Mitogenic activity of pine cone extracts against cultured splenocytes from normal and tumor-bearing animals

An acidic pine cone extract, Fr. V. of Pinus parviflora Sieb. et Zucc. significantly stimulated DNA synthesis of isolated splenocytes from both mice and rats, but only marginally affected the DNA synthesis of leukemic cell lines. The maximum stimulation level attained by Fr. V slightly exceeded that of plant lectins, whereas much weaker stimulating activity was found in natural and chemically modified antitumor polysaccharides, sialic acid-rich glycoproteins, and polyphenolic compounds such as lignin and tannic acid. In mice with subcutaneously transplanted sarcoma-180, responses of splenocytes against Con A declines in the terminal stage of tumor development, whereas responses against Fr. V remained relatively constant throughout all periods of tumor progression. The suppression of Fr. V activity by acetylation or methylation suggests the importance of the hydroxyl group in the expression of its stimulation activity.

[Controlled prospective trial to evaluate Syosakiko-to in preventing hepatocellular carcinoma in patients with cirrhosis of the liver]

A controlled prospective study was conducted to evaluate the potential of Syo-saiko-to (Xiao-Chai-Hu-Tang) for the prevention of hepatocellular carcinoma (HCC). Pairs of patients were matched for age, sex, presence of HBs antigen and the scores of the severity of liver dysfunction from 260 cirrhotic subjects. We randomly assigned each patient to receive either a conventional medicine (control group), or 7.5 g/day of Syo-saiko-to (trial group). The patients were monitored during 34 months of treatment, and the incidence of HCC in the two groups were compared. Seventeen patients were found to have HCC in the control group, and nine were found to have HCC in the trial group. The incidence of HCC was significantly lower in the trial group. The results of this study suggested that Syo-saiko-to may prevent or delay the emergence of latent HCC in patients with cirrhosis of the liver.

Natural cytotoxicity of human serum. A natural IgM 'antibody' sensitizes transformed murine cells to the lytic action of complement

The natural cytotoxicity of human serum on murine L cells, EA and Sa 180 cells is expressed as a rapid cytolysis at 37 degrees C. This cytotoxic system is analyzed as to its active constituents and their functional relationships. Ultrastructural studies indicate that cell injury and death are initiated within 10 min by membrane disruption. A trypan blue assay for cell death was used to study serum toxicity in individual normal healthy adults, pregnant females and newborn infants. Pregnancy sera, particularly in the 2nd and 3rd trimesters, were consistently more toxic than male serum or nonpregnant females. Cord serum was typically nontoxic. Pools of normal fresh pregnancy serum were used for immunochemical analysis of the cytotoxic activity. By a variety of immunologic and immunochemical techniques it was shown that the cytotoxicity was, in part, due to the combined action of alternative and classical pathways of complement, the former being more prominent. The lytic action of complement was shown to be greatly amplified by the prior adsorption of IgM on the target cells' surface. This IgM is a critical determinant of the cytotoxic reaction. It probably contains a natural 'antibody' to cell surface antigen(s), whose combination activates both pathways of C.

A new immunomodulator, FR-900490

FR-900490 is a new type of immunoactive substance produced by a fungus Discosia sp. F-11809. The colony forming units in culture (cfu-c) in bone marrow cells, which were suppressed by immunosuppressive factor obtained from the serum of sarcoma 180 tumor bearing mouse, was restored to normal level by the addition of FR-900490 in vitro. Furthermore, in mitomycin C (MMC)-treated mice the subsequent administration of FR-900490 caused a significant increase of cfu-c in bone marrow cells depressed by MMC.

Tumor and tissue distribution of 125I-labeled natural and antitumor antibodies in murine experimental tumor systems

The binding and tissue distribution of 125I-labeled rabbit anti-sarcoma 180 (S-180) immunoglobulin G (IgG) (RAS-180G), normal rabbit IgG (NRG) and ICR mouse IgGs from normal (NMG) and S-180-bearing ICR mice (AS-180G) were studied in ICR mice bearing S-180. 125I-labelled IgGs preparted from normal (NC57G) or Adenocarconoma 755 (Ca 755)-bearing C57BL/6 mice (A755G) were also examined in C57BL/6 mice bearing ca755. Not only RAS-180G and AS-180G but also NRG and NMG persisted in the tumor site. This result suggests that allogeneic natural IgG could be used as a carrier protein for antitumor agents.

