Suppression of late asthmatic response by low-dose oral administration of interferon-beta in the guinea pig model of asthma.

We investigated the anti-asthmatic effects of low-dose oral and subcutaneous administration of interferon-beta (IFN-beta) on an ovalbumin (OVA)-sensitized and challenged guinea pig model of asthma. Subcutaneous administration of IFN-beta suppressed the eosinophil infiltration by 14.2% of the control and the respiratory resistance (Rrs) by 58.2% at 2.0 MIU/kg. Oral administration of IFN-beta inhibited the late asthmatic response (LAR) by suppressing the increase of Rrs by 29% of the control at 1 IU/ml and the eosinophil infiltration into the trachea and lung by 34.6% at the optimum dosage of 10 IU/ml. Both subcutaneous and oral administration could not inhibit the early asthmatic response (EAR). Additionally we found 2',5'-oligoadenylate synthetase (2',5'-OAS) induction by low-dose oral administration (LDOA) of IFN-beta to the same extent as by subcutaneous administration in whole blood in vivo. These data suggest that LDOA of IFN-beta would have some clinical benefit for patients with asthma.

Endogenous gamma interferon produced in central nervous system by systemic infection with Theiler's virus in mice.

Theiler's virus GD VII strain causes acute encephalomyelitis by intracerebral inoculation. We established acute encephalomyelitis in mice by the intravenous (i.v.) inoculation of Theiler's virus GD VII strain. Replication of Theiler's virus injected i.v. could be observed in both the brain and spinal cord of mice, and interferon (IFN)-gamma could be detected in the extracts of brain and spinal cord in parallel with viral replication. Furthermore, by the injection of anti-IFN-gamma monoclonal antibody (mAb) on Day 1 post-infection (p.i.), mortality and virus titres in the spinal cord increased compared with the control mice treated with normal rat globulin. The histological exacerbation of inflammation was observed in spinal cord of anti-IFN-gamma mAb-treated mice. These results indicate that endogenous IFN-gamma, produced locally in the brain and spinal cord of mice through both antiviral action and anti-inflammatory action of IFN-gamma in central nervous system, plays an important role in Theiler's virus infection.

Theiler's virus is eliminated by a gamma-interferon-independent mechanism in the brain.

The intravenous infection of Theiler's virus GD VII strain causes acute encephalomyelitis in infected mice. To determine the cellular mechanism of resistance and interferon (IFN)-gamma-producing cell populations, mononuclear cells isolated from tissues of the brain were analyzed by the flow cytometry method. Antibodies specific for CD3, CD4, CD8, T cell receptor (TCR)-alpha beta, and Asialo GM1 were used to deplete the corresponding cell populations in Theiler's virus-infected mice. CD4+ lymphocytes and CD8+ lymphocytes infiltrated in the brains of infected mice from 5 days postinfection (p.i.). The number of CD3+/TCR-gamma delta+ lymphocytes increased in the brains on Day 6 p.i. The elimination of CD3+ lymphocytes or CD4+ lymphocytes augmented viral replication and suppressed the production of IFN-gamma. The suppression of IFN-gamma production by anti-CD3 monoclonal antibody (mAb) persisted, although the suppression by anti-CD4 mAb was observed only on Day 6 p.i. The depletion of CD8+ lymphocytes as well as TCR-alpha beta+ lymphocytes also augmented the viral replication; however, it did not alter the production of IFN-gamma. Anti-Asialo GM1 antibody had no effect on viral replication and IFN-gamma production. These results indicate that T lymphocytes are important for eliminating Theiler's virus from the brain, CD3+/CD4+/CD8- lymphocytes and CD3+/TCR alpha beta-/CD4-/CD8- lymphocytes would produce IFN-gamma in brain. However, from the result on the experiment of the depletion of TCR-alpha beta+ lymphocytes, the defence mechanisms by T lymphocytes against Theiler's virus would be independent of endogenous IFN-gamma production.

FDG uptake and glucose transporter subtype expressions in experimental tumor and inflammation models.

