Vol. 36, No. 2
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Feb. 1992, p. 492-494
0066-4804/92/020492-03$02.00/0 Copyright © 1992, American Society for Microbiology
Inhibitory Effects of Polyethers on Human Immunodeficiency Virus Replication MARIKO NAKAMURA,' SETSUKO KUNIMOTO,2 YOSHIKAZU TAKAHASHI,2 HIROSHI NAGANAWA,2 MORITO SAKAUE,l SHIGEHARU INOUE,3 TSUNEYA OHNO,1* AND TOMIO TAKEUCHI2 Department of Microbiology, The Jikei University School of Medicine, 3-254 Nishi-shinbashi, Minato-ku, Tokyo 105,1 Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141,2 and Pharmaceutical Research Laboratories, Meiji Seika Kaisha, Ltd., Yokohama 222,3 Japan Received 19 July 1991/Accepted 29 November 1991
We examined the inhibitory activities of 10 polyether antibiotics on human immunodeficiency virus (HIV) type 1. These compounds caused concentration-dependent inhibition of HIV replication in primary infected cultures of human T-lymphoblastoid H9 cells. The ratio of 50 % effective concentrations for cellular cytotoxicity (MTT assay) to antiviral activity (reverse transcriptase assay) was over 5. Anti-HIV activity was also observed in cultures of monocytic lineage U937 cells chronically infected with HIV. at 37°C and were then inoculated with HIV-1 at a multiplicity
With the identification of human immunodeficiency virus as the etiological agent of AIDS (1, 5), a number of approaches are being explored to develop therapeutic agents for treating this disease. One strategy for the treatment of HIV infection has been to develop compounds that interfere with replication of the virus. Polyethers exhibit selective toxicity against coccidia (16), and they are used as prophylaxis of chicken coccidiosis. We report here the inhibitory effects of polyethers on the ability of HIV-1 to replicate in both lymphoid lineage H9 cells (15) and monocytic U937 cells (2). Monensin, salinomycin, lasalocid, and nigericin were purchased as sodium salts from Sigma Chemical Company. Dianemycin, alborixin, and kijimicin were prepared at the Institute of Microbial Chemistry as sodium salts from cultures of MG250-CF1, M1198-fF29, and MI215-NF3, respectively. SF2361, SF2324, and SF2487 were prepared by the Pharmaceutical Research Laboratories, Meiji Seika Kaisha, Ltd. (Fig. 1). Dextran sulfate (molecular weight, 8,000) was also obtained from Sigma. H9 cells (3 x 106/ml) were pretreated with serial dilutions (100, 33, 11, 3.7, 1.2, and 0.4 ,ugIml) of polyethers for 30 min
of infection of 0.05 in a 96-well plate. The infected H9 cells then diluted to a final concentration of 1.5 x 105/ml. On day 7, viral replication was monitored by reverse transcriptase (RT) assay of culture supernatants (9), and cytotoxicity was examined by MTT (3-4,5-dimethylthiazol-2,5diphenyl tetrazolium bromide) assay (13, 17). At that time, untreated infected cells reached a concentration of 2 x 106/ml. The 50% inhibitory (antiviral) concentrations (IC50s) of 10 different polyethers are listed in Table 1. All of them resulted in concentration-dependent inhibition in this primary assay system and showed HIV-1 inhibitory activity at doses which were noncytotoxic. The ratio of IC50 (MTT) to the 50% effective concentration (EC50) (RT) was at least 5. The cellular viability of identically treated but uninfected cultures was not significantly different from that of infected cultures (data not shown). Chronically HIV-1-infected U937 cells (1.5 x 105/ml) were also seeded into a 96-well plate in the presence of serial dilutions of the polyethers. RT and MTT assays were performed on day 4. The untreated, HIV-1-infected U937 cells reached a concentration of 2 x 106/ml on day 4.
type 1 (HIV-1)
were
TABLE 1. HIV infectivity and cytotoxicitya Compound
Monensin Salinomycin Lasalocid Nigericin Dianemycin SF2361 SF2324 SF2487 Alborixin Kijimicin Dextran sulfate
Acute infection (H9)
EC50 (,g/ml) 4.22 ± 2.6 0.40 ± 0.040 2.37 ± 2.9 0.68 ± 0.46 7.12 ± 4.4 0.64 ± 0.36 >100 0.49 ± 0.18 2.5 ± 1.1 1.63 ± 1.9
IC50 (,ug/ml)
± ± ± ±
13.44 2.8 6.98 2.9 48.80 4.7 14.46 8.0 78.40 ± 4.7 49.10 ± 4.6 >100 7.80 ± 1.3 13.50 ± 3.1 18.62 ± 11
Chronic (U937)
IC5sEC5o
EC50 (4g/ml)
IC50 (,g/ml)
IC5sEC5o
3.18 17.63 20.63 21.26
± ± ± ± ± ± ± ±
± ± ± ±
1.18 3.14
11.01 76.72 >1.00 15.92 5.40 11.41 >100
0.50 0.09
0.25 0.02
0.20 0.02 0.05 0.33 1.10 0.14 1.35 0.49 3.70 0.71 0.03 0.15 0.12 ± 0.04 0.10 ± 0.007 NT
0.59 0.28 1.35 0.40 1.1 2.1 10.1 1.85 0.80 0.55
± +
± ± ± ±
0.19 0.05 0.35 0.007 0 0.14 0.14 0.28 0.28 0.07
6.92 8.32 1.00 1.56 2.73 64.91 6.53 5.79
