技术资料

H7 avian influenza viruses represent a major public health concern,and worldwide outbreaks raise the risk of a potential pandemic. Understanding the memory B cell response to avian (H7) influenza virus infection in humans could provide insights in the potential key to human infection risks. We investigated an epizootic of the highly pathogenic A(H7N7) in the Netherlands,which in 2003 led to infection of 89 persons and one fatal case. Subtype-specificity of antibodies were determined for confirmed H7N7 infected individuals (cases) (n = 19),contacts of these cases (n = 21) and a comparison group controls (n = 16),by microarray,using recombinant hemagglutinin (HA)1 proteins. The frequency and specificity of memory B cells was determined by detecting subtype-specific antibodies in the culture supernatants from in vitro stimulated oligoclonal B cell cultures,from peripheral blood of cases and controls. All cases (100{\%}) had high antibody titers specific for A(H7N7)2003 (GMT {\textgreater} 100),whereas H7-HA1 antigen binding was detected in 29{\%} of contacts and 31{\%} of controls,suggesting that some of the H7 reactivity stems from cross reactive antibodies. To unravel homotypic and heterotypic responses,the frequency and specificity of memory B cells were determined in 2 cases. Ten of 123 HA1 reactive clones isolated from the cases bound to only H7- HA1,whereas 5 bound both H7 and other HA1 antigens. We recovered at least four different epitopal reactivities,though none of the H7 reactive antibodies were able to neutralize H7 infections in vitro. Our study serologically confirms the infection with H7 avian influenza viruses,and shows that H7 infection triggers a mixture of strain -specific and cross-reactive antibodies. View Publication

Abdominal aortic aneurysm (AAA) is life-threatening,for which efficient nonsurgical treatment strategy has not been available so far. Several previous studies investigating the therapeutic effect of mesenchymal stem cells (MSCs) in AAA indicated that MSCs could inhibit aneurysmal inflammatory responses and extracellular matrix destruction,and suppress aneurysm occurrence and expansion. Vascular smooth muscle cell (VSMC) phenotypic plasticity is reported to be predisposed in AAA initiation and progression. However,little is known about the effect of MSCs on VSMC phenotypic modulation in AAA. In this study,we investigate the therapeutic efficacy of umbilical cord mesenchymal stem cells (UC-MSCs) in elastase-induced AAA model and evaluate the effect of UC-MSC on VSMC phenotypic regulation. We demonstrate that the intravenous injection of UC-MSC attenuates elastase-induced aneurysmal expansion,reduces elastin degradation and fragmentation,inhibits MMPs and TNF-$\alpha$ expression,and preserves and/or restores VSMC contractile phenotype in AAA. Taken together,these results highlight the therapeutic and VSMC phenotypic modulation effects of UC-MSC in AAA progression,which further indicates the potential of applying UC-MSC as an alternative treatment candidate for AAA. View Publication

Mutational inactivation of ATRX ($\alpha$-thalassemia mental retardation X-linked) represents a defining molecular alteration in large subsets of malignant glioma. Yet the pathogenic consequences of ATRX deficiency remain unclear,as do tractable mechanisms for its therapeutic targeting. Here we report that ATRX loss in isogenic glioma model systems induces replication stress and DNA damage by way of G-quadruplex (G4) DNA secondary structure. Moreover,these effects are associated with the acquisition of disease-relevant copy number alterations over time. We then demonstrate,both in vitro and in vivo,that ATRX deficiency selectively enhances DNA damage and cell death following chemical G4 stabilization. Finally,we show that G4 stabilization synergizes with other DNA-damaging therapies,including ionizing radiation,in the ATRX-deficient context. Our findings reveal novel pathogenic mechanisms driven by ATRX deficiency in glioma,while also pointing to tangible strategies for drug development. View Publication

Interpreting how multicellular interactions in the tumor affect resistance pathways to BRAF and MEK1/2 MAPK inhibitors (MAPKi) remains a challenge. To investigate this,we profiled global ligand-receptor interactions among tumor and stromal/immune cells from biopsies of MAPK-driven disease. MAPKi increased tumor-associated macrophages (TAMs) in some patients,which correlated with poor clinical response,and MAPKi coamplified bidirectional tumor-TAM signaling via receptor tyrosine kinases (RTKs) including AXL,MERTK,and their ligand GAS6. In xenograft tumors,intravital microscopy simultaneously monitored in situ single-cell activities of multiple kinases downstream of RTKs,revealing MAPKi increased TAMs and enhanced bypass signaling in TAM-proximal tumor cells. As a proof-of-principle strategy to block this signaling,we developed a multi-RTK kinase inhibitor nanoformulation that accumulated in TAMs and delayed disease progression. Thus,bypass signaling can reciprocally amplify across nearby cell types,offering new opportunities for therapeutic design. View Publication

Self-assembling virus-like particles represent highly attractive tools for developing next-generation vaccines and protein therapeutics. We created ADDomer,an adenovirus-derived multimeric protein-based self-assembling nanoparticle scaffold engineered to facilitate plug-and-play display of multiple immunogenic epitopes from pathogens. We used cryo–electron microscopy at near-atomic resolution and implemented novel,cost-effective,high-performance cloud computing to reveal architectural features in unprecedented detail. We analyzed ADDomer interaction with components of the immune system and developed a promising first-in-kind ADDomer-based vaccine candidate to combat emerging Chikungunya infectious disease,exemplifying the potential of our approach. View Publication