UNLABELLED: Although FDG uptake is closely related to the expression of the glucose transporter (GLUT) in malignant tumors, such a relationship has not been fully investigated in inflammatory lesions. The aim of our study was to determine the expression of GLUT subtypes in experimental inflammatory lesions and to compare the results with those in malignant tumors in relation to FDG accumulation. METHODS: Rats were inoculated with a suspension of Staphylococcus aureus or allogenic hepatoma cells (KDH-8) into the left calf muscle. Five days after S. aureus inoculation (n = 9) and 14 d after KDH-8 inoculation (n = 11), [(14)C]FDG was injected intravenously and its accumulation in the infectious and tumor tissues was determined as the percentage activity of the injected dose per gram of tissue (%ID/g). The expression of glucose transporters (GLUT-1 to GLUT-5) was investigated by immunostaining the infectious tissues (n = 6) and the tumor tissues (n = 6). Immunohistochemical grading was assessed semiquantitatively by 5 observers. RESULTS: The [(14)C]FDG uptake was significantly higher in the tumor lesion than in the inflammatory lesion (2.04 +/- 0.38 %ID/g vs. 0.72 +/- 0.15 %ID/g; P < 0.0001). The tumor and inflammatory tissues highly expressed GLUT-1 and GLUT-3. The GLUT-1 expression level was significantly higher in the tumor tissue than in the inflammatory tissue (P < 0.05). CONCLUSION: The results based on our models showed a high FDG uptake and high GLUT-1 expression level not only in the tumor lesion but also in the inflammatory lesion. The higher GLUT-1 expression level in the tumor lesion may partially explain the higher FDG accumulation in the tumor than in the inflammatory lesion.

Bleeding induced interleukin-6 decreases blood loss via activation of coagulation.

Hemorrhage is known to induce the production of inflammatory cytokines such as interleukin-6 (IL-6). IL-6 plays an intermediate role as a factor in the activation of coagulation cascade and exerts a lethal effect in sepsis. To examine the effect of endogenous IL-6 on blood loss, we performed four experiments in female ddY mice. Enzyme immunoassay using an uncontrolled hemorrhage model, i.e., 75% tail resection, revealed the production of serum IL-6 (Experiment 1). We also measured cumulative blood loss and survival rate (Experiment 2); measured blood pressure and performed thrombelastogram (TEG) (Experiment 3); and measured plasma thrombin-antithrombin III (TAT) complex levels in two groups, one pretreated with 1 mg of anti-IL-6 monoclonal antibody (mAb), and one with normal rat globulin (NRG) using the same model (Experiment 4). The mAb group showed a significantly higher blood loss than the NRG group. All mice survived for 5 days in both groups. Blood pressure did not differ between either group. The TEG results suggest that administration of anti-IL-6 mAb caused mild suppression of coagulation activation, but did not affect fibrinolysis or platelets. In the mAb group, plasma TAT complex concentrations showed a significant decrease compared with the NRG group. In conclusion, hemorrhage-induced IL-6 may contribute to hemostasis through activation of coagulation, thus reducing blood loss.

A monoclonal antibody against T-cell receptor alpha beta induces endogenous cytokines and prevents mice from a lethal infection with Listeria monocytogenes.

In vivo induction of cytokines by a monoclonal antibody (mAb) against T-cell receptor (TCR) alpha beta and the protective effect induced by the mAb on a lethal infection with Listeria monocytogenes were studied. Injection of anti-TCR alpha beta mAb induced rapid production of endogenous tumour necrosis factor in the spleens, and gamma interferon and interleukin-6 in the blood streams and spleens of mice. Administration of anti-CD4 mAb, anti-CD8 mAb, or anti-Thy1.2 mAb resulted in suppression of anti-TCR alpha beta mAb-induced endogenous cytokine production. Mice were protected against lethal L. monocytogenes infection when treated with anti-TCR alpha beta mAb. The protective effect was not demonstrated in CD4+ cell- or CD8+ cell-depleted mice. These results suggest that anti-TCR alpha beta mAb shows a protective effect on a lethal infection with L. monocytogenes in mice and that the mAb-induced endogenous cytokines might be involved in the effect of anti-TCR alpha beta mAb.

Neuropeptides in the livers of mice during bacterial infections.

Neuropeptides such as substance P (SP) and vasoactive intestinal peptide (VIP) are known to act as immunomodulators. We investigated the induction of SP and VIP in the livers of mice infected with Listeria monocytogenes or injected with Tsukamurella paurometabolum. VIP was detected in the livers of mice after L. monocytogenes infection by an immunohistochemical technique and preproVIP mRNA, which was detected by reverse transcription-polymerase chain reaction (PCR), was induced post infection. However, no SP was detected. In contrast, SP, but not VIP was detected within granulomas in the livers of T. paurometabolum-injected mice, suggesting VIP and SP might be selectively induced in the liver by different bacterial infections.

