Inhibition of P-glycoprotein and multidrug resistance-associated proteins modulates the intracellular concentration of lopinavir in cultured CD4 T cells and primary human lymphocytes

• Published in: Journal of antimicrobial chemotherapy 2007-11, Vol.60 (5), p.987-993
• Main Authors: Janneh, Omar, Jones, Elizabeth, Chandler, Becky, Owen, Andrew, Khoo, Saye H.
• Format: Article
• Language: English
• Subjects: Anti-HIV Agents - metabolism; Anti-HIV Agents - pharmacology; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antiretroviral drugs; antiretroviral transport; ATP-Binding Cassette, Sub-Family B, Member 1 - antagonists & inhibitors; ATP-Binding Cassette, Sub-Family B, Member 1 - genetics; ATP-Binding Cassette, Sub-Family B, Member 1 - metabolism; Biological and medical sciences; CD4-Positive T-Lymphocytes - metabolism; Chemotherapy; Dose-Response Relationship, Drug; Drug resistance; Drug Resistance, Multiple, Viral; Gene Expression Regulation; Glycoproteins; HIV; HIV-1 - drug effects; Human immunodeficiency virus; Human viral diseases; Humans; Immunodeficiencies; Immunodeficiencies. Immunoglobulinopathies; Immunopathology; Infectious diseases; Lopinavir; Medical sciences; Membrane Transport Proteins - genetics; Membrane Transport Proteins - metabolism; MRP1; MRP2; Multidrug Resistance-Associated Proteins - antagonists & inhibitors; Multidrug Resistance-Associated Proteins - genetics; Multidrug Resistance-Associated Proteins - metabolism; P-gp; Pharmacology; Pharmacology. Drug treatments; Protease inhibitors; Proteins; Pyrimidinones - metabolism; RNA, Messenger - genetics; RNA, Messenger - metabolism; Viral diseases; Viral diseases of the lymphoid tissue and the blood. Aids
• ISSN: 0305-7453; 1460-2091
• DOI: 10.1093/jac/dkm353

Background HIV protease inhibitors (HPIs) are an important component of highly active antiretroviral therapy. However, the activity of drug efflux transporters, such as P-glycoprotein (P-gp) and multidrug resistance-associated proteins (MRP1/MRP2), may limit intracellular drug accumulation. Drugs that inhibit the activity of drug efflux proteins may, in combination with HPIs, enhance the clinical efficacy of the drugs. Methods The transport of [14C]lopinavir was evaluated in peripheral blood mononuclear cells (PBMCs) in the absence or presence of known inhibitors: tariquidar (P-gp), MK571 (MRP), frusemide (MRP1/2), dipyridamole (MRP1/P-gp) and probenecid (MRP2/OATP). The effects of ritonavir, amprenavir and atazanavir on the accumulation of lopinavir were also evaluated in cultured CD4+ T-lymphoblastoid cells [CEM (parental), CEMVBL (P-gp-overexpressing) and CEME1000 (MRP1-overexpressing)] and PBMCs. The relative expression of the drug efflux proteins on the PBMCs was assessed by flow cytometric and real-time PCR methods. Results Tariquidar, MK571, frusemide and dipyridamole all significantly increased the intracellular accumulation of lopinavir in the PBMCs, whereas probenecid decreased it. The cellular accumulation ratio (CAR) of lopinavir was also increased by ritonavir, amprenavir and atazanavir in a concentration-dependent manner in both cell types. The expression of P-gp, MRP1 and MRP2 mRNA were variable and individually did not correlate with CARs of lopinavir. Conclusions We provide evidence that lopinavir is a substrate of P-gp, MRP1 and MRP2. The intracellular concentration of lopinavir is increased when co-incubated with ritonavir, amprenavir and atazanavir in PBMCs. Manipulation of drug efflux transporters may be a useful strategy for increasing the intracellular concentration and thereby enhancing the clinical efficacy of lopinavir.