搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

Eosinophils are associated with type 2 immune responses to allergens and helminths. They release various proinflammatory mediators and toxic proteins on activation and are therefore considered proinflammatory effector cells. Eosinophilia is promoted by the cytokines interleukin (IL)-3,IL-5,and granulocyte macrophage-colony-stimulating factor (GM-CSF) and can result from enhanced de novo production or reduced apoptosis. In this study,we show that only IL-5 induces differentiation of eosinophils from bone marrow precursors,whereas IL-5,GM-CSF,and to a lesser extent IL-3 promote survival of mature eosinophils. The receptors for these cytokines use the common β chain,which serves as the main signaling unit linked to signal transducer and activator of transcription 5,p38 mitogen-activated protein kinase,and nuclear factor (NF)-κB pathways. Inhibition of NF-κB induced apoptosis of in vitro cultured eosinophils. Selective deletion of IκBα in vivo resulted in enhanced expression of Bcl-xL and reduced apoptosis during helminth infection. Retroviral overexpression of Bcl-xL promoted survival,whereas pharmacologic inhibition of Bcl-xL in murine or human eosinophils induced rapid apoptosis. These results suggest that therapeutic strategies targeting Bcl-xL in eosinophils could improve health conditions in allergic inflammatory diseases. View Publication

SummaryHeterotaxy is a disorder characterized by severe congenital heart defects (CHDs) and abnormal left-right patterning in other thoracic or abdominal organs. Clinical and research-based genetic testing has previously focused on evaluation of coding variants to identify causes of CHDs,leaving non-coding causes of CHDs largely unknown. Variants in the transcription factor zinc finger of the cerebellum 3 (ZIC3) cause X-linked heterotaxy. We identified an X-linked heterotaxy pedigree without a coding variant in ZIC3. Whole-genome sequencing revealed a deep intronic variant (ZIC3 c.1224+3286A>G) predicted to alter RNA splicing. An in vitro minigene splicing assay confirmed the variant acts as a cryptic splice acceptor. CRISPR-Cas9 served to introduce the ZIC3 c.1224+3286A>G variant into human embryonic stem cells demonstrating pseudoexon inclusion caused by the variant. Surprisingly,Sanger sequencing of the resulting ZIC3 c.1224+3286A>G amplicons revealed several isoforms,many of which bypass the normal coding sequence of the third exon of ZIC3,causing a disruption of a DNA-binding domain and a nuclear localization signal. Short- and long-read mRNA sequencing confirmed these initial results and identified additional splicing patterns. Assessment of four isoforms determined abnormal functions in vitro and in vivo while treatment with a splice-blocking morpholino partially rescued ZIC3. These results demonstrate that pseudoexon inclusion in ZIC3 can cause heterotaxy and provide functional validation of non-coding disease causation. Our results suggest the importance of non-coding variants in heterotaxy and the need for improved methods to identify and classify non-coding variation that may contribute to CHDs. Coding variants in the transcription factor ZIC3 cause X-linked heterotaxy,a laterality defect causing congenital anomalies. Functional genomic analyses of a ZIC3 intronic variant identified in an X-linked heterotaxy pedigree demonstrated pseudoexon inclusion leading to RNA-splicing disruption,highlighting the importance of whole-genome sequencing to identify potential disease-causing variants. View Publication

The scarcity of reliable devices for diagnosis of Animal African trypanosomiasis (AAT) presents a limitation to control of the disease. Existing high-sensitivity technologies such as PCR are costly,laborious,time-consuming,complex,and require skilled personnel. Hence,utilisation of most diagnostics for AAT is impracticable in rural areas,where the disease occurs. A more accessible point-of-care test (POCT) capable of detecting cryptic active infection,without relying on expensive equipment,would facilitate AAT detection. In turn,early management,would reduce disease incidence and severity. Today,several ongoing research projects aim at modifying complex immunoassays into POCTs. In this context,we report the development of an antigen (Ag) detection sandwich ELISA prototype for diagnosis of T . congolense infections,which is comprised of nanobody (Nb) and monoclonal antibody (mAb) reagents. The Nb474H used here,originated from a past study. Briefly,the Nb was engineered starting from mRNA of peripheral blood lymphocytes of an alpaca immunized with soluble lysate of Trypanosoma congolense (TC13). T . congolense glycosomal fructose-1,6-bisphosphate aldolase ( Tco ALD) was discovered as the cognate Ag of Nb474H. In this study,splenocytes were harvested from a mouse immunized with recombinant Tco ALD and fused with NS01 cells to generate a hybridoma library. Random screening of the library on Tco ALD retrieved a lone binder,designated IgM8A2. Using Nb474H as Ag-capture reagent in combination with the IgM8A2 monoclonal antibody Ag-detection reagent resulted in a tool that effectively detects native Tco ALD released during infection by T . congolense parasites. Hitherto,development of POCT for detection of active trypanosome infection is elusive. The Nanobody/Monoclonal Antibody (Nb/mAb) “hybrid” sandwich technology offers prospects for exploration,using the unique specificity of Nb as a key determinant in Ag capturing,while using the versatility of monoclonal Ab to adapt to various detection conditions. View Publication

