P1-15-01: Oral Fluoropyrimidine (UFT and S-1) May Augment the Efficacy of Aromatase Inhibitor Via the Down-Regulation of Estrogen Receptor in Estrogen-Responsive Breast Cancer Xenografts

Breast cancer patients has tended to be more personalized by biomarkers, such as estrogen receptor (ER), HER-2 and other risk factors. Adjuvant endocrine therapy is recommended for all ER-positive breast cancer patients, and the addition of adjuvant chemotherapy to endocrine therapy has been shown to further improve the prognosis of ER-positive breast cancer patients. Addition of an oral fluoropyrimidine, UFT was shown to improve the outcome of patients with luminal A cancer. Based on these studies, the present preclinical study was designed to evaluate a new combination therapy comprised of the aromatase inhibitor anastrozole (ANA) and the oral fluoropyrimidines, UFT and S-1 against luminal A human breast cancer cell line MCF-7/Arom 14, which was stably transfected with the cDNA of human aromatase. MCF-7/Arom 14 cells showed a high aromatase activity (111.6±69.6 fmole/mg protrin/hr) in vivo. Testosterone failed to induce cell growth of parent MCF-7. But, MCF-7/Arom 14 cells were potentiated by both testosterone and E2 in vitro, and ANA and 5-fluorouracil (5-FU) inhibited cell growth at concentrations of 0.005 to 10 and 0.2 to 5 μM, respectively. The combination of 5-FU and ANA additively inhibited cell growth. MCF-7/Arom 14 was implantable in vivo, but it failed to grow in he absence of E2 or testosterone releasing pellet (Tes-P). The growth of MCF-7/Arom 14 was significantly inhibited by ANA and S-1 or UFT alone vs Control (Tes-P alone) in vivo. The combination of ANA with S-1 or UFT administered using a 21-day consecutive, metronomic-like regimen. On day 22, relative tumor volume (RTV) treated by ANA and UFT or ANA and S-1 was significantly lower than either mono-therapy by Welch's t-test. Based on RTV change the period required for the RTV to reach 3 was estimated, and its differences between control was designated as growth delay period (GDP). GDP of combination-therapy was 2 to 4 times longer than either mono-therapy.

Identification of thymidylate synthase as a potential therapeutic target for lung cancer

Background:

Thymidylate synthase (TS), a key enzyme in the de novo synthesis of thymidine, is an important chemotherapeutic target for malignant tumours including lung cancer. Although inhibition of TS has an antiproliferative effect in cancer cells, the precise mechanism of this effect has remained unclear.

Methods:

We examined the effects of TS inhibition with an RNA interference-based approach. The effect of TS depletion on the growth of lung cancer cells was examined using colorimetric assay and flow cytometry.

Results:

Measurement of the enzymatic activity of TS in 30 human lung cancer cell lines revealed that such activity differs among tumour histotypes. Almost complete elimination of TS activity by RNA interference resulted in inhibition of cell proliferation in all tested cell lines, suggestive of a pivotal role for TS in cell proliferation independent of the original level of enzyme activity. The antiproliferative effect of TS depletion was accompanied by arrest of cells in S phase of the cell cycle and the induction of caspase-dependent apoptosis as well as by changes in the expression levels of cyclin E and c-Myc. Moreover, TS depletion induced downregulation of the antiapoptotic protein X-linked inhibitor of apoptosis (XIAP), and it seemed to activate the mitochondrial pathway of apoptosis.

Conclusion:

Our data provide insight into the biological relevance of TS as well as a basis for clinical development of TS-targeted therapy for lung cancer.

Interaction of suplatast tosilate (IPD) with chloride channels in human blood eosinophils: a potential mechanism underlying its anti-allergic and anti-asthmatic effects

INTRODUCTION

Alterations in chloride ion channels have been implicated in the induction of changes in cell shape and volume. Because blood and tissue eosinophilia are hallmarks of bronchial asthma, in this study we examined the role of chloride channels in the underlying effects of suplatast tosilate (IPD), an anti-allergic drug, in human blood eosinophils.

METHODS

Eosinophils were isolated and purified from the blood of allergic asthmatic donors. Chloride ion currents were recorded using the whole-cell patch-clamp technique in freshly isolated eosinophils. The current-voltage relationship of whole-cell currents in human blood eosinophils was calculated and recorded. The effect of chloride channel blockers was examined on superoxide release, eosinophil chemotaxis as measured by the Boyden chamber, and eosinophil adhesion to endothelial cells. Radioligand binding studies with [3H]IPD and competition curves with chloride channel blockers were performed.

