Impact of conditioning regimen on peripheral blood hematopoietic cell transplant

AIM To investigate infused hematopoietic cell doses and their interaction with conditioning regimen intensity +/-total body irradiation(TBI) on outcomes after peripheral blood hematopoietic cell transplant(PBHCT).METHODS Our retrospective cohort included 247 patients receiving a first, T-replete, human leukocyte antigen-matched allogeneic PBHCT and treated between 2001 and2012. Correlations were calculated using the Pearson product-moment correlation coefficient. Overall survival and progression free survival curves were generated using the Kaplan-Meier method and compared using the log-rank test.RESULTS Neutrophil engraftment was significantly faster after reduced intensity TBI based conditioning [reduced intensity conditioning(RIC) + TBI] and > 4 × 10~6 CD34+cells/kg infused. A higher total nucleated cell dose led to a higher incidence of grade II-IV acute graft-versus-host disease in the myeloablative + TBI regimen group(P = 0.03), but no significant difference in grade III-IV graft-versus-host disease. A higher total nucleated cell dose was also associated with increased incidence of moderate/severe chronic graft-versus-host disease, regardless ofconditioning regimen. Overall and progression-free survival were significantly better in patients with a RIC + TBI regimen and total nucleated cell dose > 8 ×10~8/kg(3 years, overall survival: 70% vs 38%, P = 0.02, 3 years, progression free survival: 64% vs 38%, P = 0.02).CONCLUSION TBI and conditioning intensity may alter the relationship between infused cell doses and outcomes after PBHCT. Immune cell subsets may predict improved survival after unmanipulated PBHCT.

The WNT1^(G177C) mutation specifically affects skeletal integrity in a mouse model of osteogenesis imperfecta type XV

The recent identification of homozygous WNT1 mutations in individuals with osteogenesis imperfecta type XV(OI-XV)has suggested that WNT1 is a key ligand promoting the differentiation and function of bone-forming osteoblasts.Although such aninfluence was supported by subsequent studies,a mouse model of OI-XV remained to be established.Therefore,we introduced a previously identified disease-causing mutation(G177C)into the murine Wnt1 gene.Homozygous Wnt1^(G177C/G177C)mice were viable and did not display defects in brain development,but the majority of 24-week-old Wnt1^(G177C/G177C)mice had skeletal fractures.This increased bone fragility was not fully explained by reduced bone mass but also by impaired bone matrix quality.Importantly,the homozygous presence of the G177C mutation did not interfere with the osteoanabolic influence of either parathyroid hormone injection or activating mutation of LRP5,the latter mimicking the effect of sclerostin neutralization.Finally,transcriptomic analyses revealed that short-term administration of WNT1 to osteogenic cells induced not only the expression of canonical WNT signaling targets but also the expression of genes encoding extracellular matrix modifiers.Taken together,our data demonstrate that regulating bone matrix quality is a primary function of WNT1.They further suggest that individuals with WNT1 mutations should profit from existing osteoanabolic therapies.

MFSD2A potentiates gastric cancer response to anti-PD-1 immunotherapy by reprogramming the tumor microenvironment to activate T cell response

Background The efficacy of anti-programmed cell death protein 1(PD-1)immunotherapy in various cancers,including gastric cancer(GC),needs to be potentiated by more effective targeting to enhance therapeutic efficacy or identifying accurate biomarkers to predict clinical responses.Here,we attempted to identify molecules predicting or/and promoting anti-PD-1 therapeutic response in advanced GC(AGC).Methods The transcriptome of AGC tissues from patients with different clinical responses to anti-PD-1 immunotherapy and GC cells was analyzed by RNA sequencing.The protein and mRNA levels of the major facilitator superfamily domain containing 2A(MFSD2A)in GC cells were assessed via quantitative real-time polymerase chain reaction,Western blotting,and immunohistochemistry.Additionally,the regulation of anti-PD-1 response by MFSD2A was studied in tumor-bearing mice.Cytometry by Time-of-Flight,multiple immunohistochemistry,and flow cytometry assays were used to explore immunological responses.The effects of MFSD2A on lipid metabolism in mice cancer tissue and GC cells was detected by metabolomics.Results Higher expression of MFSD2A in tumor tissues of AGC patients was associated with better response to anti-PD-1 immunotherapy.Moreover,MFSD2A expression was lower in GC tissues compared to adjacent normal tissues,and its expression was inversely correlated with GC stage.The overexpression of MFSD2A in GC cells enhanced the efficacy of anti-PD-1 immunotherapy in vivo by reprogramming the tumor microenvironment(TME),characterized by increased CD8+T cell activation and reduced its exhaustion.MFSD2A inhibited transforming growth factorβ1(TGFβ1)release from GC cells by suppressing cyclooxygenase 2(COX2)-prostaglandin synthesis,which consequently reprogrammed TME to promote anti-tumor T cell activation.Conclusions MFSD2A potentially serves as a predictive biomarker for anti-PD-1 immunotherapy response in AGC patients.MFSD2A may be a promising therapeutic target to potentiate the efficacy of anti-PD-1 immunotherapy by reprogramming the TME to promote T cells activation.