Combined effects of host antitumor immune responses and chemotherapy. Studies with hexamethylmelamine

The antitumor activity of hexamethylmelamine (HMM) was tested in various mouse tumor models in the presence or absence of host-vs-tumor graft responses. The drug was moderately active against Sarcoma-180 growing in different strains of non-sensitized mice. Strong protection was afforded when recipients were preimmunized with irradiated tumor cells 15 days before tumor challenge followed by HMM treatment. The drug did not show antitumor activity against two radiation-induced lymphomas of congenic mice of B10 background, inoculated into H-2 compatible hosts, or into mice incompatible for subregions of H-2. In this model HMM increased mortality of allogeneic mice presumably through impairment of host-vs-lymphoma graft resistance. In conclusion this study shows that synergistic or antagonistic effects can be obtained by combining chemotherapy with antitumor immune responses.

[Age-dependent anti-tumor activity of lentinan in mice]

During the course of aging, the weight percentage of organs such as kidney to body weight remain almost unchanged, whereas the weight of the thymus decreases significantly. The antitumor activity of Lentinan is constant in mice younger than 1 year (52 weeks). From 52 weeks, aging has a suppressive effect on antitumor activity. Even in aged mice, administration of Lentinan was shown to be effective, and better results were obtained through chronic administration, even with a smaller dose. Lentinan enhanced delayed cutaneous hypersensitivity in aged mice similarly to that in young mice. Thymus homogenate showed synergism with Lentinan in 2-year-old mice for suppression of tumor growth, although thymus homogenate alone showed no effect. These results show that Lentinan is effective as an anticancer immunopotentiator in aged animals in a similar way to young animals.

[Effect of the tumor-bearing host serum on the leukocyte adherence inhibition reaction mediated by immune RNA]

51Cr-labelled leucocyte adherence inhibition (LAI) assay was used as an index to study the activity of xenogenic immune RNA (iRNA) in inducing normal LACA mouse spleen lymphocytes to mediate tumor specific response in vitro. RNA was extracted from the spleen and lymph nodes of the guinea pigs immunized by S180 or H22 ascitic tumor cells and from those of the normal guinea pigs. Extracts of S180 or H22 tumor cells and that of normal LACA mouse livers were prepared by PBS method respectively. Three kinds of RNA and three kinds of cell (tissue) extracts were grouped into nine combinations. A defined number of 51Cr-labelled lymphocytes was added to each group. The results showed that only in the combination of two kinds of iRNA and the corresponding tumor cell extract, adherence of normal lymphocyte was significantly inhibited. Serum from tumor bearing host inhibited LAI reaction mediated by iRNA. The "blocking" effect was specific since it occurred only when the serum and tumor extract in the reaction system were taken from the same tumor-bearing donor.

Participation of tumor killing factor in the antitumor effect of Sarcophaga lectin

Antibody against tumor-killing factor inhibited cytotoxic activities produced in vitro by mouse peritoneal macrophages and in vivo in the serum of tumor-bearing mice in response to Sarcophaga lectin. These results suggest that tumor-killing factor participates in the antitumor effect of Sarcophaga lectin.

