Bone loss in the oral and maxillofacial region caused by trauma, tumors, congenital disorders, or degenerative diseases is a health care problem worldwide. To restore (reconstruct) these bone ...defects, human or animal bone grafts or alloplastic (synthetic) materials have been used. However, several disadvantages are associated with bone graft transplantation, such as limited bone volume, donor-site morbidity, surgical and immune rejection risks, and lack of osseo-integration. Bone tissue engineering is emerging as a valid alternative to treat bone defects allowing the regeneration of lost bony tissue, thereby recovering its functionality. During the last decades, the increasing aged population worldwide has also raised the prevalence of maxillary atrophy. Maxillary sinus floor elevation (MSFE) has become a standard surgical procedure to overcome the reduced amount of bone, thus enabling the placement of dental implants. MSFE aims to increase the bone height in the posterior maxilla, by elevating the Schneiderian membrane and placing the graft material into the surgically created space in the maxillary sinus floor. Importantly, oral bone regeneration during MSFE offers a unique human clinical model in which new cell-based bone tissue engineering applications might be investigated, since biopsies can be taken after MSFE before a dental implant placement and analyzed at the cellular level. New approaches in oral bone regeneration are focusing on cells, growth factors, and biomaterials. Recently, adipose tissue has become interesting as an abundant source of mesenchymal stem cells, which might be applied immediately after isolation to the patient allowing a one-step surgical procedure, thereby avoiding expensive cell culture procedures and another surgical operation. In this new cell-based tissue engineering approach, stem cells are combined with an osteoconductive scaffold and growth factors, and applied immediately to the patient. In this review, MSFE is discussed as a valid model to test bone tissue engineering approaches, such as the one-step surgical procedure. This procedure might be applied in other regenerative medicine applications as well.
Trifluorothymidine (TFT) is part of the novel oral formulation TAS-102, which is currently evaluated in phase II studies. Drug resistance is an important limitation of cancer therapy. The aim of the ...present study was to induce resistance to TFT in H630 colon cancer cells using two different schedules and to analyze the resistance mechanism. Cells were exposed either continuously or intermittently to TFT, resulting in H630-cTFT and H630-4TFT, respectively. Cells were analyzed for cross-resistance, cell cycle, protein expression, and activity of thymidine phosphorylase (TP), thymidine kinase (TK), thymidylate synthase (TS), equilibrative nucleoside transporter (hENT), gene expression (microarray), and genomic alterations. Both cell lines were cross-resistant to 2'-deoxy-5-fluorouridine (>170-fold). Exposure to IC(75)-TFT increased the S/G(2)-M phase of H630 cells, whereas in the resistant variants, no change was observed. The two main target enzymes TS and TP remained unchanged in both TFT-resistant variants. In H630-4TFT cells, TK protein expression and activity were decreased, resulting in less activated TFT and was most likely the mechanism of TFT resistance. In H630-cTFT cells, hENT mRNA expression was decreased 2- to 3-fold, resulting in a 5- to 10-fold decreased TFT-nucleotide accumulation. Surprisingly, microarray-mRNA analysis revealed a strong increase of secretory phospholipase-A2 (sPLA2; 47-fold), which was also found by reverse transcription-PCR (RT-PCR; 211-fold). sPLA2 inhibition reversed TFT resistance partially. H630-cTFT had many chromosomal aberrations, but the exact role of sPLA2 in TFT resistance remains unclear. Altogether, resistance induction to TFT can lead to different mechanisms of resistance, including decreased TK protein expression and enzyme activity, decreased hENT expression, as well as (phospho)lipid metabolism. Mol Cancer Ther; 9(4); 1047-57. (c)2010 AACR.
Summary
Bioluminescence imaging (BLI) is a powerful new method to study virus dissemination in the live animal. Here we used this method to monitor the spatial and temporal progression of mouse ...hepatitis coronavirus (MHV) infection in mice using luciferase‐expressing viruses. Upon intranasal inoculation, virus replication could initially be observed in the nasal cavity and the cervical lymph nodes, after which the infection spread to the brain and frequently to the eyes. The kinetics of virus spread to and clearance from the brain appeared to depend on the inoculation dose. After intraperitoneal inoculation, virus replication was predominantly observed in the liver and occasionally in the intestines, but interestingly also in the tail and paws. BLI thus elucidated new anatomic locations of virus replication. Furthermore, MHV dissemination was shown to be critically depended on the viral spike protein, but also on the mouse strain used. Widespread dissemination was observed in mice lacking a functional type I interferon response. The importance of the type I interferon system in limiting viral spread was also demonstrated by the administration of type I interferons to mice. Our results provide new insights in coronavirus pathogenesis and demonstrate the potential of BLI to study coronavirus–host interactions in vivo.
