title: Determination of P-glycoprotein surface expression and functional ability after in vitro treatment with darunavir or raltegravir in lymphocytes of healthy donors.
abstract: It has been shown that P-glycoprotein (P-gp) can greatly affect the cell uptake of antiretroviral drugs, thus hampering their access to HIV-1 replication sites. Lymphocytes are important sites of replication of HIV and target of other drugs, modification on these cells of P-gp could have an effect on pharmacokinetic of antiretrovirals and drug substrates. Blood samples from 16 healthy volunteers were used to determine the expression of P-gp on total, T and T helper lymphocytes after exposure to darunavir, a second generation protease inhibitor, and raltegravir, the first approved integrase inhibitor. Moreover, the effect of the drugs on P-gp functional activity was also studied by the rhodamine-123 efflux test. Darunavir, but not raltegravir, exposure caused a moderate, dose-dependent increment in P-gp expression in total, T and T helper lymphocytes, as demonstrated by the relative frequency of P-gp+ cells and by the amount of P-gp molecules present on cell surface. Functionally, incubation with darunavir led to a marked inhibition of P-gp activity measured by the efflux of rhodamine-123 similar to that observed by verapamil, a specific P-gp inhibitor. Raltegravir was not able to modify the efflux of rhodamine-123 level. Data show that darunavir, unlike raltegravir, may modify the expression and functionality of P-gp on human lymphocytes, thus leading to potential changes in intracellular concentrations of darunavir in patients treated with other drugs substrate of P-gp and vice versa. Our study highlights the need for studies on drug interactions via the P-gp modulation mechanism, especially with the current multi-drug regimens.
authors.affiliation: National Institute for Infectious Diseases "Lazzaro Spallanzani" IRCCS, Via Portuense 292, 00149 Rome, Italy. massimo.tempestilli@inmi.it
authors.forename: Massimo
authors.initials: M
authors.lastname: Tempestilli
authors.forename: Elisa
authors.initials: E
authors.lastname: Gentilotti
authors.forename: Chiara
authors.initials: C
authors.lastname: Tommasi
authors.forename: Emanuele
authors.initials: E
authors.lastname: Nicastri
authors.forename: Federico
authors.initials: F
authors.lastname: Martini
authors.forename: Pasquale
authors.initials: P
authors.lastname: De Nardo
authors.forename: Pasquale
authors.initials: P
authors.lastname: Narciso
authors.forename: Leopoldo P
authors.initials: LP
authors.lastname: Pucillo
mesh_terms: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1 / Q000037:antagonists & inhibitors / Q000096:biosynthesis*; D000328:Adult; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D000069454:Darunavir; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D018432:Drug Resistance, Multiple; D024882:Drug Resistance, Viral; D005434:Flow Cytometry; D019428:HIV Integrase Inhibitors / Q000493:pharmacokinetics / Q000494:pharmacology*; D017320:HIV Protease Inhibitors / Q000493:pharmacokinetics / Q000494:pharmacology*; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects* / Q000378:metabolism; D008875:Middle Aged; D011760:Pyrrolidinones / Q000493:pharmacokinetics / Q000494:pharmacology*; D000068898:Raltegravir Potassium; D020112:Rhodamine 123; D013379:Substrate Specificity; D013449:Sulfonamides / Q000493:pharmacokinetics / Q000494:pharmacology*; D055815:Young Adult
chemical_list: D020168:ATP Binding Cassette Transporter, Subfamily B, Member 1; D019428:HIV Integrase Inhibitors; D017320:HIV Protease Inhibitors; D011760:Pyrrolidinones; D013449:Sulfonamides; D020112:Rhodamine 123; D000068898:Raltegravir Potassium; D000069454:Darunavir