Hybrid mRNA Nano Vaccine Potentiates Antigenic Peptide Presentation and Dendritic Cell Maturation for Effective Cancer Vaccine Therapy and Enhances Response to Immune Checkpoint Blockade.

Cancer vaccines combined with immune checkpoint blockades (ICB) represent great potential application, yet the insufficient tumor antigen presentation and immature dendritic cells hinder improved efficacy. Here, a hybrid nano vaccine composed by hyper branched poly(beta-amino ester), modified iron oxide nano adjuvant and messenger RNA (mRNA) encoded with model antigen ovalbumin (OVA) is presented. The nano vaccine outperforms three commercialized reagents loaded with the same mRNA, including Lipofectamine MessengerMax, jetPRIME, and in vivo-jetRNA in promoting dendritic cells' transfection, maturation, and peptide presentation. In an OVA-expressing murine model, intratumoral administration of the nano vaccine significantly induced macrophages and dendritic cells' presenting peptides and expressing co-stimulatory CD86. The nano vaccine also elicited strong antigen-specific splenocyte response and promoted CD8+ T cell infiltration. In combination with ICB, the nano vaccine aroused robust tumor suppression in murine models with large tumor burdens (initial volume >300 mm3 ). The hybrid mRNA vaccine represents a versatile and readily transformable platform and augments response to ICB.

Tyrosinase-Related Protein2 Peptide with Replacement of N-Terminus Residue by Cysteine Binds to H-2Kb and Induces Antigen-Specific Cytotoxic T Lymphocytes after Conjugation with CpG-DNA.

Recent studies have shown the potent efficacy of peptide-based vaccines for cancer immunotherapy. Immunological performance is optimized through the co-delivery of adjuvant and antigenic peptide molecules to antigen-presenting cells simultaneously. In our previous study, we showed that a conjugate consisting of 40-mer CpG-DNA and an antigenic ovalbumin peptide through disulfide bonding could efficiently induce ovalbumin-specific cytotoxic T lymphocyte (CTL) responses in vivo. In this study, based on the conjugation design, we prepared a conjugate consisting of 30-mer CpG-DNA (CpG30) and a cancer antigenic peptide of Tyrosinase-related protein 2 (TRP2180-188) using a cysteine residue attached at the N-terminus of TRP2180-188. However, the immunization of mice with this conjugate did not induce efficient TRP2180-188-specific immune responses. It was thought that the resultant peptide (10-mer) cleaved from the conjugate might be too long to fit into the H-2Kb molecule because the optimal length for binding to it is 8-9 amino acids. We newly designed a conjugate consisting of CpG30 and the C-TRP2181-188 peptide (9-mer), in which the N-terminal serine residue of TRP2180-188 is replaced by a cysteine. By adjusting the peptide length, we succeeded in inducing strong TRP2180-188 peptide-specific CTL activity upon immunization with the CpG30-C-TRP2181-188 conjugate. Furthermore, various CpG30-C-TRP2181-188 conjugates having other CpG-DNA sequences or cysteine analogues also induced the same level of CTL activity. Therefore, CpG-C-peptide conjugates prepared by replacement of the amino acid residue at the N-terminus with a cysteine residue could be a new and effective platform for peptide vaccines for targeting specific antigens of cancers and infectious diseases.

Bouganin, an Attractive Weapon for Immunotoxins.

Bougainvillea (Bougainvillea spectabilis Willd.) is a plant widely used in folk medicine and many extracts from different tissues of this plant have been employed against several pathologies. The observation that leaf extracts of Bougainvillea possess antiviral properties led to the purification and characterization of a protein, named bouganin, which exhibits typical characteristics of type 1 ribosome-inactivating proteins (RIPs). Beyond that, bouganin has some peculiarities, such as a higher activity on DNA with respect to ribosomal RNA, low systemic toxicity, and immunological properties quite different than other RIPs. The sequencing of bouganin and the knowledge of its three-dimensional structure allowed to obtain a not immunogenic mutant of bouganin. These features make bouganin a very attractive tool as a component of immunotoxins (ITs), chimeric proteins obtained by linking a toxin to a carrier molecule. Bouganin-containing ITs showed very promising results in the experimental treatment of both hematological and solid tumors, and one bouganin-containing IT has entered Phase I clinical trial. In this review, we summarize the milestones of the research on bouganin such as bouganin chemico-physical characteristics, the structural properties and de-immunization studies. In addition, the in vitro and in vivo results obtained with bouganin-containing ITs are summarized.

