Protective effect of forphenicinol, a low molecular weight immunomodifier, against infection with Pseudomonas aeruginosa in mice and its mechanisms

The oral administration of forphenicinol increased the survival rate of both normal and immunodepressed mice intraperitoneally or intratracheally infected with clinically isolated strains of Pseudomonas aeruginosa. The therapeutic effect of amikacin on intraperitoneal infection with P. aeruginosa was enhanced by combined use with forphenicinol. Forphenicinol did not enhance the bactericidal activity of polymorphonuclear cells (PMN) towards P. aeruginosa in vitro, but enhanced it in vivo. In vitro study indicated that the macrophages taken from mice treated with forphenicinol or the cultured supernatant of these macrophages enhanced the bactericidal activity of PMN. The protective effect of forphenicinol against P. aeruginosa infection was thus suggested to be due to macrophage activation followed by the enhancement of the bactericidal activity of PMN.

[Generation of superoxide anion by the reaction of bleomycin-Cu (II) with cysteine]

We examined if superoxide anions would be produced when bleomycin-Cu (II) were incubated with cysteine under an aerobic condition. Strong reductions of cytochrome c and nitroblue tetrazolium chloride were observed when 0.065 mM bleomycin-Cu (II) and 0.1 mM cysteine were incubated. Neocuproine, which binds specifically with Cu (I), inhibited the reduction of both agents, while superoxide dismutase inhibited only the reduction of nitroblue tetrazolium chloride. These results suggest that cytochrome c is directly reduced by the cuprous ion released from bleomycin-Cu (II) in a reducing reaction with cysteine and nitroblue tetrazolium chloride is reduced by the superoxide anion formed in the reaction of the cuprous ion with oxygen.

Enhancement of interleukin 1 and interleukin 2 releases by ubenimex

The effect of ubenimex on the release of interleukin 1 (IL-1) and interleukin 2 (IL-2) from immuno-competent cells was studied. Ubenimex enhanced release of IL-1 from mouse peritoneal macrophages at 1.0 and 100 micrograms/ml in vitro and the release at 1.0 microgram/ml was larger. When ubenimex was administered to mice IL-1-releasing activity of the peritoneal macrophages was enhanced 3 and 5 days after the administration but not enhanced 1 day after the administration. Ubenimex also enhanced IL-2 release from rat spleen cells at 0.1 and 10 micrograms/ml, when concanavalin A (Con A) was added in the IL-2-releasing system. The enhancement was still observed with mouse spleen cells, when serum was further added. Moreover, thymocyte-proliferating activity was attained in the broths which rat spleen cells were incubated with ubenimex from 0.1 to 10 micrograms/ml in the absence and presence of Con A.

The nature of thiol-compounds which trap cuprous ion reductively liberated from bleomycin-Cu(II) in cells

Bleomycin-Cu(II) [BLM-Cu(II)], which does not cause DNA strand breaks in vitro, exhibits antitumor activity in vivo. The copper in BLM-Cu(II) is reductively removed in vivo, and the liberated Cu(I) is trapped by intracellular thiol-proteins, thus yielding metal-free BLM. The bioactive species of BLM appears to be the iron-complex. For characterization of the thiol-proteins, thiol-compounds such as dithiothreitol (DTT), cysteine, metallothionein (MT) and alcohol dehydrogenase (ADH) were examined for their ability to trap Cu(I) liberated from BLM-Cu(II). BLM-Cu(II) was incubated at 37 degrees C with the thiol-compounds anaerobically for 1 hour followed by aerobic incubation for 10 minutes. Under these conditions DTT converted BLM-Cu(II) to metal-free BLM, but cysteine did not. However, in the presence of MT, cysteine gave metal-free BLM. The Cu(I) liberated from BLM-Cu(II) by cysteine was trapped by MT with accompanying liberation of Zn(II) and Cd(II) from MT. A part of the liberated Zn(II) formed the complex with the metal-free BLM. Metal-free BLM was also formed from BLM-Cu(II) by combined treatment with cysteine and ADH. BLM-Cu(II) was aerobically incubated with cytosol of MT-induced rat liver at 37 degrees C for 1 hour, and the mixture was analyzed with Sephadex G-75 column chromatography. The amount of copper in the MT fraction was increased concomitant with decrease of the Zn(II) and Cd(II). These results suggest that MT, ADH and other thiol-compounds, which have polythiol ligands, act as Cu(I)-trapping agents to yield metal-free BLM in cells.

Dissociation between serine proteinases and proline related enzymes in spleen of MRL mouse as a model of systemic lupus erythematodes

We investigated the changes in the activities of proteases and other hydrolytic enzymes in spleens of MRL mice as a model of systemic lupus erythematodes (SLE). Although there are various abnormalities in the activities of proteases in the spleens of such animals, a multivariate study helped to extract two important components. The first component, representing the activities of serine proteinases, tended to decrease with advancing age in MRL mice but not in control animals. The second component, representing Pro-IP and prolyl endopeptidase, tended to decrease with advancing age in control animals, but not in the MRL mice. The discrepancy between these two components may be related to the immunopathologic disturbances in this model.

Nucleotide sequence of the streptomycinphosphotransferase and amidinotransferase genes from Streptomyces griseus

Genes for streptomycin phosphotransferase and inosamine-P-amidinotransferase from a streptomycin-producing Streptomyces griseus were cloned on a 3.8kb BamHI-SphI fragment in S. lividans using the multicopy cloning vector pIJ702. The nucleotide sequence of this 3.8kb fragment was determined and the coding sequences for the two genes were identified by comparison with the amino-terminal sequences of the two enzymes purified from S. lividans clones.

