DNA-dependent targeting of cell nuclei by a lupus autoantibody

Weisbart, Richard H.; Chan, Grace; Jordaan, Gwen; Noble, Philip W.; Liu, Yanfeng; Glazer, Peter M.; Nishimura, Robert N.; Hansen, James E.

doi:10.1038/srep12022

Cited by 45 publications

(50 citation statements)

References 14 publications

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“…In light of this, our results showing that 3E10 directly inhibits RAD51 activity may provide a mechanistic basis to anticipate a therapeutic gain in the use of 3E10 in cancer therapy. Interestingly, while 3E10 is capable of penetrating most cells, tissues with high cell turnover and excessive extracellular DNA, such as tumors, show increased uptake of 3E10 (50). This property may further contribute to an increased therapeutic window, further highlighting the clinical potential of this unusual cell-penetrating antibody.…”

Section: Discussionmentioning

confidence: 99%

A cell-penetrating antibody inhibits human RAD51 via direct binding

Turchick¹,

Hegan²,

Jensen³

et al. 2017

Nucleic Acids Research

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RAD51, a key factor in homology-directed repair (HDR), has long been considered an attractive target for cancer therapy, but few specific inhibitors have been found. A cell-penetrating, anti-DNA, lupus autoantibody, 3E10, was previously shown to inhibit HDR, sensitize tumors to radiation, and mediate synthetic lethal killing of BRCA2-deficient cancer cells, effects that were initially attributed to its affinity for DNA. However, as the molecular basis for its ability to inhibit DNA repair, we report that 3E10 directly binds to the N-terminus of RAD51, sequesters RAD51 in the cytoplasm, and impedes RAD51 binding to DNA. Further, we generate separation-of-function mutations in the complementarity-determining regions of 3E10 revealing that inhibition of HDR tracks with binding to RAD51 but not to DNA, whereas cell penetration is linked to DNA binding. The consequences of these mutations on putative 3E10 interactions with RAD51 and DNA are correlated with in silico molecular modeling. Taken together, the results identify 3E10 as a novel inhibitor of RAD51 by direct binding, accounting for its ability to suppress HDR and providing the molecular basis to guide pre-clinical development of 3E10 as an anti-cancer agent.

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Section: Discussionmentioning

confidence: 99%

A cell-penetrating antibody inhibits human RAD51 via direct binding

Turchick¹,

Hegan²,

Jensen³

et al. 2017

Nucleic Acids Research

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“…The target selectivity of 3E10 in vivo is based on the simple concept that tissues undergoing significant cell injury possess a high concentration of extracellular DNA. Binding to DNA is necessary for 3E10 passage (12). Salvaging of nucleosides by surrounding cells, through the ENT2 channel, provides 3E10 the opportunity to enter those cells still hanging on to life.…”

Section: Discussionmentioning

confidence: 99%

“…A single-chain variable fragment (Fv) of a monoclonal antibody 3E10 binds deoxyribonucleic acid (DNA) and penetrates viable cells through the energy independent channel equilibrative nucleoside transporter 2 (ENT2), located in the plasma membrane. To enter cells, 3E10 must bind nucleosides from DNA (12); hence, its specificity for tissues undergoing damage where extracellular DNA is accessible. Fusion of the 3E10-Fv to human HSP72 (referred to as Fv-Hsp70 in earlier publications) has been tested in a rat ischemic brain model (13).…”

