Inhibition of ABC transporters abolishes antimony resistance in Leishmania Infection.
The emergence of antimony (Sb) resistance has jeopardized the treatment of visceral leishmaniasis in various countries. Previous studies have considered the part played by leishmanial parasites in antimony resistance, but the involvement of host factors in the clinical scenario remained to be investigated. Here we show that unlike infection with Sb-sensitive (Sbs) Leishmania donovani, infection with Sb-resistant (Sb r) L. donovani induces the upregulation of multidrug resistance-associated protein 1 (MRP1) and permeability glycoprotein (P-gp) in host cells, resulting in a nonaccumulation of intracellular Sb following treatment with sodium antimony gluconate (SAG) favoring parasite replication. The inhibition of MRP1 and P-gp with resistance-modifying agents such as lovastatin allows Sb accumulation and parasite killing within macrophages and offers protection in an animal model in which infection with Sb r L. donovani is otherwise lethal. The occurrence of a similar scenario in clinical cases is supported by the findings that unlike monocytes from SAG-sensitive kala-azar (KA) patients, monocytes from SAG-unresponsive KA patients overexpress P-gp and MRP1 and fail to accumulate Sb following in vitro SAG treatment unless pretreated with inhibitors of ABC transporters. Thus, the expression status of MRP1 and P-gp in blood monocytes may be used as a diagnostic marker for Sb resistance and the treatment strategy can be designed accordingly. Our results also indicate that lovastatin, which can inhibit both P-gp and MRP1, might be beneficial for reverting Sb resistance in leishmaniasis as well as drug resistance in other clinical situations, including cancer.
Department of Immunology, Indian Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, WB, India.
Jayati
J
Mookerjee Basu
Ananda
A
Mookerjee
Rajdeep
R
Banerjee
Manik
M
Saha
Subhankar
S
Singh
Ksudiram
K
Naskar
Gayetri
G
Tripathy
Prabhat K
PK
Sinha
Krishna
K
Pandey
Shyam
S
Sundar
Sanjeev
S
Bimal
Pradip K
PK
Das
Soumitra K
SK
Choudhuri
Syamal
S
Roy
D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000818:Animals; D000967:Antimony Sodium Gluconate / Q000494:pharmacology*; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D045744:Cell Line, Tumor; D006224:Cricetinae; D004351:Drug Resistance; D006801:Humans; D007194:India; D007893:Leishmania donovani / Q000187:drug effects*; D007898:Leishmaniasis, Visceral / Q000188:drug therapy / Q000469:parasitology; D017737:Macrophages, Peritoneal / Q000469:parasitology; D008647:Mesocricetus; D051379:Mice; D008807:Mice, Inbred BALB C; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism
D018528:ATP-Binding Cassette Transporters; D000967:Antimony Sodium Gluconate; D000981:Antiprotozoal Agents; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C421109:multidrug resistance-associated protein 1