RESULTS

IPD increased both inward and outward chloride currents in human blood eosinophils. IPD in 1 ng/mL did not have significant effect on chloride current. However, at 5 ng/mL IPD activated both outward and inward currents in human blood eosinophils. Chloride channel blockers inhibited IPD-induced respiratory burst in eosinophils, eosinophil chemotaxis, and eosinophil adhesion to endothelial cells. All these effects of IPD on chloride current and the resultant functional responses in human blood eosinophils were not due to its basic salt, p-toluenesulphonic acid monohydrate. Human blood eosinophils contained specific binding sites for [3H]IPD with K(D) and B(max) values of 187.7+/-105.8 nm and 58.7+/-18.7 fmol/10(6) cells, respectively. Both NPPB and DIDS competed, in a dose-dependent manner, for the specific binding of [3H]IPD in human blood eosinophils.

CONCLUSION

These data suggest that the anti-allergic and anti-asthmatic effects of IPD could be due to its interaction with chloride channels in human blood eosinophils.

Role of prostaglandin D2 and E2 terminal synthases in chronic rhinosinusitis

BACKGROUND

Prostaglandin (PG)D(2) and E(2), two major cyclooxygenase (COX) products, are generated by PGD(2) synthase (PGDS) and PGE(2) synthase (PGES), respectively, and appear to mediate airway inflammation.

OBJECTIVE

We sought to determine the role of PGDS and PGES in the pathophysiology of chronic rhinosinusitis (CRS).

METHODS

The study examined the expression of PGDS and PGES in nasal polyps of 22 CRS patients. As controls, uncinate process mucosae were obtained from 12 CRS patients not having nasal polyps and five subjects without sinusitis. Immunohistochemistry and quantitative real-time PCR were used to evaluate the expression.

RESULTS

Both PGDS and PGES were detected in nasal polyps by immunohistochemistry. Significantly greater levels of PGDS mRNA and lesser levels of PGES mRNA were observed in the nasal polyps as compared with uncinate process mucosae, and an inverse correlation between PGDS and PGES expression was observed. Levels of PGDS mRNA in nasal polyps were positively correlated with degree of infiltration by EG2+ eosinophils, whereas the levels of PGES were inversely correlated. Significantly increased levels of PGDS and conversely decreased levels of PGES were observed in asthmatics as compared with non-asthmatics. In addition, PGDS and PGES levels were positively and inversely correlated with the radiological severity of sinusitis, respectively.

CONCLUSIONS

These results suggest that PGDS and PGES display an opposite and important role in the pathophysiology of CRS such as polyp formation, and more specifically, a biased expression of these synthases might contribute to the development of CRS by affecting eosinophilic inflammation.

Effects of a novel antihyperlipidemic agent, S-2E, on the blood lipid abnormalities in homozygous WHHL rabbits

To improve mixed hyperlipidemia in the low-density lipoprotein (LDL) receptor-deficient state, suppression of very-low-density lipoprotein (VLDL) particle production may be an important approach. We previously reported that S-2E, (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl] methoxybenzoic acid, suppressed VLDL particle production by inhibiting the biosynthesis of both sterol and fatty acids in the liver. We therefore examined whether S-2E lowered the blood cholesterol and triglyceride (TG) levels simultaneously in homozygous Watanabe heritable hyperlipidemic (WHHL) rabbits, which correspond to human familial hypercholesterolemia. S-2E given orally at doses of 30 to 300 mg/kg significantly lowered serum total cholesterol (TC) levels at 1 week as well as TG at 2 weeks, and the lowering of TC and TG levels by S-2E reached a maximum at 3 to 4 weeks. In contrast, oral administration of pravastatin at doses of 10 to 100 mg/kg resulted in a significant suppression of TC levels (100 mg/kg) but not TG levels. Further analysis of the TC content in fractionated serum of control and S-2E-treated animals showed that suppression of TC level by S-2E is attributable to a decrease in the proportions of VLDL, intermediate-density lipoprotein (IDL), and LDL. It is, therefore, reasonable to assume that S-2E may be useful to improve the blood lipid abnormalities in the LDL receptor-deficient state.

The roles of IL-4, IL-5 and mast cells in the accumulation of eosinophils during allergic cutaneous late phase reaction in mice

Late phase allergic response has been implicated in the pathogenesis of allergic diseases. In the current study, we investigated the role of IL-4, IL-5 and mast cells in the development of cutaneous late phase reaction (LPR) in mice. Antigenic challenge of ears of ovalbumin (OVA)-immunized BALB/c mice caused a biphasic ear swelling peaking at 1 hr (immediate phase reaction; IPR) and 24 hr (LPR). Ear swelling in LPR was significantly suppressed by the treatment with anti-IL-4 monoclonal antibody (mAb) before antigen challenge. Local eosinophil accumulation during LPR, however, was not inhibited by anti-IL-4 mAb. Moreover, anti-IL-5 mAb had no effect on the swelling response though it significantly suppressed the local accumulation of eosinophils. Interestingly, mast cell-deficient mice (WBB6F1-W/Wv) developed LPR without exhibiting IPR, while the magnitude of ear swelling and local eosinophilia was significantly lower than in normal congenic mice (+/+ mice). The present findings show that IL-4 and IL-5 differently regulate the development of LPR, and that IgE-mediated mast cell activation is required for full response.