Patient-derived organoids (PDOs) have recently emerged as robust preclinical models; however,their potential to predict clinical outcomes in patients has remained unclear. We report on a living biobank of PDOs from metastatic,heavily pretreated colorectal and gastroesophageal cancer patients recruited in phase 1/2 clinical trials. Phenotypic and genotypic profiling of PDOs showed a high degree of similarity to the original patient tumors. Molecular profiling of tumor organoids was matched to drug-screening results,suggesting that PDOs could complement existing approaches in defining cancer vulnerabilities and improving treatment responses.We compared responses to anticancer agents ex vivo in organoids and PDO-based orthotopic mouse tumor xenograft models with the responses of the patients in clinical trials. Our data suggest that PDOs can recapitulate patient responses in the clinic and could be implemented in personalized medicine programs. View Publication

High-grade gliomas are lethal brain cancers whose progression is robustly regulated by neuronal activity. Activity-regulated release of growth factors promotes glioma growth,but this alone is insufficient to explain the effect that neuronal activity exerts on glioma progression. Here we show that neuron and glioma interactions include electrochemical communication through bona fide AMPA receptor-dependent neuron-glioma synapses. Neuronal activity also evokes non-synaptic activity-dependent potassium currents that are amplified by gap junction-mediated tumour interconnections,forming an electrically coupled network. Depolarization of glioma membranes assessed by in vivo optogenetics promotes proliferation,whereas pharmacologically or genetically blocking electrochemical signalling inhibits the growth of glioma xenografts and extends mouse survival. Emphasizing the positive feedback mechanisms by which gliomas increase neuronal excitability and thus activity-regulated glioma growth,human intraoperative electrocorticography demonstrates increased cortical excitability in the glioma-infiltrated brain. Together,these findings indicate that synaptic and electrical integration into neural circuits promotes glioma progression. View Publication

Although the association between the microbiome and IBD and liver diseases is known,the cause and effect remain elusive. By connecting human microphysiological systems of the gut,liver,and circulating Treg and Th17 cells,we created a multi-organ model of ulcerative colitis (UC) ex vivo. The approach shows microbiome-derived short-chain fatty acids (SCFAs) to either improve or worsen UC severity,depending on the involvement of effector CD4 T cells. Using multiomics,we found SCFAs increased production of ketone bodies,glycolysis,and lipogenesis,while markedly reducing innate immune activation of the UC gut. However,during acute T cell-mediated inflammation,SCFAs exacerbated CD4+ T cell-effector function,partially through metabolic reprograming,leading to gut barrier disruption and hepatic injury. These paradoxical findings underscore the emerging utility of human physiomimetic technology in combination with systems immunology to study causality and the fundamental entanglement of immunity,metabolism,and tissue homeostasis. View Publication

Our previous study demonstrated that conditional reprogramming (CR) allows the establishment of patient-derived normal and tumor epithelial cell cultures from a variety of tissue types including breast,lung,colon and prostate. Using CR,we have established matched normal and tumor cultures,GUMC-29 and GUMC-30 respectively,from a patient's prostatectomy specimen. These CR cells proliferate indefinitely in vitro and retain stable karyotypes. Most importantly,only tumor-derived CR cells (GUMC-30) produced tumors in xenografted SCID mice,demonstrating maintenance of the critical tumor phenotype. Characterization of cells with DNA fingerprinting demonstrated identical patterns in normal and tumor CR cells as well as in xenografted tumors. By flow cytometry,both normal and tumor CR cells expressed basal,luminal,and stem cell markers,with the majority of the normal and tumor CR cells expressing prostate basal cell markers,CD44 and Trop2,as well as luminal marker,CD13,suggesting a transit-amplifying phenotype. Consistent with this phenotype,real time RT-PCR analyses demonstrated that CR cells predominantly expressed high levels of basal cell markers (KRT5,KRT14 and p63),and low levels of luminal markers. When the CR tumor cells were injected into SCID mice,the expression of luminal markers (AR,NKX3.1) increased significantly,while basal cell markers dramatically decreased. These data suggest that CR cells maintain high levels of proliferation and low levels of differentiation in the presence of feeder cells and ROCK inhibitor,but undergo differentiation once injected into SCID mice. Genomic analyses,including SNP and INDEL,identified genes mutated in tumor cells,including components of apoptosis,cell attachment,and hypoxia pathways. The use of matched patient-derived cells provides a unique in vitro model for studies of early prostate cancer. View Publication

INTRODUCTION The stem cell portion of the dental pulp derived cultures (DPSCs) showed a higher resistance to cytotoxic effect of restorative dental materials compared to pulpal fibroblasts (DPFs). Here,we aimed to compare the expression of some drug resistant genes between these cells. METHODS AND MATERIALS To separate DPSCs from DPFs,we used magnetic cell sorting technique based on CD146 expression. To assess the stem cell properties,the positive and negative portions underwent colony forming assays and were induced to be differentiated into the adipocytes,osteoblasts,hepatocytes,and neural cells. Cell surface antigen panels were checked using immune fluorescence and flow-cytometry techniques. The mRNA expression of 14 ABC transporters including ABCA2,ABCB1,ABCB11,ABCC1,ABCC2,ABCC3,ABCC4,ABCC5-2,ABCC5-4,ABCC5-13,ABCC6,ABCC10,ABCC11,and ABCG2 genes was assessed,using quantitative RT-PCR technique. RESULTS Only the CD146 positive portion could be differentiated into the desired fates,and they formed higher colonies (16.7 ± 3.32 vs. 1.7 ± 1.67,p {\textless} .001). The cell surface antigen panels were the same,except for CD146 and STRO-1 markers which were expressed only in the positive portion. Among the ABC transporter genes studied,the positive portion showed a higher expression (approximately two-fold) of ABCA2,ABCC5-13,and ABCC5-2 genes. CONCLUSION Dental pulp stem cells which can be separated from dental pulp fibroblasts based on CD146 expression,express higher levels of some drug resistance genes which probably accounts for their features of more resistance to cytotoxic effects of some dental materials. This needs to be more validated in future. View Publication