ABSTRACT
Nonrandom DNA segregation (NDS) is a mitotic event in which sister chromatids carrying the oldest DNA strands are inherited exclusively by one of the two daughter cells. Although this phenomenon has been observed across various organisms, the mechanism and physiological relevance of this event remain poorly defined. Here, we demonstrate that DNA replication stress can trigger NDS in human cells. This biased inheritance of old template DNA is associated with the asymmetric DNA damage response (DDR), which derives at least in part from telomeric DNA. Mechanistically, we reveal that the ATR/CHK1 signaling pathway plays an essential role in mediating NDS. We show that this biased segregation process leads to cell-cycle arrest and cell death in damaged daughter cells inheriting newly replicated DNA. These data therefore identify a key role for NDS in the maintenance of genomic integrity within cancer cell populations undergoing replication stress due to oncogene activation.
Subject(s)
Ataxia Telangiectasia Mutated Proteins/metabolism , Checkpoint Kinase 1/metabolism , Chromosomes, Human/genetics , DNA Damage , DNA Replication , Mitosis , Ataxia Telangiectasia Mutated Proteins/genetics , Checkpoint Kinase 1/genetics , Chromosome Segregation , HeLa Cells , Humans , Signal TransductionABSTRACT
Severe eosinophilic asthma (SEA) is a therapy-resistant respiratory condition with poor clinical control. Treatment efficacy and patient compliance of current therapies remain unsatisfactory. Here, inspired by the remarkable success of chimeric antigen receptor-based cellular adoptive immunotherapies demonstrated for the treatment of a variety of malignant tumors, we engineered a cytokine-anchored chimeric antigen receptor T (CCAR-T) cell system using a chimeric IL-5-CD28-CD3ζ receptor to trigger T-cell-mediated killing of eosinophils that are elevated during severe asthma attacks. IL-5-anchored CCAR-T cells exhibited selective and effective killing capacity in vitro and restricted eosinophil differentiation with apparent protection against allergic airway inflammation in two mouse models of asthma. Notably, a single dose of IL-5-anchored CCAR-T cells resulted in persistent protection against asthma-related conditions over three months, significantly exceeding the typical therapeutic window of current mAb-based treatments in the clinics. This study presents a cell-based treatment strategy for SEA and could set the stage for a new era of precision therapies against a variety of intractable allergic diseases in the future.
ABSTRACT
Nonrandom DNA segregation (NDS) is a mitotic event in which sister chromatids carrying the old (parent) DNA strands are distributed exclusively to one of the two daughter cells. Although this phenomenon occurs in multiple organisms, the low frequency poses an obstacle to observation. Here, we present an improved protocol to induce NDS under replication stress. This protocol can be modified to accommodate various cell lines. For complete details on the use and execution of this protocol, please refer to Xing et al. (2020).