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Abstract
MECHANISMS FOR STIMULATION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 REPLICATION BY AOP-RANTES
MAROZSAN A, TORRE V, BALL S, CROSS J, TEMPLETON D, QUINONES-MATEU M, ARTS E
OBJECT OF STUDY: Aminooxypentane (AOP)-RANTES, an analog of the chemokine RANTES(Regulated upon Activation Normal T-cell Expressed and Secreted), is a potent inhibitor of CCR5-tropic (R5) viral replication. However, concentrations of AOP-RANTES approximately 100-fold greater than IC50 values for inhibition (IC50 = 0.2 – 1.5 nM) result in a breakthrough of viral replication. A similar, but greater stimulation is seen in CXCR4-tropic (X4) virus that is not inhibited by the drug. This study investigated the mechanisms responsible for the breakthrough and stimulation of HIV-1 replication of R5 and X4 viruses, respectively.
METHODS: PBMC were treated with different concentrations (313 nM, 125 nM, 12.5 nM, and 0.31 nM) of AOP-RANTES and tested for HIV-1 replication by radioactive RT assay. PCR and RT-PCR were used to determine the level of the drug effects upon the viral lifecycle at entry, reverse transcription, and transcriptional activation. Activation of MAPK/ERK pathway was determined by western blot for phosphorylated ERK-1,2 and nested PCR was used to determine integration of HIV-1.
RESULTS: No significant effects were found at the levels of viral entry, reverse transcription, or transcriptional activation. Additionally, FACS and RPA (RNase Protection Assay) experiments showed that AOP-RANTES had little or no effect upon receptor expression. However, western blots of PBMC treated with 125 nM AOP-RANTES showed activation of the MAPK/ERK pathway, which was blocked by the MEK inhibitor PD98059 and Pertussis Toxin. This activation corresponded to an increased frequency of integrated HIV-1 in AOP-RANTES treated PBMC.
CONCLUSIONS: Breakthrough and stimulation of HIV-1 in AOP-RANTES treated cells may be caused by an activation of the MAPK/ERK signaling pathway that affects the viral lifecycle after reverse transcription and before cellular transcription as displayed by the increase in successful viral integration.
The 1st. IAS Conference on HIV Pathogenesis and Treatment
Abstract no.
76
Suggested Citation
"MAROZSANA, et al.
MECHANISMS FOR STIMULATION OF HUMAN IMMUNODEFICIENCY VIRUS TYPE-1 REPLICATION BY AOP-RANTES.
Oral Presentation:
The 1st. IAS Conference on HIV Pathogenesis and Treatment
:
Abstract no.
76"
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