Effect of forphenicinol on the production of lipopolysaccharide-induced interferon and tumor necrosis factor and on the growth of Meth A fibrosarcoma in mice

Oral administration of forphenicinol stimulated the production of lipopolysaccharide (LPS)-induced interferon (IFN) in mice up to 21-fold over control when given more than 10 days before the elicitation. The IFN production in mice sensitized with bacillus Calmette-Guerin (BCG) 14 days before LPS injection was further augmented by forphenicinol given after BCG. In addition to the IFN production, forphenicinol increased production of LPS-induced tumor necrosis factor (TNF) in mice sensitized with BCG, and the dose of LPS required to induce TNF was reduced by the drug. Furthermore, forphenicinol augmented the antitumor effect of BCG and LPS on Meth A fibrosarcoma.

Relative deficiency of serine proteinase activities in spleens of aged mice

We examined the relation of hydrolytic enzymes in spleen to the aging process in mice over a period of 30 months. When the enzymatic activities were expressed as activities per milligrams protein, those of serine proteinases and dipeptidyl peptidase IV (Gly-Pro-AP) significantly decreased with age, whereas that of L-leucine aminopeptidase (Leu-AP) increased significantly. However, when expressed as total activities, the enzymatic activities in spleen generally tended to increase with age, except in the case of serine proteinases, because of the age-related increase in spleen weight. The results were taken to indicate that the activities of serine proteinases become relatively more deficient in the spleen as age increases. The results of a multivariate study maintained this peculiarity of serine proteinases in comparison with other enzymes. The relative deficiency of serine proteinases in spleen may be somehow related to immunodeficiency in aged animals, as judged from similar findings in animal models of systemic erythematodes.

Induction of antitumor resistance to mouse leukemia L1210 by spergualins

Spergualin and its analog, 15-deoxyspergualin showed a marked antitumor effect against L1210 by intraperitoneal and oral administrations. After treatment with these substances 40- or 60-day survivors (cured mice of L1210) were resistant to reinoculation of L1210 cells. They were resistant only to L1210. The antitumor effector cells in these mice were determined to be T cells. NK activity of spleen cells was also enhanced by spergualins. The antitumor activity of 15-deoxyspergualin was markedly reduced in immuno-deficient mice. IL (interleukin)-2 production, but not IL-1, was enhanced in supernatant of mixed lymphocyte cultures by treatment with 15-deoxyspergualin. The mechanism of action of 15-deoxyspergualin on the immune system was discussed.

Antitumor activity of spergualin, a novel antitumor antibiotic

Spergualin (SGL), a novel antitumor antibiotic, exhibited strong antitumor activity against transplantable leukemias in mice: L1210, L1210(IMC), P388, P815, C1498, EL-4 and RL male 1. It also exhibited antitumor activity against M5076 fibrosarcoma, AH66 and AH66F rat hepatomas, but not against Meth-A fibrosarcoma, B16 melanoma, Lewis lung carcinoma (LL) and C26 colon adenocarcinoma. The antitumor activity of SGL was administration-schedule dependent. The strongest activity against L1210 was obtained by ip continuous infusion for 7 days or daily ip administration for 9 days. Single ip injection of SGL at 100 mg/kg to mice caused convulsion and death within 15 minutes after injection. Such acute toxicity was not observed by continuous infusion. SGL showed its strongest activity at subtoxic dose against sensitive tumors except for L1210(IMC). Mice implanted ip with L1210(IMC) were cured by treatment with SGL at 3.13 mg/kg/day for 9 days, but died from the tumor at 50 mg/kg/day X 9. The cured mice rejected a second inoculation of up to 10(6) tumor cells. The tumor cells isolated from mice after treatment with the high dose showed resistance to SGL in vivo. Mice implanted sc with L1210(IMC) were also cured by 9 daily ip administrations of SGL at 12.5 mg/kg/day, but solid tumor was observed at the implantation site until 3 days after the final injection of SGL in some cured mice. These results suggest that the therapeutic effect of SGL has a relatively high specificity for leukemias and that the immunological effect is involved in the antitumor activity.

Relation of hydrolytic enzymes in spleen to immunological dysregulation in mice

In order to know the role of hydrolytic enzymes in various immunological disturbances, we compared the enzymatic changes in the spleens of nude mice and NZB/W mice relative to their respective controls. In spite of the different immunological features of these models, multivariate analysis demonstrated that there is some commonness in enzymatic changes between the two models. The enzymes related to such commonness included glycosidases, alkaline phosphatase, fMet-AP, and esterase. These enzymes may play some important roles in immunologic dysregulation , especially in relation to B-cell dominance in these disease models.

Effects of o-phenanthroline, 2,2'-dipyridyl and neocuproine on the activities of bleomycin to inhibit DNA synthesis and growth of cultured cells

Effects of o-phenanthroline, 2,2'-dipyridyl and neocuproine, which form stable complexes preferentially with Fe(II), Fe(II) and specifically with Cu(I), respectively, on the inhibitory activity of bleomycin against DNA synthesis of rat ascites hepatoma AH66 cells were examined. The inhibitory activity of metal-free bleomycin was suppressed in the presence of o-phenanthroline or 2,2'-dipyridyl, but not by neocuproine, though these chelating agents also showed the inhibitory activity against the DNA synthesis of the cells by themselves alone. The activity of bleomycin-Cu(II) was also suppressed by o-phenanthroline, but bleomycin-Fe(II) and bleomycin-Fe(III) exhibited some activities in the presence of o-phenanthroline. The growth inhibitory activity of bleomycin against HeLa cells was also suppressed by o-phenanthroline. From these results, bleomycin-iron complexes were suggested to be responsible to the bleomycin action in cells.