Clinical translation of tissue-engineered advanced therapeutic medicinal products is hindered by a lack of patient-dependent and independent in-process biological quality controls that are reflective of in vivo outcomes. Recent insights into the mechanism of native bone repair highlight a robust path dependence. Organoid-based bottom-up developmental engineering mimics this path-dependence to design personalized living implants scaffold-free,with in-build outcome predictability. Yet,adequate (noninvasive) quality metrics of engineered tissues are lacking. Moreover,insufficient insight into the role of donor variability and biological sex as influencing factors for the mechanism toward bone repair hinders the implementation of such protocols for personalized bone implants. Here,male and female bone-forming organoids were compared to non-bone-forming organoids regarding their extracellular matrix composition,transcriptome,and secreted proteome signatures to directly link in vivo outcomes to quality metrics. As a result,donor variability in bone-forming callus organoids pointed towards two distinct pathways to bone,through either a hypertrophic cartilage or a fibrocartilaginous template. The followed pathway was determined early,as a biological sex-dependent activation of distinct progenitor populations. Independent of donor or biological sex,a cartilage-to-bone transition was driven by a common panel of secreted factors that played a role in extracellular matrix remodeling,mineralization,and attraction of vasculature. Hence,the secreted proteome is a source of noninvasive biomarkers that report on biological potency and could be the missing link toward data-driven decision-making in organoid-based bone tissue engineering. Subject terms: Bone,Bone quality and biomechanics View Publication

Because primary myelofibrosis (PMF) originates at the level of the pluripotent hematopoietic stem cell (HSC),we examined the effects of various therapeutic agents on the in vitro and in vivo behavior of PMF CD34(+) cells. Treatment of PMF CD34(+) cells with chromatin-modifying agents (CMAs) but not hydroxyurea,Janus kinase 2 (JAK2) inhibitors,or low doses of interferon-α led to the generation of greater numbers of CD34(+) chemokine (C-X-C motif) receptor (CXCR)4(+) cells,which were capable of migrating in response to chemokine (C-X-C motif) ligand (CXCL)12 and resulted in a reduction in the proportion of hematopoietic progenitor cells (HPCs) that were JAK2V617F(+). Furthermore,sequential treatment of PMF CD34(+) cells but not normal CD34(+) cells with decitabine (5-aza-2'-deoxycytidine [5azaD]),followed by suberoylanilide hydroxamic acid (SAHA; 5azaD/SAHA),or trichostatin A (5azaD/TSA) resulted in a higher degree of apoptosis. Two to 6 months after the transplantation of CMAs treated JAK2V617F(+) PMF CD34(+) cells into nonobese diabetic/severe combined immunodeficient (SCID)/IL-2Rγ(null) mice,the percentage of JAK2V617F/JAK2(total) in human CD45(+) marrow cells was dramatically reduced. These findings suggest that both PMF HPCs,short-term and long-term SCID repopulating cells (SRCs),are JAK2V617F(+) and that JAK2V617F(+) HPCs and SRCs can be eliminated by sequential treatment with CMAs. Sequential treatment with CMAs,therefore,represents a possible effective means of treating PMF at the level of the malignant SRC. View Publication

