Inhibition of HIV-1 Replication by Cell-penetrating Peptides Binding Rev

Abstract

New therapeutic agents able to block HIV-1 replication are eagerly sought after to increase the possibilities of treatment of resistant viral strains. In this report, we describe a rational strategy to identify small peptide sequences owning the dual property of penetrating within lymphocytes and of binding to a protein target. Such sequences were identified for two important HIV-1 regulatory proteins, Tat and Rev. Their association to a stabilizing domain consisting of human small ubiquitin-related modifier-1 (SUMO-1) allowed the generation of small proteins named SUMO-1 heptapeptide protein transduction domain for binding Tat (SHPT) and SUMO-1 heptapeptide protein transduction domain for binding Rev (SHPR), which are stable and efficiently penetrate within primary lymphocytes. Analysis of the antiviral activity of these proteins showed that one SHPR is active in both primary lymphocytes and macrophages, whereas one SHPT is active only in the latter cells. These proteins may represent prototypes of new therapeutic agents targeting the crucial functions exerted by both viral regulatory factors. HIV-11 expresses several regulatory proteins that divert key cellular factors to allow rapid and efficient production of viral particles. After two decades of extensive studies, significant progresses have been achieved in the understanding of the molecular mechanisms mediating various actions of these regulatory proteins. Particular attention has been paid to two of them, Tat and Rev. The first potently activates transcription of the integrated provirus by establishing contacts with both transcription factors and the transactivation-responsive element motif located at the 5Ј end of the viral RNA (for reviews see Refs. 1 and 2). This activator has been shown to interact with the Sp1 upstream transcription factor (3), general initiation factors including TBP (4, 5), TFIIB (6), and RNA polymerase II (7), and coactivators as p300 and PCAF (8, 9). It has also been shown that Tat is able to interact simultaneously with transactivation-responsive element and the CDK9/cyclin T complex (10, 11), thereby stimulating the phosphorylation of the RNA polymerase II large subunit carboxyl-terminal domain and ensuring a stable elongation (12, 13). These interactions, which are regulated by posttranslational modification of the protein as acetylation (14, 15), allow Tat to potently activate transcription of the provirus by acting both at the initiation and elongation steps (16). Besides its transcriptional activation power, Tat exhibits other properties that are likely to intervene in the onset of the immunodeficiency resulting from HIV-1 infection (17)(18)(19).Rev also has the dual ability to interact with RNA, the Rev response element motif present in intronic position in the 3Ј part of the viral RNA in this case, as well as with cellular nuclear factors (for a review see Ref. 20). This viral protein includes both a nuclear localization signal (NLS) and a nuclear export sequence (NES) and, by shuttling between the nucleus and the cytopl...

Improving the Stability of Aptamers by Chemical Modification

“…The expressed peptides were fused to the SUMO-1 stabilizer and termed SUMO-1 heptapeptide-PTD for binding Tat (SHPT) or SUMO-1 heptapeptide-PTD for binding Rev (SHPR). Both SHPT and SHPR efficiently entered lymphocytes without cytotoxicities when concentrations are less than 2 M, and some SHPR at 1-2 M concentrations exerted inhibition of HIV-1 replications to the extent of 70% -100% [112].…”

“…2'-O-methyl-4'-thio [53] 5-N-(6-aminohexyl) carbamoyl-2'-deoxyuridine [53] 4'-C-(aminoethyl) thymidine [53] 4'-Thio [53,[74][75][76] [ 53,76] Unnatural amino acid [102][103][104] Cyclization [105,106] Chemical crosslinking [108,109] Conjugation to stabilizing proteins [112] Switch of scaffold [95] (*: modifications that can be directly incorporated to the SELEX, without additional post-SELEX modifications).…”

Pharmacological inhibition of Frizzled-7 displays anti-tumor properties in hepatocellular carcinoma

“…Rhodamine-tagging served as a tracer, and the polyarginine sequence (Protein Transduction Domain) allowed cell entry [13]. Each heptapeptide corresponded to one hemiportion of the FZD7 intracellular tail containing different PDZ binding domains (Table 1): (i) P1, the wild-type NH 2-hemiportion with the KTLQSW domain having the highest affinity for DVL PDZ [11]; (ii) P2, its negative control with the mutated MVLQS domain (P2); (iii) P3, the wild-type COOH-hemiportion containing the ETAV domain having the lowest affinity for DVL PDZ; and (iv) P4, its negative control with the mutated EAAA domain.…”

A New Generation of Peptide-based Inhibitors Targeting HIV-1 Reverse Transcriptase Conformational Flexibility

“…Antiviral Assay-The anti-HIV activities of the whole series of peptides were assayed according to previously described methods (38). Phytohemagglutinin-P (PHA-P)-activated peripheral blood mononuclear cells (PBMCs) were infected with the reference lymphotropic HIV-1-LAI strain (39).…”