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Higgins PG, Barrow GI, Tyrrell DAJ, Snell NJC, Jones K, Jolley WB. A Study of the Efficacy of the Immunomodulatory Compound 7-thia-8-oxoguanosine in Coronavirus 229E Infections in Human Volunteers. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/095632029100200110] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intranasal 7-thia-8-oxoguanosine (NARI 10146) compared with placebo had no influence on the course of experimental coronavirus 229E infections in human volunteers. Possible reasons are discussed for the failure to confirm successful rodent experiments in man.
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Affiliation(s)
- P. G. Higgins
- MRC Common Cold Unit, Harvard Hospital, Coombe Road, Salisbury, Wilts SP2 8BW, U.K
| | - G. I. Barrow
- MRC Common Cold Unit, Harvard Hospital, Coombe Road, Salisbury, Wilts SP2 8BW, U.K
| | - D. A. J. Tyrrell
- MRC Common Cold Unit, Harvard Hospital, Coombe Road, Salisbury, Wilts SP2 8BW, U.K
| | - N. J. C. Snell
- ICN European Medical Affairs Group, Eagle House, Peregrine Business Park, Gomm Road, High Wycombe, Bucks HP13 7DL, U.K
| | - K. Jones
- ICN European Medical Affairs Group, Eagle House, Peregrine Business Park, Gomm Road, High Wycombe, Bucks HP13 7DL, U.K
| | - W. B. Jolley
- ICN Nucleic Acid Research Institute, ICN Plaza, 3300 Hyland Avenue, Costa Mesa, CA 92626, U.S.A
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2
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Swaggerty C, He H, Genovese K, Duke S, Kogut M. Loxoribine pretreatment reduces Salmonella Enteritidis organ invasion in 1-day-old chickens. Poult Sci 2012; 91:1038-42. [DOI: 10.3382/ps.2011-01939] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Colić M, Jandrić D, Gasić S, Vucević D, Popović P, Medić-Mijacević L, Rakić L. Immunosine (7-thia-8-oxoguanosine) acts as a cofactor for proliferation of T cells. Fundam Clin Pharmacol 2000; 14:209-17. [PMID: 15602797 DOI: 10.1111/j.1472-8206.2000.tb00018.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Immunosine (7-thia-8-oxoguanosine) is a novel guanosine analogue showing immunostimulatory activity both in vivo and in vitro. This compound acts on different components of the immune system including B cells, natural killer (NK) cells and antigen-presenting cells (APC). However, its influence on functions of T cells is poorly understood. In this work we studied the effect of immunosine on proliferation of total rat splenocytes and purified T cells triggered by different mitogens and the mechanisms involved. The results demonstrate that immunosine significantly stimulates proliferation of T cells. The effect was dose-dependent and also depended on concentrations of specific stimulators. Maximal stimulation was seen using 250 microM immunosine. The stimulatory effect of immunosine on lymphocyte proliferation triggered by Concanavalin A (Con A) correlated with increased interleukin 2 (IL-2) production and upregulation of the IL-2 receptor alpha (IL-2Ralpha) expression. The dependency of T-cell proliferation on IL-2/IL-2R was confirmed using neutralizing anti-IL-2Ralpha monoclonal antibodies (mAbs). Higher concentrations of immunosine in the presence of optimal concentrations of Con A (5 microg/mL) inhibited proliferation of T cells. A similar stimulatory effect of immunosine on proliferation of purified T cells and IL-2 production was observed using an anti-T-cell receptor (TCR) mAb and a combination of anti-TCR mAb and IL-2. However, the guanosine analogue did not significantly modulate proliferation of T cells triggered by IL-2 alone. When the combination of phorbol myristate acetate (PMA) and ionomycin was used for T-cell stimulation different results were obtained. Under lower cell stimulation immunosine significantly potentiated T-cell proliferation, expression of IL-2Ralpha and IL-2 production. In the presence of suboptimal stimulation the compound stimulated T-cell proliferation and IL-2Ralpha expression, whereas under maximal stimulation an enhancing effect on IL-2 production was seen. Since direct stimulatory effect of immunosine on T-cell growth in culture was rather weak it can be postulated that the compound acts as a cofactor for T-lymphocyte proliferation.
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Affiliation(s)
- M Colić
- Institute of Medical Research, MMA, Crnotravska 17, 11002 Belgrade, Yugoslavia.
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Colić M, Gasić S, Vucević D, Pavicić L, Popović P, Jandrić D, Medić-Mijacević L, Rakić L. Modulatory effect of 7-thia-8-oxoguanosine on proliferation of rat thymocytes in vitro stimulated with concanavalin A. INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 2000; 22:203-12. [PMID: 10685003 DOI: 10.1016/s0192-0561(99)00077-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
7-thia-8-oxoguanosine (immunosine) is a guanosine analogue showing immunostimulatory activity on different components of the immune system, including B lymphocytes, natural killer cells and macrophages. However, little is known about its effect on T-cell functions. In this work it was demonstrated that immunosine at concentrations between 10 microM and 1 mM stimulated proliferation of rat thymocytes in vitro triggered by suboptimal concentrations of concanavalin A (Con A). The effect correlated with increased interleukin 2 (IL-2) production, upregulation of the IL-2 receptor alpha (IL-2Ralpha) expression and decreased apoptosis of thymocytes in comparison to the effect of Con A alone.