Vaccination with Antigen Combined with αß-ATP as a Vaccine Adjuvant Enhances Antigen-Specific Antibody Production via Dendritic Cell Activation.

Adjuvants are required to enhance antigen-specific immune responses by vaccines. Extracellular ATP serves as a danger signal to alert the immune system of tissue damage by acting on P2X and P2Y receptors and triggers the activation of dendritic cells (DCs). Here we investigated the in vivo adjuvant efficacy of α,ß-methylene-ATP (αß-ATP), a non-hydrolysable form of ATP. We found that intradermal injection of ovalbumin (OVA), as a model antigen, combined with αß-ATP, as the adjuvant, enhanced OVA-specific immune responses more than OVA alone. Additionally, DCs in the skin of mice injected with OVA and αß-ATP had increased expression of major histocompatibility complex class II and co-stimulator molecules, CD40, CD80, and CD86, suggesting that αß-ATP activated DC. These findings indicate that αß-ATP functions as a potent vaccine adjuvant.

Modulation of basophils' degranulation and allergy-related enzymes by monomeric and dimeric naphthoquinones.

Allergic disorders are characterized by an abnormal immune response towards non-infectious substances, being associated with life quality reduction and potential life-threatening reactions. The increasing prevalence of allergic disorders demands for new and effective anti-allergic treatments. Here we test the anti-allergic potential of monomeric (juglone, menadione, naphthazarin, plumbagin) and dimeric (diospyrin and diosquinone) naphthoquinones. Inhibition of RBL-2H3 rat basophils' degranulation by naphthoquinones was assessed using two complementary stimuli: IgE/antigen and calcium ionophore A23187. Additionally, we tested for the inhibition of leukotrienes production in IgE/antigen-stimulated cells, and studied hyaluronidase and lipoxidase inhibition by naphthoquinones in cell-free assays. Naphthazarin (0.1 µM) decreased degranulation induced by IgE/antigen but not A23187, suggesting a mechanism upstream of the calcium increase, unlike diospyrin (10 µM) that reduced degranulation in A23187-stimulated cells. Naphthoquinones were weak hyaluronidase inhibitors, but all inhibited soybean lipoxidase with the most lipophilic diospyrin, diosquinone and menadione being the most potent, thus suggesting a mechanism of competition with natural lipophilic substrates. Menadione was the only naphthoquinone reducing leukotriene C4 production, with a maximal effect at 5 µM. This work expands the current knowledge on the biological properties of naphthoquinones, highlighting naphthazarin, diospyrin and menadione as potential lead compounds for structural modification in the process of improving and developing novel anti-allergic drugs.

Entrapment in plasma microparticles: a promising strategy for antigen delivery.

We report the preparation of plasma microparticles (PMPs) from autologous blood plasma for sustained in vivo delivery of the entrapped antigens. The PMPs were prepared by high speed-stirring of calcium-enriched plasma, mixed with the antigen to be entrapped, in mineral oil. The preparation of PMPs did not necessitate addition of any external protein/enzyme nor special laboratory setup. Our results suggest that the PMPs release the entrapped invertase in a sustained manner both in vitro and in vivo, especially after crosslinking with glutaraldehyde. The preparations are reasonably stable to proteolysis and constitute strong candidates for eliciting immune response. Induction of humoral immune response by the PMP-entrapped invertase, as evident from the high antibody titers, was remarkable and comparable with that observed in animals receiving the antigen emulsified with Freund's Complete Adjuvant. Isotypic analysis of antibodies showed a Th1-biased immune response in animals administered uncrosslinked or crosslinked PMPs-entrapped invertase, especially after a booster dose. The analysis in animals of the group immunized with adjuvant-emulsified antigen suggested a combined Th1 and Th2 response. PMP-entrapment also caused high expression of surface markers (CD80 and CD86) on antigen presenting cells, as well as effector T-cells surface markers (CD4(+) and CD8(+) ) as revealed by FACS. The study suggests that PMPs offer remarkable promise as adjuvant-free and biocompatible vaccine delivery systems.

