SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo - PubMed (original) (raw)

. 2001 Oct 23;98(22):12718-23.

doi: 10.1073/pnas.221375398. Epub 2001 Oct 16.

S Xu, N E Wagner, L Wojcik, J Liu, Y Hou, M Endres, A Palani, S Shapiro, J W Clader, W J Greenlee, J R Tagat, S McCombie, K Cox, A B Fawzi, C C Chou, C Pugliese-Sivo, L Davies, M E Moreno, D D Ho, A Trkola, C A Stoddart, J P Moore, G R Reyes, B M Baroudy

Affiliations

SCH-C (SCH 351125), an orally bioavailable, small molecule antagonist of the chemokine receptor CCR5, is a potent inhibitor of HIV-1 infection in vitro and in vivo

J M Strizki et al. Proc Natl Acad Sci U S A. 2001.

Abstract

We describe here the identification and properties of SCH-C (SCH 351125), a small molecule inhibitor of HIV-1 entry via the CCR5 coreceptor. SCH-C, an oxime-piperidine compound, is a specific CCR5 antagonist as determined in multiple receptor binding and signal transduction assays. This compound specifically inhibits HIV-1 infection mediated by CCR5 in U-87 astroglioma cells but has no effect on infection of CXCR4-expressing cells. SCH-C has broad and potent antiviral activity in vitro against primary HIV-1 isolates that use CCR5 as their entry coreceptor, with mean 50% inhibitory concentrations ranging between 0.4 and 9 nM. Moreover, SCH-C strongly inhibits the replication of an R5-using HIV-1 isolate in SCID-hu Thy/Liv mice. SCH-C has a favorable pharmacokinetic profile in rodents and primates with an oral bioavailability of 50-60% and a serum half-life of 5-6 h. On the basis of its novel mechanism of action, potent antiviral activity, and in vivo pharmacokinetic profile, SCH-C is a promising new candidate for therapeutic intervention of HIV infection.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Structure and receptor-binding properties of SCH-C. (A) The structure of SCH-C. (B) SCH-C inhibits RANTES binding to CCR5. SCH-C was titrated over the concentration range indicated in the presence of [125I]RANTES, and the binding of RANTES to human CCR5 expressed on CHO-cell membranes was measured (■). (C) SCH-C binds with high affinity to CCR5. [3H]SCH-C was titrated over the concentration range indicated; the amount bound to human CCR5 on B550 cells was measured, and the _B_max and _K_D values were calculated from the Scatchard plot (Inset). The value of each assay point is an average of triplicates (●).

Figure 2

Figure 2

SCH-C is a CCR5 antagonist. (A) SCH-C antagonizes the calcium response to RANTES but does not itself induce a calcium signal. SCH-C at the concentrations indicated was added to B-550 cells loaded with the calcium-sensitive dye FURA-2 before addition of RANTES (10 nM). (B) SCH-C inhibits agonist-induced [35S]GTPγS binding to the CCR5 receptor. SCH-C at the concentrations indicated was added to membrane preparations from CHO cells expressing hCCR5 in the presence (●) or absence (○) of MIP-1β (10 nM), and the amount of membrane-bound [35S]GTPγS was determined. (C) SCH-C inhibits chemotaxis induced by MIP-1β. SCH-C (▴) at the concentrations indicated, or the equivalent concentration of DMSO (■), was added to B550 cells in the presence of MIP-1β (0.01 nM), and the extent of cell migration was determined. Spontaneous migration in the absence of chemokine was also measured (●).

Figure 3

Figure 3

SCH-C inhibits HIV-1 entry and replication in vitro. (A) SCH-C inhibits the entry of Env-pseudotyped HIV-1 into U87-CD4-CCR5 cells. SCH-C at the concentrations indicated was added to the cells immediately before infection with HIV-1 pseudotypes containing the envelope glycoproteins of the ADA (⧫) or YU-2 (●) isolates. The extent of infection was determined by measuring luciferase expression 3 days after infection and is plotted as a percentage of that occurring in the absence of inhibitor. (B) SCH-C has no effect on HIV-1 entry via CXCR4. U87-CD4-CCR5 cells (Left) or U87-CD4-CXCR4 cells (Right) were infected with a dual-tropic primary virus, HIV-1 P17 (solid bars) or HIV-1 2073cl.3 (hatched bars), in the presence or absence of SCH-C (1 μM) or AMD3100 (1 μM) as indicated. The extent of infection was determined by measuring p24 antigen production and is plotted as a percentage of that occurring in the absence of inhibitor.

Figure 4

Figure 4

SCH-C inhibits HIV-1 replication _in viv_o. SCID-hu Thy/Liv mice were treated by twice-daily oral gavage with SCH-C at the indicated doses or i.p. with ddI at 50 mg/kg per day. Mice were treated 1 day before inoculation of Thy/Liv implants with 2,000 TCID50 of HIV-1 Ba-L by direct injection, and dosing was continued until implant collection 28 days after inoculation. Antiviral efficacy was assessed by determining cell-associated p24, viral RNA, and MHC class I expression on immature CD4+ CD8+ thymocytes. Asterisks indicate P < 0.050 compared with untreated mice by the Mann–Whitney u test.

Similar articles

Cited by

References

    1. Palella F J, Delaney K M, Moorman A C, Loveless M O, Fuhrer J, Satten G A, Aschman D J, Holmberg S D The HIV Outpatient Study Investigators. N Engl J Med. 1998;338:853–860. - PubMed
    1. Lucas G M, Chiasson R E, Moore R D. Ann Intern Med. 1999;131:81–87. - PubMed
    1. Yerly S, Kaiser L, Race E, Bru J P, Clavel F, Perrin L. Lancet. 1999;354:729–733. - PubMed
    1. Furtado M R, Callaway D S, Phair J P, Kunstman K J, Stanton J L, Macken C A, Perelson A S, Wolinsky S M. N Engl J Med. 1999;340:1614–1622. - PubMed
    1. Michael N L, Moore J P. Nat Med. 1999;5:740–742. - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources