Hypermethylation of CD19 promoter enables antigen-negative escape to CART-19 in vivo and in vitro

BackgroundAnti-CD19 chimeric antigen receptor T cells (CART-19) frequently induce remissions in hemato-oncological patients with recurred and/or refractory B-cell tumors. However, malignant cells sometimes escape the immunotherapeutic targeting by CD19 gene mutations, alternative splicing or lineage switch, commonly causing lack of CD19 expression on the surface of neoplastic cells. We assumed that, in addition to the known mechanisms, other means could act on CD19 to drive antigen-negative relapse.MethodsHerein, we studied the mechanism of antigen loss in an in vivo CD19-negative recurrence model of chronic lymphocytic leukemia (CLL) to CART-19, established using NOD-scid IL2Rgnull mice and HG3 cell line. We validated our findings in vitro in immortalized B-cell lines and primary CLL cells.ResultsIn our in vivo CLL recurrence model, up to 70% of CART-19-treated mice eventually recurred with CD19-negative disease weeks after initial positive response. We found that the lack of CD19 expression was caused by promoter DNA hypermethylation. Importantly, the expression loss was partially reversible by treatment with a demethylating agent. Moreover, this escape mechanism was common for 3 B-cell immortalized lines as well as primary CLL cells, as assessed by in vitro coculture experiments.ConclusionsEpigenetically driven antigen escape could represent a novel, yet at least partially reversible, means of CD19 loss to CART-19 in B-cell tumors.

Earthquake Recurrence Model for the Colombia–Ecuador Subduction Zone Constrained from Seismic and Geodetic Data, Implication for PSHA

ABSTRACT Probabilistic seismic hazard assessment relies on long-term earthquake forecasts and ground-motion models. Our aim is to improve earthquake forecasts by including information derived from geodetic measurements, with an application to the Colombia–Ecuador megathrust. The annual rate of moment deficit accumulation at the interface is quantified from geodetically based interseismic coupling models. We look for Gutenberg–Richter recurrence models that match both past seismicity rates and the geodetic moment deficit rate, by adjusting the maximum magnitude. We explore the uncertainties on the seismic rates (a- and b-values, shape close to Mmax) and on the geodetic moment deficit rate to be released seismically. A distribution for the maximum magnitude Mmax bounding a series of earthquake recurrence models is obtained for the Colombia–Ecuador megathrust. Models associated with Mmax values compatible with the extension of the interface segment are selected. We show that the uncertainties mostly influencing the moment-balanced recurrence model are the fraction of geodetic moment released through aseismic processes and the form of the Gutenberg–Richter model close to Mmax. We combine the computed moment-balanced recurrence models with a ground-motion model, to obtain a series of uniform hazard spectra representative of uncertainties at one site on the coast. Considering the recent availability of a massive quantity of geodetic data, our approach could be used in other well-instrumented regions of the world.

Paleo-earthquake Evidence and Earthquake Recurrence for Düzce Fault, Turkey

Paleoseismological trenching was performed along the Düzce fault providing some preliminary insight about its seismogenic behavior. Dating was based on radiocarbon analysis of peat samples collected from the trenches and suggested seven earthquakes have occurred since 1740 BC. Integrating date constraints of events exposed in the trenches suggests a periodical earthquake recurrence model. According to a linear sequential event serial that has minimum misfit determined by considering the probability curve limits of the sample dates, the earthquake recurrence interval is between 384 and 460 years (or possibly between AD 394 and 400). A probability curve was also calculated for the date of the last earthquake (1999 Düzce earthquake) considering the probability distributions of sample dates based on the same event serial. This probability-distribution-based method, similarly, predicted that the 1999 Düzce earthquake occurred between 1933–2005 (± 36 years) with a 68 % probability. After this verification. Using this method, it was estimated that the next earthquake along the Düzce fault has a 68 % probability of occurring between 2328–2392. According to this calculation, the earthquake recurrence interval is about 391 ± 34 years with a 68 % probability and the AD 967 historical earthquake likely ruptured the Düzce fault. Assuming an average slip of 350 cm (the average slip of the 1999 earthquake), the slip rate was estimated to be between 8.7–11.2 mm/a.