Protection by dexamethasone from a lethal infection with Listeria monocytogenes in mice.

The effects of dexamethasone (DEX) on a lethal infection with Listeria monocytogenes were studied in mice. Mice were completely protected against the lethal infection when treated with 3.3 mg per kg of DEX. The effect was observed only when DEX was injected before infection. The control mice died from day 3 to day 5 of infection, whereas DEX-treated mice could eliminate L. monocytogenes cells from the organs by day 11 of infection. High titres of endogenous tumour necrosis factor (TNF), interleukin-6 (IL-6) and gamma interferon (IFN-gamma) were induced in the bloodstreams and organs of the drug-free mice. DEX suppressed IL-6 production, but augmented TNF and IFN-gamma production within 24 h of infection, whereas production of all three endogenous cytokines was suppressed in the DEX-treated mice on day 3 of infection when the control mice began to die. These results suggest that DEX shows a protective effect on a lethal infection with L. monocytogenes in mice and that regulation of production of endogenous cytokines might be involved in the effect of DEX.

Detection of high levels of immunoreactive human beta-1 interferon in sera from HIV-infected patients.

We have examined human interferon beta-1 (HuIFN-beta 1) levels in the sera from patients with various diseases by using a newly developed highly sensitive enzyme-linked immunosorbent assay system (ELISA). High levels of HuIFN-beta 1 were detected in the sera from Human Immunodeficiency Virus-I (HIV-I) infected patients, especially of asymptomatic carriers. The serum level of HuIFN-beta 1 may be a good indicator of HIV-I infection and of other immunological disorders.

Fluorodeoxyglucose uptake and glucose transporter expression in experimental inflammatory lesions and malignant tumours: effects of insulin and glucose loading.

The expression of glucose transporters (GLUTs) and its relationship to fluorodeoxyglucose accumulation in malignant tumours have been well investigated, while such a relation has not been studied in inflammatory lesions. The aim of the present study was to investigate the effects of insulin and glucose loading on the expression of GLUTs in inflammatory lesions and compare them with those in malignant tumours in relation to fluorodeoxyglucose accumulation. All tissue specimens used in this study were obtained in our previous study, in which rats were inoculated with allogenic hepatoma cells (KDH-8), Staphylococcus aureus, or turpentine oil into the left calf muscle and divided into three subgroups: insulin loaded, glucose loaded, and control groups. The expression of glucose transporters (GLUT-1 to GLUT-5) was investigated by immunostaining the lesions (n=5-6, for each group). In all control groups, the expression levels of GLUT-1 and GLUT-3 were significantly higher than those of GLUT-2, GLUT-4 and GLUT-5. Insulin loading did not significantly affect the expression levels of GLUT-1 and GLUT-3 in these lesions except for a significant but slight decrease in the GLUT-1 expression level in the inflammatory lesion of non-infectious origin (89% of the control value). Glucose loading significantly decreased the expression level of GLUT-1 in the inflammatory lesion of non-infectious origin (70% of the control value, P<0.01), and that of GLUT-3 in the inflammatory lesion of infectious origin (70% of the control value, P<0.05), while the expression levels of GLUT-1 and GLUT-3 in the tumour were not significantly affected. These results demonstrate the effects of insulin and glucose loading on the expression level of a molecule (GLUT proteins). The decreased GLUT-1 and GLUT-3 expression levels induced by glucose loading may partly explain the impaired FDG uptake observed in our previous study.

Pathological changes of experimental polychlorinated biphenyl poisoning in chickens.