The expression of murine cutaneous late phase reaction requires both IgE antibodies and CD4 T cells

BACKGROUND

Exposure of atopic patients to a specific allergen evokes an immediate response which is followed, in many cases, by a late phase reaction (LPR) some hours later. Here we have examined the immunological mechanisms required for the expression of cutaneous LPR in mice.

METHODS

BALB/c mice were immunized by i.p. injection of ovalbumin (OVA) and alum actively or by i.v. injection of anti-OVA IgE monoclonal antibody (mAb) passively. After challenge by intradermal injection of OVA into ears, the changes in ear thickness, the number of eosinophils, and the levels of IL-4 and IFN-gamma protein at the site of antigen challenge were examined.

RESULTS

Actively immunized mice developed a biphasic response at the site of OVA injection, while mice passively immunized with IgE anti-OVA mAb displayed a strong early response but no LPR. Cell transfer experiments using BALB/c nu/nu mice revealed that both OVA-specific IgE mAb and OVA-primed CD4 T cells were required to evoke LPR. Moreover, LPR was associated with increased levels of IL-4 production concomitant with reduced IFN-gamma production and was abolished by pretreatment with anti-IL-4 neutralizing mAb.

CONCLUSION

It is suggested that murine cutaneous LPR against OVA is a type 2 inflammatory response in which both IgE antibodies and CD4 T cells play an obligatory role.

Suplatast tosilate, a new type of antiallergic agent, prevents the expression of airway hyperresponsiveness in guinea pigs

Suplatast tosilate (suplatast) is an antiallergic agent capable of down-regulating the functions of CD4+ T cells. We now investigated the effects of suplatast on the antigen-induced airway hyperresponsiveness and the underlying allergic inflammatory response in sensitized guinea pigs. Animals that had been immunized twice by ovalbumin inhalation on day 0 and day 7 developed an increased airway responsiveness against inhaled acetylcholine 24 h after the ovalbumin challenge on day 14. Suplatast (10 and 100 mg/kg per day) and ketotifen (10 mg/kg per day) given orally from day 0 to day 14 effectively inhibited the expression of airway hyperresponsiveness. They also inhibited the infiltration of eosinophils and macrophages into broncho-bronchiolar walls and lumen. Interestingly, suplatast, but not ketotifen, inhibited the infiltration of lymphocytes including CD4+ T cells. Collectively, these results strongly suggest that suplatast prevents the expression of airway hyperresponsiveness due to the ability to suppress the infiltration of inflammatory cells into lung tissues.

Activated T cells induce interleukin-12 production by monocytes via CD40-CD40 ligand interaction

Previous studies on the production of interleukin-12 (IL-12) have shown that it is released, together with other proinflammatory cytokines, shortly after exposure of phagocytic cells to a variety of pathogens. We here report that IL-12 is also released during the recall response to soluble antigen (Ag) devoid of intrinsic adjuvant activity. We show that activated T cells induce the production of IL-12 by monocytes via a mechanism involving the interaction of T cell-associated CD40 ligand with CD40 on monocytes. The data suggest that Ag presentation on monocytes favors the persistence of type 1 responses.

Down-regulation of Th2 cell-mediated murine peritoneal eosinophilia by antiallergic agents

Local eosinophilia has been linked to the pathogenesis of the inflammatory aspect of allergic diseases. The present study found that co-injection of D10G4.1 (D10) cells, a murine Th2 clone, with conalbumin (CA) into the peritoneal cavity of AKR/J mice increased the number of peritoneal eosinophils. The accumulation of eosinophils reached a maximum level at 24 to 48 hr and was accompanied by a marked increase in the number of neutrophils and a minor increase in the number of mononuclear cells. D10-induced peritoneal eosinophilia was suppressed by administration of either anti-IL-4 and anti-IL-5 monoclonal antibodies in an additive manner or by cyclosporin A (CsA). Interestingly, suplatast tosilate (IPD-1151T), known to be antiallergic agent capable of suppressing IgE synthesis and chemical mediator release, but not disodium cromoglycate, selectively suppressed eosinophil accumulation. Taken together with the observation that CsA and IPD-1151T suppressed IL-4 and IL-5 production by CA-stimulated D10 cells in vitro, the present results strongly suggest that agents capable of down-regulating Th2 cell cytokine production may attenuate allergic inflammation by impairing the recruitment of eosinophils that is mediated by Th2 cells.

