Durant, M. | Search bioRxiv

bioRxiv2020

Development of a Coronavirus Disease 2019 Nonhuman Primate Model Using Airborne Exposure

Airborne transmission is predicted to be a prevalent route of human exposure with SARS-CoV-2. Aside from African green monkeys, nonhuman primate models that replicate airborne transmission of SARS-CoV-2 have not been investigated. A comprehensive and comparative evaluation of COVID-19 in African green monkeys, rhesus macaques, and cynomolgus macaques following airborne exposure to SARS-CoV-2 was performed to define parameters critical to disease progression and the extent to which they correlate with human COVID-19. Respiratory abnormalities and viral shedding were noted for all animals, indicating successful infection. Cynomolgus macaques developed fever, and thrombocytopenia was measured for African green monkeys and rhesus macaques. Type II pneumocyte hyperplasia and alveolar fibrosis were more frequently observed in lung tissue from cynomolgus macaques and African green monkeys. The data indicate that, in addition to African green monkeys, macaques can be successfully infected by airborne SARS-CoV-2, providing viable macaque natural transmission models for medical countermeasure evaluation. One Sentence SummaryNonhuman primates develop COVID-19 following airborne virus exposure.

microbiology↗

bioRxiv2019

Selective inhibition of HDAC3 targets synthetic vulnerabilities and activates immune surveillance in lymphoma

CREBBP mutations are highly recurrent in B-cell lymphomas and either inactivate its histone acetyltransferase (HAT) domain or truncate the protein. Herein, we show that these two classes of mutations yield different degrees of disruption of the epigenome, with HAT mutations being more severe and associated with inferior clinical outcome. Genes perturbed by CREBBP mutation are direct targets of the BCL6/HDAC3 onco-repressor complex. Accordingly, we show that HDAC3 selective inhibitors fully reverse CREBBP mutant aberrant epigenetic programming resulting in: a) growth inhibition of lymphoma cells through induction of BCL6 target genes such as CDKN1A and b) restoration of immune surveillance due to induction of BCL6 repressed IFN pathway and antigen presentation genes. By reactivating these genes, exposure to HDAC3-i restored the ability of tumor infiltrating lymphocytes to kill DLBCL cells in an MHC II and MHC I dependent manner. Hence HDAC3-i represent a novel mechanism-based immune-epigenetic therapy for CREBBP mutant lymphomas. STATEMENT OF SIGNIFICANCEWe have leveraged the molecular characterization of different types of CREBBP mutations to define a rational approach for targeting these mutations through selective inhibition of HDAC3. This represents an attractive therapeutic avenue for targeting synthetic vulnerabilities in CREBBP mutant cells in tandem with promoting anti-tumor immunity.

cancer biology↗