The feeding of beta-carotene down-regulates serum IgE levels and inhibits the type I allergic response in mice

Feed containing beta-carotene was administered orally to BALB/c mice immunized intraperitoneally with ovalbumin (OVA) for approximately 1 month. The titers of OVA-specific IgE, OVA-specific IgG1 and OVA-specific IgG2a in the mouse sera were determined. The OVA-specific IgE titer and OVA-specific IgG1 titer by mice fed beta-carotene were significantly inhibited. On the other hand, the OVA-specific IgG2a titer in mice fed beta-carotene was significantly greater than those of control mice. The OVA-specific IgE suppression of beta-carotene feeding was dose-dependent. We also examined the effect of fed beta-carotene on active systemic anaphylaxis. Feeding beta-carotene to mice immunized with OVA inhibited the immediate reduction of the body temperature induced by antigen stimulation. Furthermore, the increase in serum histamine in the mice fed beta-carotene under active systemic anaphylaxis was lower than in controls. We then examined the pattern of cytokine production by spleen cells from mice followed by restimulation with OVA in vitro. The spleen cells from the mice fed beta-carotene produced more IFN-gamma, IL-12 and IL-2 than those from the control group. In contrast, the spleen cells from the mice fed beta-carotene produced less IL-4, IL-5, IL-6, IL-10 than those from the control group. Furthermore, analysis of IFN-gamma mRNA levels of the splenocytes using the real-time quantitative RT-PCR technique revealed higher levels in the splenocytes from the mice fed beta-carotene. These findings suggest that feeding beta-carotene improves the helper T cell (T(H))1-T(H)2 balance, inhibiting specific IgE and IgG1 production and antigen-induced anaphylactic response.     

Effect of methotrexate on Th1 and Th2 immune responses in mice

We investigated the effect of the anti-rheumatic drug methotrexate (MTX) on Th1 and Th2 immune responses in mice. For this investigation, mice were immunized subcutaneously at the base of the tail with ovalbumin (OVA) emulsified with complete Freund's adjuvant (day 0). Varying doses of MTX were orally administered daily from days 0 to 20. On day 21, anti-OVA IgG2a and interferon-gamma (IFN-gamma) as indicators of Th1 responses and anti-OVA IgG1 and interleukin-10 (IL-10) as those of Th2 responses were measured. The results showed that treatment with MTX was followed by decreases in OVA-specific IgG and proliferation of spleen cells to the antigen. The anti-rheumatic drug inhibited both anti-OVA IgG2a and IgG1 production, although the inhibitory effect of MTX on the antigen-specific IgG2a production appeared to be greater than that on IgG1 production. IFN-gamma, but not IL-10, secretion was markedly downregulated by MTX. Administration of MTX resulted in suppression of antigen (OVA)-induced arthritis in mice. The suppression of the joint inflammation by MTX was associated with inhibition of OVA-specific proliferative responses of spleen cells, anti-OVA IgG, IgG2a and IgG1 production, and IFN-gamma and IL-10 secretion, although more pronounced decreases in IgG2a and IFN-gamma were observed compared with those in IgG1 and IL-10 in MTX-treated mice. These results indicate that MTX appears to suppress Th1 and, to a lesser extent, Th2 immune responses and its anti-arthritic effect on human rheumatoid arthritis might be at least in part explained by down-regulation of Th1 responses involved in the disease.     

The paradoxical effects of lead in interferon-gamma knockout BALB/c mice.