The role of protein phosphorylation in the regulation of class switch recombination

Antibody is an important part of adaptive immune system and is produced only by B cells.There are five main classes(IgM,IgD,IgG,IgA,IgE)and some subclasses in antibodies.IgM and IgD are produced by mature naïve B cells.On the other hand,IgG,IgA and IgE are produced by activated antigen-specific B cells via class switch recombination(CSR).CSR is the irreversible DNA rearrangement from upstream to downstream classes in immunoglobulin heavy chain genes.Co-stimulations of CD40 ligand(CD40L)and cytokines are required for induction of CSR by activating several transcription factors.These signal transduction pathways involve many protein phosphorylation.Phosphorylation or dephosphorylation of cellular protein is an important kind of post-translational protein modification in intracellular signal transduction.In the fact,more than one third of the intracellular proteins are said to be transiently phosphorylated in human.A protein kinase is an enzyme that catalyzes the addition of phosphate to substrate protein.Whereas,a protein phosphatase catalyzes the removal of phosphate from the substrate.This review focuses on the mechanism of CSR controlled by protein phosphorylation and dephosphorylation.We provide the role of protein kinase and phosphatase in the regulation of class switch recombination.

Characterization of intratumor microbiome in cancer immunotherapy

Dear Editor,As an illuminating cancer hallmark,polymorphic microbiomes profoundly impact cancer phenotypes by promoting or repressing cancer initiation and progression.1 Diversity and composition in the gut microbiome are significantly associated with the response rate of anti-PD1 immunotherapy in melanoma.2 In addition to the gut microbiome,a large number of microbiomes colonizing in human tumors have been shown to play significant roles in cancer development.3 However,a comprehensive understanding of intratumor microbiomes in cancer immunotherapy is lacking,largely due to the challenge of investigating intratumor microbiomes in anti-cancer immunotherapy.

The RNA m^(6)A demethylase ALKBH5 drives emergency granulopoiesis and neutrophil mobilization by upregulating G-CSFR expression

Emergency granulopoiesis and neutrophil mobilization that can be triggered by granulocyte colony-stimulating factor(G-CSF)through its receptor G-CSFR are essential for antibacterial innate defense.However,the epigenetic modifiers crucial for intrinsically regulating G-CSFR expression and the antibacterial response of neutrophils remain largely unclear.N6-methyladenosine(m^(6)A)RNA modification and the related demethylase alkB homolog 5(ALKBH5)are key epigenetic regulators of immunity and inflammation,but their roles in neutrophil production and mobilization are still unknown.We used cecal ligation and puncture(CLP)-induced polymicrobial sepsis to model systemic bacterial infection,and we report that ALKBH5 is required for emergency granulopoiesis and neutrophil mobilization.ALKBH5 depletion significantly impaired the production of immature neutrophils in the bone marrow of septic mice.In addition,Alkbh5-deficient septic mice exhibited higher retention of mature neutrophils in the bone marrow and defective neutrophil release into the circulation,which led to fewer neutrophils at the infection site than in their wild-type littermates.During bacterial infection,ALKBH5 imprinted production-and mobilization-promoting transcriptome signatures in both mouse and human neutrophils.Mechanistically,ALKBH5 erased m^(6)A methylation on the CSF3R mRNA to increase the mRNA stability and protein expression of G-CSFR,consequently upregulating cell surface G-CSFR expression and downstream STAT3 signaling in neutrophils.The RIP-qPCR results confirmed the direct binding of ALKBH5 to the CSF3R mRNA,and the binding strength declined upon bacterial infection,accounting for the decrease in G-CSFR expression on bacteria-infected neutrophils.Considering these results collectively,we define a new role of ALKBH5 in intrinsically driving neutrophil production and mobilization through m^(6)A demethylation-dependent posttranscriptional regulation,indicating that m^(6)A RNA modification in neutrophils is a potential target for treating bacterial infections and neutropenia.

