The effects of proresolution of ellagic acid in an experimental model of allergic airway inflammation.

Asthma is a disease of airway inflammation characterized by airway hyperresponsiveness, eosinophilic inflammation, and hypersecretion of mucus. Ellagic acid, a compound derived from medicinal plants and fruits, has shown anti-inflammatory activity in several experimental disease models. We used the classical experimental model, in BALB/c mice, of sensibilization with ovalbumin to determine the effect of ellagic acid (10 mg/kg; oral route) in the resolution of allergic airways response. Dexamethasone (1 mg/kg; subcutaneous route) was used as a positive control. The control group consisted of nonimmunized mice that received challenge with ovalbumin. Ellagic acid and dexamethasone or vehicle (water) were administered before or after intranasal allergen challenge. Ellagic acid accelerated the resolution of airways inflammation by decreasing total leukocytes and eosinophils numbers in the bronchoalveolar lavage fluid (BALF), the mucus production and lung inflammation in part by reducing IL-5 concentration, eosinophil peroxidase (EPO) activity, and P-selectin expression, but not activator protein 1 (AP-1) and nuclear factor kappa B (NF-κB) pathways. In addition, ellagic acid enhanced alveolar macrophage phagocytosis of IgG-OVA-coated beads ex vivo, a new proresolving mechanism for the clearance of allergen from the airways. Together, these findings identify ellagic acid as a potential therapeutic agent for accelerating the resolution of allergic airways inflammation.

Effect of Tong Qiao drops on the expression of eotaxin, IL-13 in the nasal mucosa of rats with allergic rhinitis.

BACKGROUND: In recent years, particularly in China, many Chinese medicines and prescriptions for treating allergic rhinitis have been evaluated for their clinical relevance. Studies have found that numerous herbs and their constituent compounds can significantly alleviate allergic symptoms and are effective treatments for allergic rhinitis. The purpose of this study was to examine the modulatory effect of Tong Qiao nose drops on allergy symptoms and the expression of cytokines in the nasal mucosa of rats with ovalbumin-induced allergic rhinitis. METHODS: Sixty healthy male Sprague Dawley rats were randomly divided into three groups (n = 20): negative, control, and experimental. Rats in the control or experimental groups were sensitized with ovalbumin to induce allergic rhinitis. The sensitized rats in the experimental group were subsequently exposed to Tong Qiao nose drops, whereas the sensitized control rats were given saline nose drops. Negative control rats were only treated with saline. Allergic symptoms and the pathologic features of the nasal mucosa were observed. The expression of eotaxin in the mucous membrane of rat nasal septums was detected by immunohistochemical staining, and the expression levels of interleukin (IL)-5 and IL-13 were measured by enzyme-linked immunosorbent assay. RESULTS: The symptom scores for the experimental group were significantly lower than those of control rats (p < 0.01). Histopathologic examination revealed pathologic changes of nasal mucosa edema in the experimental group was mild and the infiltration of eosinophils was insubstantial. The expression levels of eotaxin, IL-5, and IL-13 in the nasal mucosa from experimental rats were significantly lower than that of control rats (p < 0.01). CONCLUSION: Tong Qiao nose drops alleviated the symptoms of allergic rhinitis in a rat model and lowered the expression levels of eotaxin, IL-5, and IL-13.

Clinical and immunological responses in ocular demodecosis.

The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1ß, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1ß in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1ß and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders.

Clinical and Immunological Responses in Ocular Demodecosis

The purpose of this study was to investigate clinical and immunological responses to Demodex on the ocular surface. Thirteen eyes in 10 patients with Demodex blepharitis and chronic ocular surface disorders were included in this study and treated by lid scrubbing with tea tree oil for the eradication of Demodex. We evaluated ocular surface manifestations and Demodex counts, and analyzed IL-1beta, IL-5, IL-7, IL-12, IL-13, IL-17, granulocyte colony-stimulating factor, and macrophage inflammatory protein-1beta in tear samples before and after the treatment. All patients exhibited ocular surface manifestations including corneal nodular opacity, peripheral corneal vascularization, refractory corneal erosion and infiltration, or chronic conjunctival inflammatory signs before treatment. After treatment, Demodex was nearly eradicated, tear concentrations of IL-1beta and IL-17 were significantly reduced and substantial clinical improvement was observed in all patients. In conclusion, we believe that Demodex plays an aggravating role in inflammatory ocular surface disorders.

