技术资料

Vaccines are among the most effective public health tools for combating certain infectious diseases such as influenza. The role of the humoral immune system in vaccine-induced protection is widely appreciated; however,our understanding of how antibody specificities relate to B cell function remains limited due to the complexity of polyclonal antibody responses. To address this,we developed the Spec-seq framework,which allows for simultaneous monoclonal antibody (mAb) characterization and transcriptional profiling from the same single cell. Here,we present the first application of the Spec-seq framework,which we applied to human plasmablasts after influenza vaccination in order to characterize transcriptional differences governed by B cell receptor (BCR) isotype and vaccine reactivity. Our analysis did not find evidence of long-term transcriptional specialization between plasmablasts of different isotypes. However,we did find enhanced transcriptional similarity between clonally related B cells,as well as distinct transcriptional signatures ascribed by BCR vaccine recognition. These data suggest IgG and IgA vaccine-positive plasmablasts are largely similar,whereas IgA vaccine-negative cells appear to be transcriptionally distinct from conventional,terminally differentiated,antigen-induced peripheral blood plasmablasts. View Publication

While it is now acknowledged that CD4+ T cells expressing CD25 and Foxp3 (Treg cells) regulate immune responses and,consequently,influence the pathogenesis of infectious diseases,the regulatory response mediated by Treg cells upon infection by Trypanosoma cruzi was still poorly characterized. In order to understand the role of Treg cells during infection by this protozoan parasite,we determined in time and space the magnitude of the regulatory response and the phenotypic,functional and transcriptional features of the Treg cell population in infected mice. Contrary to the accumulation of Treg cells reported in most chronic infections in mice and humans,experimental T. cruzi infection was characterized by sustained numbers but decreased relative frequency of Treg cells. The reduction in Treg cell frequency resulted from a massive accumulation of effector immune cells,and inversely correlated with the magnitude of the effector immune response as well as with emergence of acute immunopathology. In order to understand the causes underlying the marked reduction in Treg cell frequency,we evaluated the dynamics of the Treg cell population and found a low proliferation rate and limited accrual of peripheral Treg cells during infection. We also observed that Treg cells became activated and acquired a phenotypic and transcriptional profile consistent with suppression of type 1 inflammatory responses. To assess the biological relevance of the relative reduction in Treg cells frequency observed during T. cruzi infection,we transferred in vitro differentiated Treg cells at early moments,when the deregulation of the ratio between regulatory and conventional T cells becomes significant. Intravenous injection of Treg cells dampened parasite-specific CD8+ T cell immunity and affected parasite control in blood and tissues. Altogether,our results show that limited Treg cell response during the acute phase of T. cruzi infection enables the emergence of protective anti-parasite CD8+ T cell immunity and critically influences host resistance. View Publication

Pathogen immune responses are profoundly attenuated in fetuses and premature infants,yet the mechanisms underlying this developmental immaturity remain unclear. Here we show transcriptomic,metabolic and polysome profiling and find that monocytes isolated from infants born early in gestation display perturbations in PPAR-$\gamma$-regulated metabolic pathways,limited glycolytic capacity and reduced ribosomal activity. These metabolic changes are linked to a lack of translation of most cytokines and of MALT1 signalosome genes essential to respond to the neonatal pathogen Candida. In contrast,they have little impact on house-keeping phagocytosis functions. Transcriptome analyses further indicate a role for mTOR and its putative negative regulator DNA Damage Inducible Transcript 4-Like in regulating these metabolic constraints. Our results provide a molecular basis for the broad susceptibility to multiple pathogens in these infants,and suggest that the fetal immune system is metabolically programmed to avoid energetically costly,dispensable and potentially harmful immune responses during ontogeny. View Publication