Allergen-specific human IgE helper T cell lines derived from patients allergic to Japanese cedar pollen

To study the regulatory mechanism of allergen-dependent human IgE synthesis, Cry j I-specific and interleukin 4 (IL-4)-producing CD4+ T cell lines (SN-4 and SS-12) were established from 2 patients allergic to Japanese cedar pollen who highly expressed IL-4 mRNA in T cells in response to Cry j I stimulation. Upon stimulation of SN-4 and SS-12 cells with Cry j I, IL-4 production, which was observed at the protein and the mRNA levels, was induced in an HLA-DR-restricted manner, using autologous and allogeneic antigen-presenting cells. In addition to IL-4, not only considerable amounts of IL-5 and IL-6 but also very small amounts of IL-2 and interferon-gamma (IFN-gamma) were secreted by SN-4 and SS-12 cells, indicating that they fit into the Th2-like phenotype. The culture supernatant from Cry j I-activated SN-4 cells had the ability to induce IL-4-dependent IgE synthesis, CD23 expression and soluble CD23 release. Moreover, Cry j I-dependent IgE synthesis medated by SN-4 cells derived from 1 patient expressing HLA-DRw8, w9 could be specifically induced in both autologous and HLA-DRw9-matched allogeneic B cell cultures. This IgE induction was inhibited by neutralizing antibodies to IL-4, IL-5 and IL-6, but was not enhanced by anti-IFN-gamma antibody. On the other hand, neither IL-4 production nor IgE synthesis was induced when SN-4 cells were cocultured in the presence of Cry j I with HLA-DRw8-matched or histoincompatible allogeneic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro maturation of human neonatal CD4 T lymphocytes. I. Induction of IL-4-producing cells after long-term culture in the presence of IL-4 plus either IL-2 or IL-12

Recent studies in the mouse have established that IL-4 and IL-12 direct the development of Ag-stimulated naive CD4 T cells into, respectively, type 2 and type 1 Th cells. We report that prolonged exposure of immunologically naive and unstimulated human neonatal CD4 T cells to IL-4 or to IL-4 plus either IL-2 or IL-12 markedly affects their cytokine production on primary stimulation with PMA and ionomycin. IL-4 induces long-term proliferation of neonatal T cells and after 3 wk of culture these are capable of producing high levels of Th1 (IL-2, IFN-gamma) but no Th2 (IL-4, IL-5) cytokines; IL-4-primed cells are homogenously CD45RO-/RA+ and CD31+. After culture in the presence of IL-4 + IL-2 or IL-4 + IL-12, neonatal T cells are enriched in CD45RO+ and CD31- cells and they can produce Th2 as well as Th1 cytokines. In response to primary stimulation with PMA and ionomycin, cells primed with IL-4 + IL-2 produce IL-4, IL-5, and IL-10 and the same levels of IL-2 and IFN-gamma as IL-4-primed cells. Cells primed with IL-4 + IL-12 produce very high levels of both IL-4 and IFN-gamma but no IL-5. Endogenous IFN-gamma that is detected in primary cultures containing IL-4 + IL-12 does not inhibit, but rather enhances, the ability of the cells to produce IL-4. Further analysis of IL-4 + IL-12-primed cells reveals that IL-4 is mainly produced by CD31- cells and that these cells can trigger B cells to synthesize Ig including IgE. Finally, positively selected CD31+ cells remain CD31+ and are poor IL-4 producers after 3 wk of culture with IL-4 + IL-12, suggesting that these two cytokines promote the selective expansion of the small number of CD31- cells that are present in freshly isolated neonatal CD4 T cells.

In vitro maturation of human neonatal CD4 T lymphocytes. I. Induction of IL-4-producing cells after long-term culture in the presence of IL-4 plus either IL-2 or IL-12

Recent studies in the mouse have established that IL-4 and IL-12 direct the development of Ag-stimulated naive CD4 T cells into, respectively, type 2 and type 1 Th cells. We report that prolonged exposure of immunologically naive and unstimulated human neonatal CD4 T cells to IL-4 or to IL-4 plus either IL-2 or IL-12 markedly affects their cytokine production on primary stimulation with PMA and ionomycin. IL-4 induces long-term proliferation of neonatal T cells and after 3 wk of culture these are capable of producing high levels of Th1 (IL-2, IFN-gamma) but no Th2 (IL-4, IL-5) cytokines; IL-4-primed cells are homogenously CD45RO-/RA+ and CD31+. After culture in the presence of IL-4 + IL-2 or IL-4 + IL-12, neonatal T cells are enriched in CD45RO+ and CD31- cells and they can produce Th2 as well as Th1 cytokines. In response to primary stimulation with PMA and ionomycin, cells primed with IL-4 + IL-2 produce IL-4, IL-5, and IL-10 and the same levels of IL-2 and IFN-gamma as IL-4-primed cells. Cells primed with IL-4 + IL-12 produce very high levels of both IL-4 and IFN-gamma but no IL-5. Endogenous IFN-gamma that is detected in primary cultures containing IL-4 + IL-12 does not inhibit, but rather enhances, the ability of the cells to produce IL-4. Further analysis of IL-4 + IL-12-primed cells reveals that IL-4 is mainly produced by CD31- cells and that these cells can trigger B cells to synthesize Ig including IgE. Finally, positively selected CD31+ cells remain CD31+ and are poor IL-4 producers after 3 wk of culture with IL-4 + IL-12, suggesting that these two cytokines promote the selective expansion of the small number of CD31- cells that are present in freshly isolated neonatal CD4 T cells.

