scholarly journals Challenging Safety and Efficacy of Retinal Gene Therapies by Retinogenesis

2021 ◽  
Vol 22 (11) ◽  
pp. 5767
Author(s):  
Elena Marrocco ◽  
Rosa Maritato ◽  
Salvatore Botta ◽  
Marianna Esposito ◽  
Enrico Maria Surace
Keyword(s):  
Autosomal Dominant ◽  
Germ Line ◽  
Wild Type ◽  
Adeno Associated Virus ◽  
Developmental Transitions ◽  
Transcript Levels ◽  
Safety And Efficacy ◽  
Transgenic Expression ◽  
Gene Therapies ◽  
Germ Line Transmission

Gene-expression programs modulated by transcription factors (TFs) mediate key developmental events. Here, we show that the synthetic transcriptional repressor (TR; ZF6-DB), designed to treat Rhodopsin-mediated autosomal dominant retinitis pigmentosa (RHO-adRP), does not perturb murine retinal development, while maintaining its ability to block Rho expression transcriptionally. To express ZF6-DB into the developing retina, we pursued two approaches, (i) the retinal delivery (somatic expression) of ZF6-DB by Adeno-associated virus (AAV) vector (AAV-ZF6-DB) gene transfer during retinogenesis and (ii) the generation of a transgenic mouse (germ-line transmission, TR-ZF6-DB). Somatic and transgenic expression of ZF6-DB during retinogenesis does not affect retinal function of wild-type mice. The P347S mouse model of RHO-adRP, subretinally injected with AAV-ZF6-DB, or crossed with TR-ZF6-DB or shows retinal morphological and functional recovery. We propose the use of developmental transitions as an effective mode to challenge the safety of retinal gene therapies operating at genome, transcriptional, and transcript levels.

Potential for germ line transmission after intramyocardial gene delivery by adeno-associated virus

2004 ◽  
Vol 313 (3) ◽  
pp. 528-533 ◽  
Author(s):  
Alok S Pachori ◽  
Luis G Melo ◽  
Lunan Zhang ◽  
Massimo Loda ◽  
Richard E Pratt ◽  
...  
Keyword(s):  
Gene Delivery ◽  
Germ Line ◽  
Adeno Associated Virus ◽  
Germ Line Transmission

scholarly journals Widespread Gene Delivery and Structure-Specific Patterns of Expression in the Brain after Intraventricular Injections of Neonatal Mice with an Adeno-Associated Virus Vector

2001 ◽  
Vol 75 (24) ◽  
pp. 12382-12392 ◽  
Author(s):  
Marco A. Passini ◽  
John H. Wolfe
Keyword(s):  
Gene Transfer ◽  
Viral Vector ◽  
Germ Line ◽  
Cell Infection ◽  
Adeno Associated Virus ◽  
Virus Serotype ◽  
Somatic Gene ◽  
The Central Nervous System ◽  
Somatic Gene Transfer ◽  
Germ Line Transmission

ABSTRACT Developing a system for widespread somatic gene transfer in the central nervous system (CNS) would be beneficial for understanding the global influence of exogenous genes on animal models. We injected an adeno-associated virus serotype 2 (AAV2) vector into the cerebral lateral ventricles at birth and mapped its distribution and transduction pattern from a promoter capable of expression in multiple targets. The injections resulted in structure-specific patterns of expression that were maintained for at least 1 year in most regions, with efficient targeting of some of the major principal neuron layers. The patterns of transduction were explained by circulation of the viral vector in the subarachnoid space via CSF flow, followed by transduction of underlying structures, rather than by progenitor cell infection and subsequent migration. This study demonstrates that gene transfer throughout the CNS can be achieved without germ line transmission and establishes an experimental strategy for introducing genes to somatic cells in a highly predictable manner.

