5 research outputs found
Activation of the human immune system by chemotherapeutic or targeted agents combined with the oncolytic parvovirus H-1
Killing of p53-deficient hepatoma cells by parvovirus H-1 and chemotherapeutics requires promyelocytic leukemia protein
AIM: To evaluate the synergistic targeting and killing of human hepatocellular carcinoma (HCC) cells lacking p53 by the oncolytic autonomous parvovirus (PV) H-1 and chemotherapeutic agents and its dependence on functional promyelocytic leukemia protein (PML)
CAR-T Cells Targeting Epstein-Barr Virus gp350 Validated in a Humanized Mouse Model of EBV Infection and Lymphoproliferative Disease.
Epstein-Barr virus (EBV) is a latent and oncogenic human herpesvirus. Lytic viral protein expression plays an important role in EBV-associated malignancies. The EBV envelope glycoprotein 350 (gp350) is expressed abundantly during EBV lytic reactivation and sporadically on the surface of latently infected cells. Here we tested T cells expressing gp350-specific chimeric antigen receptors (CARs) containing scFvs derived from two novel gp350-binding, highly neutralizing monoclonal antibodies. The scFvs were fused to CD28/CD3ζ signaling domains in a retroviral vector. The produced gp350CAR-T cells specifically recognized and killed gp350+ 293T cells in vitro. The best-performing 7A1-gp350CAR-T cells were cytotoxic against the EBV+ B95-8 cell line, showing selectivity against gp350+ cells. Fully humanized Nod.Rag.Gamma mice transplanted with cord blood CD34+ cells and infected with the EBV/M81/fLuc lytic strain were monitored dynamically for viral spread. Infected mice recapitulated EBV-induced lymphoproliferation, tumor development, and systemic inflammation. We tested adoptive transfer of autologous CD8+gp350CAR-T cells administered protectively or therapeutically. After gp350CAR-T cell therapy, 75% of mice controlled or reduced EBV spread and showed lower frequencies of EBER+ B cell malignant lymphoproliferation, lack of tumor development, and reduced inflammation. In summary, CD8+gp350CAR-T cells showed proof-of-concept preclinical efficacy against impending EBV+ lymphoproliferation and lymphomagenesis
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Hemizygous variants in protein phosphatase 1 regulatory subunit 3F (<i>PPP1R3F</i>) are associated with a neurodevelopmental disorder characterized by developmental delay, intellectual disability, and autistic features
Abstract
PPP1R3F (R3F) is a member of the glycogen targeting subunits (GTSs), which belong to the large group of regulatory subunits of protein phosphatase 1 (PP1), a major eukaryotic serine/threonine protein phosphatase that regulates diverse cellular processes. Here, we describe the identification of hemizygous variants in PPP1R3F associated with a novel X-linked recessive neurodevelopmental disorder in 13 unrelated individuals. This disorder is characterized by developmental delay, mild intellectual disability, neurobehavioral issues such as autism spectrum disorder, seizures, and other neurological findings including tone, gait, and cerebellar abnormalities. PPP1R3F variants segregated with disease in affected hemizygous males that inherited the variants from their heterozygous carrier mothers. We show that R3F is predominantly expressed in brain astrocytes and localizes to the endoplasmic reticulum in cells. Glycogen content in PPP1R3F knockout astrocytoma cells appears to be more sensitive to fluxes in extracellular glucose levels than in wild-type cells, suggesting that R3F functions in maintaining steady brain glycogen levels under changing glucose conditions. We performed functional studies on nine of the identified variants and observed defects in PP1 binding, protein stability, subcellular localization, and regulation of glycogen metabolism in most of them. Collectively, the genetic and molecular data indicate that deleterious variants in PPP1R3F are associated with a new X-linked disorder of glycogen metabolism, highlighting the critical role of GTSs in neurological development. This research expands our understanding of neurodevelopmental disorders and the role of PP1 in brain development and proper function.</jats:p