Substrate reduction therapy (SRT) with miglustat has been proposed for treatment of some lysosomal storage disorders. Based on the positive experience in Gaucher disease and experimental data in Tay-Sachs (TSD) and Sandhoff animal models, the authors investigated the clinical efficacy of SRT in two patients with infantile TSD. SRT could not arrest the patients' neurologic deterioration. However, a significant drug concentration in CSF as well as macrocephaly prevention were observed.

Gaucher disease is the most frequent lysosomal storage disorder due to the deficiency of the acid b-glucosidase, encoded by the GBA gene. In this study, we report the structural and functional characterization of 11 novel GBA alleles. Seven single missense alleles, P159S, N188I, E235K, P245T, W312S, S366R and W381C, and two alleles carrying in cis mutations, (N188S; G265R) and (E326K; D380N), were studied for enzyme activity in transiently transfected cells. All mutants were inactive except the P159S, which retained 15% of wild-type activity. To further characterize the alleles carrying two in cis mutations, we expressed constructs bearing singly each mutation. The presence of G265R or D380N mutations completely abolished enzyme activity, while N188S and E326K mutants retained 25 and 54% of wild-type activity, respectively. Two mutations, affecting the acceptor splice site of introns 5 (c.589-1G4A) and 9 (c.1389-1G4A), led to the synthesis of aberrant mRNA. Unpredictably, family studies showed that two alleles resulted from germline or 'de novo' mutations. These results strengthen the importance of performing a complete and accurate molecular analysis of the GBA gene in order to avoid misleading conclusions and provide a comprehensive functional analysis of new GBA mutations.

Recent reports have provided evidence for the association of simian virus 40 (SV40) with human lymphomas (6,13,16,18,19) and other lymphoproliferative disorders (13). In this study, we investigated a series of Epstein-Barr virus (EBV)-immortalized lymphoblastoid cell lines (LCLs) for the presence of SV40 sequences encoding the large-T-antigen (Tag) N-terminal domain (2, 12, 13; F. Martini, M. De Mattei, L. Iaccheri, L. Lazzarin, G. Barbanti-Brodano, M. Gerosa, and M. Tognon, Letter, J. Natl. Cancer Inst. 87:1331, 1995). This conserved SV40 DNA region was detected in 22 of 42 (52.3%) LCLs analyzed, with similar prevalence in LCLs obtained by spontaneous in vitro outgrowth (7 of 15, 46.7%) and those induced with the prototype B95.8 EBV strain (15 of 27, 55.5%). No evidence of SV40 sequences was found in the marmoset B95.8 cell line from which infectious EBV virions were produced and in mock samples, thus ruling out laboratory contamination. SV40 Tag sequences were also detected in peripheral blood mononuclear cells (PBMCs) of two blood donors (DPPI-16 and DFM-17) from whom SV40-positive B95.8 LCLs were obtained, whereas no Tag sequences were found in PBMCs of two other donors from whom SV40-negative B95.8 LCLs were derived (Table 1).Analysis of B cells purified by immunomagnetic separation confirmed that SV40 was present in circulating CD19ϩ B lymphocytes of the DPPI-16 donor, consistent with the detection of SV40 sequences in the related B95.8-induced LCL. Moreover, all six lymph nodes (LN) from which the six SV40-negative LCLs were obtained were also SV40 negative, whereas in two cases, both the LN and the corresponding spontaneous LCLs were SV40 positive. Conversely, SV40 DNA was not found in two LN from which two SV40-positive spontaneous LCLs were obtained, probably because the viral DNA load in these specimens were below the detection limit of our PCR.

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Gaucher disease, the most common genetic lysosomal disorder, is caused by the lack of functional acid beta-glucosidase (GCase) and is currently treated at a very high cost by enzyme replacement therapy. In an attempt to provide a safe and cost-effective production system, human placental GCase was produced and purified from transgenic tobacco seeds. Plant-derived recombinant GCase was found to be enzymatically active, uptaken by human fibroblasts and free of immunogenic xylose and fucose residues. This report demonstrates the potential of plant bioreactors in the large-scale production of injectable proteins required for lifelong therapy.