Introduction The aim of allogeneic stem cell transplantation (allo-SCT) is to reach graft-versus-host disease, relapse free survival (GRFS). To reduce the incidence of graft-versus-host disease ...(GVHD), we have developed an allo-SCT platform combining ex vivo αβTCR/CD19 depletion with in vivo T-cell depletion through administration of antithymoglobulin (ATG). Here we compare GRFS to historical cohorts of T-cell replete allo-SCT. Methods Adults with hematological malignancies and transplanted between 2011 and 2022 were included in this retrospective analysis. Written informed consent was obtained in accordance with the JACIE guidelines. Clinical data was extracted from the EBMT registry. 3 cohorts were identified. Cohort A: Allo-SCT of unmanipulated peripheral blood derived mononuclear cells (PBMCs) of matched related donors (MRD) after non-myeloablative (NMA) or myeloablative (MA) conditioning without ATG. Cohort B: Allo-SCT of unmanipulated PBMCs of 10/10 or 9/10 matched unrelated donors (MUD) after NMA or MA conditioning with ATG. Patients in cohorts A & B received dual immunosuppression with cyclosporin (CsA) and mycophenolic acid (MMF). Cohort C: Allo-SCT of αβTCR/CD19 depleted PBMCs of MRD and MUD (10/10 and 9/10) after ATG and a myeloablative conditioning as previously described1. Patients in cohort C received 28 days of MMF. Cumulative incidence (CI) of GVHD was defined as time to onset of GVHD, with relapse and death as competing events. Overall survival (OS) was defined as time to death from any cause. CI of relapse was defined as time to relapse, with death as a competing event. Non-relapse mortality (NRM) was defined as time to death, without relapse or progression. Event free survival (EFS) was defined as the time to relapse, graft failure or death. GRFS was defined as the time to relapse, aGVHD 3-4 or extensive cGVHD, graft failure or death. CI of CMV and EBV reactivations were calculated with relapse and death as competing events. Results 341 patients were included (cohort A: N=63; cohort B: N=150; cohort C: N=128) (table 1). In T cell replete allo-SCT (A&B) ATG was administered to recipients of MUD and MA conditioning was administered to patients < 40 years with acute leukemia. In cohort C, all patients received ATG and an MA conditioning, regardless of age or underlying malignancy. This explains differences donor types and intensity of conditioning between the cohorts (table 1). Other clinical characteristics were comparable. Two year OS (A=66.7%; B=58.7%; C=63.8%) and EFS (A=57.1%; B=52%; C=55.7%) was comparable between the cohorts. Two year CI of relapse was also comparable (A=30%; B=23%; C=28%). Two year NRM appeared higher in B, but this difference did not reach significance (A= 9.8%; B=24%; C=15%). The CI of aGVHD grade 2-4 and 3-4 at day 100 was significantly higher in T cell replete allo-SCT with MUD (2-4; A=23%; B=37%; C=20% (p=0.002); 3-4: A=5%; B=16%; C=4.7% (p=0.043)). The incidence of extensive cGVHD was significantly higher in T cell replete allo-SCT of MRD. (A= 25%; B=13%; C= 2.3% (p=< 0.001)). The low incidence of grade 3-4 aGVHD and extensive cGVHD without an increase in relapse or NRM, translated into a superior 2 year GRFS in patients receiving ATG combined with an αβTCR/CD19 allograft (C=55.6%) as compared to T cell replete allo-HSCT of MRD (A=38.1%) and MUD (B=40.8%) (Figure 1, p=0.04). This difference remained significant in a multivariate analysis. Conclusion We demonstrate that αβTCR/CD19 depletion combined with ATG, with a myeloablative conditioning and a very short course of immunosuppression results in very low incidences of life-threatening GVHD and an improved GRFS as compared to T cell replete allo-SCT for adult patients up to the age of 70. This is likely to positively impact the long term quality of life in survivors of allo-SCT2. In addition, this platform provides a window for additional early post allo-interventions to further improve the control of underlying hematological malignancies. 1. de Witte, M.A., et al., alphabeta T-cell graft depletion for allogeneic HSCT in adults with hematological malignancies. Blood Adv, 2021. 5(1): p. 240-249. 2. Oerlemans, S., et al. Relapse and severe Graft-versus-Host Disease have a negative impact on long-term symptoms and quality of life of patients three years after allogeneic haematopoietic stem cell transplantation. Annual meeting EBMT 2022.
