Anti-SOD1 Nanobodies That Stabilize Misfolded SOD1 Proteins Also Promote Neurite Outgrowth in Mutant SOD1 Human Neurons

Int J Mol Sci. 2022 Dec 16;23(24):16013. doi: 10.3390/ijms232416013.


ALS-linked mutations induce aberrant conformations within the SOD1 protein that are thought to underlie the pathogenic mechanism of SOD1-mediated ALS. Although clinical trials are underway for gene silencing of SOD1, these approaches reduce both wild-type and mutated forms of SOD1. Here, we sought to develop anti-SOD1 nanobodies with selectivity for mutant and misfolded forms of human SOD1 over wild-type SOD1. Characterization of two anti-SOD1 nanobodies revealed that these biologics stabilize mutant SOD1 in vitro. Further, SOD1 expression levels were enhanced and the physiological subcellular localization of mutant SOD1 was restored upon co-expression of anti-SOD1 nanobodies in immortalized cells. In human motor neurons harboring the SOD1 A4V mutation, anti-SOD1 nanobody expression promoted neurite outgrowth, demonstrating a protective effect of anti-SOD1 nanobodies in otherwise unhealthy cells. In vitro assays revealed that an anti-SOD1 nanobody exhibited selectivity for human mutant SOD1 over endogenous murine SOD1, thus supporting the preclinical utility of anti-SOD1 nanobodies for testing in animal models of ALS. In sum, the anti-SOD1 nanobodies developed and presented herein represent viable biologics for further preclinical testing in human and mouse models of ALS.

Keywords: amyotrophic lateral sclerosis (ALS) (Lou Gehrig disease); antibody engineering; neurite outgrowth; protein misfolding; superoxide dismutase (SOD).

MeSH terms

  • Amyotrophic Lateral Sclerosis* / metabolism
  • Animals
  • Humans
  • Mice
  • Motor Neurons / metabolism
  • Mutation
  • Neuronal Outgrowth
  • Protein Folding
  • Single-Domain Antibodies* / metabolism
  • Superoxide Dismutase / genetics
  • Superoxide Dismutase / metabolism
  • Superoxide Dismutase-1 / genetics
  • Superoxide Dismutase-1 / metabolism


  • Superoxide Dismutase-1
  • Superoxide Dismutase
  • Single-Domain Antibodies
  • SOD1 protein, human