Shih-hsin Kan - Academia.edu (original) (raw)

Papers by Shih-hsin Kan

The Journal of general virology, 1999

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is a protein expressed consistently in EBV-in... more Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is a protein expressed consistently in EBV-infected cells and EBV-associated malignant tissues. A panel of monoclonal antibodies (MAbs) was generated against the C terminus of EBNA-1 and evaluated for the detection of EBNA-1 in different cell lines. The epitopes recognized were mapped. Since sequence variations of EBNA-1 have been reported in nasopharyngeal carcinoma (NPC) tissues and in infected healthy individuals, the ability of these MAbs to recognize a recombinant protein derived from an NPC biopsy was also analysed. MAb 4H11 appeared to react with EBNA-1 sequences from different sources, whereas MAbs 5C11, 5F12 and 8F6 failed to recognize a recombinant EBNA-1 protein cloned from an NPC patient. Using different recombinant EBNA-1 fragments in an immunoblot format, this study demonstrates that the domain bounded by amino acids 408 and 498 is very immunogenic in mice in that epitopes in this region are recognized by various MAbs...

Inflammatory Bowel Diseases, 2008

Genes and Immunity, 2008

Alternative splicing of mRNA is an important mechanism for organisms to enhance protein diversity... more Alternative splicing of mRNA is an important mechanism for organisms to enhance protein diversity from a limited number of genes. In this report, we described a novel exon insertion in the interleukin 23 (IL-23) receptor between exons 9 and 10, denoted as exon 9a. This 162 base-pair insertion was the only insertion variant discovered in more than 20 IL23R deletion variants found in the mRNA of mitogen-stimulated peripheral blood mononuclear cells (PBMC). Sequence analysis revealed that a pair of GT/AG splice donor-acceptor site and several putative cis-acting sequences were present; the insertion was identified throughout the genome and found to contain homology to the L1 retrotransposon protein. This report describes an insertion in the IL-23 receptor and due to consequent early termination within the intracellular region, causing a possible nonresponsive receptor isoform.

Antimicrobial Agents and Chemotherapy, 2010

Behavioural brain research, Jan 23, 2016

Sanfilippo B syndrome is a progressive neurological disorder caused by inability to catabolize he... more Sanfilippo B syndrome is a progressive neurological disorder caused by inability to catabolize heparan sulfate glycosaminoglycans. We studied neurobehavior in male Sanfilippo B mice and heterozygous littermate controls from 16 to 20 weeks of age. Affected mice showed reduced anxiety, with a decrease in the number of stretch-attend postures during the elevated plus maze (p=0.001) and an increased tendency to linger in the center of an open field (p=0.032). Water maze testing showed impaired spatial learning, with reduced preference for the target quadrant (p=0.01). In radial arm maze testing, affected mice failed to achieve above-chance performance in a win-shift working memory task (t-test relative to 50% chance: p=0.289), relative to controls (p=0.037). We found a 12.4% reduction in mean acetylcholinesterase activity (p<0.001) and no difference in choline acetyltransferase activity or acetylcholine in whole brain of affected male animals compared to controls. Cholinergic pathway...

Molecular Genetics and Metabolism, 2016

Introduction: Mucopolysaccharidosis type IIIB (MPS-IIIB; Sanfilippo B) is an inherited neurodegen... more Introduction: Mucopolysaccharidosis type IIIB (MPS-IIIB; Sanfilippo B) is an inherited neurodegenerative disorder for which no effective treatment is currently available. The cause of MPS-IIIB is deficiency in the lysosomal enzyme, a-N-acetyl-glucosaminidase (NAGLU), and resultant storage of heparan sulfate. Recombinantly produced NAGLU shows inadequate mannose 6-phosphorylation (M6P), which limits cellular uptake. We found that a modified human NAGLU fused to the receptor-binding motif of insulin-like growth fac-tor 2 (hNAGLU-IGF2) can enhance entry into MPS-IIIB fibro-blasts via M6P/IGF2 receptor-mediated endocytosis. In this study, we used a recombinant adenoassociated virus, serotype 5 (AAV5) vector expressing rhNAGLU-IGF2 that targets the choroid plexus epithelia to deliver the missing enzyme to the cerebrospinal fluid (CSF) of MPS-IIIB mice. Methods: The rhNAGLU-IGF2 complementary DNA was cloned into the AAV vector plasmid and recombinant AAV5 vector was gen-erated by triple t...

Mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo B) is an inherited neurodegenerative disord... more Mucopolysaccharidosis type IIIB (MPS IIIB; Sanfilippo B) is an inherited neurodegenerative disorder for which no effective treatment is currently available. The cause of MPS IIIB is deficiency of the lysosomal enzyme, α-N-acetyl-glucosaminidase (NAGLU) and accumulation of heparan sulfate glycosaminoglycans (GAG). Impediments to enzyme replacement therapy include the short half-lives, absence of mannose 6-phosphate (M6P), and poor blood-brain barrier penetration associated with recombinant human NAGLU. A modified human NAGLU fused to the receptor binding motif of insulin-like growth factor 2 (hNAGLU-IGF2) has been shown to enhance entry to MPS IIIB fibroblasts via M6P/IGF2 receptor-mediated endocytosis. In this study, we administered a recombinant adeno-associated virus, serotype 5 (AAV5) vector expressing rhNAGLU-IGF2 that targets the choroid plexus epithelia via lateral ventricle injection to deliver the deficient enzyme to the cerebrospinal fluid (CSF) of MPS IIIB mice. We cloned ...

Experimental Neurology, 2015

Children with mucopolysaccharidosis I (MPS I) develop hyperintense white matter foci on T2-weight... more Children with mucopolysaccharidosis I (MPS I) develop hyperintense white matter foci on T2-weighted brain magnetic resonance (MR) imaging that are associated clinically with cognitive impairment. We report here a diffusion tensor imaging (DTI) and tissue evaluation of white matter in a canine model of MPS I. We found that two DTI parameters, fractional anisotropy (a measure of white matter integrity) and radial diffusivity (which reflects degree of myelination) were abnormal in the corpus callosum of MPS I dogs compared to carrier controls. Tissue studies of the corpus callosum showed reduced expression of myelin-related genes and an abnormal composition of myelin in MPS I dogs. We treated MPS I dogs with recombinant alpha-l-iduronidase, which is the enzyme that is deficient in MPS I disease. The recombinant alpha-l-iduronidase was administered by intrathecal injection into the cisterna magna. Treated dogs showed partial correction of corpus callosum myelination. Our findings suggest that abnormal myelination occurs in the canine MPS I brain, that it may underlie clinically-relevant brain imaging findings in human MPS I patients, and that it may respond to treatment.

Background: Idursulfase has limited passage through the bloodbrain barrier when administered intr... more Background: Idursulfase has limited passage through the bloodbrain barrier when administered intravenously.

Comparative medicine, 2013

The mucopolysaccharidosis type I (MPS I) dog model has been important in the development of thera... more The mucopolysaccharidosis type I (MPS I) dog model has been important in the development of therapies for human patients. We treated dogs with enzyme replacement therapy (ERT) by various approaches. Dogs assessed included untreated MPS I dogs, heterozygous carrier dogs, and MPS I dogs treated with intravenous ERT as adults (beginning at age 13 to 16 mo), intrathecal and intravenous ERT as adults (beginning at age 13 to 16 mo), or intrathecal ERT as juveniles (beginning at age 4 mo). We then characterized the neuroimaging findings of 32 of these dogs (age, 12 to 30 mo). Whole and midsagittal volumes of the corpus callosum, measured from brain MRI, were significantly smaller in affected dogs compared with unaffected heterozygotes. Corpus callosum volumes in dogs that were treated with intrathecal ERT from 4 mo until 21 mo of age were indistinguishable from those of age-matched carrier controls. Dogs with MPS I showed cerebral ventricular enlargement and cortical atrophy as early as 12...

