scholarly journals Emerging Immunogenicity and Genotoxicity Considerations of Adeno-Associated Virus Vector Gene Therapy for Hemophilia

2021 ◽  
Vol 10 (11) ◽  
pp. 2471
Author(s):  
Paul E. Monahan ◽  
Claude Négrier ◽  
Michael Tarantino ◽  
Leonard A. Valentino ◽  
Federico Mingozzi
Keyword(s):  
Gene Therapy ◽  
Gene Transfer ◽  
Immune Responses ◽  
Aav Vector ◽  
Adeno Associated Virus ◽  
Gene Therapy Trial ◽  
Vector Integration ◽  
Optimal Outcomes ◽  
Potential Safety ◽  
Long Term Follow Up

Adeno-associated viral (AAV) vector gene therapy has shown promise as a possible cure for hemophilia. However, immune responses directed against AAV vectors remain a hurdle to the broader use of this gene transfer platform. Both innate and adaptive immune responses can affect the safety and efficacy of AAV vector–mediated gene transfer in humans. These immune responses may be triggered by the viral capsid, the vector’s nucleic acid payload, or other vector contaminants or excipients, or by the transgene product encoded by the vector itself. Various preclinical and clinical strategies have been explored to overcome the issues of AAV vector immunogenicity and transgene-related immune responses. Although results of these strategies are encouraging, more efficient approaches are needed to deliver safe, predictable, and durable outcomes for people with hemophilia. In addition to durability, long-term follow-up of gene therapy trial participants will allow us to address potential safety concerns related to vector integration. Herein, we describe the challenges with current methodologies to deliver optimal outcomes for people with hemophilia who choose to undergo AAV vector gene therapy and the potential opportunities to improve on the results.

scholarly journals Hemophilia gene therapy comes of age

2017 ◽  
Vol 1 (26) ◽  
pp. 2591-2599 ◽  
Author(s):  
Lindsey A. George
Keyword(s):  
Clinical Trial ◽  
Gene Therapy ◽  
Gene Transfer ◽  
Factor Ix ◽  
Large Animal Model ◽  
Large Animal ◽  
Adeno Associated Virus ◽  
Target Disease ◽  
American Society ◽  
Clinical Trial Results

Abstract Concurrent with the development of recombinant factor replacement products, the characterization of the F9 and F8 genes over 3 decades ago allowed for the development of recombinant factor products and made the hemophilias a target disease for gene transfer. The progress of hemophilia gene therapy has been announced in 3 American Society of Hematology scientific plenary sessions, including the first “cure” in a large animal model of hemophilia B in 1998, first in human sustained vector-derived factor IX activity in 2011, and our clinical trial results reporting sustained vector-derived factor IX activity well into the mild or normal range in 2016. This progression to clinically meaningful success combined with numerous ongoing recombinant adeno-associated virus (rAAV)–mediated hemophilia gene transfer clinical trials suggest that the goal of gene therapy to alter the paradigm of hemophilia care may soon be realized. Although several novel therapeutics have recently emerged for hemophilia, gene therapy is unique in its potential for a one-time disease-altering, or even curative, treatment. This review will focus on the prior progress and current clinical trial investigation of rAAV-mediated gene transfer for hemophilia A and B.

Adeno-Associated Viral Vectors for Gene Transfer and Gene Therapy

1999 ◽  
Vol 380 (6) ◽  
Author(s):  
H. Büeler
Keyword(s):  
Gene Expression ◽  
Gene Therapy ◽  
Gene Transfer ◽  
Gene Delivery ◽  
Viral Vectors ◽  
Delivery Systems ◽  
Adeno Associated Virus ◽  
Viral Genes ◽  
Virus Recombinant

AbstractAdeno-associated virus (AAV) is a defective, non-pathogenic human parvovirus that depends for growth on coinfection with a helper adenovirus or herpes virus. Recombinant adeno-associated viruses (rAAVs) have attracted considerable interest as vectors for gene therapy. In contrast to other gene delivery systems, rAAVs lack all viral genes and show long-term gene expression

Myeloid Expansion after Insertional Activation of MDS1/EVI1, PRDM16 and SETBP1 in a Successful Chronic Granulomatous Gene Therapy Trial.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 198-198
Author(s):  
Kerstin Schwarzwaelder ◽  
Manfred Schmidt ◽  
Marion G. Ott ◽  
Stefan Stein ◽  
Hanno Glimm ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Side Effects ◽  
High Efficiency ◽  
Post Treatment ◽  
Multiple Time ◽  
Gene Therapy Trial ◽  
Vector Integration ◽  
Integration Sites ◽  
Therapy Trial