Effects of the antitumor agents from various natural sources on drug-metabolizing system, phagocytic activity and complement system in sarcoma 180-bearing mice

Correlation between antitumor activity and effects on some biological properties, such as phagocytic activity of the reticuloendothelial system, the third component of complement (C3) activation, hepatic drug-metabolizing activities and pentobarbital-induced narcosis, of antitumor agents from various natural sources such as B B (Broncasma Berna), GU-P (Grifora umbellata polysaccharide), OK-432, PS-K (Polysaccharide Kureha), and RA-P (Rumex acetosa polysaccharide) were studied with female ICR mice implanted with Sarcoma 180 solid tumor. All of these agents depressed aniline hydroxylase and aminopyrine demethylase activities, prolonged the duration of pentobarbital-induced narcosis, and significantly enhanced the phagocytic activity and C3 activity. Especially, RA-P which has the strongest antitumor activity was the most effective in changing these activities. The biological activities of GU-P at a dose of 10 mg/kg reached the same level as that found with PS-K at a dose of 100 mg/kg. a possible mechanism of inhibition of Sarcoma 180 solid tumor growth by the treatment with the antitumor agents could be interpreted as due to the C3 activation, the stimulation of phagocytic activity and depression of the hepatic microsomal drug-metabolizing system in tumor-bearing mice.

Identification of a mouse serum protein increased by administration of an antitumor polysaccharide, PSK, as a variant of mouse transferrin and some of its biological activities

One of the so-called LC components, the content of which is increased in the serum of PSK (antitumor polysaccharide) treated mice, was purified by repeated ion-exchange column chromatography on DEAE-Sephadex A-50. The purified protein, designated as LC-2, was identified as a variant of mouse transferrin, which is a serum beta 1-globulin having an iron-binding capacity. The absorption spectrum and ultraviolet circular dichroism (CD) curve of LC-2 were identical with those of mouse transferrin. The molecular weight, isoelectric point and amino acid composition of LC-2 were in good agreement with the results obtained previously for mouse transferrin. However, the carbohydrate content of LC-2 was different from that of mouse transferrin. This protein restored the depressed spleen cell response of tumor-bearing mice to concanavalin A (Con A) and promoted the metabolism of proteose-peptone induced peritoneal macrophages obtained from tumor-bearing mice. Furthermore, it had weak but definite antitumor activity against Sarcoma 180 cells in vivo.

Rapid tumor regression and induction of tumor-regressing activity in serum by various immune-modulating agents

A rapid decrease in the number of tumor cells from S180 tumors was caused by several antitumor polysaccharides including the beta (1-3)glucans lentinan and TAK-N and a mannoglucan MGA, but not by those lacking antitumor activity. MGA was demonstrated to induce potent tumor-regressing activity in the serum of tumor-bearing mice similar to that reported previously to be induced after an injection of CM-TAK, a carboxymethylated beta (1-3)glucan. It is probable that the induction of rapid regression of established tumors is a phenomenon common to antitumor polysaccharides and some microbiological products and that the tumor-regressing factor in the serum underlies a common mechanism.

Cytotoxicity of cortisone-resistant lymphocytes from mice treated with a group A streptococcus or Freund's complete adjuvant against tumor cells

The cortisone-resistant lymphocytes (CR lymphocytes) of mice treated with a group A streptococcus, Su strain, or Freund's complete adjuvant (FCA) were examined for their cytotoxicity on Ehrlich carcinoma cells and sarcoma-180 cells. Female mice of the ddY strain, 7-8 weeks of age, were injected subcutaneously with streptococci or FCA in emulsion, and they were killed 14 days later. To obtain CR lymphocytes, mice treated with and without agents were injected intraperitoneally with hydrocortisone acetate (125 mg/kg) 2 days before killing. Tumor cells and CR lymphocytes from thymus, spleen or mesenteric lymph node were suspended in Hanks balanced salt solution supplemented with 2% bovine albumin. The cytotoxicity of CR lymphocytes on tumor cells was examined by the Winn test: Tumor growth was observed in mice inoculated s.c. with the mixture of tumor cells (T) and CR lymphocytes (L) at a T/L ratio of 1/10 (10(6) tumor cells/mouse). The mesenteric and thymic CR lymphocytes of mice treated with streptococci or FCA were more effective than the corresponding lymphocytes of untreated mice in suppressing the tumor growth in animals given the cell mixture. This suggests that the treatment of mice with streptococci or FCA results in an enhancement in the cytotoxicity of mesenteric and thymic CR lymphocytes against the tumor cells.

