Inhibiting HIV 1 infection in I by lentiviral mediated delivei interfering RNA against CCRO
Double stranded RNAs =21 nucleotides long [small interfering 5'RNA (siRNA) are recognized as powerful reagents to reduce the gtl expression of specific genes. To use them as reagents to protect en cells against viral infection, effective methods for introducing of siRNAs into primary cells are required. Here, we describe success in Hi constructing a lentivirus based vector to introduce siRNAs against ysi the HIV 1 coreceptor, CCR5, into human peripheral blood T lym i phocytes. With high titer vector stocks, >40% of the peripheral U blood T lymphocytes could be transduced, and the expression of a M potent CCR5 siRNA resulted in up to 10 fold inhibition of CCR5 or expression on the cell surface over a period of 2 weeks in the absence of selection. In contrast, the expression of another major HIV 1 coreceptor, CXCR4, was not affected. Importantly, blocking il CCR5 expression by siRNAs provided a substantial protection for the lymphocyte populations from CCR5 tropic HIV 1 virus infection, be dropping infected cells by 3 to 7 fold; only a minimal effect on infection by a CXCR4 tropic virus was observed. Thus, our studies demonstrate the feasibility and potential of lentiviral vector 5 mediated delivery of siRNAs as a general means of intracellular ar immunization for the treatment of HIV 1 and other viral diseases. alN ser