Periarticular bone loss in antigen-induced arthritis.

OBJECTIVE: Bone loss in arthritis is a complex process characterized by bone erosions and periarticular and generalized bone loss. The antigen-induced arthritis (AIA) model is mainly used to study synovitis and joint destruction, including bone erosions; however, periarticular bone loss has been less extensively investigated. The objectives of this study were to characterize and establish AIA as a model for periarticular bone loss, and to determine the importance of NADPH oxidase 2 (NOX-2)-derived reactive oxygen species (ROS) in periarticular bone loss. METHODS: Arthritis was induced in mice by local injection of antigen in one knee; the other knee was used as a nonarthritis control. At study termination, the knees were collected for histologic assessment. Periarticular bone mineral density (BMD) was investigated by peripheral quantitative computed tomography. Flow cytometric analyses were performed using synovial and bone marrow cells. RESULTS: AIA resulted in decreased periarticular trabecular BMD and increased frequencies of preosteoclasts, neutrophils, and monocytes in the arthritic synovial tissue. Arthritis induction resulted in an increased capability to produce ROS. However, induction of arthritis in Ncf1 / mice, which lack NOX-2-derived ROS, and control mice resulted in similar reductions in periarticular trabecular BMD. CONCLUSION: The initiation of AIA resulted in periarticular bone loss associated with local effects on inflammatory cells and osteoclasts. Furthermore, based on our observations using this model, we conclude that NOX-2-derived ROS production is not essential for inflammation-mediated periarticular bone loss. Thus, AIA can be used as a model to investigate the pathogenesis of local inflammation-mediated bone loss.

Fructans from aged garlic extract produce a delayed immunoadjuvant response to ovalbumin antigen in BALB/c mice.

Garlic (Allium sativum) is known for its innumerable biological activities including immunomodulation. Aged garlic extract (AGE), an odorless garlic preparation, has been shown to have superior immunomodulatory properties over raw garlic extract. Although garlic is a very rich source of fructans (17%, fresh weight basis), AGE contains only 0.22% of raw garlic fructans. Aged garlic fructans (AGF) have recently been shown to possess immunomodulatory activities in vitro. Natural adjuvants capable of eliciting better immune response of a model antigen are important in developing newer vaccines. In the present study, the adjuvant activity of AGF has been investigated in BALB/c mice using ovalbumin (OVA, 30 µg) as an experimental antigen. The body weights of animals did not change significantly indicating that the administration of garlic fructans is well-tolerated. AGF produce a significant humoral (serum IgG) response to OVA in BALB/c mice administered mucosally by either intranasal or oral route--a delayed response appearing on 50th day at a dose of 30 µg AGF by intranasal route. However, the serum IgG response was seen earlier on 35th day at a dose of 100 µg AGF by oral route. Higher concentrations of AGF (>50 µg) were inhibitory for adjuvant activity by intranasal administration. These observations indicate that AGF display immunoadjuvant activity for a test antigen though the humoral immune response is delayed.

The effect of a phytosphingosine-like substance isolated from Asterina pectinifera on involucrin expression in mite antigen-stimulated HaCaT cells.

The aim of the present study was to investigate the effect of phytosphingosine (PS) on mite antigen-induced terminal differentiation abnormalities in HaCaT cells. For this purpose, a PS-like substance was isolated from Asterina pectinifera (starfish PS) using high-performance liquid chromatography and was partially characterized through 1H NMR analysis. The level of involucrin expression in HaCaT cell was measured by immunoblotting assay. Our results showed that PS treatments remarkably up-regulated the involucrin expression, which is known as a terminal differentiation marker in the epidermal mite antigen-treated HaCaT cells. This indicates that starfish PS could regulate mite antigen-induced terminal differentiation fluctuation in the epidermis. Taken together, the results suggest that starfish PS might be a useful therapeutic agent for atopic dermatitis.