The development of resistance to chemotherapy is a major obstacle for lasting effective treatment of cancer. Here, we demonstrate that endogenous mesenchymal stem cells (MSCs) become activated during ...treatment with platinum analogs and secrete factors that protect tumor cells against a range of chemotherapeutics. Through a metabolomics approach, we identified two distinct platinum-induced polyunsaturated fatty acids (PIFAs), 12-oxo-5,8,10-heptadecatrienoic acid (KHT) and hexadeca-4,7,10,13-tetraenoic acid (16:4(n-3)), that in minute quantities induce resistance to a broad spectrum of chemotherapeutic agents. Interestingly, blocking central enzymes involved in the production of these PIFAs (cyclooxygenase-1 and thromboxane synthase) prevents MSC-induced resistance. Our findings show that MSCs are potent mediators of resistance to chemotherapy and reveal targets to enhance chemotherapy efficacy in patients.
► Mesenchymal stem cells (MSCs) systemically induce resistance to chemotherapy ► Platinum-activated MSCs release two specific platinum-induced fatty acids (PIFAs) ► At minute quantities PIFAs induce resistance to various chemotherapeutics ► COX-1 and thromboxane synthase inhibition prevents MSC-induced resistance
Cancer patients benefit from early tumor detection since treatment outcomes are more favorable for less advanced cancers. Platelets are involved in cancer progression and are considered a promising ...biosource for cancer detection, as they alter their RNA content upon local and systemic cues. We show that tumor-educated platelet (TEP) RNA-based blood tests enable the detection of 18 cancer types. With 99% specificity in asymptomatic controls, thromboSeq correctly detected the presence of cancer in two-thirds of 1,096 blood samples from stage I–IV cancer patients and in half of 352 stage I–III tumors. Symptomatic controls, including inflammatory and cardiovascular diseases, and benign tumors had increased false-positive test results with an average specificity of 78%. Moreover, thromboSeq determined the tumor site of origin in five different tumor types correctly in over 80% of the cancer patients. These results highlight the potential properties of TEP-derived RNA panels to supplement current approaches for blood-based cancer screening.
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•Eighteen tumor types are identified by blood platelet RNA analysis with high specificity•Tumor-type-associated platelet RNA profiles allow for tumor-site-of-origin analysis•Platelets may be educated by multiple locations of tumor activity•Platelet RNAs may complement the field of liquid biopsies
In ’t Veld et al. employ blood platelet RNA profiles to develop a highly specific pan-cancer blood test covering 18 different tumor types and enabling localization of the primary tumor. This study highlights the value of platelets for early cancer detection and can serve as a complementary biosource for “liquid biopsies.”
CAR T cell immunotherapy has achieved impressive outcomes against hematological malignancies, however current approaches limit broad clinical application. The use of iPSC technology has been proposed ...as a promising source of universal off-the-shelf therapeutic T cells. Although several groups have reported the production of iPSC-derived CAR-T cells (iCAR-T), current methods either produce lymphoid cells with innate qualities due to premature TCR and constitutive CAR expression or require CAR introduction after successful T cell generation, compromising protocol efficiency and applicability.
To address the aforementioned issues, we have engineered T cell-derived iPSCs (T-iPSC) to express a drug-regulated inducible CAR with simultaneous elimination of TCR expression. Differentiation via embryoid body formation gave rise to CD4+CD8αβ+ thymocytes which upon CAR expression matured into adaptive CD8αβ+ T cells. Those cells exhibited significant non-alloreactive lytic potential against tumour cell lines as well tumour regression in a xenograft mouse model. To address any potential immunogenicity due to donor mismatch, we silenced the expression of HLA class I molecules by disrupting the β2-microglobulin (β2m) locus and introduced HLA-E on T-iPSCs. Our studies revealed that lack of β2m causes a developmental defect leading to the generation of innate T cells. Notably the signal induced by a high affinity Notch ligand is able to restore adaptive T cell development, producing cells with hypoimmunogeneic and antigen-specific potential, highlighting the importance of Notch signalling intensity.
Overall, we provide a proof-of-concept for the generation of hypoimmunogeneic iCAR-T cells with mature adaptive phenotype from engineered iPSC. Such strategy can provide the basis for the generation of universal cellular immunotherapeutics in the future.
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