Pediatric Research, 2013

Intrathecal (IT) enzyme replacement therapy with recombinant human α-L-iduronidase (rhIDU) has be... more Intrathecal (IT) enzyme replacement therapy with recombinant human α-L-iduronidase (rhIDU) has been studied to treat glycosaminoglycan storage in the central nervous system of mucopolysaccharidosis (MPS) I dogs and is currently being studied in MPS I patients. We studied the immune response to IT rhIDU in MPS I subjects with spinal cord compression who had been previously treated with intravenous rhIDU. We measured the concentrations of specific antibodies and cytokines in serum and cerebrospinal fluid (CSF) collected before monthly IT rhIDU infusions and compared the serologic findings with clinical adverse event (AE) reports to establish temporal correlations with clinical symptoms. Five MPS I subjects participating in IT rhIDU trials were studied. One subject with symptomatic spinal cord compression had evidence of an inflammatory response with CSF leukocytosis, elevated interleukin-5, and elevated immunoglobulin G. This subject also complained of lower back pain and buttock paresthesias temporally correlated with serologic abnormalities. Clinical symptoms were managed with oral medication, and serologic abnormalities were resolved, although this subject withdrew from the trial to have spinal decompressive surgery. IT rhIDU was generally well tolerated in the subjects studied, although one subject had moderate to severe clinical symptoms and serologic abnormalities consistent with an immune response.

Molecular Therapy — Methods & Clinical Development, 2015

Mucopolysaccharidosis type I (MPS I) is an inherited α-L-iduronidase (IDUA, I) deficiency in whic... more Mucopolysaccharidosis type I (MPS I) is an inherited α-L-iduronidase (IDUA, I) deficiency in which glycosaminoglycan (GAG) accumulation causes progressive multisystem organ dysfunction, neurological impairment, and death. Current MPS I mouse models, based on a NOD/SCID (NS) background, are short-lived, providing a very narrow window to assess the long-term efficacy of therapeutic interventions. They also develop thymic lymphomas, making the assessment of potential tumorigenicity of human stem cell transplantation problematic. We therefore developed a new MPS I model based on a NOD/SCID/Il2rγ (NSG) background. This model lives longer than 1 year and is tumor-free during that time. NSG MPS I (NSGI) mice exhibit the typical phenotypic features of MPS I including coarsened fur and facial features, reduced/abnormal gait, kyphosis, and corneal clouding. IDUA is undetectable in all tissues examined while GAG levels are dramatically higher in most tissues. NSGI brain shows a significant inflammatory response and prominent gliosis. Neurological MPS I manifestations are evidenced by impaired performance in behavioral tests. Human neural and hematopoietic stem cells were found to readily engraft, with human cells detectable for at least 1 year posttransplantation. This new MPS I model is thus suitable for preclinical testing of novel pluripotent stem cell-based therapy approaches. ARTICle MPS I model for stem cell transplantation DC Mendez et al.

Molecular Genetics and Metabolism, 2014

findings, interventions to reduce heart rate and general anaesthesia should be considered with ca... more findings, interventions to reduce heart rate and general anaesthesia should be considered with caution in patients with MPS IVA.

Molecular Genetics and Metabolism, 2015

Proceedings of the National Academy of Sciences of the United States of America, Jan 14, 2014

Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage dis... more Mucopolysaccharidosis type IIIB (MPS IIIB, Sanfilippo syndrome type B) is a lysosomal storage disease characterized by profound intellectual disability, dementia, and a lifespan of about two decades. The cause is mutation in the gene encoding α-N-acetylglucosaminidase (NAGLU), deficiency of NAGLU, and accumulation of heparan sulfate. Impediments to enzyme replacement therapy are the absence of mannose 6-phosphate on recombinant human NAGLU and the blood-brain barrier. To overcome the first impediment, a fusion protein of recombinant NAGLU and a fragment of insulin-like growth factor II (IGFII) was prepared for endocytosis by the mannose 6-phosphate/IGFII receptor. To bypass the blood-brain barrier, the fusion protein ("enzyme") in artificial cerebrospinal fluid ("vehicle") was administered intracerebroventricularly to the brain of adult MPS IIIB mice, four times over 2 wk. The brains were analyzed 1-28 d later and compared with brains of MPS IIIB mice that receiv...