Eosinophils promote CD8+ T cell memory generation to potentiate anti-bacterial immunity

Memory CD8+T cell generation is crucial for pathogen elimination and effective vaccination against infection.The cellular and molecular circuitry that underlies the generation of memory CD8+T cells remains elusive.Eosinophils can modulate inflammatory allergic responses and interact with lymphocytes to regulate their functions in immune defense.Here we report that eosinophils are required for the generation of memory CD8+T cells by inhibiting CD8+T cell apoptosis.Eosinophil-deficient mice display significantly impaired memory CD8+T cell response and weakened resistance against Listeria monocytogenes(L.m.)infection.Mechanistically,eosinophils secrete interleukin-4(IL-4)to inhibit JNK/Caspase-3 dependent apoptosis of CD8+T cells upon L.m.infection in vitro.Furthermore,active eosinophils are recruited into the spleen and secrete more IL-4 to suppress CD8+T cell apoptosis during early stage of L.m.infection in vivo.Adoptive transfer of wild-type(WT)eosinophils but not IL-4-deficient eosinophils into eosinophil-deficient mice could rescue the impaired CD8+T cell memory responses.Together,our findings suggest that eosinophil-derived IL-4 promotes the generation of CD8+T cell memory and enhances immune defense against L.m.infection.Our study reveals a new adjuvant role of eosinophils in memory T cell generation and provides clues for enhancing the vaccine potency via targeting eosinophils and related cytokines.

Identification of immune-activating metabolite for enhancing T cell therapy of cancer

T cell activation by antigens is followed by rapid growth,expansion,and differentiation to perform effector functions against infection or tumor.Upon antigen stimulation,T-cell receptor(TCR)signaling triggers the remodeling of metabolic activities to meet the demand of energy and nutrients for activating and launching effective immune responses[1].

Immune response differences in degradable and non-degradable alloy implants

Alloy based implants have made a great impact in the clinic and in preclinical research.Immune responses are one of the major causes of failure of these implants in the clinic.Although the immune responses toward non-degradable alloy implants are well documented,there is a poor understanding of the immune responses against degradable alloy implants.Recently,there have been several reports suggesting that degradable implants may develop substantial immune responses.This phenomenon needs to be further studied in detail to make the case for the degradable implants to be utilized in clinics.Herein,we review these new recent reports suggesting the role of innate and potentially adaptive immune cells in inducing immune responses against degradable implants.First,we discussed immune responses to allergen components of non-degradable implants to give a better overview on differences in the immune response between non-degradable and degradable implants.Furthermore,we also provide potential areas of research that can be undertaken that may shed light on the local and global immune responses that are generated in response to degradable implants.

Dendritic cell migration in inflammation and immunity

Dendritic cells(DCs)are the key link between innate immunity and adaptive immunity and play crucial roles in both the promotion of immune defense and the maintenance of immune tolerance.The trafficking of distinct DC subsets across lymphoid and nonlymphoid tissues is essential for DC-dependent activation and regulation of inflammation and immunity.DC chemotaxis and migration are triggered by interactions between chemokines and their receptors and regulated by multiple intracellular mechanisms,such as protein modification,epigenetic reprogramming,metabolic remodeling,and cytoskeletal rearrangement,in a tissue-specific manner.Dysregulation of DC migration may lead to abnormal positioning or activation of DCs,resulting in an imbalance of immune responses and even immune pathologies,including autoimmune responses,infectious diseases,allergic diseases and tumors.New strategies targeting the migration of distinct DC subsets are being explored for the treatment of inflammatory and infectious diseases and the development of novel DC-based vaccines.In this review,we will discuss the migratory routes and immunological consequences of distinct DC subsets,the molecular basis and regulatory mechanisms of migratory signaling in DCs,and the association of DC migration with the pathogenesis of autoimmune and infectious diseases.

Cellular and molecular regulation of innate inflammatory responses

Innate sensing of pathogens by pattern-recognition receptors （PRRs） plays essential roles in the innate discrimination between self and non-self components, leading to the generation of innate immune defense and inflammatory responses. The initiation, activation and resolution of innate inflammatory response are mediated by a complex network of interactions among the numerous cellular and molecular components of immune and non- immune system. While a controlled and beneficial innate inflammatory response is critical for the elimination of pathogens and maintenance of tissue homeostasis, dysregulated or sustained inflammation leads to pathological conditions such as chronic infection, inflammatory autoimmune diseases. In this review, we discuss some of the recent advances in our understanding of the cellular and molecular mechanisms for the establishment and reJzulation of innate immunity and inflammatory responses.