It has been reported that lead (Pb) exposure enhances interleukin (IL)-4 and inhibits interferon-gamma (IFNgamma) production in wild-type (WT) BALB/c mice. Here, we examined Pb effects on immunity in IFNgamma knockout (KO) mice. Lead significantly enhanced serum IgG1 anti-keyhole limpet hemocyanin (KLH) levels in WT mice compared to the controls; Pb also increased serum IgG2a anti-KLH levels, but the IgG1:IgG2a ratio was greater with Pb. In addition, total serum IgE levels, but not IgE anti-KLH levels, were increased. In the KO mice, the serum IgG1, IgG2a, IgE anti-KLH, and total IgE levels were significantly lower than those of WT mice. Surprisingly, Pb significantly enhanced IgG1 and IgG2a anti-KLH levels in the KO mice. However, for these mice, unlike the WT mice, Pb caused a greater percentage change in IgG2a than in IgG1 anti-KLH, indicating less skewing toward type-2 immunoglobulins. Lead also enhanced the delayed-type hypersensitivity (DTH) response in WT mice. Not surprisingly, very low DTH occurred in the KO mice; however, Pb induced a strong KLH-specific DTH response. The in vivo Pb exposure significantly increased in vitro production of IL-4, IL-5, and IL-10, but not IFNgamma, IL-2 and IL-12, by KLH-induced WT and KO spleen cells. In contrast to KLH, dinitrofluorobenzene contact hypersensitivity (DNFB CHS) was detected in all groups, and Pb did not affect this response, which suggests that Pb has only a slight effect on CD8+ T cell-related responses. As previously reported, Pb enhances Th2 responses in WT mice; however, in the KO mice, Pb enhanced Th1-related anti-KLH production and a Th2-related DTH. The Pb enhancement of DTH in IFNgamma-deficient mice is likely due to promotion of type-2 cytokines and enhancement of major histocompatibility complex (MHC) class II expression.     

Effects of the phosphodiesterase IV inhibitor rolipram on Th1 and Th2 immune responses in mice

The present study was designed to investigate the effect of the phosphodiesterase IV inhibitor rolipram on Th1 and Th2 immune responses in mice. Mice were immunized subcutaneously at the base of the tail with ovalbumin (OVA) emulsified with complete Freund's adjuvant (day 0) and were treated daily with oral administration of various doses of rolipram from days 0 to 20. On day 21, production of anti-OVA IgG and proliferative responses to the antigen were determined. Anti-OVA IgG2a and interferon-gamma (IFN-gamma), as indicators of Th1 responses, and anti-OVA IgG1 and interleukin-10 (IL-10), as indicators of Th2 responses, were also measured. The results showed that treatment with rolipram failed to affect the production of OVA-specific IgG but decreased the proliferation of spleen cells to the antigen. Its inhibitory effect on these immune responses was correlated with a marked decrease in IFN-gamma but not IL-10 production, although neither anti-OVA IgG2a nor IgG1 production was affected by rolipram. These results suggest that rolipram may preferentially inhibit Th1 responses more effectively than Th2 responses. Administration of rolipram resulted in suppression of antigen (OVA)-induced arthritis in mice. The suppression of joint inflammation by rolipram was associated with the inhibition of the OVA-specific proliferative responses of spleen cells and IFN-gamma secretion. These results indicate that rolipram may be effective in regulating Th1-mediated diseases such as rheumatoid arthritis.     

Suppression of Th1 and Th2 immune responses in mice by Sinomenine, an alkaloid extracted from the chinese medicinal plant Sinomenium acutum

The present study was designed to investigate the effect of sinomenine (SIN), an alkaloid extracted from Sinomenium acutum, on Th1 and Th2 immune responses in mice. For this investigation, mice were S. C. immunized with ovalbumin (OVA) emulsified with complete Freund's adjuvant (day 0). Varying doses of SIN were orally administered daily over a period of 21 days, commencing on day 0. On day 21, anti-OVA IgG and proliferative responses of spleen cells to the antigen were measured. Anti-OVA IgG2a and IFN-gamma were measured as indicators of Th1 immune responses and anti-OVA IgG1, IgE, and IL-5 as those of Th2 responses. TGF-beta was measured as an indicator of Th3 immune responses. The results showed that treatment with SIN was followed by decreases in anti-OVA IgG and the antigen-specific splenocyte proliferation. Production of all isotypes of antibodies including anti-OVA IgG2a, IgG1 and IgE as well as secretion of cytokines such as IFN-gamma and IL-5 was suppressed by SIN, although the suppression of anti-OVA IgG2a and IFN-gamma by the alkaloid appeared to be greater than that of anti-OVA IgG1, IgE, and IL-5. In addition, SIN enhanced the secretion of TGF-beta. These results suggest that SIN appears to have suppressive effects on both Th1 and Th2 immune responses. The results also suggest that Th1 responses may be more preferentially suppressed by the Sinomenium acutum-derived alkaloid compared to Th2 responses. TGF-beta may at least in part contribute to the suppression of Th1 as well as Th2 immune responses.     