[Response of hypothalamic orexin-containing neurons to stimuli of antigen and non-antigen nature].

Orexin is a hypothalamic peptide, a neurotransmitter described in 1998. Orexinergic neurons are localized in hypothalamic structures and play a significant role in regulation of various physiological functions. The localization oforexin-containing neurons and their projections in hypothalamus of Wistar rats and other structures of CNS are presented. The participation of orexinergic neurons in the regulation of feeding behavior and in the sleep/wake cycle as well as their involvement in the regulation of immune functions is discussed. There are experimental data, containing comparative analysis oforexin-containing neurons responses to stimuli of antigenic and non-antigenic nature, which suggest functional heterogeneity of orexin-containing neurons of hypothalamus that leads, particularly, to involvement of different neurons in the realization of brain reaction to antigen and non-antigen stimuli. Both analyses ofpreproorexin gene expression level and morphofunctional characteristics of orecxin-containing neurons of hypothalamus after antigen challenge suggest the possibility of their participation in the mechanisms of realization of brain reaction to antigen challenge.

Mast cell-mediated allergic response is suppressed by Sophorae flos: inhibition of SRC-family kinase.

Complementary and alternative medicines are considered as a promising direction for the development of anti-allergic therapies in oriental countries. We screened approximately 100 oriental herbal medicines for anti-allergic activity. Sophorae flos exhibited the most potent effect on degranulation in antigen-stimulated mast cells. We further investigated the effect of Sophorae flos on the IgE-mediated allergic response in vivo and its mechanism of action in mast cells. Sophorae flos exhibited a significant inhibitory effect on degranulation in antigen-stimulated mast cells with IC(50) values of approximately 31.6 microg/mL (RBL-2H3 mast cells) and approximately 47.8 microg/mL (bone marrow-derived mast cells). Sophorae flos also suppressed the expression and secretion of TNF-alpha and IL-4 in the cells and IgE-mediated passive cutaneous anaphylaxis (PCA) in mice. Sophorae flos inhibited the activating phosphorylation of Syk and LAT in mast cells. Further downstream, activating phosphorylation of Akt and the prototypic MAP kinases, namely, p38, ERK1/2, and JNK, were also inhibited. These results suggest that Sophorae flos inhibits the Src family kinase-dependent signaling cascades in mast cells and may thus exert anti-allergic activity.

Alum adjuvant boosts adaptive immunity by inducing uric acid and activating inflammatory dendritic cells.

Alum (aluminum hydroxide) is the most widely used adjuvant in human vaccines, but the mechanism of its adjuvanticity remains unknown. In vitro studies showed no stimulatory effects on dendritic cells (DCs). In the absence of adjuvant, Ag was taken up by lymph node (LN)-resident DCs that acquired soluble Ag via afferent lymphatics, whereas after injection of alum, Ag was taken up, processed, and presented by inflammatory monocytes that migrated from the peritoneum, thus becoming inflammatory DCs that induced a persistent Th2 response. The enhancing effects of alum on both cellular and humoral immunity were completely abolished when CD11c(+) monocytes and DCs were conditionally depleted during immunization. Mechanistically, DC-driven responses were abolished in MyD88-deficient mice and after uricase treatment, implying the induction of uric acid. These findings suggest that alum adjuvant is immunogenic by exploiting "nature's adjuvant," the inflammatory DC through induction of the endogenous danger signal uric acid.

Effect of providing a formula supplemented with long-chain polyunsaturated fatty acids on immunity in full-term neonates.