The function and regulation of TET2 in innate immunity and inflammation

TET2,a member of ten-eleven translocation(TET)family as a-ketoglutarate-and Fe2+-dependent dioxygenase catalyzing the iterative oxidation of 5-methylcytosine(5mC),has been widely recognized to be an important regulator for normal hematopoiesis especially myelopoiesis.Mutation and dysregulation of TET2 contribute to the development of multiple hematological malignancies.Recent studies reveal that TET2 also plays an important role in innate immune homeostasis by promoting DNA demethylation or independent of its enzymatic activity.Here,we focus on the functions of TET2 in the initiation and resolution of inflammation through epigenetic regulation and signaling network.In addition,we highlight regulation of TET2 at various molecular levels as well as the correlated inflammatory diseases,which will provide the insight to intervene in the pathological process caused by TET2 dysregulation.

RNA-binding protein ZCCHC4 promotes human cancer chemoresistance by disrupting DNA-damage-induced apoptosis

RNA-binding proteins(RBPs)play important roles in cancer development and treatment.However,the tumor-promoting RBPs and their partners,which may potentially serve as the cancer therapeutic targets,need to be further identified.Here,we report that zinc finger CCHC domain-containing protein 4(ZCCHC4)is of aberrantly high expression in multiple human cancer tissues and is associated with poor prognosis and chemoresistance in patients of hepatocellular carcinoma(HCC),pancreatic cancer and colon cancer.ZCCHC4 promotes chemoresistance of HCC cells to DNA-damage agent(DDA)both in vitro and in vivo.HCC cell deficiency of ZCCHC4 reduces tumor growth in vivo and intratumoral interference of ZCCHC4 expression obviously enhances the DDAinduced antitumor effect.Mechanistically,ZCCHC4 inhibits DNA-damage-induced apoptosis in HCC cells by interacting with a new long noncoding RNA(lncRNA)AL133467.2 to hamper its pro-apoptotic function.Also,ZCCHC4 blocks the interaction between AL133467.2 andγH2AX upon DDA treatment to inhibit apoptotic signaling and promote chemoresistance to DDAs.Knockout of ZCCHC4 promotes AL133467.2 andγH2AX interaction for enhancing chemosensitivity in HCC cells.Together,our study identifies ZCCHC4 as a new predictor of cancer poor prognosis and a potential target for improving chemotherapy effects,providing mechanistic insights to the roles of RBPs and their partners in cancer progression and chemoresistance.

Metabolic control of T-cell immunity via epigenetic mechanisms

Metabolism has been increasingly considered to play an important role in inflammation and immunity via modulating cellular signaling and transcriptional networks.1 Dysregulation of metabolic enzymes or mediators is increasingly linked to clinical diseases,such as type I diabetes,gliomas and breast cancer.2,3 Numerous metabolic sensors,such as AMP-mediated protein kinase,mammalian target of rapamycin complex1 and hypoxia-induced factor 1α(HIF-1α),have been shown to regulate immunological responses,such as T-cell activation and macrophage polarization,via modulating the property and activity of signaling pathways.4,5 Moreover,emerging evidence suggests that intermediates from multiple metabolic pathways are important in orchestrating transcriptional and epigenetic programs.This interaction between metabolic and epigenetic pathways is crucial for coordinating cellular immunological events in response to extracellular stimuli,such as infection,injury and stress,leading to varied biological and pathological outcomes.

Mast cells as rapid innate sensors of cytomegalovirus by TLR3/TRIF signaling-dependent and -independent mechanisms

The succinct metaphor,‘the immune system＇s loaded gun＇, has been used to describe the role of mast cells （MCs） due to their storage of a wide range of potent pro-inflammatory and antimicrobial mediators in secretory granules that can be released almost instantly on demand to fight invaders. Located at host-environment boundaries and equipped with an arsenal of pattern recognition receptors, MCs are destined to be rapid innate sensors of pathogens penetrating endothelial and epithelial surfaces. Although the importance of MCs in antimicrobial and antiparasitic defense has long been appreciated, their role in raising the alarm against viral infections has been noted only recently. Work on cytomegalovirus （CMV） infection in the murine model has revealed MCs as players in a novel cross-talk axis between innate and adaptive immune surveillance of CMV, in that infection of MCs, which is associated with MC degranulation and release of the chemokine CCL5, enhances the recruitment of protective CD8 T cells to extravascular sites of virus replication, specifically to lung interstitium and alveolar epithelium. Here, we have expanded on these studies by investigating the conditions for MC activation and the consequent degranulation in response to host infection. Surprisingly, the data revealed two temporally and mechanistically distinct waves of MC activation： an almost instant indirect activation that depended on TLR3/TRIF signaling and delayed activation by direct infection of MCs that did not involve TLR3/rRIF signaling. Cell type-specific Cre-recombination that yielded eGFP-expressing reporter virus selectively originating from MCs identified MC as a new in vivo, first-hit target cell of productive murine CMV infection.

