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Abstract: Fibrillization and aggregation of α-synuclein may play a critical role in neurodegenerative diseases like Parkinson’s diseases. Adeno-associated virus (AAV) vector delivery of an α-synuclein ribozyme was tested for its silencing effect on degenerating nigrostriatal neurons in the MPP+ model of Parkinson’s disease. We designed α-synuclein ribozyme against human α-synuclein gene expression and constructed α-synuclein ribozymes-carrying rAAV vector (designated rAAV-SynRz). Co-transfection of rAAV-SynRz and rAAV-α-synuclein into HEK293 cells resulted in down-regulation of α-synuclein protein expression in vitro. Then, rAAV-SynRz was injected into the substantia nigra (SN) of MPP+-treated rats. Cell counts of TH-positive neurons in the SN revealed that rAAV-SynRz significantly protected TH-positive cells against apoptotic death, compared with those of rAAV-EGFP or no rAAV injected rats. Our results indicate that the use of rAAV-SynRz allowed the survival of higher number of TH-positive neurons in SN in the MPP+ model. Down-regulation of α-synuclein expression could be potentially a suitable target for gene therapy of Parkinson’s disease. [Copyright &y& Elsevier]

Abstract: Our previous study demonstrated that the immunization with a cycloimmunogen derived from extracellular loop-2 (ECL-2) of CCR5 (cDDR5) attenuated acute phase of CCR5-tropic simian-human immunodeficiency virus (SHIV)SF162P3 replication in vivo. Although the study showed that the antisera raised against cDDR5 reacted with cell-expressed CCR5, we have not yet demonstrated whether the antisera can react with virion-incorporated CCR5. Here, we show that rhesus cDDR5 (rcDDR5)-specific antibodies react with not only cell-expressed but also virion-incorporated simian CCR5s (siCCR5s), but may predominantly exert their inhibitory effects on simian immunodeficiency virus (SIV) infection by the binding of cell-expressed rather than virion-incorporated CCR5s. These results suggest that the virion-incorporated CCR5 may contribute to the reactivation of the anti-rcDDR5 antibody-producing B-cells by SIV particles after rcDDR5 immunization, although the binding of anti-rcDDR5 antibody to virion-incorporated CCR5 results in a partial inhibitory effect on SIV infection. [Copyright &y& Elsevier]