IL-12 induces the production of IFN-gamma by neonatal human CD4 T cells

A major difference between "naive" and "memory" or "effector" Th cells is the spectrum of cytokines that they are capable of producing. After stimulation naive cells produce only IL-2, whereas memory cells produce several cytokines including IFN-gamma and IL-4. Using umbilical cord blood-derived CD4 T cells as a source of naive T cells, we first report that these cells are capable of producing large amounts of IFN-gamma when cultured with low concentrations of IL-12. The response is time- and dose-dependent, and it is observed at the protein and mRNA levels. IL-12 also induces neonatal CD4 T cells to produce lymphotoxin but not IL-2, TNF-alpha, or IL-4. The production of IFN-gamma by IL-12-stimulated neonatal T cells is associated with a small but significant T cell activation evidenced by DNA synthesis and by the expression of the activation markers CD25, CD71, and HLA-DR; moreover, it is inhibited by hydrocortisone, cyclosporin A, and transforming growth factor-beta. The response to IL-12 is enhanced and is much more rapid when CD4 T cells are cultured in the presence of accessory cells or of exogenous IL-1, IL-2, or TNF-alpha. Using a three-step culture system, we next show that IL-12 induces the maturation of resting naive CD4 T cells into cells producing both IL-2 and IFN-gamma but not IL-4 upon stimulation with PMA and ionomycin. Endogenously produced IFN-gamma plays a role in this IL-12-induced T cell maturation, as shown by the inhibitory effect of neutralizing IFN-gamma antibodies. Finally, we show that IL-12 supports the production of IFN-gamma during primary stimulation of neonatal T cells via the CD3/TCR complex by means of either immobilized anti-CD3 mAb or superantigen-coated (Staphylococcus enterotoxin B) fixed L cell transfectants expressing HLA-DR. It is suggested that IL-12 is involved in the selection of Th1 type immune responses.

IL-12 induces the production of IFN-gamma by neonatal human CD4 T cells

A major difference between "naive" and "memory" or "effector" Th cells is the spectrum of cytokines that they are capable of producing. After stimulation naive cells produce only IL-2, whereas memory cells produce several cytokines including IFN-gamma and IL-4. Using umbilical cord blood-derived CD4 T cells as a source of naive T cells, we first report that these cells are capable of producing large amounts of IFN-gamma when cultured with low concentrations of IL-12. The response is time- and dose-dependent, and it is observed at the protein and mRNA levels. IL-12 also induces neonatal CD4 T cells to produce lymphotoxin but not IL-2, TNF-alpha, or IL-4. The production of IFN-gamma by IL-12-stimulated neonatal T cells is associated with a small but significant T cell activation evidenced by DNA synthesis and by the expression of the activation markers CD25, CD71, and HLA-DR; moreover, it is inhibited by hydrocortisone, cyclosporin A, and transforming growth factor-beta. The response to IL-12 is enhanced and is much more rapid when CD4 T cells are cultured in the presence of accessory cells or of exogenous IL-1, IL-2, or TNF-alpha. Using a three-step culture system, we next show that IL-12 induces the maturation of resting naive CD4 T cells into cells producing both IL-2 and IFN-gamma but not IL-4 upon stimulation with PMA and ionomycin. Endogenously produced IFN-gamma plays a role in this IL-12-induced T cell maturation, as shown by the inhibitory effect of neutralizing IFN-gamma antibodies. Finally, we show that IL-12 supports the production of IFN-gamma during primary stimulation of neonatal T cells via the CD3/TCR complex by means of either immobilized anti-CD3 mAb or superantigen-coated (Staphylococcus enterotoxin B) fixed L cell transfectants expressing HLA-DR. It is suggested that IL-12 is involved in the selection of Th1 type immune responses.

Suppression of IgE production by IPD-1151T (suplatast tosilate), a new dimethylsulfonium agent: (1). Regulation of murine IgE response

The effect of IPD-1151T, a new dimethylsulfonium compound, on the IgE response was investigated in the mouse system. The oral administration of IPD-1151T to immunized BALB/c mice suppressed the primary IgE antibody response and depressed the elevation of serum IgE levels, whereas the same treatment did not affect the IgG antibody response. The enhanced expression of low-affinity IgE receptor (Fc epsilon RII/CD23) on the spleen cells of immunized mice was also inhibited by IPD-1151T administration. It was further demonstrated from the adoptive transfer experiment that IPD-1151T, administered to hapten-primed B cell donors, but not to carrier-primed T cell donors, exerted its suppressive influence on the hapten-specific secondary IgE antibody response in irradiated syngeneic recipients. Interestingly, IPD-1151T concentration-dependently inhibited the production of interleukin 4 (IL-4) by D10G4.1, known to be a typical Th2 clone. However, IPD-1151T did not suppress the production of IgE and IgG1 by normal splenic B cells stimulated with lipopolysaccharide and IL-4. Moreover, IL-4-induced expression of Fc epsilon RII on normal spleen cells was not inhibited by the agent. These results strongly suggest that the IgE-suppressive activity of IPD-1151T is most likely due to the inhibition of IL-4 production at the T cell level.