Two experiments were carried out to study pathological changes of polychlorinated biphenyl (PCB) "KC 400" poisoning. In them chickens were administered with this agent for a relatively short time. Eleven experimental diets were prepared to contain 11 different PCB concentrations, 4,800 ppm being the highest, respectively. They were given to broiler chickens in initial feeding and later. All the chickens fed 300 ppm and higher concentrations of PCB died, showing the serious dilatation of uriniferous tubules and involution of the bursa of Fabricius, by the time when they reached 12 days of age. All the chickens, except a very few, fed 100 ppm remained alive at the end of the experimental period, when they were 41 days of age and exhibited such edematous changes as hydropericardium. Few chickens fed 50 ppm and less manifested pathological changes until the end of the experimental period, when they were 22 days of age. Two experimental diets were prepared to contain 600 and 200 ppm of PCB, respectively. They were given to layer chickens in initial feeding and later. These layers were sacrificed for autopsy every fourth day. A gain in body weight was retarded mostly in those fed 600 ppm. Dilatation of uriniferous tubules and involution of the bursa of Fabricius began in the very early stage of experimental feeding in both groups. Hydropericardium occurred to many of the chickens fed 200 ppm in the late stage of the experimental period. The results of both experiments indicated that there was no essential difference in changes of PCB poisoning between broiler and layer chickens. The principal changes of the poisoning were dilatation of uriniferous tubules, involution of the bursa of Fabricius, and edematous alterations. They appeared in a relatively early stage of the experimental period of PCB feeding. Their severity was strongly dependent upon the concentration of PCB contained in the diet.

Movement disorders in encephalitis induced by Rhodococcus aurantiacus infection relieved by the administration of L-dopa and anti-T-cell antibodies.

Mice injected with Rhodococcus aurantiacus by the intravenous (i.v.) route show neurological disorders, hemiparesis, vertical headshake and turn-round gait after day 7 postinfection (p.i.). Neurological symptoms caused by i.v. inoculation of R. aurantiacus were relieved by treatment with levodopa (l-dopa). R. aurantiacus was isolated from the brain and was found to be completely eliminated at day 7 p. i. Focal encephalitis was mainly observed in the brain stem, and T cells could be isolated from the brain after day 7 p.i. Administration of both an anti-CD4 monoclonal antibody (mAb) and an anti-CD8 mAb suppressed neurological symptoms. These results suggest that R. aurantiacus induces movement disorders in mice, and that the symptoms are mediated by T cells infiltrating the brain, rather than directly by the bacterium.

CD3+/TCR-alpha beta- cells are important in protecting spinal cord tissues against Theiler's virus strain GD VII infection.

Intravenous infection with Theiler's virus strain GD VII causes acute encephalomyelitis in mice. Endogenous IFN-gamma produced in the spinal cord is important to protect the tissue in mice infected with this virus. Neither CD4+ cells nor CD8+ cells infiltrated the spinal cords of infected mice until Day 9 postinfection. However, the number of CD3+/TCR-gamma delta+ cells increased in the spinal cords of mice infected with the virus. These cells resided in the spinal cords of normal mice, and produced IFN-gamma as a result of stimulation by immobilized anti-CD3 mAb. Elimination of CD3+ cells by the administration of a specific mAb augmented viral replication and suppressed production of endogenous IFN-gamma. Depletion of TCR-alpha beta+ cells and ASGM1+ cells did not affect the viral replication, and did not alter the production of IFN-gamma. Therefore, CD3+/TCR-alpha beta- cells producing IFN-gamma play an important role in the protection of the spinal cord against Theiler's virus infection. These results suggest that CD3+/TCR-alpha beta- cells might be identical to TCR-gamma delta+ cells.

Sequential involvement of NK cells and CD8+ T cells in granuloma formation of Rhodococcus aurantiacus-infected mice.

We investigated the effect of in vivo administration of antibodies against T-cell subsets and natural killer (NK) cells on endogenous gamma interferon (IFN-gamma) production and granuloma formation in Rhodococcus aurantiacus-infected mice. High titers of endogenous IFN-gamma were detected in the extracts of the livers and spleens during 24 hr of the infection, reaching the peak at 8 hr, and the IFN-gamma production was reduced by in vivo administration of anti-NK 1.1 monoclonal antibody (MAb) or antibody against asialo GM1+ cells. Endogenous IFN-gamma declined until 2 days of the infection, then reappeared from 1 week and peaked at 3 weeks. Endogenous IFN-gamma at 1 and 3 weeks was reduced by in vivo administration of anti-CD8 MAb, but not by anti-CD4 MAb or anti-NK 1.1 MAb. Granulomatous lesions in the livers and spleens began to appear from 1 week of the infection and developed in 3 weeks. In vivo administration of rat anti-IFN-gamma MAb reduced the development of granulomas. In addition, granuloma formation was reduced by depletion of NK cells prior to the infection or depletion of CD8+ T cells at 1 week of the infection. Based on these findings, it is presumed that the biphasic production of IFN-gamma is attributable to NK cells in the early phase of the infection and CD8+ T cells in the phase of granuloma formation, and that granuloma formation is regulated by NK cells and CD8+ T cells through the secretion of endogenous IFN-gamma.