Intranasal PUVA phototherapy in nasal polyposis--a pilot study.

Nasal polyposis (NP) affects 4% of the general population, representing a major health problem. In spite of complex (surgical and medical) treatment, the relapse rate is high and it has a negative impact on the quality of life. Recently we found that intranasal photochemotherapy with ultraviolet A light (PUVA) is effective in allergic rhinitis. In the present study PUVA was administered for 6 weeks in 7 patients with NP. Nasal lavages were performed in all patients before and at the end of the treatment; from four patients a biopsy specimen was also collected. Eosinophils significantly decreased in patients with NP and slightly in a patient who had associated aspirin sensitivity. IL-5 and eosinophil cationic protein (ECP) levels showed a decreasing trend in patients with NP and an increasing trend in patients with associated aspirin sensitivity. Our results suggest that intranasal PUVA might represent a future therapeutic method in a subset of patients with NP.

The effect of MS14 on Th2 cytokines pattern in Balb/C mice.

The tendency of immune response toward either Th1 or Th2 cytokine pattern can cause a number of pathologic conditions. Multiple sclerosis is postulated to be a Th1-type cell-mediated autoimmune disease. MS14--an Iranian natural product--seems to possess anti-inflammatory properties. Thus, we studied the effect of orally administered MS14 on Th2 cytokines (IL-5 and IL-10) in normal Balb/C mice (100 mg/kg; 5 days). The result indicated that activated splenocytes of MS14 group produced significantly more IL-5 and IL-10 (3-4 times in comparison with control group mice). MS14 could upregulate Th2 cytokine and thereby it may possess immunoregulatory properties probably useful in treatment of some diseases.

Specific immunotherapy to birch allergen does not enhance suppression of Th2 cells by CD4(+)CD25(+) regulatory T cells during pollen season.

INTRODUCTION: The aim of this study was to investigate the suppressive capacity of CD25(+) regulatory T cells on birch allergen-induced T-cell responses during the first birch pollen season after initiation of specific immunotherapy (SIT). METHODS: CD25(pos) and CD25(neg) T cells were purified from blood of birch-allergic SIT patients and birch-allergic controls, stimulated with birch pollen extract, and analyzed for T-cell proliferation and production of interferon gamma (IFN-gamma), interleukin (IL)-5 and IL-10. RESULTS: We show that allergen-induced proliferation and IFN-gamma production were suppressed equally well by CD25(pos) T cells from SIT patients and controls, while the IL-5 production was not suppressed by either of the groups. IL-10 levels were higher in SIT patients relative to controls only when CD25(neg) and CD25(pos) were cultured together. Furthermore, neither FOXP3 levels nor proportions of CD25(high) T cells were enhanced in SIT patients compared to allergic controls. DISCUSSION: These results suggest that the Th2-suppressive capacity of allergen-stimulated CD25(pos) Treg in vitro is not improved by SIT in spite of increased IL-10 production from T cells.

Preventive and therapeutic anti-inflammatory properties of the sesquiterpene alpha-humulene in experimental airways allergic inflammation.

