Scientific Resources

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

Preventing the immune escape of tumor cells by blocking inhibitory checkpoints,such as the interaction between programmed death ligand-1 (PD-L1) and programmed death-1 (PD-1) receptor,is a powerful anticancer approach. However,many patients do not respond to checkpoint blockade. Tumor PD-L1 expression is a potential efficacy biomarker,but the complex mechanisms underlying its regulation are not completely understood. Here,we show that the eukaryotic translation initiation complex,eIF4F,which binds the 5' cap of mRNAs,regulates the surface expression of interferon-$\gamma$-induced PD-L1 on cancer cells by regulating translation of the mRNA encoding the signal transducer and activator of transcription 1 (STAT1) transcription factor. eIF4F complex formation correlates with response to immunotherapy in human melanoma. Pharmacological inhibition of eIF4A,the RNA helicase component of eIF4F,elicits powerful antitumor immune-mediated effects via PD-L1 downregulation. Thus,eIF4A inhibitors,in development as anticancer drugs,may also act as cancer immunotherapies. View Publication

Circulating tumor cells (CTCs) are important clinical indicators for prognosis and treatment efficacy. However,CTC investigation is hampered by their low number,making the establishment of permanent CTC lines very challenging. We derived and characterized nine CTC lines using blood samples from a patient with metastatic colorectal cancer collected before and after chemotherapy and targeted therapy,and during cancer progression. These cell lines displayed an intermediate epithelial/mesenchymal phenotype,stem-cell like characteristics,angiogenesis potential,an osteomimetic signature and the capacity to escape from the immune system. Moreover,they showed changes in mRNA and protein expression (e.g.,DEFA6,ABCB1 and GAL),whereas analysis of chromosomal copy number aberrations revealed no significant variation over time. These data indicate that although CTC lines derived from sequential blood samples during therapy have common traits,treatment-resistant CTC clones with distinct phenotypic characteristics are selected over time. View Publication

Indoleamine 2,3-dioxygenase 2 (Ido2) is a recently identified catalytic enzyme in the tryptophan-kynurenine pathway that is expressed primarily in monocytes and dendritic cells. To elucidate the biological role of Ido2 in immune function,we introduced lipopolysaccharide (LPS) endotoxin shock to Ido2 knockout (Ido2 KO) mice,which led to higher mortality than that in the wild type (WT) mice. LPS-treated Ido2 KO mice had increased production of inflammatory cytokines (including interleukin-6; IL-6) in serum and signal transducer and activator of transcription 3 (stat3) phosphorylation in the spleen. Moreover,the peritoneal macrophages of LPS-treated Ido2 KO mice produced more cytokines than did the WT mice. By contrast,the overexpression of Ido2 in the murine macrophage cell line (RAW) suppressed cytokine production and decreased stat3 expression. Finally,RAW cells overexpressing Ido2 did not alter nuclear factor $\kappa$B (NF-$\kappa$B) or stat1 expression,but IL-6 and stat3 expression decreased relative to the control cell line. These results reveal that Ido2 modulates IL-6/stat3 signalling and is induced by LPS,providing novel options for the treatment of immune disorders. View Publication

Recognition of nucleic acids by endosomal Toll-like receptors (TLR) is essential to combat pathogens,but requires strict control to limit inflammatory responses. The mechanisms governing this tight regulation are unclear. We found that single-stranded oligonucleotides (ssON) inhibit endocytic pathways used by cargo destined for TLR3/4/7 signaling endosomes. Both ssDNA and ssRNA conferred the endocytic inhibition,it was concentration dependent,and required a certain ssON length. The ssON-mediated inhibition modulated signaling downstream of TLRs that localized within the affected endosomal pathway. We further show that injection of ssON dampens dsRNA-mediated inflammatory responses in the skin of non-human primates. These studies reveal a regulatory role for extracellular ssON in the endocytic uptake of TLR ligands and provide a mechanistic explanation of their immunomodulation. The identified ssON-mediated interference of endocytosis (SOMIE) is a regulatory process that temporarily dampens TLR3/4/7 signaling,thereby averting excessive immune responses. View Publication

PURPOSE Tumor-associated macrophages (TAMs) and the hyperactivation of phosphoinositide 3-kinase(PI3K)/AKT pathway are involved in the pathogenesis of Hodgkin lymphoma (HL) and affect disease outcome. Since the $\delta$ and $\gamma$ isoforms of PI3K are overexpressed in Hodgkin/Reed-Sternberg (HRS) cells and the tumor microenvironment (TME),we propose that the PI3K$\delta$/$\gamma$ inhibitor RP6530 might affect both HRS cells and TME,ultimately leading to an enhanced antitumor response. EXPERIMENTAL DESIGN HL cell lines (L-540,KM-H2 and L-428) and primary human macrophages were used to investigate the activity of RP6530 in vitro and in vivo in HL cell line xenografts. RESULTS In vitro,RP6530 besides killing and inhibiting the proliferation of HL cells,downregulated lactic acid metabolism,switching the activation of macrophages from an immunosuppressive M2-like phenotype to a more inflammatory M1-like state. By RNA sequencing,we define tumor glycolysis as a specific PI3K$\delta$/$\gamma$-dependent pathway implicated in the metabolic reprogramming of cancer cells. We identify the metabolic regulator Pyruvate Kinase M2 (PKM2) as the main mediator of tumor-induced immunosuppressive phenotype of macrophages. Furthermore,we show in human tumor xenografts that RP6530 repolarizes TAMs into pro-inflammatory macrophages and inhibits tumor vasculature,leading to tumor regression. Interestingly,HL patients experiencing objective responses (CR and PR) in a phase 1 trial using RP6530 showed a significant inhibition of circulating MDSCs and an average mean reduction in serum TARC levels of 40{\%} (range,4-76{\%}). CONCLUSIONS Our results support PI3K$\delta$/$\gamma$ inhibition as a novel therapeutic strategy that targets both malignant cells and the TME to treat HL patients. View Publication