innate immune response in relapsed HGG by intracranially injecting poly(I:C)to establish a robust antitumor immune response in this registered clinical trial(NCT03392545).During the follow-up,12/27(44.4%)patients who achieved tumor control concomitant with survival benefit were regarded as responders in our study.We found that the T-cell receptor(TCR)repertoire in the TME was reshaped after poly(I:C)treatment.Based on the RNA-seq analysis of tumor samples,the expression of annexin A1(ANXA1)was significantly upregulated in the tumor cells of nonresponders,which was further validated at the protein level.In vitro and in vivo experiments showed that ANXA1 could induce the production of M2-like macrophages and microglia via its surface receptor formyl peptide receptor 1(FPR1)to establish a Treg cell-driven immunosuppressive TME and suppress the antitumor immune response facilitated by poly(I:C).The ANXA1/FPR1 signaling axis can inhibit the innate immune response of glioma patients by promoting an anti-inflammatory and Treg-driven TME.Moreover,ANXA1 could serve as a reliable predictor of response to poly(I:C),with a notable predictive accuracy rate of 92.3%.In light of these notable findings,this study unveils a new perspective of immunotherapy for gliomas.

Melatonin decreases GSDME mediated mesothelial cell pyroptosis and prevents peritoneal fibrosis and ultrafiltration failure

Peritoneal fibrosis together with increased capillaries is the primary cause of peritoneal dialysis failure.Mesothelial cell loss is an initiating event for peritoneal fibrosis.We find that the elevated glucose concentrations in peritoneal dialysate drive mesothelial cell pyroptosis in a manner dependent on caspase-3 and Gasdermin E,driving downstream inflammatory responses,including the activation of macrophages.Moreover,pyroptosis is associated with elevated vascular endothelial growth factor A and C,two key factors in vascular angiogenesis and lymphatic vessel formation.GSDME deficiency mice are protected from high glucose induced peritoneal fibrosis and ultrafiltration failure.Application of melatonin abrogates mesothelial cell pyroptosis through a MT1R-mediated action,and successfully reduces peritoneal fibrosis and angiogenesis in an animal model while preserving dialysis efficacy.Mechanistically,melatonin treatment maintains mitochondrial integrity in mesothelial cells,meanwhile activating m TOR signaling through an increase in the glycolysis product dihydroxyacetone phosphate.These effects together with quenching free radicals by melatonin help mesothelial cells maintain a relatively stable internal environment in the face of high-glucose stress.Thus,Melatonin treatment holds some promise in preserving mesothelium integrity and in decreasing angiogenesis to protect peritoneum function in patients undergoing peritoneal dialysis.

ZEB2驱动自身免疫性疾病中年龄相关B细胞的分化

As a novel type of B cell that expands with increasing age,which was first observed in 2011[1,2],age-associated B cells(ABCs)are becoming a hotspot area in the field of immunology.More importantly,ABCs accumulate progressively in chronic inflammatory states such as autoimmunity,chronic infection,and aging,and are closely associated with developing autoimmune diseases[3].

RBP-J is required for M2 macrophage polarization in response to chitin and mediates expression of a subset of M2 genes

Development of alternatively activated （M2） macrophage phenotypes is a complex process that is coordinately regulated by a plethora of pathways and factors. Here, we report that RBP-J, a DNA-binding protein that integrates signals from multiple pathways including the Notch pathway, is critically involved in polarization of M2 macrophages. Mice deficient in RBP-J in the myeloid compartment exhibited impaired M2 phenotypes in vivo in a chitin-induced model of M2 polarization. Consistent with the in vivo findings, M2 polarization was partially compromised in vitro in Rbpj-deficient macrophages as demonstrated by reduced expression of a subset of M2 effector molecules including arginase 1. Functionally, myeloid Rbpj deficiency impaired M2 effector functions including recruitment of eosinophils and suppression of T cell proliferation. Collectively, we have identified RBP- Jas an essential regulator of differentiation and function of alternatively activated macrophages.