Virus evolution reveals an exclusive role for LEDGF/p75 in chromosomal tethering of HIV.
Retroviruses by definition insert their viral genome into the host cell chromosome. Although the key player of retroviral integration is viral integrase, a role for cellular cofactors has been proposed. Lentiviral integrases use the cellular protein LEDGF/p75 to tether the preintegration complex to the chromosome, although the existence of alternative host proteins substituting for the function of LEDGF/p75 in integration has been proposed. Truncation mutants of LEDGF/p75 lacking the chromosome attachment site strongly inhibit HIV replication by competition for the interaction with integrase. In an attempt to select HIV strains that can overcome the inhibition, we now have used T-cell lines that stably express a C-terminal fragment of LEDGF/p75. Despite resistance development, the affinity of integrase for LEDGF/p75 is reduced and replication kinetics in human primary T cells is impaired. Detection of the integrase mutations A128T and E170G at key positions in the LEDGF/p75-integrase interface provides in vivo evidence for previously reported crystallographic data. Moreover, the complementary inhibition by LEDGF/p75 knockdown and mutagenesis at the integrase-LEDGF/p75 interface points to the incapability of HIV to circumvent LEDGF/p75 function during proviral integration. Altogether, the data provide a striking example of the power of viral molecular evolution. The results underline the importance of the LEDGF/p75 HIV-1 interplay as target for innovative antiviral therapy. Moreover, the role of LEDGF/p75 in targeting integration will stimulate research on strategies to direct gene therapy vectors into safe landing sites.
Hombrouck
Anneleen
A
The Laboratory for Molecular Virology and Gene Therapy, KULeuven and IRC KULAK, Leuven, Flanders, Belgium.
De Rijck
Jan
J
Hendrix
Jelle
J
Vandekerckhove
Linos
L
Voet
Arnout
A
De Maeyer
Marc
M
Witvrouw
Myriam
M
Engelborghs
Yves
Y
Christ
Frauke
F
Gijsbers
Rik
R
Debyser
Zeger
Z
D002460:Cell Line; D002875:Chromosomes / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005786:Gene Expression Regulation; D049452:Green Fluorescent Proteins; D019427:HIV Integrase / Q000378:metabolism*; D015497:HIV-1 / Q000235:genetics / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000502:physiology*; D019169:Jurkat Cells; D009154:Mutation; D010446:Peptide Fragments / Q000235:genetics / Q000378:metabolism; D016662:Virus Integration; D014779:Virus Replication / Q000502:physiology*
D004279:DNA, Viral; D004268:DNA-Binding Proteins; D036341:Intercellular Signaling Peptides and Proteins; D010446:Peptide Fragments; C485184:enhanced green fluorescent protein; C119380:lens epithelium-derived growth factor; D049452:Green Fluorescent Proteins; D004247:DNA; D019427:HIV Integrase