Cyclosporin A and its analogs inhibit hepatitis B virus entry into cultured hepatocytes through targeting a membrane transporter, sodium taurocholate cotransporting polypeptide (NTCP)

Abstract

Chronic hepatitis B virus (HBV) infection is a major public health problem worldwide. Although nucleos(t)ide analogs inhibiting viral reverse transcriptase are clinically available as anti-HBV agents, emergence of drug-resistant viruses highlights the need for new anti-HBV agents interfering with other targets. Here we report that cyclosporin A (CsA) can inhibit HBV entry into cultured hepatocytes. The anti-HBV effect of CsA was independent of binding to cyclophilin and calcineurin. Rather, blockade of HBV infection correlated with the ability to inhibit the transporter activity of sodium taurocholate cotransporting polypeptide (NTCP). We also found that HBV infection-susceptible cells, differentiated HepaRG cells and primary human hepatocytes expressed NTCP, while nonsusceptible cell lines did not. A series of compounds targeting NTCP could inhibit HBV infection. CsA inhibited the binding between NTCP and large envelope protein in vitro. Evaluation of CsA analogs identified a compound with higher anti-HBV potency, having a median inhibitory concentration <0.2 μM. Conclusion: This study provides a proof of concept for the novel strategy to identify anti-HBV agents by targeting the candidate HBV receptor, NTCP, using CsA as a structural platform. (Hepatology 2014;59:1726–1737)

Association of Genetic Variation of Sodium Taurocholate Cotransporting Polypeptide with Chronic Hepatitis B Virus Infection

“…Recent studies showed that cyclosporin A and its derivatives, neutralizing antibody against HBV surface protein, and compounds known to inhibit the NTCP transporter activity could inhibit HBV entry using NTCP through interfering with the binding between NTCP and the pre-S1 domain of the HBV large envelope protein (Iwamoto et al, 2014;Nkongolo et al, 2013;Watashi et al, 2013), thus, proposing a novel strategy to identify anti-HBV agents by targeting NTCP. Whether NTCP polymorphisms, including the rs2296651 polymorphism, are relevant to the action of anti-HBV agents targeting NTCP may be a focus of future investigation.…”

Current and future directions for treating hepatitis B virus infection

“…Iwamoto et al [120] , Watashi et al [121] and Tsukuda et al [122] reported that cyclosporine A and its analogs blocked HBV entry through inhibiting the interaction between NTCP and the HBV large surface protein. HBV entry inhibitors might also be useful for controlling HBV infection in the near future.…”

Deciphering the mystery of hepatitis B virus receptors: A historical perspective

“…The other possibility is that after binding of HBV envelope protein with NTCP, the receptor is internalized by endocytosis allowing virus to enter the hepatocyte [72,73]. If virus enters the cells through endocytosis then what would be the signal for internalization and how is that signal generated?…”

“…These includes Myrcludex-B [43], Cyclosporin A (CsA), progesterone, propranolol and bosentan [73]. NTCP substrates, such as taurocholate, tauroursodeoxycholate and bromosulfophthalein, also inhibited HBV infection [43,49,73].…”