Multimodal single-cell omics analysis identifies epithelium-immune cell interactions and immune vulnerability associated with sex differences in COVID-19

Sex differences in the susceptibility of SARS-CoV-2 infection and severity have been controversial,and the underlying mechanisms of COVID-19 in a sex-specific manner remain understudied.Here we inspected sex differences in SARS-CoV-2 infection,hospitalization,admission to the intensive care unit(ICU),sera inflammatory biomarker profiling,and single-cell RNA-sequencing(scRNA-seq)profiles across nasal,bronchoalveolar lavage fluid(BALF),and peripheral blood mononuclear cells(PBMCs)from COVID-19 patients with varying degrees of disease severities.Our propensity score-matching observations revealed that male individuals have a 29%elevated likelihood of SARS-CoV-2 positivity,with a hazard ratio(HR)1.32(95%confidence interval[Cl]1.18-1.48)for hospitalization and HR 1.51(95%Cl 1.24-1.84)for admission to ICU.Sera from male patients at hospital admission had elevated neutrophil-lymphocyte ratio and elevated expression of inflammatory markers(C-reactive protein and procalcitonin).We found that SARS-CoV-2 entry factors,including ACE2,TMPRSS2,FURIN,and NRP1,have elevated expression in nasal squamous cells from male individuals with moderate and severe COVID-19.We observed male-biased transcriptional activation in SARS-CoV-2-infected macrophages from BALF and sputum samples,which offers potential molecular mechanism for sex-biased susceptibility to viral infection.Cell-cell interaction network analysis reveals potential epithelium-immune cell interactions and immune vulnerability underlying male-elevated disease severity and mortality in COVID-19.Mechanistically,monocyte-elevated expression of Toll-like receptor 7{TLR7)and Bruton tyrosine kinase{BTK)is associated with severe outcomes in males with COVID-19.In summary,these findings provide basis to decipher immune responses underlying sex differences and designing sex-specific targeted interventions and patient care for COVID-19.

Genome-wide in vivo screen identifies host molecule in promoting cancer metastasis

Metastasis, the movement of tumor cells from a primary site to progressively colonize distant organs, is the leading cause of cancer mortality. Emerging evidences show that tumor- educated host microenvironment cooperates with tumor cells during the multiple stage of metastasis, making tumor cells evade immune attack, resistant to apoptosis, and proliferate in distant organ （Liu et al., 2016; Quail and Joyce, 2013）. This microenvironment consists of an elaborate array of inflammatory cells, flbroblastic cells, blood vessels, and the extracellular matrix （Joyce and Fearon, 2015; Liu and Cao, 2016）.

Insights into the co-evolution of glioblastoma and associated macrophages

Glioblastoma(GBM)is one of the most immunosuppressive and heterogeneous tumors with limited treatment options.Most studies relied on treatment-experienced patient samples to elucidate the origins of tumor heterogeneity,introducing bias into the analysis.The analysis of samples from multifocal GBM patients,in which independent lesions arise from the same progenitor and undergo parallel evolution,enables the study of the natural evolution of GBM while removing the effect of therapy on the emergence of heterogeneity.This enables the identification of critical events in the evolution of GBM and the unbiased study of subtype progression,diversity,and invasive potential.The tumor microenvironment of GBM undergoes significant changes throughout tumor progression.Recent studies have highlighted the switch from an abundance of resident microglia-derived macrophages in earlier stages to the prevalence of blood-derived macrophages in later stages of GBM.There is conclusive evidence that these alterations cannot be viewed in isolation and that the tumor microenvironment co-evolves with tumor cells during cancer progression.Together with an increasingly hypoxic environment,this culminates in highly immunosuppressive conditions,resulting in a feedback loop further reinforcing evolutionary changes in the tumor.A new study now provides a unique look at the natural evolution of GBM,identifies critical events in its development,and has the potential to help improve the diagnosis and therapy of this deadly disease.