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Affiliation(s)
- M Colić
- Institute of Medical Research, MMA, Crnotravska 17, 11002 Belgrade, Yugoslavia
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Colić M, Gasić S, Vasilijić S, Pejanović V, Jandrić D, Medić-Mijacević L, Rakić L. A nucleoside analogue, 7-thia-8-oxoguanosine stimulates proliferation of thymocytes in vitro. Immunol Lett 1999; 69:293-300. [PMID: 10528791 DOI: 10.1016/s0165-2478(99)00101-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
7-thia-8-oxoguanosine (immunosine) is a nucleoside analogue with immunoenhancing activity. In this work, its effects on proliferation of thymocytes in vitro were studied. It was found that immunosine stimulated proliferation of thymocytes both of mice and rats. The stimulatory effect depended on antigen presenting cells (APC), since thymocytes depleted of accessory cells did not proliferate to immunosine. In addition, pretreatment of APC with immunosine for 24 h significantly increased proliferation of thymocytes. Immunosine stimulated interleukin 2 (IL-2) production and the expression of activation markers (CD25 and CD71). The upregulation of CD25 (alpha subunit of IL-2R) was detected both on thymocytes and thymic dendritic cells. Proliferation of thymocytes in the presence of immunosine was predominantly mediated by IL-2 since blocking IL-2Ralpha by specific monoclonal antibodies inhibited cell proliferation by 65-85%.
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Affiliation(s)
- M Colić
- Institute of Medical Research, MMA, Belgrade, Yugoslavia
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Pope BL, Sigindere J, Chourmouzis E, MacIntyre P, Goodman MG. 7-Allyl-8-oxoguanosine (loxoribine) inhibits the metastasis of B16 melanoma cells and has adjuvant activity in mice immunized with a B16 tumor vaccine. Cancer Immunol Immunother 1994; 38:83-91. [PMID: 8306370 PMCID: PMC11038224 DOI: 10.1007/bf01526202] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/1993] [Accepted: 09/28/1993] [Indexed: 01/29/2023]
Abstract
We have shown previously that loxoribine exhibits adjuvant activity for B cells, activates natural killer (NK) cells, and enhances the activation of lymphokine-activated killer cells by interleukin-2 (IL-2). In this study, we examined loxoribine for protective effects in a B16 melanoma lung tumor metastasis model. Significant inhibition of B16 metastasis was seen in mice given a single injection of 2 mg loxoribine as late as day 3 of tumor growth but the greatest inhibition (96%) was seen in mice given four injections of loxoribine on alternate days starting the day before tumor injection. In experiments in which both IL-2 and loxoribine were administered, both agents were active when tested alone, but the combination of IL-2 and loxoribine gave significantly greater inhibition of metastasis. Loxoribine partially inhibited the development of tumors in mice that had been depleted of NK cells by the administration of anti-asialo-GM1 or anti-NK1.1 antibodies and in NK-deficient beige mice. In all cases, protection was seen only when smaller tumor inocula were injected. Taken together, these data suggest that both NK and non-NK cell populations or effector mechanisms with antitumor activity were activated by loxoribine. Since substituted guanosine analogs have been shown to have adjuvant activity in B cell systems, we evaluated whether loxoribine was active as an adjuvant in a tumor protection model. Mice immunized with both irradiated tumor cells and loxoribine developed a significantly lower number of lung tumors when challenged by live B16 tumor cells, whereas mice injected with either vaccine or loxoribine alone were not protected. There was a clear dose response seen with both loxoribine and the vaccine preparations. These data suggest that loxoribine may be useful in tumor therapy as an immunomodulator or as an adjuvant for use with tumor vaccines.