We examined the unique contributions of the cytokines IL-21 and IL-4 on germinal center (GC) B cell initiation and subsequent maturation in a murine model system. Similar to other reports,we found T follicular helper cell expression of IL-21 begins prior to T follicular helper cell migration into the B cell follicle and precedes that of IL-4. Consistent with this timing,IL-21 signaling has a greater influence on the perifollicular pre-GC B cell transition to the intrafollicular stage. Notably,Bcl6hi B cells can form in the combined absence of IL-21R- and STAT6-derived signals; however,these nascent GC B cells cease to proliferate and are more prone to apoptosis. When B cells lack either IL-21R or STAT6,aberrant GCs form atypical centroblasts and centrocytes that differ in their phenotypic maturation and costimulatory molecule expression. Thus,IL-4 and IL-21 play nonredundant roles in the phased progression of GC B cell development that can initiate in the combined absence of these cytokine signals. View Publication

The costimulation of immune cells using first-generation anti-4-1BB monoclonal antibodies (mAbs) has demonstrated anti-tumor activity in human trials. Further clinical development,however,is restricted by significant off-tumor toxicities associated with Fc$\gamma$R interactions. Here,we have designed an Fc-free tumor-targeted 4-1BB-agonistic trimerbody,1D8N/CEGa1,consisting of three anti-4-1BB single-chain variable fragments and three anti-EGFR single-domain antibodies positioned in an extended hexagonal conformation around the collagen XVIII homotrimerization domain. The1D8N/CEGa1 trimerbody demonstrated high-avidity binding to 4-1BB and EGFR and a potent in vitro costimulatory capacity in the presence of EGFR. The trimerbody rapidly accumulates in EGFR-positive tumors and exhibits anti-tumor activity similar to IgG-based 4-1BB-agonistic mAbs. Importantly,treatment with 1D8N/CEGa1 does not induce systemic inflammatory cytokine production or hepatotoxicity associated with IgG-based 4-1BB agonists. These results implicate Fc$\gamma$R interactions in the 4-1BB-agonist-associated immune abnormalities,and promote the use of the non-canonical antibody presented in this work for safe and effective costimulatory strategies in cancer immunotherapy. View Publication

Despite showing success in treating melanoma and haematological malignancies,adoptive cell therapy (ACT) has generated only limited effects in solid tumors. This is,in part,due to a lack of specific antigen targets,poor trafficking/infiltration and immunosuppression in the tumor microenvironment. In this study,we combined ACT with oncolytic virus vaccines (OVV) to drive expansion and tumor infiltration of transferred antigen-specific T cells,and demonstrated that the combination is highly potent for the eradication of established solid tumors. Consistent with other successful immunotherapies,this approach elicited severe autoimmune consequence when the antigen targeted was a self-protein. However,modulation of IFN$\alpha$/$\beta$ signaling,either by functional blockade or rational choice of an OVV backbone,ameliorated autoimmune side effects without compromising antitumor efficacy. Our study uncovers a pathogenic role for IFN$\alpha$/$\beta$ in facilitating autoimmune toxicity during cancer immunotherapy and offers a safe and powerful combinatorial regimen with immediate translational applications. View Publication

Chronic periodontitis (CP) is a microbial dysbiotic disease linked to increased risk of oral squamous cell carcinomas (OSCCs). To address the underlying mechanisms,mouse and human cell infection models and human biopsy samples were employed. We show that the 'keystone' pathogen Porphyromonas gingivalis,disrupts immune surveillance by generating myeloid-derived dendritic suppressor cells (MDDSCs) from monocytes. MDDSCs inhibit CTLs and induce FOXP3 + Tregs through an anti-apoptotic pathway. This pathway,involving pAKT1,pFOXO1,FOXP3,IDO1 and BIM,is activated in humans with CP and in mice orally infected with Mfa1 expressing P. gingivalis strains. Mechanistically,activation of this pathway,demonstrating FOXP3 as a direct FOXO1-target gene,was demonstrated by ChIP-assay in human CP gingiva. Expression of oncogenic but not tumor suppressor markers is consistent with tumor cell proliferation demonstrated in OSCC-P. gingivalis cocultures. Importantly,FimA + P. gingivalis strain MFI invades OSCCs,inducing inflammatory/angiogenic/oncogenic proteins stimulating OSCCs proliferation through CXCR4. Inhibition of CXCR4 abolished Pg-MFI-induced OSCCs proliferation and reduced expression of oncogenic proteins SDF-1/CXCR4,plus pAKT1-pFOXO1. Conclusively,P. gingivalis,through Mfa1 and FimA fimbriae,promotes immunosuppression and oncogenic cell proliferation,respectively,through a two-hit receptor-ligand process involving DC-SIGN+hi/CXCR4+hi,activating a pAKT+hipFOXO1+hiBIM-lowFOXP3+hi and IDO+hi- driven pathway,likely to impact the prognosis of oral cancers in patients with periodontitis. View Publication