Analysis of the Risk Factors for the Recurrence of Ischemic Stroke with Diabetes Mellitus and Establishment of Cox’s Regression Model and the Personal Prognosis Index in Two Years of Follow-Up

Background: Ischemic stroke is a major cause of disability and mortality in patients with type 2 diabetes mellitus (T2DM), and diabetic stroke has a high recurrence rate. Objectives: This prospective cohort study aimed at investigating the risk factors and establishing Cox’s regression model and personal prognosis index for the recurrence of ischemic stroke at a two-year follow-up in T2DM patients. Methods: T2DM patients with ischemic stroke, who were consecutively admitted to the Neurology Department of North China University of Science and Technology Affiliated Hospital between January 1, 2015, and December 31, 2015, were retrospectively reviewed. These cases were followed up since the onset of ischemic stroke for 2 years. Univariate and multivariate Cox’s proportional hazard regression model was used to analyze risk factors associated with the recurrence rate. Thus, a recurrence model and personal prognosis index were set up. Results: During the follow-up period, 44 cases relapsed. Furthermore, the 1-year recurrence rate was 16.48%, while the 2-year recurrence rate was 24.18%. The univariate and multivariate Cox proportional hazard regression model revealed that the independent risk factors associated with recurrence were TOAST criteria (X1) (RR = 1.663; 95% CI = 1.015 - 2.760, P = 0.032), hypertension grade (X2) (RR = 1.897; 95% CI = 1.097 - 3.280, P = 0.022), duration of diabetes mellitus (X3) (RR = 1.151; 95% CI = 1.009 - 1.991, P = 0.039), total cholesterol (X4) (RR = 1.13; 95% CI = 1.006 - 1.876, P = 0.035), and Essen stroke risk score (ESRS) (X5) (RR = 2.055; 95% CI = 1.357 - 3.134, P = 0.001). The personal prognosis index of the recurrence model was as follows: PI = 0.504 X1 + 0.640 X2 + 0.345 X3 + 0.759 X4 + 0.823 X5. Conclusions: TOAST criteria, hypertension grade, duration of diabetes mellitus, total cholesterol, and ESRS were the independent risk factors associated with the recurrence of ischemic stroke with diabetes mellitus. The recurrence model and personal prognosis index equation were successfully established.

Integrative Analysis of lncRNAs, miRNAs, and mRNA-Associated ceRNA Network in an Atopic Dermatitis Recurrence Model

Atopic dermatitis (AD) is a prevalent inflammatory skin disease characterized by its chronic nature and relapse. Ample evidence suggests that non-coding RNAs play a major role in AD pathogenesis. However, the mechanism remains unknown, particularly in AD recurrence. Dynamic morphological and cytokine changes were measured throughout the whole course of an FITC-induced AD recurrence murine model. Microarray assay and integrative analysis were performed to comprehensively explore long non-coding RNA (lncRNA), messenger RNA (mRNA), and microRNA (miRNA) networks. Our results showed that an AD recurrence model was established. Overall, 5766 lncRNAs, 4025 mRNAs, and 202 miRNAs changed after elicitation, whereas, 419 lncRNAs, 349 mRNAs, and more notably, only 23 miRNAs, were dysregulated in the remission phase. Gene ontology (GO) and KEGG pathway enrichment analyses were used to investigate the potential functions of the dysregulated genes. The altered regulation of seven miRNAs and seven lncRNAs were validated in different stages of the model. The competing endogenous RNA (ceRNA) network inferred that lncRNA humanlincRNA0490+ could compete for miR-155-5p binding, through which it might affect Pkiα expression. Altogether, our findings have provided a novel perspective on the potential roles of non-coding RNAs in AD, and suggest that specific non-coding RNAs could be new therapeutic targets against AD recurrence.