Large-volume Intrathecal Enzyme Delivery Increases Survival of a Mouse Model of Late Infantile Neuronal Ceroid Lipofuscinosis

Abstract

Late infantile neuronal ceroid lipofuscinosis (LINCL) is a progressive neurodegenerative lysosomal storage disorder caused by mutations in TPP1, the gene encoding the lysosomal protease tripeptidyl-peptidase (TPP1). LINCL primarily affects children, is fatal and there is no effective treatment. Administration of recombinant protein has proved effective in treatment of visceral manifestations of other lysosomal storage disorders but to date, only marginal improvement in survival has been obtained for neurological diseases. In this study, we have developed and optimized a large-volume intrathecal administration strategy to deliver therapeutic amounts of TPP1 to the central nervous system (CNS) of a mouse model of LINCL. To determine the efficacy of treatment, we have monitored survival as the primary endpoint and demonstrate that an acute treatment regimen (three consecutive daily doses started at 4 weeks of age) increases median lifespan of the LINCL mice from 16 (vehicle treated) to 23 weeks (enzyme treated). Consistent with the increase in life-span, we also observed significant reversal of pathology and improvement in neurological phenotype. These results provide a strong basis for both clinical investigation of large-volume/high-dose delivery of TPP1 to the brain via the cerebrospinal fluid (CSF) and extension of this approach towards other neurological lysosomal storage diseases.

Effective Intravenous Therapy for Neurodegenerative Disease With a Therapeutic Enzyme and a Peptide That Mediates Delivery to the Brain

“…Recombinant human TPP1 proenzyme was produced in CHO cells and purified as described. 11 For injection, TPP1 was buffer exchanged into phosphate-buffered saline (Gibco) using PD-10 size exclusion columns (GE Healthcare). TPP1 was concentrated using Vivaspin 20 centrifugal concentrators (Sartorius Stedim Biotech, Aubagne, France) to a maximum of 17 mg/ml and stored at −80 °C.…”

“…One brain hemisphere was drop-fixed in Bouin's reagent and 10 µm sagittal cryosections were processed for TPP1 immunohistochemistry as described. 11 The remaining hemisphere was used to prepare frozen tissue powder using a Bessman pulverizer (Spectrum Laboratories, Rancho Dominguez, CA). For TPP1 enzyme assay, powders were homogenized in 50 volumes (brain, heart, kidney, and lung) or 100 volumes (liver and spleen) of homogenization buffer (0.15 mol/l NaCl /0.1% Triton X-100) using a Polytron homogenizer (Kinematica, Bohemia, NY).…”

“…7 The BBB can be bypassed by administration via the cerebrospinal fluid 8,9 and this has shown promise for LINCL. [10][11][12] However, cerebrospinal fluid delivery is invasive and may not be suitable for a life-long therapy. There are also concerns 13 that widespread distribution throughout the human brain may be difficult given that the cerebrospinal fluid-brain interface is anatomically limited, requiring significant diffusion of a therapeutic for complete coverage.…”

Pathogenesis and therapies for infantile neuronal ceroid lipofuscinosis (infantile CLN1 disease)

“…Since both late infantile CLN2 disease and infantile CLN1 disease share a common defect (soluble lysosomal enzyme deficiency), similar therapeutic strategies might be effective for both. In fact, it has been shown that intracerebroventricular or intrathecal administration of recombinant TPP1 reduces neuroinflammation, decreases the accumulation of autofluorescent material, and improves the clinical course of disease in the murine model of late infantile CLN2 disease (Chang et al 2008; Xu et al 2011). Encouragingly, intrathecal administration of recombinant TPP1 also reduces lysosomal storage in a large animal model (canine) of late infantile CLN2 disease (Vuillemenot et al 2011).…”

Biochemical evidence for superior correction of neuronal storage by chemically modified enzyme in murine mucopolysaccharidosis VII

“…However, important concerns associated with gene therapy currently limit its clinical utility (19,20). Another approach is direct administration of enzyme into the cerebrospinal fluid (CSF) (21,22). Even though treated mice showed improvements in disease phenotypes, concerns remain whether such invasive methods are practical in humans.…”