An ER–Golgi Tethering Factor SLOH4/MIP3 Is Involved in Long-term Heat Tolerance of Arabidopsis

2020 ◽  
Author(s):  
Kazuho Isono ◽  
Ryo Tsukimoto ◽  
Satoshi Iuchi ◽  
Akihisa Shinozawa ◽  
Izumi Yotsui ◽  
...  
Keyword(s):  
Heat Stress ◽  
Heat Tolerance ◽  
Secretory Proteins ◽  
Wild Type ◽  
Additional Function ◽  
Transcript Levels ◽  
Unfolded Protein ◽  
In The Wild ◽  
Protein Response

Abstract Plants are often exposed not only to short-term (S-) heat stress but also to diurnal long-term (L-) heat stress over several consecutive days. To reveal the mechanisms underlying L-heat stress tolerance, we here used a forward genetic screening for sensitive to long-term heat (sloh) mutants and isolated sloh4. The mutant was hypersensitive to L- but not S-heat stress. The causal gene of sloh4 was identical to MIP3 encoding a member of the MAIGO2 (MAG2) tethering complex, which is composed of the MAG2, MIP1, MIP2, and MIP3 subunits and is localized at the endoplasmic reticulum (ER) membrane. Although sloh4/mip3 was hypersensitive to L-heat stress, the sensitivity of the mag2-3 and mip1–1 mutants was similar to that of the wild type. Under L-heat stress, the ER stress and the following unfolded protein response (UPR) were more pronounced in sloh4 than in the wild type. Transcript levels of bZIP60-regulated UPR genes were strongly increased in sloh4 under L-heat stress. Two processes known to be mediated by INOSITOL REQUIRING ENZYME1 (IRE1)—accumulation of the spliced bZIP60 transcript and a decrease in the transcript levels of PR4 and PRX34, encoding secretory proteins—were observed in sloh4 in response to L-heat stress. These findings suggest that misfolded proteins generated in sloh4 under L-heat stress may be recognized by IRE1 but not bZIP28, resulting in initiation of the UPR via activated bZIP60. Therefore, it would be possible that only MIP3 in MAG2 complex has an additional function in L-heat tolerance, which is not related to the ER–Golgi vesicle tethering.

scholarly journals Safety and efficacy of panitumumab in combination with trifluridine/tipiracil for pre-treated patients with unresectable, metastatic colorectal cancer with wild-type RAS: The phase 1/2 APOLLON study

2021 ◽  
Author(s):  
Takeshi Kato ◽  
Yoshinori Kagawa ◽  
Yasutoshi Kuboki ◽  
Makio Gamoh ◽  
Yoshito Komatsu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Metastatic Colorectal Cancer ◽  
Therapeutic Option ◽  
Phase 1 ◽  
Progression Free Survival ◽  
Phase 2 ◽  
Wild Type ◽  
Open Label ◽  
Safety And Efficacy ◽  
Multicentre Phase

Abstract Background We aimed to assess the safety and efficacy of combination treatment with panitumumab plus trifluridine/tipiracil (FTD/TPI) in patients with wild-type RAS metastatic colorectal cancer (mCRC) who were refractory/intolerant to standard therapies other than anti-epidermal growth factor receptor therapy. Methods APOLLON was an open-label, multicentre, phase 1/2 trial. In the phase 1 part, 3 + 3 de-escalation design was used to investigate the recommended phase 2 dose (RP2D); all patients in the phase 2 part received the RP2D. The primary endpoint was investigator-assessed progression-free survival (PFS) rate at 6 months. Secondary endpoints included PFS, overall survival (OS), overall response rate (ORR), disease control rate (DCR), time to treatment failure (TTF), and safety. Results Fifty-six patients were enrolled (phase 1, n = 7; phase 2, n = 49) at 25 Japanese centres. No dose-limiting toxicities were observed in patients receiving panitumumab (6 mg/kg every 2 weeks) plus FTD/TPI (35 mg/m2 twice daily; days 1–5 and 8–12 in a 28-day cycle), which became RP2D. PFS rate at 6 months was 33.3% (90% confidence interval [CI] 22.8–45.3). Median PFS, OS, ORR, DCR, and TTF were 5.8 months (95% CI 4.5–6.5), 14.1 months (95% CI 12.2–19.3), 37.0% (95% CI 24.3–51.3), 81.5% (95% CI 68.6–90.8), and 5.8 months (95% CI 4.29–6.21), respectively. Neutrophil count decreased (47.3%) was the most common Grade 3/4 treatment-emergent adverse event. No treatment-related deaths occurred. Conclusion Panitumumab plus FTD/TPI exhibited favourable anti-tumour activity with a manageable safety profile and may be a therapeutic option for pre-treated mCRC patients.