Oral administration of heat-killed Lactobacillus brevis SBC8803 ameliorates the development of dermatitis and inhibits immunoglobulin E production in atopic dermatitis model NC/Nga mice

We have previously shown that the oral administration of heat-killed Lactobacillus brevis (L. brevis) SBC8803 strain inhibits IgE production in ovalbumin (OVA)-sensitized BALB/c mice through improvement of the type-1 helper T (Th1)/Th2 balance toward Th1 dominance. Atopic dermatitis is one of the most common skin diseases and is frequently associated with elevated immunoglobulin E (IgE) antibodies against many kinds of allergens. In this study, we investigated the inhibitory effect of oral administration of L. brevis SBC8803 on the development of dermatitis and IgE elevation using the NC/Nga atopic dermatitis model mice. Male 8-week-old NC/Nga mice were sensitized by the topical application of picryl chloride to foot pads and shaved abdomen. These mice were boosted with picryl chloride by topical application onto the ears once a week for 9 weeks. The mice (n=10 per group) were fed a diet containing 0%, 0.05% or 0.5% of heat-killed L. brevis SBC8803 from 2 weeks before the first sensitization to the end of the study. Total IgE concentration in serum, clinical score, and ear thickness were periodically examined throughout the study. Finally, cytokine (interleukin (IL)-4, IL-5, IL-6, IL-10, IL-12, IFN-gamma and transforming growth factor (TGF)-beta) productions from splenocytes and Peyer's patch (PP) cells of mice were measured. Oral administration of L. brevis SBC8803 significantly inhibited IgE production and ear swelling, and suppressed the development of dermatitis in a dose-dependent manner. Immunosuppressive cytokines such as IL-10 and TGF-beta production from PP cells significantly increased in the 0.5% group compared to the control group although Th1-type and Th2-type cytokines production was not affected.     

Baicalin inhibits IgG production by regulating Treg/Th17 axis in a mouse model of red blood cell transfusion

This study was conducted to evaluate whether baicalin inhibits red blood cell (RBC) immunization and elucidate the underlying mechanism. We used human RBCs with adjuvant lipopolysaccharide (LPS) and transfused mice to induce antibodies as an experimental system for studying the effect of baicalin on RBC immunization. Mice were divided into a human RBC transfused positive control group administered with human RBC and LPS intravenously once or weekly for 4 weeks, control group administered dexamethasone (DEX) intraperitoneally daily for 4 weeks, and treatment group administered baicalin intraperitoneally daily for 4 weeks. Assessment of human RBC immunization was performed by measuring serum immunoglobulin G (IgG) and immunoglobulin M (IgM) against human RBC weekly. Lymphocyte changes in spleen were monitored by flow cytometry. We found that baicalin treatment significantly decreased serum IgG but not IgM production in a time and does dependent manner, with a concomitant reduction in Th17 cells and increase in CD4 regulatory T cells in the spleen. The percentage of CD4-positive cells in the spleen was not decreased in the baicalin-treated group but was decreased in the dexamethasone-treated group. In conclusion, baicalin inhibited RBC immunization, particularly IgG production by regulating the Treg/Th17 axis without damaging spleen function.     

