Inhibiting HIV-1 infection in human T cells by lentiviral-mediated delivery of small interfering RNA against CCR5

TLDR

siRNAs are powerful tools for silencing specific genes. The study aimed to develop an efficient method to deliver siRNAs into primary cells to protect them from viral infection. A lentivirus‑based vector was engineered to introduce CCR5‑targeting siRNAs into human peripheral blood T lymphocytes. High‑titer lentiviral delivery of the CCR5 siRNA transduced >40 % of T cells, reduced surface CCR5 by up to tenfold for two weeks, and conferred 3‑ to 7‑fold protection against CCR5‑tropic HIV‑1 while sparing CXCR4‑tropic infection, demonstrating the feasibility of lentiviral siRNA immunization for HIV‑1 and other viral diseases.

Abstract

Double-stranded RNAs ≈21 nucleotides long [small interfering RNA (siRNA)] are recognized as powerful reagents to reduce the expression of specific genes. To use them as reagents to protect cells against viral infection, effective methods for introducing siRNAs into primary cells are required. Here, we describe success in constructing a lentivirus-based vector to introduce siRNAs against the HIV-1 coreceptor, CCR5, into human peripheral blood T lymphocytes. With high-titer vector stocks, >40% of the peripheral blood T lymphocytes could be transduced, and the expression of a potent CCR5-siRNA resulted in up to 10-fold inhibition of CCR5 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 CCR5 expression by siRNAs provided a substantial protection for the lymphocyte populations from CCR5-tropic HIV-1 virus infection, 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-mediated delivery of siRNAs as a general means of intracellular immunization for the treatment of HIV-1 and other viral diseases.