Suppression of IgE production by IPD-1151T (suplatast tosilate), a new dimethylsulfonium agent: (2). Regulation of human IgE response

The ability of IPD-1151T to suppress the induction of human IgE synthesis was investigated with an in vitro model of IgE production mediated by an allergen-specific helper T cell line (SN-4) from a patient allergic to Japanese cedar pollen. IPD-1151T induced a concentration-dependent suppression of purified allergen (Cry j 1)-dependent IgE synthesis in autologous B cell cultures mediated by SN-4, without significantly affecting the IgG synthesis. In addition, the production of interleukin 4 (IL-4) by Cry j 1-activated SN-4 as well as that by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) of normal donors was inhibited in a concentration-dependent manner by the agent. Interestingly, IPD-1151T clearly depressed PHA-induced expression of IL-4 mRNA in normal PBMC, indicating that this agent inhibits IL-4 gene transcription. However, IPD-1151T had no antagonistic action on IL-4, since neither IL-4-induced expression of low-affinity IgE receptor (Fc epsilon RII/CD23) on normal B cells nor soluble Fc epsilon RII release from IL-4-stimulated B cells was affected by the agent. On the other hand, IPD-1151T had no effect on the production of interferon-gamma by both Cry j 1-stimulated SN-4 and anti-CD3 monoclonal antibody-activated T cells of normal donors. These results suggest that the selective suppression of IgE synthesis by IPD-1151T results from the inhibition of IL-4 production by T cells at the gene level.

Recombinant interleukin-12 suppresses the synthesis of immunoglobulin E by interleukin-4 stimulated human lymphocytes

Interleukin-12 is a recently discovered lymphokine displaying an array of in vitro activities suggesting a major role in protective immunity against infectious agents like viruses. This study provides evidence that IL-12 may also be implicated in the selection of the immunoglobulin isotypes. We show that picomolar concentrations of rIL-12 markedly inhibit the synthesis of IgE by IL-4-stimulated PBMC. The suppression of IgE is observed at the protein and at the mRNA levels, it is isotype specific, and it is abolished by neutralizing anti-IL-12 mAbs. IL-12 may suppress IgE synthesis by: (a) inducing the production of IFN-gamma, a known inhibitor of IgE synthesis and (b) by a novel mechanism which is IFN-gamma independent. The best evidence for this is from studies on IgE synthesis by IL-4-plus hydrocortisone-stimulated umbilical cord blood lymphocytes, which do not produce detectable amounts of IFN-gamma. In such cultures, rIL-12 inhibits IgE synthesis even in the presence of a large excess of neutralizing anti-IFN-gamma mAb.

Establishment of a sensitive radioimmunoassay for the detection of human IgE-binding factor (soluble CD23)

A monoclonal antibody (mAb) specific to low-affinity receptor for IgE (FceRII/CD23) was established by the fusion of spleen cells of BALB/c mice immunized with the FceRII+ human B lymphoblastoid cell line (RPMI 8866) with mouse myeloma P3U1. Four mAbs, 10/3 (IgG1), 11/4 (IgG1), 12/2 (IgG2b) and 15/6 (IgM), almost completely inhibited the IgE binding to FceRII+ cells but not to FceRII- cells. More directly, they were demonstrated to react only with 43-kD component/FceRII of the cell lysate of RPMI 8866 cells by sodium dodecyl sulfate polyacrylamide gel electrophoresis and Western blot analysis. Since they have a different epitope specificity, a solid-phase radioimmunoassay (RIA) for the measurement of IgE-binding factor (IgE-BF) was established. It was found that the RIA with the use of 10/3 and 125I-labeled 11/4 or 12/2 gave good results in the detection of IgE-BF derived from B cells and monocytes as well as of T-cell-derived IgE-BF. More importantly, serum IgE-BF was also quantitatively measured by this RIA. Although increased serum levels of IgE-BF were observed in atopic patients, serum IgE-BF was decreased rather than increased in patients with very high serum IgE. This phenomenon may be explained by the decreased ability of the patients' B cells to spontaneously release IgE-BF in vitro.