A newly devised formulation for self-medication enhances interferon-gamma production and proliferation of splenic lymphocytes

A newly devised formulation for self-medication in Toyama, PanaWang, is a new herbal medicine (so called Toyama original brand formulation) developed based on traditional philosophy and scientific evidence. We here tried to examine the effect of oral administration of PanaWang on the balance of type I helper T cells (Th1) and Th2 cells. Splenic lymphocytes from normal mice were stimulated with Concanavalin A (Con A) in vitro and the secretion of Th1- and Th2-type cytokines, interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) respectively, was investigated. Con A-induced production of IFN-gamma from spleen cells, but not IL-4, was enhanced by the administration of PanaWang. Increased production of IFN-gamma was also detected in splenic lymphocytes from Th2-predominant BALB/c mice after DNP-immunization, without a change in antigen-specific IgE levels in vivo. Antigen-specific proliferative responses were also increased in lymphocytes from PanaWang-treated mice. These findings raise the possibility that PanaWang has Th1-stimulating activity and induces Th1-predominant immunity.     

Nivalenol inhibits total and antigen-specific IgE production in mice

Nivalenol (NIV) has been reported to induce hyperproduction of IgA, which is regulated by T-helper 2 cells (Th2); however, whether IgE production, which is under the regulation of Th2 cells, is induced by this compound remains largely unknown. We examined the effect of NIV on antigen-specific IgE production using ovalbumin (OVA)-specific T cell receptor alphabeta-transgenic mice. The mice produced significant amounts of total and antigen-specific IgE, IgG1, and IgA in serum when given OVA orally. Administration of NIV with OVA suppressed total IgE and OVA-specific IgE, IgG1, and IgA production significantly. Cytokine assay using splenocytes obtained from mice given the OVA plus NIV diet revealed that interleukin 4 (IL-4) production was suppressed and interleuin-2 (IL-2) production was enhanced. These results suggest that the inhibition of IL-4 production and enhancement of IL-2 production induced by NIV suppressed total and antigen-specific IgE production.     

Inhibitory effect of chaga mushroom extract on compound 48/80-induced anaphylactic shock and IgE production in mice

Chaga mushrooms (Inonotus obliquus) are hypothesised to exhibit general immune-potentiating, anti-inflammatory, and antitumor properties, but their anti-allergic activities are not fully understood. Therefore, this study investigated whether a chaga mushroom extract (C-HE) might have anti-allergic activity. This activity was assessed through the levels of the IgE Ab produced in response to an allergen (OVA). The administration of C-HE prophylactically inhibited the systemic anaphylactic shock induced by compound 48/80 in mice. The oral administration of C-HE significantly reduced the total IgE levels in mice and slightly affected the production of IgG1. Furthermore, spleen cell cultures harvested from OVA-sensitised mice that had received C-HE orally showed a significant increase in Th1-derived responses (IFN-γ production). Therefore, our results suggest that the chaga mushroom extract may be used as an anti-allergic functional food.     

Differential immunogenic and neurogenic inflammatory responses in an allergic mouse model exposed to low levels of formaldehyde

It is suspected that exposure to low levels of formaldehyde induces or aggravates airway inflammation mediated by immunological and neurological reactions. To clarify the effect of this exposure on allergic inflammatory responses, we exposed female C3H/He mice to 0, 80, 400, or 2000ppb formaldehyde for 12 weeks. When mice were immunized with ovalbumin (OVA) and then exposed to formaldehyde, the numbers of total bronchoalveolar lavage cells, macrophages, and eosinophils in the mice exposed to 2000ppb formaldehyde were significantly increased compared to 0ppb controls. However, the production of interleukin-1beta from bronchoalveolar lavage fluid of these mice decreased significantly. Immunization with OVA significantly increased the production of nerve growth factor, but exposure to 80 and 400ppb formaldehyde significantly reduced the nerve growth factor levels in bronchoalveolar lavage fluid of the immunized mice. In in vitro study, markedly increased lipopolysaccharide-stimulated interferon-gamma production in culture supernatants of spleen cells from 2000ppb formaldehyde-exposed, nonimmunized mice, and significantly increased OVA-stimulated monocyte chemoattractant protein-1 production in culture supernatants of spleen cells from 400 and 2000ppb formaldehyde-exposed, immunized mice were observed. Exposure to 400ppb formaldehyde induced significant decreases in anti-OVA IgG1 and IgG3 antibody productions in plasma, whereas anti-OVA IgE antibody production was not affected. In addition, the levels of nerve growth factor in plasma of 80 and 400ppb formaldehyde-exposed, immunized mice significantly decreased compared to 0ppb control, immunized mice. These results provide the first experimental evidence that low levels of long-term formaldehyde inhalation can induce differential immunogenic and neurogenic responses in allergic mice.     