Studies of an immunomodulator, swainsonine. I. Enhancement of immune response by swainsonine in vitro

Swainsonine isolated from Metarhizium sp., was found to enhance the activities of the mouse immune system in vitro. Concanavalin A stimulated lymphocyte proliferation and proliferative response in mixed lymphocytes culture, which were suppressed by immunosuppressive factor obtained from serum of sarcoma 180 tumor bearing mouse, were restored to normal levels by the addition of swainsonine. Furthermore, the concanavalin A induced incorporation of [3H]thymidine into mouse spleen cells was remarkably increased by treatment with swainsonine over a wide dose range, From studies using fluorescence activated cell sorting, swainsonine was shown to enhance the expression of concanavalin A receptors of spleen cells.

Increased translocation of bacteria from the gastrointestinal tracts of tumor-bearing mice

Aerobic gram-negative bacilli and other indigenous gastrointestinal (GI) bacteria are important opportunistic pathogens in immunosuppressed cancer patients. These same bacteria frequently translocate from the GI tracts of mice immunosuppressed by single injections of certain anticancer drugs or by T-lymphocyte impairments. Since similar cellular and humoral immune deficiencies may be present in the tumor-bearing host, we sought to determine if progressive growth of a tumor alone would be sufficient to enhance the translocation of indigenous bacteria from the murine GI tract. Pathogen-free DBA/2 mice were injected intraperitoneally with 10(6) viable sarcoma 180 (S-180) cells or 0.5 ml of sterile buffer. Mesenteric lymph nodes, livers, spleens, and kidneys were tested for the presence of translocated aerobic GI bacteria on various days after tumor injection. Immunity was assessed by measuring footpad delayed-type hypersensitivity and serum hemagglutinins to sheep erythrocytes. Overall, translocated aerobic GI bacteria infected 33 of 92 S-180-bearing mice (36%) and only 9 of 99 control mice (9%) (P less than 10(-6)). Cumulatively, 50 of 460 sites (10.9%) in S-180-bearing mice were infected with translocated GI bacteria as opposed to only 9 of 485 sites (1.9%) in control animals (P less than 10(-7)). GI bacteria often translocated to infect more than one site in tumor-bearing mice, but not in controls. Aerobic gram-negative bacilli translocated 11 times in tumor-bearing mice, but only once in controls, even though the mean cecal population levels of these bacteria were relatively low (range, 4.33 to 5.28 log10 bacteria per g). The population levels of cecal aerobic bacteria were similar in S-180 and control mice throughout the period of observation. S-180 mice had significantly suppressed (P less than 0.04) delayed-type hypersensitivity and serum hemagglutinin responses when sensitized 4 or 8 days after S-180 injection. S-180 growth was associated with a neutrophilic leukocytosis and a slight drop in platelet counts; no bleeding was detected. Thus, the translocation of gram-negative bacilli and other indigenous aerobic bacteria from the GI tract to the mesenteric lymph nodes and other organs was increased in immunosuppressed S-180-bearing mice, and this increase was not caused by bacterial overgrowth in the intestines or by neutropenia.

Effect of a polysaccharide fraction from Grifola frondosa on immune response in mice

The biological and immunomodulating activities of polysaccharide fraction (GF-1), an antitumor poysaccharide fraction from cultured fruiting bodies of Grifola frondosa, was examined in mice. GF-1 showed no cytocidal effect on culturing tumor cells. However, GF-1 induced resistance against Sarcoma 180 in ICR mice which had completely regressed from the tumor by the effect of GF-1. The administration of GF-1 into mice increased the weights or cell numbers of spleen, and peritoneal cavity. GF-1 enhanced the antigen specific antibody response and carbon clearance activity, whereas GF-1 did not show polyclonal B cell activation and mitogenic activities, and the effect on delayed type hypersensitivity.

