Regulated hAAT Expression from a Novel rAAV Vector and Its Application in the Prevention of Type 1 Diabetes

Abstract

We, and others, have previously achieved high and sustained levels of transgene expression from viral vectors, such as recombinant adeno-associated virus (rAAV). However, regulatable transgene expression may be preferred in gene therapy for diseases, such as type 1 diabetes (T1D) and rheumatoid arthritis (RA), in which the timing and dosing of the therapeutic gene product play critical roles. In the present study, we generated a positive feedback regulation system for human alpha 1 antitrypsin (hAAT) expression in the rAAV vector. We performed quantitative kinetics studies in vitro and in vivo demonstrating that this vector system can mediate high levels of inducible transgene expression. Transgene induction could be tailored to occur rapidly or gradually, depending on the dose of the inducing drug, doxycycline (Dox). Conversely, after withdrawal of Dox, the silencing of transgene expression occurred slowly over the course of several weeks. Importantly, rAAV delivery of inducible hAAT significantly prevented T1D development in non-obese diabetic (NOD) mice. These results indicate that this Dox-inducible vector system may facilitate the fine-tuning of transgene expression, particularly for hAAT treatment of human autoimmune diseases, including T1D.

The Role of NKG2D in Vitiligo

“…Notably, studies from our group have established in animal models that NKG2D signaling also leads to the development of long-lasting CD8 T cells with enhanced cytolytic function (33)(34)(35). NKG2DL upregulation and NKG2D signaling activation in effector CD8 T cells play a role in the onset or development of some autoimmune diseases, including vitiligo, rheumatoid arthritis, celiac disease, type 1 diabetes, alopecia areata, systemic lupus erythematosus (SLE), among others (36)(37)(38)(39)(40)(41). Moreover, inhibiting NKG2D engagement can prevent inflammation and disease development in some models of type 1 diabetes (42), vitíligo (30), and other inflammatory diseases (16).…”

Therapeutic Potential of Alpha-1 Antitrypsin in Type 1 and Type 2 Diabetes Mellitus

“…Recently, the application of CRISPR-Cas9 technology to correct AAT mutations in vivo was utilized to either correct an AAT mutation or enhance AAT production [ 85 ]. Equally, recombinant adeno-associated virus delivery of inducible human AAT significantly prevented T1DM development in NOD mice, and similar approaches could be utilized as future treatment approaches [ 86 ]. Therefore, AAT plays important roles in emphysema and T1DM, and possibly T2DM.…”

Human Alpha 1 Antitrypsin Suppresses NF-κB Activity and Extends Lifespan in Adult Drosophila

“…In addition, hAAT can act as a scavenger of reactive oxygen species (ROS), which is a major inflammatory mediator and a marker of senescence [ 1 , 6 ]. As a potent inflammation regulator, hAAT has a potential protective function in a variety of inflammatory diseases, including rheumatoid arthritis [ 7 , 8 , 9 ], graft-versus-host disease [ 10 ], osteoporosis [ 11 , 12 , 13 , 14 ], inflammatory bowel disease [ 15 ], and type 1 diabetes [ 16 ]. With a reliable safety profile, hAAT has significant prospects for use in treating aging-related inflammatory diseases [ 17 ].…”