Section: Introductionmentioning

confidence: 99%

Cardioprotective Effects of HSP72 Administration on Ischemia-Reperfusion Injury

Tanimoto

Parseghian

Nakahara

et al. 2017

Journal of the American College of Cardiology

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BACKGROUND Although early reperfusion is the most desirable intervention after ischemic myocardial insult, it may add to damage through oxidative stress. OBJECTIVES We investigated the cardioprotective effects of a single intravenous dose of heat shock protein (HSP72) coupled to a single-chain variable fragment (Fv) of monoclonal antibody 3E10 (3E10Fv) in a rabbit ischemia-reperfusion model. The Fv facilitates rapid transport of HSP72 into cells, even with intact membranes. METHODS A left coronary artery occlusion (40 min), reperfusion (3 h) model was employed in 31 rabbits. Of these, 12 rabbits received the fusion protein (Fv-HSP72) intravenously. The remaining 19 control rabbits received a molar equivalent of 3E10Fv alone (n = 6), HSP72 alone (n = 6), or phosphate buffered saline (n = 7). Serial echocardiographic examinations were performed to assess left ventricular (LV) function before and after reperfusion. Micro-single photon emission computed tomography imaging of 99mTc-labeled annexin-V was performed with micro-computed tomography to characterize apoptotic damage in vivo, followed by gamma counting of the excised myocardial specimens to quantify cell death. Histopathological characterization of the myocardial tissue, and sequential cardiac troponin I measurements were also undertaken. RESULTS Myocardial annexin-V uptake was 43% lower in the area at risk (p = 0.0003) in Fv-HSP72-treated rabbits compared to controls receiving HSP72 or 3E10Fv alone. During reperfusion, troponin I release was 42% lower and the echocardiographic LV ejection fraction 27% higher in the Fv-HSP72-treated group compared to controls. Histopathological analyses confirmed penetration of 3E10Fv-containing molecules into cardiomyocytes in vivo, and treatment with Fv-HSP72 showed fewer apoptotic nuclei compared to control rabbits. CONCLUSIONS A single-dose administration of Fv-HSP72 fusion protein at the time of reperfusion reduced myocardial apoptosis almost by half, and improved LV functional recovery following myocardial ischemia-reperfusion injury in rabbits. It might have a potential to serve as an adjunct to early reperfusion in the management of myocardial infarction.

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“…This fusion molecule is referred to in the literature as Fv–HSP70 and was found safe when the whole IgG was used in phase I clinical trials for the treatment of lupus . The 3E10 monoclonal antibody targets extracellular DNA and nucleosides . These targets are abundant, stable, and quite accessible during tissue damage, where there is cell necrosis .…”

Section: Targeted Hsp72 Delivery Into Cellsmentioning

confidence: 99%

“…These targets are abundant, stable, and quite accessible during tissue damage, where there is cell necrosis . The 3E10 antibody's unique cell‐penetration pathway has been described . It binds an antigen that includes the 1′‐thymine base and the 2′‐deoxyribose sugar moiety of DNA, a determination made by studying inhibition of 3E10 binding to DNA using several competitors .…”

Section: Targeted Hsp72 Delivery Into Cellsmentioning

confidence: 99%

Targeted heat shock protein 72 for pulmonary cytoprotection

Parseghian

Hobson

Richieri

2016

Annals of the New York Academy of Sciences

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Heat shock protein 72 (HSP72) is perhaps the most important member of the HSP70 family of proteins, given that it is induced in a wide variety of tissues and cells to combat stress, particularly oxidative stress. Here we review independent observations of the critical role this protein plays as a pulmonary cytoprotectant and discuss the merits of developing HSP72 as a therapeutic for rapid delivery to cells and tissues after a traumatic event. We also discuss the fusion of HSP72 to a cell-penetrating single-chain Fv (scFv) antibody fragment derived from mAb 3E10, referred to as Fv-HSP70. This fusion construct has been validated in vivo in a cerebral infarction model and is currently in testing as a clinical therapeutic to treat ischemic events and as a fieldable medical countermeasure to treat inhalation of toxicants caused by terrorist actions or industrial accidents.

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DNA-dependent targeting of cell nuclei by a lupus autoantibody

Cited by 45 publications

References 14 publications

A cell-penetrating antibody inhibits human RAD51 via direct binding

A cell-penetrating antibody inhibits human RAD51 via direct binding

Cardioprotective Effects of HSP72 Administration on Ischemia-Reperfusion Injury

Targeted heat shock protein 72 for pulmonary cytoprotection

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