[Antitumor activity of Lactobacillus casei YIT 9018 (LC 9018)--effect of administration route]

Antitumor activity of lactobacilli on Sarcoma 180 was investigated and was shown to be different from strain to strain. In general, Lactobacillus casei had higher antitumor activity compared with other species of lactobacilli. Among these, L. casei YIT 9018 (LC 9018) had significant antitumor activity against Meth A fibrosarcoma when administered into BALB/c mice intravenously, intraperitoneally, subcutaneously, intratumorally or orally. LC 9018 showed antitumor activity against rat ascites hepatoma by intravenous or oral administration, but this activity was lower than that against Meth A in mice.

Depression of resistance against Salmonella infection in sarcoma 180-bearing mice and its restoration by Salmonella mini-cells

The reduction of resistance against Salmonella infection was resulted from the reduction of macrophage activities in Sarcoma 180-bearing mice. Mean survival day of S180-bearing mice was markedly reduced to 1.4 +/- 0.5 days after the challenge with 1 X 10(8) of Salmonella typhimurium LT2 cells in contrast with 6.8 +/- 1.9 days of normal mice. Eighty percent of S180-bearing mice died within 14 days after the challenge with 1 X 10(6) of LT2 cells, whereas all of normal mice survived more than 30 days after the challenge with 3 X 10(6) or less of LT2 cells. Chemotactic and O2- producing activities of macrophages collected from S180-bearing mice which were treated with Salmonella mini-cells restored to normal level. Bactericidal activity of macrophages was also restored by the mini-cell treatment. The restoration of the resistance to Salmonella was accompanied with increases of macrophage activities.

Studies on the mechanisms of action of the immunomodulator Bestatin in various screening test systems

The effects of Bestatin, a low molecular weight metabolite of Streptomyces olivoreticuli on the human and mouse/rat immune system, have been studied in detail. To describe the activity of the immunomodulating dipeptide, it has been tested in vitro, ex vivo and in vivo in various experimental models. Bestatin simultaneously applied with selected antigens to mice was able to enhance the DTH response against a challenge injection of the respective antigen given into the footpad. Serum antibody levels against those antigens were uneffected. However, an increase of PFC could be found in those mice given high doses of Bestatin. On natural killer cell activity against Yac-1 tumor cells the dipeptide had no effect in low responder (DBA2/J) mice. In high responder mice (CBA/JCr), however, a significant increase of NK cell activity of spleen cells could be found, when the drug was given on day 0 or on days 0 to 3 and the test was performed on day 4. Bestatin had no effect on the generation of allogeneic cytotoxic T-lymphocytes in vivo or in vitro and even a suppressive effect on the induction of syngeneic antitumor CTL. Contrary to this suppressive effect, Bestatin increases in the popliteal lymph node assay the weights in a dose-dependent way. When mouse macrophages or human monocytes were either incubated in vitro with Bestatin or mice were treated with the dipeptide parenterally or orally and the macrophages from those mice were investigated, Bestatin induced in vitro and in vivo a dose-dependent increase in pinocytic uptake of radioactive colloidal gold. Also the oxidative metabolism was dose-dependently augmented as measured by chemiluminescence. Bestatin modulates the macrophage mediated cytotoxicity. In vitro or in vivo activated mononuclear phagocytes exhibited a dose-dependent increase in cytotoxic activity for several tumor target cells. A minimum ratio of 50:1 effector to target cells was necessary for this cytotoxic effect. A similar degree of activation was observed in macrophages from athymic nu/nu-mice or from endotoxin resistant C3H/HeJ-mice. Other parameters of macrophage activation were determined by measuring secretion of lysosomal enzymes and liberation of prostaglandins. Bestatin interacts with macrophages in vivo and in vitro by increasing their secretory activity of acid hydrolases (beta-glucuronidase, beta-galactosidase, and N-acetyl-beta-D-glucosaminidase). This release was dose- and time-dependent and not associated with any sign of cell death. Another class of mediators produced by macrophages after stimulation with Bestatin were the prostaglandins E2 and F2a.(ABSTRACT TRUNCATED AT 400 WORDS)