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Affiliation(s)
- B L Pope
- R. W. Johnson Pharmaceutical Research Institute, Don Mills, Ontario, Canada
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Pope BL, Chourmouzis E, Sigindere J, Capetola RJ, Lau CY. In vivo enhancement of murine natural killer cell activity by 7-allyl-8-oxoguanosine (loxoribine). INTERNATIONAL JOURNAL OF IMMUNOPHARMACOLOGY 1992; 14:1375-82. [PMID: 1464469 DOI: 10.1016/0192-0561(92)90008-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
7-Allyl-8-oxoguanosine (loxoribine) is a novel immunostimulatory compound which has been shown previously to enhance the antibody synthesis of antigen-stimulated B-lymphocytes. In this report, loxoribine was tested for the ability to activate murine natural killer (NK) cells. In studies in which mice were given a single subcutaneous (s.c.) or intravenous (i.v.) injection of loxoribine, splenic NK cell activity was increased in a dose-related manner with clear enhancement seen within 2 h of drug administration. The enhancement was optimal at 48 h but persisted for a minimum of 4 days. Slow and continuous administration of loxoribine via subcutaneously implanted infusion pumps successfully enhanced the NK activity for several days after all of the pump contents had been delivered. Peak NK responses were seen following s.c. or i.v. administration of 2-3 mg loxoribine per mouse in sesame oil, intralipid, or saline vehicles. Significant oral activity was seen after the administration of 8-10 mg/mouse in sesame oil or intralipid. The in vivo enhancement of NK activity was observed in spleen, blood, and bone marrow but was negligible in lymph nodes and thymus. Multiple injections of optimal concentrations of loxoribine did not tend to enhance the NK activity above that seen with a single injection, suggesting that the timing of injections was critical for optimal responsiveness.
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Affiliation(s)
- B L Pope
- R. W. Johnson Pharmaceutical Research Institute, Don Mills, Ontario, Canada
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Tripathi AK, Taplits M, Puri J, Hoffman T. Augmentation of monocyte-mediated antibody-dependent cellular cytotoxicity by protein synthesis inhibitors: evidence for an endogenous regulatory mechanism. Cell Immunol 1991; 134:491-504. [PMID: 2021975 DOI: 10.1016/0008-8749(91)90320-b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Protein synthesis inhibitors, cycloheximide and puromycin, were used in cytotoxic assays employing human peripheral blood monocytes as effectors and sheep erythrocytes as target cells. ADCC could be initiated and could also achieve its full lytic activity in the absence of new protein synthesis. Furthermore, an augmentation of ADCC was observed in the presence of protein synthesis inhibitors. This augmentation was due to an increase in the cytotoxic ability of effector cells rather than a change in the lytic susceptibility of the target. Enhanced cytotoxic potential could not be attributed to an increase in the expression of FcRI but could be due to increased availability of antibody for mediating ADCC as a result of reduced numbers of FcRII. Suppression of prostaglandin-E2 release by monocytes was noted in the presence of cycloheximide, possibly as a result of inhibition of synthesis of cyclooxygenase. However, prostaglandin-E2 and other arachidonic acid metabolites did not appear likely to play a role in negatively regulating human monocyte ADCC since neither cytotoxicity nor cycloheximide-induced augmentation was affected by the presence of exogenous prostaglandin-E2 or arachidonic acid. Cycloheximide was found to induce the secretion of superoxide anions by monocytes, but a role for reactive oxygen species in cycloheximide-induced augmentation of ADCC could not be established by experiments involving the use of catalase or superoxide dismutase. These results raise the possibility that a rapidly turning over protein which negatively regulates monocyte-mediated ADCC exists.
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Affiliation(s)
- A K Tripathi
- Division of Hematology, U.S. Food and Drug Administration, Bethesda, Maryland 20892
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Smee DF, Alaghamandan HA, Gilbert J, Burger RA, Jin A, Sharma BS, Ramasamy K, Revankar GR, Cottam HB, Jolley WB. Immunoenhancing properties and antiviral activity of 7-deazaguanosine in mice. Antimicrob Agents Chemother 1991; 35:152-7. [PMID: 1707603 PMCID: PMC244957 DOI: 10.1128/aac.35.1.152] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The nucleotide analog 7-deazaguanosine has not previously been reported to possess biological (antiviral or antitumor) properties in cell culture or in vivo. Up to 10(5) U of interferon per ml was detected in mouse sera 1 to 4 h following oral (200-mg/kg of body weight) and intraperitoneal (50-mg/kg) doses of the compound. 7-Deazaguanosine also caused significant activation of natural killer and phagocytic cells but did not augment T- and B-cell blastogenesis. Intraperitoneal treatments of 50, 100, and 200 mg/kg/day administered 24 and 18 h before virus inoculation were highly protective in mice inoculated with lethal doses of Semliki Forest or San Angelo viruses. Less but still significant survivor increases were evident in treated mice infected with banzi or encephalomyocarditis viruses. In most cases, the degree of antiviral activity was similar to that exhibited by the biological response modifier 7-thia-8-oxoguanosine. 7-Thia-8-oxoguanosine was more potent than 7-deazaguanosine against encephalomyocarditis virus in mice, however. Oral efficacy was achieved with 7-deazaguanosine treatments of greater than or equal to 100 mg/kg against all virus infections, whereas 7-thia-8-oxoguanosine is reported to be devoid of oral activity in rodents. Thus, 7-deazaguanosine represents the first reported orally active nucleoside biological response modifier exhibiting broad-spectrum antiviral activity against particular types of RNA viruses.
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Affiliation(s)
- D F Smee
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan 84322-5600
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