To determine the effect of feeding formula containing long-chain PUFA (LCP) on immune function, healthy term infants were randomised at age 2 weeks to either a standard term formula (Formula; n 14) or the same formula supplemented with the LCP 20 : 4n-6 and 22 : 6n-3 (Formula+LCP; n 16). Peripheral blood was collected at 2 and 6 weeks to measure immune cell response (the rate of [3H]thymidine uptake and cytokine production after stimulation with phytohaemagglutinin (PHA)). Compared with cells from infants receiving only human milk (HM), the rate of [3H]thymidine uptake in response to PHA, but not IL-2 production, was lower for Formula+LCP infants (P < 0.05). Compared with HM-fed infants, Formula-fed infants (but not Formula+LCP infants) produced more TNF-alpha (unstimulated) and had a fewer CD3+CD44+ cells before stimulation and fewer CD11c+ cells post-stimulation (P < 0.05). However, compared with Formula-fed infants, the Formula+LCP infants had an immune cell distribution (higher percentage CD3+CD44+ and CD4+CD28+ cells) and cytokine profile (lower production of TNF-alpha post-stimulation) that did not differ from HM infants. Additionally, it was found that feeding infants formula during the first 10 d of life influenced immune function. These infants had a higher percentage of CD3+, CD4+CD28+, and lower percentage of CD14+ cells and produced more TNF-alpha and interferon-gamma after PHA stimulation than HM-fed infants (P < 0.05). These results demonstrate that early diet influences both the presence of specific cell types and function of infant blood immune cells. Since many diseases have a strong immunological component, these immune changes may be of physiological importance to the developing infant.

Polygoni cuspidati radix inhibits the activation of Syk kinase in mast cells for antiallergic activity.

The antiallergic activity of Polygoni cuspidati radix (PR) and the mechanism of action by which it functions were investigated in this study. The extract of PR exhibited potent inhibitory activity in mast cells; its IC50 values were 62 +/- 2.1 microg/ml for RBL-2H3 mast cells and 46 +/- 3.2 microg/m for bone marrow-derived mast cells by antigen stimulation, and it also suppressed the expression of tumor necrosis factor-alpha and interleukin-4 in RBL-2H3 cells. According to the in vivo animal allergy model, it inhibited a local allergic reaction, passive cutaneous anaphylaxis, in a dose-dependent manner. With regard to its mechanism of action, PR inhibited the activating phosphorylation of Syk, a key signaling protein for the activation of mast cells. It also suppressed Akt and the mitogen-activated protein kinases ERK1/2, p38, and JNK, which are critical for the production of various inflammatory cytokines in mast cells. The results of the study indicate that the antiallergic activity of PR is mediated through the inhibition of histamine release and allergic cytokine production by the inhibition of Syk activating phosphorylation in mast cells.

Monoclonal antibody "gold rush".

The market, sales and regulatory approval of new human medicines, during the past few years, indicates increasing number and share of new biologics and emergence of new multibillion dollar molecules. The global sale of monoclonal antibodies in 2006 were $20.6 billion. Remicade had annual sales gain of $1 billion during the past 3 years and five brands had similar increase in 2006. Rituxan with 2006 sales of $4.7 billion was the best selling monoclonal antibody and biological product and the 6th among the top selling medicinal brand. It may be the first biologic and monoclonal antibody to reach $10 billion annual sales in the near future. The strong demand from cancer and arthritis patients has surpassed almost all commercial market research reports and sales forecast. Seven monoclonal antibody brands in 2006 had sales exceeding $1 billion. Humanized or fully human monoclonal antibodies with low immunogenicity, enhanced antigen binding and reduced cellular toxicity provide better clinical efficacy. The higher technical and clinical success rate, overcoming of technical hurdles in large scale manufacturing, low cost of market entry and IND filing, use of fully human and humanized monoclonal antibodies has attracted funds and resources towards R&D. Review of industry research pipeline and sales data during the past 3 years indicate a real paradigm shift in industrial R&D from pharmaceutical to biologics and monoclonal antibodies. The antibody bandwagon has been joined by 200 companies with hundreds of new projects and targets and has attracted billions of dollars in R&D investment, acquisitions and licensing deals leading to the current Monoclonal Antibody Gold Rush.

Enhanced desensitization efficacy by liposomal conjugation of a specific antigen.