CD24 expression on pro-B cells plays a role in B cell selection and development in the bone marrow. We previously detected higher CD24 expression and frequency within IgD+ na{\{i}}ve and memory B cells in patients with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) compared with age-matched healthy controls (HC). Here we investigated the relationship between CD24 expression and B cell maturation. In vitro stimulation of isolated B cells in response to conventional agonists were used to follow the dynamics of CD24 positivity during proliferation and differentiation (or maturation). The relationship between CD24 expression to cycles of proliferation and metabolism in purified B cells from HC was also investigated using phospho-flow (phosphorylation of AMPK-pAMPK) 1proton nuclear magnetic resonance and Mitotracker Far-red (Mitochondrial mass-MM). In vitro in the absence of stimulation there was an increased percentage of CD24+ viable B cells in ME/CFS patients compared to HC (p {\textless} 0.05) following 5 days culture. Following stimulation with B cell agonists percentage of CD24+B cells in both na{\"{i}}ve and memory B cell populations decreased. P {\textless} 0.01). There was a negative relationship between percentage of CD24+B cells with MM (R2 = 0.76; p {\textless} 0.01) which was subsequently lost over sequential cycles of proliferation. There was a significant correlation between CD24 expression on B cells and the usage of glucose and secretion of lactate in vitro. Short term ligation of the B cell receptor with anti-IgM antibody significantly reduced the viability of CD24+ memory B cells compared to those cross-linked by anti-IgD or anti-IgG antibody. A clear difference was found between na{\""{i}}ve and memory B cells with respect to CD24 expression and pAMPK most notably a strong positive association in IgD+IgM+ memory B cells. In vitro findings confirmed dysregulation of CD24-expressing B cells from ME/CFS patients previously suggested by immunophenotype studies of B cells from peripheral blood. CD24-negative B cells underwent productive proliferation whereas CD24+ B cells were either unresponsive or susceptible to cell death upon BCR-engagement alone. We suggest that CD24 expression may reflect variations in energy metabolism on different B cell subsets.""" View Publication

BACKGROUND Plasma cell neoplasms (PCNs) encompass a spectrum of disorders including monoclonal gammopathy of undetermined significance,smoldering myeloma,plasma cell myeloma,and plasma cell leukemia. Molecular subtypes have been defined by recurrent cytogenetic abnormalities and somatic mutations that are prognostic and predictive. Karyotype and fluorescence in situ hybridization (FISH) have historically been used to guide management; however,new technologies and markers raise the need to reassess current testing algorithms. METHODS We convened a panel of representatives from international clinical laboratories to capture current state-of-the-art testing from published reports and to put forward recommendations for cytogenomic testing of plasma cell neoplasms. We reviewed 65 papers applying FISH,chromosomal microarray (CMA),next-generation sequencing,and gene expression profiling for plasma cell neoplasm diagnosis and prognosis. We also performed a survey of our peers to capture current laboratory practice employed outside our working group. RESULTS Plasma cell enrichment is widely used prior to FISH testing,most commonly by magnetic bead selection. A variety of strategies for direct,short- and long-term cell culture are employed to ensure clonal representation for karyotyping. Testing of clinically-informative 1p/1q,del(13q) and del(17p) are common using karyotype,FISH and,increasingly,CMA testing. FISH for a variety of clinically-informative balanced IGH rearrangements is prevalent. Literature review found that CMA analysis can detect abnormalities in 85-100{\%} of patients with PCNs; more specifically,in 5-53{\%} (median 14{\%}) of cases otherwise normal by FISH and cytogenetics. CMA results in plasma cell neoplasms are usually complex,with alteration counts ranging from 1 to 74 (median 10-20),primarily affecting loci not covered by FISH testing. Emerging biomarkers include structural alterations of MYC as well as somatic mutations of KRAS,NRAS,BRAF,and TP53. Together,these may be measured in a comprehensive manner by a combination of newer technologies including CMA and next-generation sequencing (NGS). Our survey suggests most laboratories have,or are soon to have,clinical CMA platforms,with a desire to move to NGS assays in the future. CONCLUSION We present an overview of current practices in plasma cell neoplasm testing as well as an algorithm for integrated FISH and CMA testing to guide treatment of this disease. View Publication