scholarly journals Mirtron-mediated RNA knockdown/replacement therapy for the treatment of dominant retinitis pigmentosa

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Harry O. Orlans ◽  
Michelle E. McClements ◽  
Alun R. Barnard ◽  
Cristina Martinez-Fernandez de la Camara ◽  
Robert E. MacLaren
Keyword(s):  
Retinitis Pigmentosa ◽  
Autosomal Dominant ◽  
Gene Mutations ◽  
Adeno Associated Virus ◽  
Treatment Development ◽  
Common Cause ◽  
Toxic Protein ◽  
Rna Knockdown

AbstractRhodopsin (RHO) gene mutations are a common cause of autosomal dominant retinitis pigmentosa (ADRP). The need to suppress toxic protein expression together with mutational heterogeneity pose challenges for treatment development. Mirtrons are atypical RNA interference effectors that are spliced from transcripts as short introns. Here, we develop a novel mirtron-based knockdown/replacement gene therapy for the mutation-independent treatment of RHO-related ADRP, and demonstrate efficacy in a relevant mammalian model. Splicing and potency of rhodopsin-targeting candidate mirtrons are initially determined, and a mirtron-resistant codon-modified version of the rhodopsin coding sequence is validated in vitro. These elements are then combined within a single adeno-associated virus (AAV) and delivered subretinally in a RhoP23H knock-in mouse model of ADRP. This results in significant mouse-to-human rhodopsin RNA replacement and is associated with a slowing of retinal degeneration. This provides proof of principle that synthetic mirtrons delivered by AAV are capable of reducing disease severity in vivo.

Induction of an Antitumoral Immune Response by Wild-Type Adeno-Associated Virus Type 2 in an In Vivo Model of Pancreatic Carcinoma

Pancreas ◽  
2007 ◽  
Vol 35 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Sven Eisold ◽  
Jan Schmidt ◽  
Eduard Ryschich ◽  
Michael Gock ◽  
Ernst Klar ◽  
...  
Keyword(s):  
Immune Response ◽  
Pancreatic Carcinoma ◽  
Virus Type ◽  
In Vivo Model ◽  
Wild Type ◽  
Adeno Associated Virus

scholarly journals Adeno-associated virus Rep proteins antagonize phosphatase PP1 to counteract KAP1 repression of the latent viral genome

2018 ◽  
Vol 115 (15) ◽  
pp. E3529-E3538 ◽  
Author(s):  
Sarah Smith-Moore ◽  
Stuart J. D. Neil ◽  
Cornel Fraefel ◽  
R. Michael Linden ◽  
Mathieu Bollen ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Helper Virus ◽  
Protein Phosphatase 1 ◽  
Wild Type ◽  
Fha Domain ◽  
Adeno Associated Virus ◽  
Histone 3 ◽  
Rep Proteins ◽  
Cellular Factors

Adeno-associated virus (AAV) is a small human Dependovirus whose low immunogenicity and capacity for long-term persistence have led to its widespread use as vector for gene therapy. Despite great recent successes in AAV-based gene therapy, further improvements in vector technology may be hindered by an inadequate understanding of various aspects of basic AAV biology. AAV is unique in that its replication is largely dependent on a helper virus and cellular factors. In the absence of helper virus coinfection, wild-type AAV establishes latency through mechanisms that are not yet fully understood. Challenging the currently held model for AAV latency, we show here that the corepressor Krüppel-associated box domain-associated protein 1 (KAP1) binds the latent AAV2 genome at the rep ORF, leading to trimethylation of AAV2-associated histone 3 lysine 9 and that the inactivation of KAP1 repression is necessary for AAV2 reactivation and replication. We identify a viral mechanism for the counteraction of KAP1 in which interference with the KAP1 phosphatase protein phosphatase 1 (PP1) by the AAV2 Rep proteins mediates enhanced phosphorylation of KAP1-S824 and thus relief from KAP1 repression. Furthermore, we show that this phenomenon involves recruitment of the NIPP1 (nuclear inhibitor of PP1)–PP1α holoenzyme to KAP1 in a manner dependent upon the NIPP1 FHA domain, identifying NIPP1 as an interaction partner for KAP1 and shedding light on the mechanism through which PP1 regulates cellular KAP1 activity.

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