Oral administration of Bifidobacterium bifidum G9-1 suppresses total and antigen specific immunoglobulin E production in mice

Recent studies have suggested that oral bacteriotherapy with probiotics might be useful in the management of allergic diseases. We investigated the effect of oral administration of Bifidobacterium bifidum G9-1 (BBG9-1) on immunoglobulin (Ig) E production in BALB/c mice. Live BBG9-1 was orally administered to mice for 2 weeks from 1 week before ovalbumin (OVA)-immunization. The treatment of BBG9-1 significantly reduced serum total IgE level. In addition, BBG9-1 significantly and largely reduced the serum level of OVA-specific IgE without lowering of the specific IgG1 and increasing of the specific IgG2a. We also examined T helper type (Th) 1 and Th2 cytokine production from OVA-immunized splenocytes by restimulation with OVA in vitro. Productions of interferon (IFN)-gamma, interleukin (IL)-4 and IL-5 from the splenocytes of mice given BBG9-1 were weaker than those of control mice. We conclude that oral administration of BBG9-1 selectively and powerfully suppresses total and antigen specific IgE production in mice. It is suggested that BBG9-1 is useful for the prophylactic treatment in IgE-dependent allergic diseases.     

Detection of anaphylactic reaction in the percutaneously sensitized mouse using the AW method.

Anaphylactic reactions of mice sensitized percutaneously with 2,4-dinitrofluorobenzene (DNFB) were investigated by the AW method assay, which is a mouse anaphylactic model using the abdominal wall as the site for induction with either 2,4-dinitrophenyl (DNP)-human serum albumin or anti-mouse IgE antibody and then estimation of the response. DNP-specific and IgE-dependent anaphylactic reaction after contact sensitization with DNFB could be induced and detected by the abdominal wall (AW) method assay in both groups with and without previous ear challenge with DNFB. Thus, the anaphylactic reaction in the group of twice-contact with 0.5% DNFB was observed on the 9th day from the sensitization (5th day from the ear challenge), and the reaction in the group of a single contact with 0.5% DNFB was observed 10 d after sensitization. The DNP-specific anaphylactic reaction was observed earlier than the 10th day with higher doses of DNFB. As for the mice of the former twice-contact group, the first and second characteristic ear swelling responses appeared within 1-6 h and 2 d of the ear challenge, respectively, and small swelling was observed 7 d after the challenge. It is suggested that Th1 and Th2 cells are activated at the almost same time, in other words, the preparation for both cell-mediated and humoral immunity could be accomplished to function, in vivo by a single percutaneous sensitization with DNFB.     

Divergent antibody isotype responses induced in mice by systemic exposure to proteins: a comparison of ovalbumin with bovine serum albumin.

Whereas many foreign proteins are immunogenic, only a proportion is associated commonly with allergy, having the potential to induce the quality of immune response necessary for IgE antibody production and the development of immediate type hypersensitivity reactions in the gastrointestinal and/or respiratory tracts. In the context of toxicological evaluations there is a need to identify those properties that confer on proteins the ability to provoke allergic reactions. The characteristics of antibody responses induced in BALB/c strain mice following administration of ovalbumin (OVA), a significant human allergen, have been compared with those provoked by bovine serum albumin (BSA), a protein considered to have more limited allergenic potential. Intranasal or intraperitoneal (ip) administration of BSA or OVA elicited vigorous IgG and IgG1 antibody responses. Differential IgE antibody production was observed, however, with OVA stimulating relatively high IgE antibody titres at all doses tested whereas no or low titre IgE antibody was detected following exposure to BSA. Furthermore, a differential capacity for IgG2a antibody responses was observed, with only BSA provoking high titres of this IgG subclass. The relative quality of induced responses was equivalent following administration of these proteins via mucosal (in) tissue or via a non-mucosal (ip) route of exposure. IgG2a antibody production is promoted by the type 1 cytokine interferon gamma (IFN-gamma), whereas IFN-gamma and the type 2 cell product interleukin 4 exert reciprocal antagonistic effects on IgE antibody responses. Although cytokine expression patterns were not analysed in this series of experiments, the differential IgE and IgG subclass antibody responses induced by BSA and OVA are consistent with the preferential activation of T helper (Th) 1- and Th2-type cells, respectively. These data indicate that proteins can provoke in mice characteristic antibody (IgE and IgG) isotype profiles suggestive of discrete T lymphocyte responses and that such differences may be associated with variable allergenic activity.     

