技术资料

The hexamethylene bisacetamide (HMBA) anticancer drug was dismissed due to limited efficacy in leukemic patients but it may re-enter into the clinics in HIV-1 eradication strategies because of its recently disclosed capacity to reactivate latent virus. Here,we investigated the impact of HMBA on the cytotoxicity of natural killer (NK) cells against acute T lymphoblastic leukemia (T-ALL) cells or HIV-1-infected T cells that exit from latency. We show that in T-ALL cells HMBA upmodulated MICB and ULBP2 ligands for the NKG2D activating receptor. In a primary CD4+ T cell-based latency model,HMBA did not reactivate HIV-1,yet enhanced ULBP2 expression on cells harboring virus reactivated by prostratin (PRO). However,HMBA reduced the expression of NKG2D and its DAP10 adaptor in NK cells,hence impairing NKG2D-mediated cytotoxicity and DAP10-dependent response to IL-15 stimulation. Alongside,HMBA dampened killing of T-ALL targets by IL-15-activated NK cells and impaired NK cell-mediated clearance of PRO-reactivated HIV-1+ cells. Overall,our results demonstrate a dominant detrimental effect of HMBA on the NKG2D pathway that crucially controls NK cell-mediated killing of tumors and virus-infected cells,providing one possible explanation for poor clinical outcome in HMBA-treated cancer patients and raising concerns for future therapeutic application of this drug. View Publication

In the inner ear,endolymph fluid surrounds the organ of Corti,which is important for auditory function; notably,even slight environmental changes mediated by trauma or infection can have significant consequences. However,it is unclear how the immune response is modulated in these tissues. Here,we report the local immune surveillance role of cleaved cochlin LCCL (Limulus factor C,Cochlin,and Lgl1) during Pseudomonas aeruginosa infection in the cochlea. Upon infection,the LCCL domain is cleaved from cochlin and secreted into the perilymph. This cleaved fragment sequesters infiltrating bacteria in the scala tympani and subsequently recruits resident immune cells to eliminate the bacteria. Importantly,hearing loss in a cochlin knockout mouse model is remedied by treatment with a cochlin LCCL peptide. These findings suggest cleaved cochlin LCCL constitutes a critical factor in innate immunity and auditory function and may be a potential therapeutic target to treat chronic otitis media-induced hearing loss. View Publication

Intestinal fibrosis is a serious complication in inflammatory bowel disease (IBD). Despite the remarkable success of recent anti-inflammatory therapies for IBD,incidence of intestinal fibrosis and need for bowel resection have not significantly changed. To clarify the contribution of haematopoietic-derived cells in intestinal fibrosis,we prepared bone marrow (BM) chimeric mice (chimeras),which were reconstituted with BM cells derived from enhanced green fluorescent protein (EGFP)-transgenic mice or CC chemokine receptor 2 (CCR2)-deficient mice. After 2 months of transplantation,BM chimeras were treated with azoxymethane/dextran sodium sulphate. During chronic inflammation,CCR2+ BM-derived monocyte and fibrocyte infiltration into the colon and CC chemokine ligand 2 production increased,leading to colon fibrosis in EGFP BM chimeras. In CCR2-deficient BM chimeras,monocyte and fibrocyte numbers in the colonic lamina propria significantly decreased,and colon fibrosis was attenuated. In colon tissue,mRNA expression of tissue inhibitor of metalloproteinase (TIMP)-1 but not of collagen I,transforming growth factor-beta1 or matrix metalloproteinases was significantly different between the two chimeras. CCR2+ monocytes and fibrocytes showed high Timp1 mRNA expression. Our results suggest that infiltrating CCR2+ monocytes and their progenies,fibrocytes,promote colon fibrosis by inhibiting collagen degradation through TIMP-1 production. View Publication

BACKGROUND The goal of antiretroviral therapy (ART) is to suppress HIV-1 replication and reconstitute CD4+ T cells. Here,we report on HIV-infected individuals who had a paradoxical decline in CD4+ T cells despite ART-mediated suppression of plasma HIV-1 load (pVL). We defined such an immunological outcome as extreme immune decline (EXID). METHODS EXID's clinical and immunological characteristics were compared to immunological responders (IRs),immunological nonresponders (INRs),healthy controls (HCs),and idiopathic CD4+ lymphopenia (ICL) patients. T cell immunophenotyping and assembly/activation of inflammasomes were evaluated by flow cytometry. PBMC transcriptome analysis and genetic screening for pathogenic variants were performed. Levels of cytokines/chemokines were measured by electrochemiluminescence. Luciferase immunoprecipitation system and NK-mediated antibody-dependent cellular cytotoxicity (ADCC) assays were used to identify anti-lymphocyte autoantibodies. RESULTS EXIDs were infected with non-B HIV-1 subtypes and after 192 weeks of consistent ART-mediated pVL suppression had a median CD4+ decrease of 157 cells/mul,compared with CD4+ increases of 193 cells/mul and 427 cells/mul in INR and IR,respectively. EXID had reduced naive CD4+ T cells,but similar proportions of cycling CD4+ T cells and HLA-DR+CD38+CD8+ T cells compared with IR and INR. Levels of inflammatory cytokines were also similar in EXID and INR,but the IL-7 axis was profoundly perturbed compared with HC,IR,INR,and ICL. Genes involved in T cell and monocyte/macrophage function,autophagy,and cell migration were differentially expressed in EXID. Two of the 5 EXIDs had autoantibodies causing ADCC,while 2 different EXIDs had an increased inflammasome/caspase-1 activation despite consistently ART-suppressed pVL. CONCLUSIONS EXID is a distinct immunological outcome compared with previously described INR. Anti-CD4+ T cell autoantibodies and aberrant inflammasome/caspase-1 activation despite suppressed HIV-1 viremia are among the mechanisms responsible for EXID. View Publication