The chemokine (C-C motif) receptor 5 (CCR5) serves as an HIV-1 co-receptor and is essential for cell infection with CCR5-tropic viruses. Loss of functional receptor protects against HIV infection. Here,we report the successful targeting of CCR5 in GFP-marked human induced pluripotent stem cells (iPSCs) using CRISPR/Cas9 with single and dual guide RNAs (gRNAs). Following CRISPER/Cas9-mediated gene editing using a single gRNA,12.5% of cell colonies demonstrated CCR5 editing,of which 22.2% showed biallelic editing as determined by a Surveyor nuclease assay and direct sequencing. The use of dual gRNAs significantly increased the efficacy of CCR5 editing to 27% with a biallelic gene alteration frequency of 41%. To ensure the homogeneity of gene editing within cells,we used single cell sorting to establish clonal iPSC lines. Single cell-derived iPSC lines with homozygous CCR5 mutations displayed the typical characteristics of pluripotent stem cells and differentiated efficiently into hematopoietic cells,including macrophages. Although macrophages from both wild-type and CCR5-edited iPSCs supported CXCR4-tropic virus replication,macrophages from CCR5-edited iPSCs were uniquely resistant to CCR5-tropic virus challenge. This study demonstrates the feasibility of applying iPSC technology for the study of the role of CCR5 in HIV infection in vitro,and generation of HIV-resistant cells for potential therapeutic applications. View Publication

Monomeric HIV envelope vaccines fail to elicit broadly neutralizing antibodies or to protect against infection. Neutralizing antibodies against HIV bind to native functionally active Env trimers on the virion surface. Gag-Env pseudovirions recapitulate the native trimer and could serve as an effective epitope presentation platform for study of the neutralizing antibody response in HIV-infected individuals. To address if pseudovirions can recapitulate native HIV virion epitope structures,we carefully characterized these particles,concentrating on the antigenic structure of the coreceptor binding site. By blue native gel shift assays,Gag-Env pseudovirions were shown to contain native trimers that were competent for binding to neutralizing monoclonal antibodies. In enzyme-linked immunosorbent assay,pseudovirions exhibited increased binding of known CD4-induced antibodies after addition of CD4. Using flow cytometric analysis,fluorescently labeled pseudovirions specifically identified a subset of antigen-specific B cells in HIV-infected subjects. Interestingly,the sequence of one of these novel human antibodies,identified during cloning of single HIV-specific B cells and designated 2C6,exhibited homology to mAb 47e,a known anti-CD4-induced coreceptor binding site antibody. The secreted monoclonal antibody 2C6 did not bind monomeric gp120,but specifically bound envelope on pseudovirions. A recombinant form of the antibody 2C6 acted as a CD4-induced epitope-specific antibody in neutralization assays,yet did not bind monomeric gp120. These findings imply specificity against a quaternary epitope presented on the pseudovirion envelope spike. These data demonstrate that Gag-Env pseudovirions recapitulate CD4 and coreceptor binding pocket antigenic structures and can facilitate identification of B-cell clones that secrete neutralizing antibodies. View Publication

OBJECTIVES: Sustained suppression of plasma viremia in HIV-infected individuals is attainable with antiretroviral therapy (ART); however,eradication of virus that would allow discontinuation of ART has been hampered by the persistence of HIV reservoirs. It is of great interest to identify individuals who had received ART for prolonged periods of time with extremely low or undetectable HIV reservoirs and monitor plasma viremia following discontinuation of therapy. METHODS: We measured the size of HIV reservoirs in CD4(+) T cells of individuals on long-term ART and monitored plasma viremia following cessation of ART in one individual with an exceptionally low viral burden after a decade of therapy. RESULTS: We demonstrated undetectable levels of HIV DNA in the blood of eight of 45 infected individuals on long-term ART. Among those eight individuals,the frequency of cells carrying infectious virus was significantly lower in those who initiated ART during the early versus the chronic phase of infection. One individual with undetectable HIV DNA in both blood and tissue and a profoundly low level of infectious virus experienced plasma viral rebound 50 days following discontinuation of ART. CONCLUSIONS: Our data suggest that a significant reduction in the size of viral reservoirs may be achievable in selected individuals who initiate standard ART early in infection. However,given re-emergence of plasma viremia in an individual with an extraordinarily low viral burden,therapeutic strategies aimed at specifically targeting these extremely rare HIV-infected cells with novel interventions may be necessary in order to achieve eradication of virus. View Publication

BACKGROUND Therapies targeting certain CFTR mutants have been approved,yet variations in clinical response highlight the need for in-vitro and genetic tools that predict patient-specific clinical outcomes. Toward this goal,the CF Canada-Sick Kids Program in Individual CF Therapy (CFIT) is generating a first of its kind" View Publication