Dichotomous effect of a traditional Japanese medicine, bu-zhong-yi-qi-tang on allergic asthma in mice

To determine the potentiality of prophylactic and/or therapeutic approaches using a traditional herbal medicine, Bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to, HOT), for the control of allergic disease, we examined the effects of oral administration of HOT on a murine model of asthma allergic responses. When oral administration of HOT was begun at the induction phase immediately after OVA sensitization, eosinophilia and Th2-type cytokine production in the airway were reduced in OVA-sensitized mice following OVA inhalation. The serum levels of OVA-specific immunoglobulin (Ig)E and IgG1 were significantly decreased, whereas the level of OVA-specific IgG2a was increased. Interleukin (IL)-4 production by spleen T cells in response to OVA was significantly suppressed, while Interferon (IFN)-gamma production was increased in mice treated with HOT in the induction phase. On the other hand, HOT given in the eliciting phase induced a predominant Th2 response with increased IgE production in OVA-sensitized mice following OVA inhalation. These results suggest that the oral administration of HOT dichotomously modulates allergic inflammation in a murine model for asthma, thus offering a different approach for the treatment of allergic disorders.     

Immunological adjuvant effect of Boswellia serrata (BOS 2000) on specific antibody and cellular response to ovalbumin in mice

In this study, the biopolymeric fraction BOS 2000 from Boswellia serrata was evaluated for its potential ability as adjuvants on the immune responses to ovalbumin (OVA) in mice. Balb/c mice were immunized subcutaneously with OVA 100 μg alone or with OVA 100 μg dissolved in saline containing alum (200 μg) or BOS 2000 (10, 20, 40 and 80 μg) on Days 1 and 15. Two weeks later, OVA specific antibodies in serum; concanavalin A (Con A), OVA stimulated splenocyte proliferation, CD4/CD8/CD80/CD86 analysis in spleen cells and its estimation of cytokines (IL-2 and IFN gamma) from cell culture supernatant were measured. OVA specific IgG, IgG1 and IgG2a antibody levels in serum were significantly enhanced by BOS 2000 (80 μg) compared with OVA control group. Moreover, the adjuvant effect of BOS 2000 (80 μg) on the OVA-specific IgG, IgG1, and IgG2a antibody responses to OVA in mice were more significant than those of alum. BOS 2000 significantly enhanced the Con A and OVA induced splenocyte proliferation in the OVA immunized mice especially at a dose of 80 μg (p<0.001). However, no significant differences were observed among the OVA group and OVA/alum group. At a dose of 80 μg (p<0.001), there was a significant increase in the CD4/CD8 and CD80/CD86 analysis in spleen cells and cytokine (IL-2 and IFN-gamma) profile in the spleen cell culture supernatant was observed. In conclusion, BOS 2000 seems to be a promising balanced Th1 and Th2 directing immunological adjuvants which can enhance the immunogenicity of vaccine.     