Circulating Tumor Cells (CTCs) represent an easy,repeatable and representative access to information regarding solid tumors. However,their detection remains difficult because of their paucity,their short half-life,and the lack of reliable surface biomarkers. Flow cytometry (FC) is a fast,sensitive and affordable technique,ideal for rare cells detection. Adapted to CTCs detection (i.e. extremely rare cells),most FC-based techniques require a time-consuming pre-enrichment step,followed by a 2-hours staining procedure,impeding on the efficiency of CTCs detection. We overcame these caveats and reduced the procedure to less than one hour,with minimal manipulation. First,cells were simultaneously fixed,permeabilized,then stained. Second,using low-speed FC acquisition conditions and two discriminators (cell size and pan-cytokeratin expression),we suppressed the pre-enrichment step. Applied to blood from donors with or without known malignant diseases,this protocol ensures a high recovery of the cells of interest independently of their epithelial-mesenchymal plasticity and can predict which samples are derived from cancer donors. This proof-of-concept study lays the bases of a sensitive tool to detect CTCs from a small amount of blood upstream of in-depth analyses. View Publication

Respiratory syncytial virus (RSV) is a common childhood infection that in young infants can progress into severe bronchiolitis and pneumonia. Disease pathogenesis results from both viral mediated and host immune processes of which alveolar macrophages play an important part. Here,we investigated the role of different types of alveolar macrophages on RSV infection using an in vitro co-culture model involving primary tissue-derived human bronchial epithelial cells (HBECs) and human blood monocyte-derived M0-like,M1-like,or M2-like macrophages. It was hypothesized that the in vitro model would recapitulate previous in vivo findings of a protective effect of macrophages against RSV infection. It was found that macrophages maintained their phenotype for the 72-hour co-culture time period and the bronchial epithelial cells were unaffected by the macrophage media. HBEC infection with RSV was decreased by M1-like macrophages but enhanced by M0- or M2-like macrophages. The medium used during the co-culture also impacted the outcome of the infection. This work demonstrates that alveolar macrophage phenotypes may have differential roles during epithelial RSV infection,and demonstrates that an in vitro co-culture model could be used to further investigate the roles of macrophages during bronchial viral infection. View Publication

Primitive hematopoietic cells from several species are known to efflux both Hoechst 33342 and Rhodamine-123. We now show that murine hematopoietic stem cells (HSCs) defined by long-term multilineage repopulation assays efflux both dyes variably according to their developmental or activation status. In day 14.5 murine fetal liver,very few HSCs efflux Hoechst 33342 efficiently,and they are thus not detected as side population" (SP) cells. HSCs in mouse fetal liver also fail to efflux Rhodamine-123. Both of these features are retained by most of the HSCs present until 4 weeks after birth but are reversed by 8 weeks of age or after a new HSC population is regenerated in adult mice that receive transplants with murine fetal liver cells. Activation of adult HSCs in vivo following 5-fluorouracil treatment� View Publication

Specific antibody opsonization significantly enhances the level of phagocytosis of Candida in the absence of complement. Furthermore,we have described a system using a recombinant human antibody single-chain variable fragment that allows a comparative study of phagocytosis of multiple Candida species opsonized via a common antigen. View Publication

We have generated mice null for IFN-beta and report the diverse consequences of IFN-beta for both the innate and adaptive arms of immunity. Despite no abnormalities in the proportional balance of CD4 and CD8 T cell populations in the peripheral blood,thymus,and spleen of IFN-beta-/- mice,activated lymph node and splenic T lymphocytes exhibit enhanced T cell proliferation and decreased tumor necrosis factor alpha production,relative to IFN-beta+/+ mice. Notably,constitutive and induced expression of tumor necrosis factor alpha is reduced in the spleen and bone marrow (BM) macrophages,respectively,of IFN-beta-/- mice. We also observe an altered splenic architecture in IFN-beta-/- mice and a reduction in resident macrophages. We identify a potential defect in B cell maturation in IFN-beta-/- mice,associated with a decrease in B220+ve/high/CD43-ve BM-derived cells and a reduction in BP-1,IgM,and CD23 expression. Circulating IgM-,Mac-1-,and Gr-1-positive cells are also substantially decreased in IFN-beta-/- mice. The decrease in the numbers of circulating macrophages and granulocytes likely reflects defective maturation of primitive BM hematopoiesis in mice,shown by the reduction of colony-forming units,granulocyte-macrophage. We proceeded to evaluate the in vivo growth of malignant cells in the IFN-beta-/- background and give evidence that Lewis lung carcinoma-specific tumor growth is more aggressive in IFN-beta-/- mice. Taken altogether,our data suggest that,in addition to the direct growth-inhibitory effects on tumor cells,IFN-beta is required during different stages of maturation in the development of the immune system. View Publication