Since liposomes are known as strong adjuvants, we attempted to use liposomes in immunotherapy as adjuvants, and to achieve desensitization in pre-sensitized mice. At first, we sensitized mice with intraperitoneal injection of model antigen, 100 microg ovalbumin (OVA), with Alum and treated them with liposome composed of distearoylphosphatidylcholine (DSPC) and cholesterol (2:1 as a molar ratio), which was coupled with a small amount of OVA (10 microg OVA in 400 nmol DSPC and 200 nmol cholesterol-liposome was injected into 20 g mouse). It is well known that antigen-specific immunotherapy increases IgG blocking antibodies and decreases in IgE antibodies. The treatment with i.v. injection of OVA-liposome at days 8, 10, and 12 after sensitization strongly suppressed OVA-specific IgE production without affecting IgG level after the boost (100 microg OVA with Alum). Moreover, the treatment with high-density OVA-liposome (10 microg OVA in 80 nmol DSPC and 40 nmol cholesterol-liposome/20 g mouse) not only strongly suppressed IgE levels but also reduced IgG production after the boost of OVA-sensitized mice suggesting the importance of liposomal characteristic in desensitization immunotherapy. Next we reduced the dose of OVA-liposome and the desensitization effect was also observed at the dose of as low as 1 microg OVA on OVA-liposome/mouse. On the contrary, free OVA did not affect the production of both IgG and IgE levels. Biodistribution study indicated that OVA-liposome was highly accumulated in spleen of OVA-sensitized mice compared to control liposome at 3 h after i.v. injection. These results suggest that the liposomal OVA effectively interacts with and desensitizes immune cells, therefore, liposomes coupling with a certain antigen may be effective in allergy immunotherapy.

[Stress-induced changes of hypothalamic structure cell responses to antigen injection (LPS) (revealed by c-Fos protein expression)].

Stress stimuli are known to influence the intensity if immune response. To elucidate the role of central regulating structures in this changes, analysis of activation level of hypothalamic neurons (revealed by quantity of c-Fos-positive cells) was carried out in rats within 2 hours after intravenous LPS injection and after this--impact associated with electric pain stimulation (EPS). The investigation was carried out in 52 male Wistar rats, 200-250 g. The c-Fos protein expression was analyzed with immunohistochemical method. The increase of c-Fos-positive cells number in 2 hours after LPS injection was observed in AFTN, PVH, LHA, VMH, DMH and PH. After electrical pain stimulation, the quantity of c-Fos-positive cells increased in the same structures. Combined application of electric pain stimulation and LPS injection results in diminished activation level in AHN, PVH, LHA and VMH as compared with typical response to single LPS injection without EPS. The EPS suppresses intensity of the immune response induced by injection of LPS (revealed by local hemolysis method with calculation of antibody-forming cells quantity (%) in the rat spleen). Thus the activation level changes of hypothalamic structures (AHN, PVH, LHA, PH) correlate with development of stress-induced immunosuppression, i. e. morphofunctional description of hypothalamic structures activation as revealed by pattern of activated cell alterations in hypothalamic structures during realization of stress-induced changes of immune system responses to antigen injection.

Effect of oral immunotherapy on nasal blockage in experimental allergic rhinitis.

We previously reported that when Japanese cedar pollen was prophylactically p.o. administered before a sensitization stage in a guinea-pig model of allergic rhinitis, pollen-induced nasal blockage was suppressed. In this study, we evaluated whether the oral immunotherapy is also effective when the pollen extract was administered starting from the day when the nasal blockage was clearly induced and whether the effectiveness continued after cessation of the immunotherapy. Sensitized animals were repeatedly challenged by pollen inhalation once every week. After the 7th challenge, the extract was orally administered twice a week until the 30th challenge. At the 11th challenge, the oral immunotherapy showed inhibition of the biphasic nasal blockage. The effectiveness was consistently observed during the immunotherapy until the 30th challenge. Furthermore, the increased nasal responsiveness to intranasal application of leukotriene D4 was markedly suppressed by the immunotherapy. Interestingly, even after cessation of the therapy, inhibition of the nasal blockage was sustained for more than 2 months. Nevertheless, neither sneezing nor antigen-specific IgE antibody production was substantially influenced by the immunotherapy. In conclusion, Oral immunotherapy may be clinically useful for allergic nasal blockage. Mechanisms underlying the effectiveness may be associated with the hyporesponsiveness of the nasal mucosa to released mediators.

