Gene therapy for alpha 1-antitrypsin deficiency with an oxidant-resistant human alpha 1-antitrypsin
Meredith L. Sosulski, Katie M. Stiles, Esther Z. Frenk, Fiona M. Hart, Yuki Matsumura, Bishnu P. De, Stephen M. Kaminsky, Ronald G. Crystal
Meredith L. Sosulski, Katie M. Stiles, Esther Z. Frenk, Fiona M. Hart, Yuki Matsumura, Bishnu P. De, Stephen M. Kaminsky, Ronald G. Crystal
View: Text | PDF
Research Article Pulmonology Therapeutics

Gene therapy for alpha 1-antitrypsin deficiency with an oxidant-resistant human alpha 1-antitrypsin

Abstract

Alpha 1-antitrypsin (AAT) deficiency, a hereditary disorder characterized by low serum levels of functional AAT, is associated with early development of panacinar emphysema. AAT inhibits serine proteases, including neutrophil elastase, protecting the lung from proteolytic destruction. Cigarette smoke, pollution, and inflammatory cell–mediated oxidation of methionine (M) 351 and 358 inactivates AAT, limiting lung protection. In vitro studies using amino acid substitutions demonstrated that replacing M351 with valine (V) and M358 with leucine (L) on a normal M1 alanine (A) 213 background provided maximum antiprotease protection despite oxidant stress. We hypothesized that a onetime administration of a serotype 8 adeno-associated virus (AAV8) gene transfer vector coding for the oxidation-resistant variant AAT (A213/V351/L358; 8/AVL) would maintain antiprotease activity under oxidant stress compared with normal AAT (A213/M351/M358; 8/AMM). 8/AVL was administered via intravenous (IV) and intrapleural (IPL) routes to C57BL/6 mice. High, dose-dependent AAT levels were found in the serum and lung epithelial lining fluid (ELF) of mice administered 8/AVL or 8/AMM by IV or IPL. 8/AVL serum and ELF retained serine protease–inhibitory activity despite oxidant stress while 8/AMM function was abolished. 8/AVL represents a second-generation gene therapy for AAT deficiency providing effective antiprotease protection even with oxidant stress.

Authors

Meredith L. Sosulski, Katie M. Stiles, Esther Z. Frenk, Fiona M. Hart, Yuki Matsumura, Bishnu P. De, Stephen M. Kaminsky, Ronald G. Crystal

×

Figure 7

In vivo levels of human AAT in ELF over time following administration of the AAV8 vectors.

Options: View larger image (or click on image) Download as PowerPoint
In vivo levels of human AAT in ELF over time following administration of...
C57BL/6 mice were administered 8/AMM, 8/AVL, or 8/Null (4 × 1011 gc) by the IV and IPL routes (n = 4–5/group). Lung ELF was collected after sacrifice at 0, 4, 12, or 24 weeks, and human AAT was quantified by ELISA. (A) Male mice, IV. (B) Male mice, IPL. (C) Female mice, IV. (D) Female mice, IPL. At 24 weeks, there was no significant (ns) difference between 8/AMM and 8/AVL for either sex or administration route using Student’s t test. (E and F) Ratio of ELF to serum AAT. (E) Male mice. (F) Female mice. For E and F, data from all doses and time points were combined, and AAT levels (per mg protein) were collectively compared in ELF and serum for mice administered 8/AVL. Statistical analysis was performed using Student’s t test.