Regulation of in vivo expression of Fc receptors for IgE (Fc epsilon R) on murine lymphocytes. II. Induction of Fc epsilon R and its inhibition in mice immunized with antigen

The induction of Fc receptors for IgE (Fc epsilon R) and its regulation were studied in BALB/c, SJL/J, and nude mice by a flow cytometric assay with the use of homologous monomeric IgE. Immunization of BALB/c mice with alum-absorbed antigen induced a remarkable increase in the expression of Fc epsilon R on spleen cells, whereas no enhancement of the Fc epsilon R expression was observed in SJL/J and nude mice after immunization. This increase was correlated with the elevation of serum IgE levels. However, the IgG antibody response, which is inducible even in SJL/J mice, was not associated with the induction of Fc epsilon R. The enhanced expression of Fc epsilon R in BALB/c mice observed in the primary or secondary IgE antibody response was detected in B cells with B220, surface IgM, and IgD, but not in T cells. The induction of Fc epsilon R in immunized BALB/c mice was inhibited by suppressive factor of allergy isolated from ascites fluids of SJL/J mice inoculated with complete Freund's adjuvant. In addition, both cyclophosphamide and prednisolone had an inhibitory effect on the induction of Fc epsilon R. These results suggest that the Fc epsilon R induction is inhibited not only by suppressive factor of allergy, which is effective in inhibiting the IgE antibody response selectively, but also by some immunosuppressive agents which are capable of suppressing all isotypes.

Regulation of in vivo expression of Fc receptors for IgE (Fc epsilon R) on murine lymphocytes. I. Detection of Fc epsilon R+ lymphocytes by flow cytometry

Homologous monomeric IgE was employed in a flow cytometric assay for the detection of IgE Fc receptors (Fc epsilon R) on mouse lymphocytes. The expression of Fc epsilon R in normal BALB/c mice was detected on splenic and circulating lymphocytes, but not on bone marrow cells. The Fc epsilon R expression was observed in B cells with B220, surface IgM, and IgD, but not in T cells. Infection of mice with Nippostrongylus brasiliensis resulted in a marked increase in the expression of Fc epsilon R on splenic B cells. T cells, however, did not express Fc epsilon R even after N. brasiliensis infection. On the other hand, the Fc epsilon R expression on normal B cells decreased after a simple incubation at 37 degrees C for 24 h, while in the presence of IgE this decrease was inhibited. In contrast, B cells stimulated with interleukin 4 display Fc epsilon R with high densities. Interestingly, IgE enhanced the Fc epsilon R expression induced by interleukin 4, suggesting that both interleukin 4 and IgE may be responsible for an increase in the expression of Fc epsilon R on B cells of N. brasiliensis infected mice.

Histamine and its actions on isolated tissues of lower vertebrates

The response to histamine (Hi) of isolated organs such as the intestinal tract and heart, obtained from certain lower vertebrates, was investigated phylogenetically and compared with the response to acetylcholine (ACh), 5-hydroxytryptamine and epinephrine (Ep). Contractions induced by Hi (10(-4) M) were not noticeable in any of the intestinal strips of fish and amphibians tested, although ACh produced marked contractions in all preparations even at 10(-6) M. Contractile responses of intestinal preparations to Hi were elicited from reptiles, and seemed to be associated with the H1 receptor in many species but not with the H2 receptor. In isolated fish auricles, neither inotropic nor chronotropic responses were produced by Hi. In bullfrogs and in the majority of species, including reptiles and higher classes, a marked positive inotropic response was elicited via H1 or H2 receptors, but in some animals chronotropic effect was less impressive. The effects of ACh and Ep on heart preparations were remarkable in almost all species tested. When the Hi contents in various tissues were studied comparatively, a determinant stage of Hi appearance in the tissue coincided with the stage in which a definite Hi response emerged in isolated organs.

Detection and characterization of IgE-producing cells in patients with clonorchiasis

The ability of peripheral B cells of patients with Clonorchis sinensis infections to secrete IgE spontaneously was investigated in vitro. The de novo synthesis of IgE was observed in unstimulated B-cell cultures of patients. There was a significant relationship between the serum IgE level and the amount of IgE spontaneously secreted by B cells. Pretreatment of patients' B cells with 10 micrograms/ml of rabbit anti-human IgE resulted in the clear suppression of spontaneous IgE synthesis without affecting the IgG synthesis. Their B cells capable of spontaneously secreting IgE were partially sensitive to irradiation with 1,000 rad. The results obtained suggest that such IgE-forming cells may be responsible for at least part of the persistent IgE formation in patients with helminthic infections as well as in those with atopic disease.