Immunomodulatory effect of the antiasthma Chinese herbal formula MSSM-002 on TH2 cells.

BACKGROUND: T(H)2 cytokines play a central role in the pathogenesis of allergic asthma. We previously showed that the "antiasthma" Chinese herbal formula MSSM-002 exhibited therapeutic effects on established allergic airway responses in a murine model of allergic asthma. However, the mechanisms underlying these effects are largely unknown. OBJECTIVE: The objective of this study was to determine whether and how MSSM-002 modulates an established T(H)2 response and whether the actions of MSSM-002 on T(H)2 cell differs from corticosteroids. METHODS: T(H)2 polarized splenocytes (T(H)2-SPCs) from mice with antigen-induced airway hyperresponsiveness and T(H)2 cloned cells, D10 G4.1 (D10), were cultured in the presence or absence of antigen with or without MSSM-002 and dexamethasone, and the proliferative responses and cytokine profiles were determined. Apoptosis and T(H)2 transcription factor GATA-3 expression and binding to IL-4 gene promoter and V(A) enhancer in MSSM-002-treated D10 cells were also determined. RESULTS: MSSM-002 significantly decreased antigen-induced proliferation and IL-4 and IL-5 production but increased IFN-gamma production by T(H)2-SPCs, whereas dexamethasone suppressed IFN-gamma as well as IL-4 and IL-5. Anti-IL-12 antibody, although abrogating MSSM-002 induction of IFN-gamma, had no significant effect on MSSM-002 suppression of IL-4 and IL-5 secretion. MSSM-002 also suppressed T(H)2 cytokine secretion by D10 cells, and in contrast to dexamethasone, MSSM-002 did not induce apoptosis of D10 cells. MSSM-002 markedly suppressed GATA-3 mRNA and protein expression and the binding to IL-4 gene promoter and V(A) enhancer in D10 cells. CONCLUSION: MSSM-002, in contrast to the overall suppression of T cells by dexamethasone, exhibits immunomodulatory actions on T(H)2 cells caused, at least partially, by downregulation of GATA-3.

Effect of oral antigen administration on nasal blockage in experimental allergic rhinitis in guinea pigs.

OBJECTIVE AND DESIGN: We evaluated the effectiveness of oral treatment with Japanese cedar pollen on experimental allergic rhinitis in guinea pigs. SUBJECTS: Male Hartley guinea pigs. TREATMENT: From 16 days before the first sensitisation, 1 and 100 mg/time/animal pollen suspension was orally administered twice weekly. Animals were then sensitised and repeatedly challenged with the pollen. METHOD: Guinea pigs were sensitised by intranasal instillation of cedar pollen extracts adsorbed onto Al(OH)3 at a dose of 0.3 microg pollen protein/0.3 mg Al(OH)3/3 microl/nostril twice a day for 7 days. Then the animal was challenged by inhalation with cedar pollen (1.8 mg/nostril) once every week. We evaluated the effects of the oral treatment with antigen on: 1) sneezing frequency, 2) nasal blockage after antigen challenge, 3) nasal hyperresponsiveness to histamine and leukotriene D4, and 4) titres of anaphylactic antibodies. RESULTS: During the course of the high dose administration, several animals died from a possible cytotoxicity, whereas the low dose caused no discernible change. The oral administration of the pollen at both the doses significantly inhibited nasal blockage, and the hyperresponsiveness to the stimuli was also strongly suppressed by the oral treatment. Inhibitory effectiveness did not differ substantially between the 1 and 100 mg/animal-treated groups. In contrast, neither sneezing frequency nor the increasing level of anaphylactic antibodies was influenced by the oral administration. CONCLUSIONS: In this study, we found that the pollen-induced nasal blockage and hyperresponsiveness were suppressed by the oral administration of the pollen in the sensitised guinea pig.