RNA interference and antiviral therapy

Table 1 Strategies designed to inhibit HIV replication via RNA interference

Target gene	RNAi inducer (length)	Promoter	Vector	Cell type	Delivery methods	Inhib. of virus prod. (fold)	Reference
Viral Gene
LTR, Vif, Nef	siRNA (21 bp)/shRNA (19 bp)1	T7	Plasmid	Magi, PBLs	Transfection	> 20	[47]
Gag, Pol	siRNA (21 bp)	-	-	HOS.T4.CXCR4	Transfection	> 10	[48]
Gag, LTR	siRNA (23 bp)/dsRNA (21nt)2	-	-	U87-CD4+-CCR5+/CXCR4+, PBMC	Transfection	4	[51]
Gag, Env	dsRNA (441-531nt)3	-	-	COS, Hela-CD4+, PBMC, ACH2	Transfection	70	[52]
Tat + Rev	siRNA (21 bp)	-	-	293T, Jurkat, PBMC	Transfection	> 15	[54]
Rev (Tat)	siRNA (21 bp)5	Dual U6	Plasmid	293/EcR	Transfection	10000	[56]
Nef	dsRNA (556nt)3	-	-	MT4-T, U937	Transfection	2.5	[57]
Env	siRNA (20 bp)/shRNA (20 bp)4	U6	Plasmid, Lentivirus	COS, MT-4	Transfection /Transduction	> 10	[53]
Nef	shRNA (21 bp)	H1	Retrovirus	SupT1	Transduction	> 10	[58]
Gag, Pol, Int, Vpu	shRNA (21 bp)	H1	Lentivirus	293T, Magi, GHOST hi5, CEM-A, Molt-4, PBMC	Transduction	> 20	[61]
Cellular gene
Tsg101	siRNA (21 bp)	-	-	293T	Transfection	10-20	[63]
LEDGF/p75	siRNA (21 bp)	-	-	Hela	Transfection	NR	[64]
P-TEFb (CDK9/CyclinT1)	siRNA (21 bp)	-	-	Hela, Magi	Transfection	3-5	[65]
hRIP	siRNA (21 bp)	-	-	Hela, Jurkat, Macrophages	Transfection	-100	[66]
Emerin	siRNA (21 bp)	-	-	Hela, Macrophages	Transfection	> 10	[67]
LEDGF/p75, HRP2	siRNA (21 bp)	-	-	Hela-P4	Transfection	2-3	[68]
CXCR4	siRNA (21 bp)	-	-	HOS-CD4+, HOS-CD4+-CXCR4+/CCR5+	Transfection	3-5	[70]
Importin 7	siRNA (21 bp)	-	-	Hela, Macrophages	Transfection	-10	[69]
CXCR4+ CD4,
CXCR4+ CCR5	shRNA (19/21 bp)6	-	-	Magi-CXCR4/CCR5, PBMC	Transfection	> 15	[71]
CCR5	shRNA (19 bp)	U6	Lentivirus	Magi-CCR5, PBLs	Transduction	3-7	[34]
Combination of viral and cellular genes
Gag, CD4	siRNA (21 bp)	-	-	Magi-CCR5, Hela-CD4	Transfection	4-25	[50]
Tat, RT, NF-κB (p65)	siRNA (21 bp)	-	-	Magi, Jurkat	Transfection	5-500	[74]

The fold inhibition of virus production refers to the results obtained with the most potent siRNA/shRNA tested in a specific cell model. All siRNAs were prepared by chemical synthesis unless indicated otherwise. LTR: Long terminal repeat; PBLs: Peripheral blood lymphocytes; PBMC: Peripheral blood mononuclear cell; Pol: Polymerase; Env: Envelope; Tsg101: Tumor susceptibility gene 101; LEDGF/P75: Lens epithelium-derived growth factor/transcription co-activator p75; NR: Not reported; P-TEF: Positive transcription elongation factors; hRIP: Human Rev-interacting protein; HRP2: Hepatoma-derived growth factor related protein 2; RT: Reverse transcriptase; NF-κB: Nuclear factor-NF-κB.

¹shRNA expressed from a transfected plasmid under the control of a T7 promoter.

²dsRNA produced by in vitro T7 promoter-mediated transcription.

³dsRNA produced by in vitro SP6/T7 promoter-mediated transcription.

⁴shRNA and siRNA expressed from transfected plasmids under the control of one and two U6 promoters respectively, shRNA further stably expressed from a recombinant lentiviral vector driven by a U6 promoter.

⁵siRNA expressed from a transfected plasmid under the control of two U6 tandem promoters that drive the synthesis of each of the siRNA strand.

⁶shRNA produced by in vitro T7 promoter-mediated transcription.