Disclosed are methods and compositions for reduced immunogenic proteins used in enzyme replacement therapy for lysosomal storage disorders. More specifically disclosed are genetically engineered variants of N-acetylgalactosamine-6-sulfatase (GALNS), which are less immunogenetic then wild-type GALNS, but maintain enzymatic activity, and may be used to treat Mucopolysaccharidosis IVA (Morquio A disease, MPS IVA).

Provided herein are gene therapy methods for the treatment of mucopolysaccharidosis type IVA (MPS IVA) involving the use of recombinant adeno-associated viruses (rAAVs) to deliver human N-acetylgalactosamine-6-sulfate sulfatase (hGALNS) to the bone of a human subject diagnosed with MPS IVA. Also provided herein are rAAVs that can be used in the gene therapy methods and methods of making such rAAVs.

The present invention provides new polynucleotide sequences, adeno-associated virus-derived vectors and pharmaceutical compositions containing the same for the treatment of lysosomal storage disorders and specially, for the treatment of mucopolysaccharidosis type IVA or Morquio A syndrome.

This invention provides compositions of active highly phosphorylated human N-acetylgalactosamine-6-sulfatase (GALNS), and pharmaceutical compositions and formulations thereof, methods of producing and purifying GALNS, and its use in the diagnosis, prophylaxis, or treatment of diseases and conditions, including particularly lysosomal storage diseases that are caused by, or associated with, a deficiency in the GALNS enzyme, e.g., Mucopolysaccharidosis IVa (MPS IVa or Morquio A syndrome).

The invention relates to means and methods for gene therapy of lysosomal storage disorders (LSDs), preferably a LSD with skeletal involvement, based on an ex vivo gene therapy approach comprising transduction of autologous hematopoietic stem and progenitor cells (HSPCs) with viral vectors for expressing enzymes that are deficient in the disorders. The final formulation is a suspension of transduced cells in culture medium for the administration to patients affected by the LSDs, preferably preceded by a conditioning regimen.

The invention relates to the field of glycoprotein production means and methods. More specifically, the present invention provides for a novel yeast strain with a mutant Och1 gene resulting in modified N-glycosylation properties of said strain. Even more specifically, said mutant Och1 gene comprises a sequence coding for a mutant OCH1 protein in which one amino acid near the catalytic site, corresponding to position 151 of the OCH1 protein of the methylotrophic wild type Pichia pastoris strain, is deleted. More specifically, the use of said mutant yeast strain for recombinant expression of glycoproteins results in more homogenous mammalian-like N-glycan structures on said heterologously produced glycoproteins.