Abstract Successful gene therapy trials of ADA-SCID and SCID-X1 demonstrated the curative potential of oncoretroviral gene transfer. Integration of the retroviral vectors used in these studies has been thought to be a random process but severe side effects in gene therapy and in vitro studies revealed preferred insertion of these vectors mainly around transcription start sites. In SCID patients proliferation advantage of gene corrected cells was one reason for the success of the trials, whereas in the most recent chronic granulomatous disease (CGD) gene therapy trial corrected cells do not have any selective advantage therefore the two patients received mild busulfan treatment before transplantation. High efficiency transduction and conditioning have helped in the successful correction of the patients. Peripheral blood granulocytes show a stable expression (>10%) of the transgene (gp91phox) in patient 1 (15 months post treatment) as well as in patient 2 (11 months post treatment). We reasoned that, unlike T cells, which have the capability to proliferate independent of their bone marrow progenitors, granulocytes more directly reflect the influence of retrovirus insertion, and should therefore allow to closely monitor clonal fate in vivo and its potential relation to vector insertion. To study the clonality of the corrected myelopoiesis, the long term activity of individual cell clones, and the distribution of integration sites in active cells we carried out high sensitive LAM-PCR. The highly polyclonal composition of transduced cells forming myelopoiesis caused the sustained expression of gp91phox. Individual clones carrying the transgene could be detected at multiple time points. To define whether corrected cells have a proliferation advantage due to their vector integration we started large-scale sequencing and mapping of involved insertion sites. We here present >700 unique mappable integration sites of the two treated patients. The distribution of the SFFV based retroviral vector integration sites in this trial turned non random 5 months after transplantation. Corrected long-term myelopoiesis expanded 3- to 5- fold in the two patients due to activating common integration sites (CIS) in the zinc finger transcription factor homologs MDS1/EVI1, PRDM16, or in SETBP1, suggesting that these genes influence regulation of normal long-term hematopoiesis in humans. Our data indicate that the therapeutic benefit in this trial was activated through insertional side effects, therefore our findings have important implications in novel gene therapy approaches.

Dose response results of self complementary adeno-associated virus (AAV) vector-mediated factor IX gene transfer in non-human primates

Haemophilia ◽  
2009 ◽  
Vol 15 (2) ◽  
pp. 635-635
Author(s):  
ULRIKE REISS ◽  
ANDREW DAVIDOFF ◽  
JOHN GRAY ◽  
ARTHUR NIENHUIS ◽  
AMIT NATHWANI
Keyword(s):  
Gene Transfer ◽  
Dose Response ◽  
Factor Ix ◽  
Aav Vector ◽  
Adeno Associated Virus

scholarly journals Assessing the potential for AAV vector genotoxicity in a murine model

Blood ◽  
2011 ◽  
Vol 117 (12) ◽  
pp. 3311-3319 ◽  
Author(s):  
Hojun Li ◽  
Nirav Malani ◽  
Shari R. Hamilton ◽  
Alexander Schlachterman ◽  
Giulio Bussadori ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Normal Tissue ◽  
Expression Patterns ◽  
Tumor Formation ◽  
High Dose ◽  
Adjacent Normal Tissue ◽  
Aav Vector ◽  
Vector Integration ◽  
Integration Sites ◽  
Vector Dna

AbstractGene transfer using adeno-associated virus (AAV) vectors has great potential for treating human disease. Recently, questions have arisen about the safety of AAV vectors, specifically, whether integration of vector DNA in transduced cell genomes promotes tumor formation. This study addresses these questions with high-dose liver-directed AAV-mediated gene transfer in the adult mouse as a model (80 AAV-injected mice and 52 controls). After 18 months of follow-up, AAV-injected mice did not show a significantly higher rate of hepatocellular carcinoma compared with controls. Tumors in mice treated with AAV vectors did not have significantly different amounts of vector DNA compared with adjacent normal tissue. A novel high-throughput method for identifying AAV vector integration sites was developed and used to clone 1029 integrants. Integration patterns in tumor tissue and adjacent normal tissue were similar to each other, showing preferences for active genes, cytosine-phosphate-guanosine islands, and guanosine/cysteine-rich regions. Gene expression data showed that genes near integration sites did not show significant changes in expression patterns compared with genes more distal to integration sites. No integration events were identified as causing increased oncogene expression. Thus, we did not find evidence that AAV vectors cause insertional activation of oncogenes and subsequent tumor formation.

Suicide gene therapy for brain tumor by means of adeno-associated virus (AAV) vector

1997 ◽  
Vol 99 ◽  
pp. S5
Author(s):  
Jun Yoshida ◽  
Masaaki Mizuno ◽  
Hideho Okada ◽  
Toshihiko Wakabayashi
Keyword(s):  
Gene Therapy ◽  
Brain Tumor ◽  
Suicide Gene ◽  
Suicide Gene Therapy ◽  
Aav Vector ◽  
Adeno Associated Virus

scholarly journals T Cell-Mediated Immune Responses to AAV and AAV Vectors

2021 ◽  
Vol 12 ◽  
Author(s):  
Hildegund C. J. Ertl
Keyword(s):  
T Cell ◽  
Gene Transfer ◽  
Immune Responses ◽  
De Novo ◽  
T Cell Responses ◽  
Adeno Associated Virus ◽  
Effector Functions ◽  
Cell Responses ◽  
High Doses

Adeno-associated virus (AAV)-mediated gene transfer has benefited patients with inherited diseases, such as hemophilia B, by achieving long-term expression of the therapeutic transgene. Nevertheless, challenges remain due to rejection of AAV-transduced cells, which in some, but not all, patients can be prevented by immunosuppression. It is assumed that CD8+ T cells induced by natural infections with AAVs are recalled by the AAV vector’s capsid and upon activation eliminate cells expressing the degraded capsid antigens. Alternatively, it is feasible that AAV vectors, especially if given at high doses, induce de novo capsid- or transgene product-specific T cell responses. This chapter discusses CD8+ T cell responses to AAV infections and AAV gene transfer and avenues to prevent their activation or block their effector functions.

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