CRISPR/Cas9 mediated gene editing of patient-derived hematopoietic stem and progenitor cells (HSPCs) ex vivo followed by autologous transplantation of the edited HSPCs back to the patient can provide a potential cure for monogenic blood disorders such as $\beta$-hemoglobinopathies. One challenge for this strategy is efficient delivery of the ribonucleoprotein (RNP) complex,consisting of purified Cas9 protein and guide RNA,into HSPCs. Because $\beta$-hemoglobinopathies are most prevalent in developing countries,it is desirable to have a reliable,efficient,easy-to-use and cost effective delivery method. With this goal in mind,we developed TRansmembrane Internalization Assisted by Membrane Filtration (TRIAMF),a new method to quickly and effectively deliver RNPs into HSPCs by passing a RNP and cell mixture through a filter membrane. We achieved robust gene editing in HSPCs using TRIAMF and demonstrated that the multilineage colony forming capacities and the competence for engraftment in immunocompromised mice of HSPCs were preserved post TRIAMF treatment. TRIAMF is a custom designed system using inexpensive components and has the capacity to process HSPCs at clinical scale. View Publication

Zika virus is a mosquito-borne flavivirus closely related to dengue virus that can cause severe disease in humans,including microcephaly in newborns and Guillain-Barr{\'{e}} syndrome in adults. Specific treatments and vaccines for Zika virus are not currently available. Here,we isolate and characterize four monoclonal antibodies (mAbs) from an infected patient that target the non-structural protein NS1. We show that while these antibodies are non-neutralizing,NS1-specific mAbs can engage Fc$\gamma$R without inducing antibody dependent enhancement (ADE) of infection in vitro. Moreover,we demonstrate that mAb AA12 has protective efficacy against lethal challenges of African and Asian lineage strains of Zika virus in Stat2-/- mice. Protection is Fc-dependent,as a mutated antibody unable to activate known Fc effector functions or complement is not protective in vivo. This study highlights the importance of the ZIKV NS1 protein as a potential vaccine antigen. View Publication

CD4+ T cells,especially T-helper (Th) cells (Th1,Th2 and Th17) and regulatory T cells (Treg) play pivotal role in the pathogenesis of multiple sclerosis (MS),a demyelinating autoimmune disease occurring in central nervous system (CNS). Astragaloside IV (ASI,CAS: 84687-43-4) is one of the saponins isolated from Astragalus membranceus,a traditional Chinese medicine with immunomodulatory effect. So far,whether ASI has curative effect on experimental autoimmune encephalomyelitis (EAE),an animal model of MS,and how it affects the subsets of CD4+ T cells,as well as the underlying mechanism have not been clearly elucidated. In the present study,ASI was found to ameliorate the progression and hamper the recurrence of EAE effectively in the treatment regimens. It significantly reduced the demyelination and inflammatory infiltration of CNS in EAE mice by suppressing the percentage of Th1 and Th17 cells,which was closely associated with the inhibition of JAK/STAT and NF-$\kappa$B signaling pathways. ASI also increased the percentage of Treg cells in spleen and CNS,which was accompanied by elevated Foxp3. However,in vitro experiments disclosed that ASI could regulate the differentiation of Th17 and Treg cells but not Th1 cells. In addition,it induced the apoptosis of MOG-stimulated CD4+ T cells probably through modulating STAT3/Bcl-2/Bax signaling pathways. Together,our findings suggested that ASI can modulate the differentiation of autoreactive CD4+ T cells and is a potential prodrug or drug for the treatment of MS and other similar autoimmune diseases. View Publication