Effect of the nonsteroidal anti-inflammatory drug indomethacin on Th1 and Th2 immune responses in mice

The present study was undertaken to study the effect of the nonsteroidal anti-inflammatory drug indomethacin on Th1 and Th2 immune responses. For this study, mice were immunized by s.c. injection of ovalbumin (OVA) emulsified with complete Freund's adjuvant into the base of the tail (day 0). Varying doses of indomethacin were orally administrated daily from days 0 to 20. On day 21, anti-OVA IgG2a and interferon-gamma as an indicator of Th1 responses and anti-OVA IgG1 and interleukin-10 as that of Th2 responses were measured. The results showed that treatment with indomethacin was followed by decreases in OVA-specific IgG and proliferation of spleen cells to the antigen. Indomethacin inhibited both Th1 and Th2 responses, although the nonsteroidal anti-inflammatory drug suppressed the former more effectively than the latter. Administration of indomethacin resulted in suppression of antigen (OVA)-induced arthritis that was associated with inhibition of anti-OVA IgG2a but not IgG1 production. These results suggest that nonsteroidal anti-inflammatory drugs may downregulate Th1 and, to a lesser extent, Th2 immune responses.     

Effect of varying types of anti-arthritic drugs on Th1 and Th2 immune responses in mice

The present study was undertaken to study the effect of varying types of anti-arthritic drugs on Th1 and Th2 immune responses in mice. To immunize mice, ovalbumin (OVA) emulsified with complete Freund's adjuvant was injected s.c. at the base of the tail (day 0). Indomethacin (IND) as a non-steroidal antiinflammatory drug (NSAID), dexamethasone (DEX) as a steroidal antiinflammatory drug, methotrexate (MTX), auranofin (AUR), and D-penicillamine (D-PA) as an anti-rheumatic drugs were orally administrated daily from days 0 to 20. On day 21, anti-OVA IgG2a and interferon (IFN)-gamma as indicators of Th1 responses and anti-OVA IgG1 and interleukin (IL)-10 as those of Th2 responses were measured. Treatments with IND, DEX, MTX and AUR were followed by decreases in OVA-specific IgG and proliferation of spleen cells to the antigen. Treatments with IND, DEX, MTX and AUR inhibited both Th1 and Th2 immune responses, although the inhibitory effects of these drugs on the antigen-specific IgG2a and IFN-gamma production appeared to be greater than those on IgG1 and IL-10 production. D-PA failed to influence anti-OVA IgG, IgG2a and IgG1 production as well as IFN-gamma and IL-10 secretion. Administrations of all the drugs used resulted in suppression of antigen (OVA)-induced arthritis in mice which was associated with inhibition of anti-OVA IgG2a but not IgG1 production. These results suggest that anti-arthritic drugs including IND, DEX, MTX and AUR appear to suppress Th1 and, to a lesser extent, Th2 immune responses, and their anti-inflammatory effects on human rheumatoid arthritis might be at least in part explained by downregulation by these drugs of Th1 responses involved in the disease.     

CpG ODN mediated prevention from ovalbumin-induced anaphylaxis in mouse through B cell pathway

Allergic inflammation is induced by type 2 T helper cell (Th2) and Th2 cytokines such as interleukin (IL)-4, IL-5 and IL-13. These cytokines induce the production of allergen-specific immunoglobulin (Ig)E by B cells, and the ensuing degranulation of mast cells via IgE cross-linking leads to most clinical manifestations of allergic diseases. We examined the ability of immunomodulatory unmethylated CpG oligodeoxynucleotides (ODN), which are potent inducers of Th1 cytokines, to prevent allergic symptoms in mice immunized and sensitized with allergen. Coadministration of CpG ODN with ovalbumin (OVA) before OVA sensitization substantially prevented mice from allergic anaphylaxis representing enhanced circulating concentrations of OVA-specific IgE and histamine, and decreased body temperature. Although CpG ODN provokes an abundance of Th1-skewing cytokines, including IL-12, interferon (IFN)-alpha and IFN-gamma, administration of CpG ODN in IFN-gamma deficient mice inhibited IgE production and prevented from OVA-induced anaphylaxis, indicating a dispensable role of IFN-gamma in mediating these protective effects. In vitro analysis revealed that CpG ODN inhibited class switching from IgM to IgE and IgG1 in response to CD40 and IL-4 in B cells, and this effect did not correlate with up-regulation of IFN-alpha production. These results imply a B cell-intrinsic, T cell-independent mechanism by which CpG ODN directly acts on B cells and inhibits IgE and IgG1 production leading to cause prevention from allergic symptoms.