Adeno-associated Virus–mediated Delivery of a Recombinant Single-chain Antibody Against Misfolded Superoxide Dismutase for Treatment of Amyotrophic Lateral Sclerosis

Abstract

There is emerging evidence that the misfolding of superoxide dismutase 1 (SOD1) may represent a common pathogenic event in both familial and sporadic amyotrophic lateral sclerosis (ALS). To reduce the burden of misfolded SOD1 species in the nervous system, we have tested a novel therapeutic approach based on adeno-associated virus (AAV)–mediated tonic expression of a DNA construct encoding a secretable single-chain fragment variable (scFv) antibody composed of the variable heavy and light chain regions of a monoclonal antibody (D3H5) binding specifically to misfolded SOD1. A single intrathecal injection of the AAV encoding the single-chain antibody in SOD1G93A mice at 45 days of age resulted in sustained expression of single-chain antibodies in the spinal cord, and it delayed disease onset and extension of life span by up to 28%, in direct correlation with scFv titers in the spinal cord. The treatment caused attenuation of neuronal stress signals and reduction in levels of misfolded SOD1 in the spinal cord of SOD1G93A mice. From these results, we propose that an immunotherapy based on intrathecal inoculation of AAV encoding a secretable scFv against misfolded SOD1 should be considered as potential treatment for ALS, especially for individuals carrying SOD1 mutations.

Recombinant AAV-mediated in vivo long-term expression and antitumour activity of an anti-ganglioside GM3(Neu5Gc) antibody

“…Antibody processing and expression were found to be just as effective in vivo, as functional recombinant antibody 14F7 was detected in animal circulation just a week after rAAV injection. This is in line with previous works reporting the in vivo expression of recombinant antibodies by rAAV-mediated gene transfer in several preclinical models of viral and parasitic diseases[37][38][39] , cancer40,43 and neurological conditions41,42 .…”

“…The in vivo expression of recombinant antibodies by rAAV-mediated gene transfer in several disease models has also been reported [37][38][39][40][41][42][43] .…”

Defining SOD1 ALS natural history to guide therapeutic clinical trial design

“…Therefore, global reduction of toxic SOD1 in ALS has been recognised as a possible therapeutic intervention. Our work with SOD1 antisense oligonucleotides 6-10 and others (ClinicalTrials.gov NCT00706147) [11][12][13][14][15][16][17] have focused on targeted SOD1-lowering therapeutics approaches for ALS SOD1 . Given the heterogeneity of disease progression in different mutation carriers, one may envision the design of a trial that stratifies results from patients with rapidly progressing disease as defined by unchanged natural history data.…”

“…3 The second most common cause of FALS is the gene encoding copper zinc superoxide dismutase 1 (SOD1), which accounts for 10-20% of FALS and mostly follow an autosomal-dominant inheritance pattern, 4 although an aspartic acid to alanine (D90A) point mutation found in the Scandanavian population displays recessive inheritance. 5 Multiple efforts (ClinicalTrials.gov NCT00706147) [6][7][8][9][10][11][12][13][14][15][16][17] have focused on targeted therapeutic approaches for SOD1-related ALS (ALS SOD1 ).…”

Current developments in gene therapy for amyotrophic lateral sclerosis

“…AAV vectors were engineered to deliver a single chain fragment variable of the D3H5 antibody, which is able to block the toxic misfolded SOD1 protein produced in the SOD1-G93A mouse model [100,101]. The increase in lifespan was up to 40 days with an average of 16, and the levels of misfolded SOD1 protein in the spinal cord were decreased, along with a reduction in neuronal stress [101].…”