The expression and function of the NK cell receptor KIR2DL4 are controversial. Two common alleles of the transmembrane domain of KIR2DL4 exist. The 10A allele with 10 adenines at the end of the transmembrane exon encodes a full length receptor,whereas the 9A allele has only 9 adenines resulting in a frame shift which in turn generates a stop codon early in the first cytoplasmic exon. The possibility that the 10A and 9A alleles might result in differences in expression and function of KIR2DL4 was explored using mAbs to KIR2DL4. Transfection experiments with cDNA from the 10A and 9A alleles revealed significant membrane expression only with the protein encoded by the 10A allele. Analysis of peripheral blood NK cells demonstrated that only in subjects with at least one 10A allele was cell surface expression of KIR2DL4 detectable,and then only on the minor CD56(bright) NK cell subset. The major CD56(dim) NK cell subset did not cell surface express KIR2DL4 but,interestingly,did so after in vitro culture. Functional analysis using cultured NK cells in redirected lysis assays demonstrated that KIR2DL4 is an activating receptor for NK cells with at least one 10A allele. No significant activity was detected for NK cells generated from subjects homozygous for the 9A allele. These data show that genotype influences cell surface expression and function of KIR2DL4 which may account for reported differences in KIR2DL4 expression and function. View Publication

Essential thrombocythemia (ET) and polycythemia vera (PV) are clonal myeloproliferative disorders that are often difficult to distinguish from other causes of elevated blood cell counts. Assays that could reliably detect clonal hematopoiesis would therefore be extremely valuable for diagnosis. We previously reported 3 X-chromosome transcription-based clonality assays (TCAs) involving the G6PD,IDS,and MPP1 genes,which together were informative in about 65% of female subjects. To increase our ability to detect clonality,we developed simple TCA for detecting the transcripts of 2 additional X-chromosome genes: Bruton tyrosine kinase (BTK) and 4-and-a-half LIM domain 1 (FHL1). The combination of TCA established the presence or absence of clonal hematopoiesis in about 90% of female subjects. We show that both genes are subject to X-chromosome inactivation and are polymorphic in all major US ethnic groups. The 5 TCAs were used to examine clonality in 46 female patients along with assays for erythropoietin-independent erythroid colonies (EECs) and granulocyte PRV-1 mRNA levels to discriminate polycythemias and thrombocytoses. Of these,all 19 patients with familial polycythemia or thrombocytosis had polyclonal hematopoiesis,whereas 22 of 26 patients with clinical evidence of myeloproliferative disorder and 1 patient with clinically obscure polycythemia were clonal. Interestingly,interferon alpha therapy in 2 patients with PV was associated with reversion of clonal to polyclonal hematopoiesis. EECs were observed in 14 of 14 patients with PV and 4 of 12 with ET,and increased granulocyte PRV-1 mRNA levels were found in 9 of 13 patients with PV and 2 of 12 with ET. Thus,these novel clonality assays are useful in the diagnosis and follow-up of polycythemic conditions and disorders with increased platelet levels. View Publication

Cytokines play a crucial role in the maintenance of polyclonal naive and memory T cell populations. It has previously been shown that ex vivo,the IL-7 cytokine induces the proliferation of naive recent thymic emigrants (RTE) isolated from umbilical cord blood but not mature adult-derived naive and memory human CD4(+) T cells. We find that the combination of IL-2 and IL-7 strongly promotes the proliferation of RTE,whereas adult CD4(+) T cells remain relatively unresponsive. Immunological activity is controlled by a balance between proliferation and apoptotic cell death. However,the relative contributions of IL-2 and IL-7 in regulating these processes in the absence of MHC/peptide signals are not known. Following exposure to either IL-2 or IL-7 alone,RTE,as well as mature naive and memory CD4(+) T cells,are rendered only minimally sensitive to Fas-mediated cell death. However,in the presence of the two cytokines,Fas engagement results in a high level of caspase-dependent apoptosis in both RTE as well as naive adult CD4(+) T cells. In contrast,equivalently treated memory CD4(+) T cells are significantly less sensitive to Fas-induced cell death. The increased susceptibility of RTE and naive CD4(+) T cells to Fas-induced apoptosis correlates with a significantly higher IL-2/IL-7-induced Fas expression on these T cell subsets than on memory CD4(+) T cells. Thus,IL-2 and IL-7 regulate homeostasis by modulating the equilibrium between proliferation and apoptotic cell death in RTE and mature naive and memory T cell subsets. View Publication