Macrophage antigen-1 positive cells are essential in the defense against Theiler's virus strain GD VII infection in the spinal cord.

Acute encephalomyelitis caused by Theiler's virus strain GD VII resembles human poliomyelitis, and T cells are essential in eliminating the virus from the brain, though not from the spinal cord. We speculated that macrophage-lineage cells might play a crucial role in eliminating the virus from the spinal cord. To analyse the role of macrophage-lineage cells in the infection, antibodies specific for beta2 integrin, as well as an anti-leukocyte function antigen 1 (LFA-1) monoclonal antibody (MAb) and an anti-complement receptor type 3 (CR3) MAb were used to deplete the corresponding cell populations in Theiler's virus-infected mice. Infiltration of CD8+ T cells into the brain and spinal cord was inhibited by the administration of the anti-LFA-1 MAb, and viral replication was augmented only in the brain. The number of CD4+ T cells and macrophage antigen-1 (Mac-1[+]) cells in the brain and spinal cord were not decreased by anti-LFA-1 MAb treatment. Anti-CR3 MAb treatment led to decrease of Mac-1(+) cells in the brain and spinal cord. The viral replication in the spinal cord of anti-CR3 MAb treated mice was augmented, but not that in the brain. These results indicate that the defense mechanism against Theiler's virus strain GD VII is dependent on Mac-1(+) cells in the spinal cord.

Reciprocal action of interferon-gamma and interleukin-4 promotes granulomatous inflammation induced by Rhodococcus aurantiacus in mice.

An intravenous injection of Rhodococcus aurantiacus to mice causes granulomatous inflammation dependent on endogenous interferon-gamma (IFN-gamma). The present study examined the role of endogenous interleukin-4 (IL-4) on granulomatous inflammation. Endogenous IL-4 in the spleen extracts was not detected during the phase of granuloma formation by enzyme-linked immunosorbent assay (ELISA). However, IL-4 protein level was elevated during the phase of granuloma regression. IL-4 mRNA expression in the livers and spleens was also elevated during the phase of granuloma regression. In addition, IL-4 levels during the phase of granuloma formation were increased by treatment with anti-IFN-gamma monoclonal antibody (mAb), suggesting that endogenous IFN-gamma might inhibit IL-4 production during the phase of granuloma formation. Administration of anti-IL-4 mAb on weeks 3 and 4 after the inoculation inhibited the regression of granulomas and augumented IFN-gamma level at 5 weeks. Endogenous IFN-gamma was produced by CD4+ T cells during the phase of granuloma regression and endogenous IL-4 was produced by both CD4+ and CD8+ T cells. These findings suggest that during the phase of granuloma formation endogenous IL-4 might be inhibited by IFN-gamma, while during the phase of granuloma regression endogenous IL-4 might play a crucial role in the reduction of granulomas and IFN-gamma production.

Paralysis caused by acute myelitis in Theiler's murine encephalomyelitis virus strain GD VII infection is induced by CD4+ lymphocytes infiltrating the spinal cord.

Intravenous infection by Theiler's murine encephalomyelitis virus strain GD VII causes acute encephalomyelitis and paralysis in infected mice. However, nude mice and cyclophosphamide-treated ddY mice did not show paralysis when they were able to survive until day 20 post-infection (p.i.). Of ddY mice infected with 5 x 10(7) p.f.u./mouse, 70-80% showed symptoms of paralysis on day 20 p.i. The viral titres in the brain and spinal cord in infected mice were not significantly different between paralytic and non-paralytic mice. In all of the mice infected with the virus, CD4+ lymphocytes and CD8+ lymphocytes had infiltrated the brain on days 10, 12, 14 and 20 p.i. as demonstrated by flow cytometric analysis. In contrast, few T lymphocytes infiltrated the spinal cord in the non-paralytic mice. Administration of an anti-CD4 monoclonal antibody (MAb) or anti-T cell receptor-alpha beta MAb on day 6 p.i. inhibited paralysis until day 20 p.i., though 20% of the MAb-treated mice and 80% of the control mice showed paralysis. Administration of anti-CD8 MAb was not effective in the suppression of paralysis. The MAb treatment did not significantly augment viral replication in the spinal cord, although the viral titres in the brain of the MAb-treated mice increased significantly. After the transfer of spleen cells from infected C3H mice, the recipient mice infected with a small amount of the virus showed paralysis, though uninfected mice did not. This transfer could be blocked by CD4+ lymphocyte depletion of the donor mice. These results indicate that paralysis caused by acute myelitis in Theiler's virus strain GD VII infection is induced by CD4+ lymphocytes infiltrating the spinal cord.

Endogenous gamma interferon, tumor necrosis factor, and interleukin-6 in Staphylococcus aureus infection in mice.

The production and roles of endogenous gamma interferon (IFN-gamma), tumor necrosis factor (TNF), and interleukin-6 (IL-6) in both lethal and nonlethal infections of Staphylococcus aureus were investigated in mice. In the case of nonlethal infection, although no bacteria were detected in the bloodstreams, bacteria that colonized and proliferated persistently for 3 weeks were found in the kidneys. All mice given lethal injections died within 7 days, and large numbers of bacteria were detected in the bloodstreams, spleens, and kidneys. The first peaks of IFN-gamma, TNF, and IL-6 were observed in the bloodstreams and spleens of the mice with nonlethal and lethal infections within 24 h. Thereafter, in the nonlethal cases, IFN-gamma, TNF, and IL-6 peaked again in the spleens and kidneys during the period of maximum growth of bacteria in the kidneys, although only IL-6 was detected in the sera. In contrast, in the case of lethal infection, the titers of IFN-gamma and IL-6 in the sera and TNF in the kidneys peaked before death. Effects of in vivo administration of monoclonal antibodies (MAbs) against IFN-gamma and TNF on the fates of S. aureus-infected mice were studied. In the nonlethal infections, anti-TNF alpha (anti-TNF-alpha) MAb-treated mice, but not anti-IFN-gamma MAb-treated mice, died as a result of worsening infection, suggesting that endogenous TNF plays a protective role in host resistance to S. aureus infection. In the mice that received lethal doses, injection of anti-TNF-alpha MAb accelerated death. However, although injection of anti-IFN-gamma MAb inhibited host resistance of the infected mice early in infection, most of the animals survived the lethal infection by injection of anti-IFN-gamma MAb, suggesting that endogenous IFN-gamma plays a detrimental role in S. aureus infection. Thus, this study demonstrated that IFN-gamma and TNF play different roles in S. aureus infection.

Evidence that endogenous gamma interferon is produced early in Listeria monocytogenes infection.

It has been presumed that gamma interferon (IFN-gamma), which plays an essential role in antilisterial resistance, is produced late in Listeria monocytogenes infection. In the present study, however, IFN-gamma was detected in the bloodstreams and spleens of mice from days 1 to 4 of L. monocytogenes infection by both a double-sandwich enzyme-linked immunosorbent assay and an immunohistochemical technique, suggesting that endogenous IFN-gamma is produced early but not late in L. monocytogenes infection.

Transforming growth factor beta is protective in host resistance against Listeria monocytogenes infection in mice.

The role of transforming growth factor beta (TGF-beta) in host resistance against Listeria monocytogenes infection was studied with mice. The constitutive expression of TGF-beta 1 mRNA was observed in the spleens and livers of mice before and after infection. Injecting the mice with anti-TGF-beta 1 peptide serum resulted in diminished antilisterial resistance, whereas the administration of human platelet-derived TGF-beta 1 enhanced the resistance. Moreover, mice were protected against lethal infection when treated with TGF-beta 1. These results suggest the TGF-beta 1 might be involved in antilisterial resistance. On the other hand, injecting the mice with TGF-beta 1 resulted in a decrease in the titers of endogenous gamma interferon, tumor necrosis factor alpha, and interleukin-6, which are crucial in antilisterial resistance, in sera and in extracts of spleen and liver. Thus, a complicated mechanism might be involved in the role of TGF-beta 1 in host resistance against L. monocytogenes infection.