>100
ANTIMICROBIAL AGENTS AND CHEMOTHERAPY, Feb. 1992, p. 492-494
0066-4804/92/020492-03$02.00/0 Copyright © 1992, American Society for Microbiology
Inhibitory Effects of Polyethers on Human Immunodeficiency Virus Replication MARIKO NAKAMURA,' SETSUKO KUNIMOTO,2 YOSHIKAZU TAKAHASHI,2 HIROSHI NAGANAWA,2 MORITO SAKAUE,l SHIGEHARU INOUE,3 TSUNEYA OHNO,1* AND TOMIO TAKEUCHI2 Department of Microbiology, The Jikei University School of Medicine, 3-254 Nishi-shinbashi, Minato-ku, Tokyo 105,1 Institute of Microbial Chemistry, 3-14-23 Kamiosaki, Shinagawa-ku, Tokyo 141,2 and Pharmaceutical Research Laboratories, Meiji Seika Kaisha, Ltd., Yokohama 222,3 Japan Received 19 July 1991/Accepted 29 November 1991
We examined the inhibitory activities of 10 polyether antibiotics on human immunodeficiency virus (HIV) type 1. These compounds caused concentration-dependent inhibition of HIV replication in primary infected cultures of human T-lymphoblastoid H9 cells. The ratio of 50 % effective concentrations for cellular cytotoxicity (MTT assay) to antiviral activity (reverse transcriptase assay) was over 5. Anti-HIV activity was also observed in cultures of monocytic lineage U937 cells chronically infected with HIV. at 37°C and were then inoculated with HIV-1 at a multiplicity
With the identification of human immunodeficiency virus as the etiological agent of AIDS (1, 5), a number of approaches are being explored to develop therapeutic agents for treating this disease. One strategy for the treatment of HIV infection has been to develop compounds that interfere with replication of the virus. Polyethers exhibit selective toxicity against coccidia (16), and they are used as prophylaxis of chicken coccidiosis. We report here the inhibitory effects of polyethers on the ability of HIV-1 to replicate in both lymphoid lineage H9 cells (15) and monocytic U937 cells (2). Monensin, salinomycin, lasalocid, and nigericin were purchased as sodium salts from Sigma Chemical Company. Dianemycin, alborixin, and kijimicin were prepared at the Institute of Microbial Chemistry as sodium salts from cultures of MG250-CF1, M1198-fF29, and MI215-NF3, respectively. SF2361, SF2324, and SF2487 were prepared by the Pharmaceutical Research Laboratories, Meiji Seika Kaisha, Ltd. (Fig. 1). Dextran sulfate (molecular weight, 8,000) was also obtained from Sigma. H9 cells (3 x 106/ml) were pretreated with serial dilutions (100, 33, 11, 3.7, 1.2, and 0.4 ,ugIml) of polyethers for 30 min
of infection of 0.05 in a 96-well plate. The infected H9 cells then diluted to a final concentration of 1.5 x 105/ml. On day 7, viral replication was monitored by reverse transcriptase (RT) assay of culture supernatants (9), and cytotoxicity was examined by MTT (3-4,5-dimethylthiazol-2,5diphenyl tetrazolium bromide) assay (13, 17). At that time, untreated infected cells reached a concentration of 2 x 106/ml. The 50% inhibitory (antiviral) concentrations (IC50s) of 10 different polyethers are listed in Table 1. All of them resulted in concentration-dependent inhibition in this primary assay system and showed HIV-1 inhibitory activity at doses which were noncytotoxic. The ratio of IC50 (MTT) to the 50% effective concentration (EC50) (RT) was at least 5. The cellular viability of identically treated but uninfected cultures was not significantly different from that of infected cultures (data not shown). Chronically HIV-1-infected U937 cells (1.5 x 105/ml) were also seeded into a 96-well plate in the presence of serial dilutions of the polyethers. RT and MTT assays were performed on day 4. The untreated, HIV-1-infected U937 cells reached a concentration of 2 x 106/ml on day 4.
type 1 (HIV-1)
were
TABLE 1. HIV infectivity and cytotoxicitya Compound
Monensin Salinomycin Lasalocid Nigericin Dianemycin SF2361 SF2324 SF2487 Alborixin Kijimicin Dextran sulfate
Acute infection (H9)
EC50 (,g/ml) 4.22 ± 2.6 0.40 ± 0.040 2.37 ± 2.9 0.68 ± 0.46 7.12 ± 4.4 0.64 ± 0.36 >100 0.49 ± 0.18 2.5 ± 1.1 1.63 ± 1.9
IC50 (,ug/ml)
± ± ± ±
13.44 2.8 6.98 2.9 48.80 4.7 14.46 8.0 78.40 ± 4.7 49.10 ± 4.6 >100 7.80 ± 1.3 13.50 ± 3.1 18.62 ± 11
Chronic (U937)
IC5sEC5o
EC50 (4g/ml)
IC50 (,g/ml)
IC5sEC5o
3.18 17.63 20.63 21.26
± ± ± ± ± ± ± ±
± ± ± ±
1.18 3.14
11.01 76.72 >1.00 15.92 5.40 11.41 >100
0.50 0.09
0.25 0.02
0.20 0.02 0.05 0.33 1.10 0.14 1.35 0.49 3.70 0.71 0.03 0.15 0.12 ± 0.04 0.10 ± 0.007 NT
0.59 0.28 1.35 0.40 1.1 2.1 10.1 1.85 0.80 0.55
± +
± ± ± ±
0.19 0.05 0.35 0.007 0 0.14 0.14 0.28 0.28 0.07
6.92 8.32 1.00 1.56 2.73 64.91 6.53 5.79
>100