Modulation of IgE synthesis by IgE-binding factors released by T cells of asthmatic patients with elevated serum IgE

The culture supernatants of unstimulated T cells (TCS) from asthmatic patients with elevated serum IgE were tested for IgE-binding factors (IgE-BFs) displaying the IgE-potentiating activity. The IgE-BFs were detected by their ability to inhibit the rosetting of RPMI 8866 cells with ox erythrocytes coupled with mouse monoclonal antibody (E-Mab) specific to Fc receptors for IgE (Fc epsilon R). TCS showing the rosette-inhibiting activity significantly enhanced the spontaneous IgE synthesis by B cells of allergic individuals. Interestingly, rosette-inhibiting factors could be removed by absorption with IgE-Sepharose from which they were subsequently eluated with acid buffer, indicating that the rosette inhibition was indeed mediated by IgE-BFs. In addition, such IgE-BFs had affinity for concanavalin A and lost their IgE-potentiating activity after treatment with trypsin and neuraminidase. In contrast, T cells treated with tunicamycin released IgE-suppressing factors capable of inhibiting the IgE-potentiating activity of TCS derived from untreated T cells. On the other hand, the culture supernatants from subpopulations depleted of Fc epsilon R+ T cells but not of Fc gamma R+ T cells contained neither rosette-inhibiting factors nor IgE-potentiating factors, suggesting that IgE-BFs were released by in vivo pre-activated Fc epsilon R+ T cells. With regard to circulating Fc epsilon R+ T cells determined by E-Mab, they were significantly higher in asthmatic patients with elevated serum IgE (0.77 +/- 0.15%) than in normal subjects (0.17 +/- 0.07%) in spite of a very small proportion of T cells bearing Fc epsilon R.

Enhancement of IgE synthesis and histamine release by T cell factors derived from atopic patients with bronchial asthma

Culture supernatants of unstimulated T cells (TCS) derived from normal donors or from atopic patients with bronchial asthma were tested for their ability to regulate the spontaneous IgE synthesis by B cells of normal and atopic subjects. The same TCS were also tested for their influence on the histamine release from leukocytes of house dust mites-sensitive patients. Addition of TCS to B cell cultures from allergic donors induced a dose-dependent increase of the spontaneous IgE production without affecting the synthesis of IgG, IgM, and IgA. The potentiating activity of TCS was observed only in B cell cultures spontaneously producing IgE; TCS were still active on irradiated B cells. The maximal IgE-enhancing activity was observed when TCS were added at the onset of B cell cultures. The supernatants of T cells lysed at day 0 did not contain IgE-potentiating factors. The antigen-induced but not the spontaneous histamine release from leukocytes of house dust mite-sensitive patients was enhanced by pretreatment with TCS from allergic donors. The enhancing activities of TCS on IgE synthesis and on histamine release could be removed by absorption with IgE-Sepharose and subsequently recovered by elution with glycine buffer. The results indicate that T cells of patients with asthma spontaneously release IgE-binding factors capable of increasing both the spontaneous IgE synthesis by B cells and the antigen-induced histamine release.

Selective local anti-inflammatory activity of THS-201, a new intra-articular steroid, in cotton pellet granuloma and monoarticular arthritis

A new steroid, THS-201 was administered locally in one of a pair of inflamed sites and its local anti-inflammatory activity was compared with those of triamcinolone acetonide, methylprednisolone acetate and hydrocortisone acetate. In rats, THS-201 (80 micrograms/pellet) completely inhibited the formation of granulation tissue even after 21 days. In antigen-induced bilaterally arthritic rabbits, THS-201 (2 mg/joint) decreased the swelling of the treated knee joint for more than 24 days, but no such effect was seen in the opposite knee joint. The anti-inflammatory activity of the other steroids employed as reference drugs were weaker than that of THS-201. These results indicate that THS-201 is an anti-inflammatory steroids exclusively acting at the site of administration for a long period, and for this reason it might be suitable for intraarticular application in clinical use.

[Anti-inflammatory effect of THS-201, a new intra-articular steroid]

The effect of THS-201, a new intra-articular steroid, on inflammations was examined using acute, subacute and chronic experimental models, and the antiinflammatory action of THS-201 was compared with those of reference steroids such as triamcinolone acetonide (TA), methylprednisolone acetate (MPA), hydrocortisone acetate (HA) and halopredone (HP). Reference steroids, which were given s.c. or locally, dose-dependently inhibited carrageenin-induced foot-pad edema, sodium carboxymethyl cellulose-induced leukocyte migration, cotton pellet granuloma and carrageenin granuloma pouch in rats. Although the inhibitory effects of reference steroids on such inflammations were unrelated to their administration routes, the inhibitory potency decreased in the following order: TA greater than MPA greater than HA = HP. THS-201 even at a dose of 100 mg/kg had no inhibitory effects on such inflammations when given s.c. By contrast, THS-201 given locally had anti-inflammatory actions: the inhibitory potency of THS-201 in chronic models was higher than that of TA, but was lower in the acute models than that of HA. In antigen-induced arthritis in rabbits, the inhibition of swelling of inflamed joints by intra-articular injection of THS-201 (2 mg/joint) persisted more than 30 days, suggesting that the elimination of THS-201 from the injected site was very slow. In contrast to the finding of reference steroids, THS-201 showed no systemic adverse reactions in all experiments. The results, which are in agreement with the findings of labeled THS-201 into arthritic joints, indicate that THS-201 can strongly inhibit recurrence of inflammation as compared with reference steroids tested.(ABSTRACT TRUNCATED AT 250 WORDS)