BACKGROUND AND PURPOSE: alpha-Humulene and trans-caryophyllene are plant sesquiterpenes with pronounced anti-inflammatory properties. Here, we evaluated the effects of these compounds in an experimental model of airways allergic inflammation. EXPERIMENTAL APPROACH: Female BALB/c mice, sensitized to and challenged with ovalbumin received daily alpha-humulene or trans-caryophyllene (50 mg.kg(-1), orally) or alpha-humulene (1 mg.mL(-1), by aerosol) as either a preventive (for 22 days) or therapeutic (from the 18th to the 22nd day) treatment. Dexamethasone or budesonide was used as a positive control drug. Inflammation was determined on day 22 post-immunization by leukocyte recruitment, interleukin-5 (IL-5), CCL11, interferon-gamma (IFN-gamma) and leukotriene (LT)B(4) levels in bronchoalveolar lavage fluid (BALF). In addition, transcription factors [nuclear factor kappaB (NF-kappaB), activator protein 1 (AP-1)] and P-selectin in lung tissue were measured by immunohistochemistry and mucus secretion by histochemistry. KEY RESULTS: Preventive or therapeutic treatments with alpha-humulene, but not with trans-caryophyllene, significantly reduced the eosinophil recruitment to the BALF. In addition, alpha-humulene recovery INF-gamma and reduced the IL-5, CCL11 and LTB(4) levels in BALF, as well as the IL-5 production in mediastinal lymph nodes (in vitro assay). Furthermore, alpha-humulene decreased the NF-kB and the AP-1 activation, the expression of P-selectin and the increased mucus secretion in the lung. CONCLUSIONS AND IMPLICATIONS: alpha-Humulene, given either orally or by aerosol, exhibited marked anti-inflammatory properties in a murine model of airways allergic inflammation, an effect that seemed to be mediated via reduction of inflammatory mediators, adhesion molecule expression and transcription factors activation.

Immunoregulation by Toxoplasma gondii infection prevents allergic immune responses in mice.

Toxoplasma gondii is a ubiquitous intracellular parasite affecting most mammals including humans. In epidemiological studies, infection with T. gondii and allergy development have been postulated to be inversely related. Using a mouse model of birch pollen allergy we investigated whether infection with T. gondii influences allergic immune responses to birch pollen. BALB/c mice were infected with T. gondii oocysts either before or at the end of sensitisation with the major birch pollen allergen Bet v 1 and thereafter aerosol challenged with birch pollen extract. During the acute phase of infection, clinical signs correlated with increased levels of serum TNF-alpha, IL-6, IFN-gamma and anti-Toxoplasma-IgM. In the chronic phase, Toxoplasma-specific serum IgG, brain tissue cysts and high IFN-gamma production in spleen cell cultures were detected. Mice infected prior to allergic sensitisation produced significantly less allergen-specific IgE and IgG1, while IgG2a levels were markedly increased. IL-5 levels in spleen cell cultures and bronchoalveolar lavage fluid were significantly reduced, and airway inflammation was prevented in these mice. Notably, in mice infected at the end of the allergic sensitisation process, systemic and local immune responses to the allergen were markedly reduced. T.gondii infection was associated with up-regulation of Toll-like receptor 2 (TLR2), 4, 9 and 11, as well as T-bet (a differentiation factor for Th1 cells) mRNA expression in splenocytes; moreover, enhanced TGF-beta, IL-10 and Foxp3 mRNA expression in these cells suggested that regulatory mechanisms were involved in suppression of the allergic immune response. Kinetic studies confirmed the induction of Foxp3(+)CD4(+)CD25(+) regulatory T cells preferentially during the chronic phase of T. gondii infection. Our data demonstrate that T. gondii exhibits strong immunomodulating properties which lead to prevention of allergic immune responses and thereby support the hygiene hypothesis.

Pollen grains induce a rapid and biphasic eczematous immune response in atopic eczema patients.

INTRODUCTION: Eczematous reactions to type I allergy-inducing antigens are documented in a subgroup of patients with atopic eczema. Yet, the underlying immunological mechanisms are not well understood. MATERIAL AND METHODS: To delineate the effect of native pollen grains on human skin of healthy and atopic individuals we performed patch tests (atopy patch test with native pollen grains, PPT). Nickel patch tests (NPT) served as an established model of contact dermatitis. Skin site biopsies were taken 6-96 h after allergen application and investigated immunohistochemically. RESULTS: Histology of positive patch tests showed an influx of mononuclear cells (predominantly CD4+, CD25+, CD45RO+). This influx was detected earlier in the PPT reaction than in the immune response to nickel. A biphasic cytokine response could be detected in the PPT: IL-5 dominated in the early, IFN-gamma in the late phase. The NPT was continuously dominated by IFN-gamma. Dendritic cell subpopulations imitated the earlier kinetics of the mononuclear infiltrate. DISCUSSION: Thus, pollen grains induce eczematous reactions in susceptible individuals. This reaction appears clinically and immunohistochemically similar to the contact hypersensitivity reaction to nickel but follows a faster kinetic and a biphasic course: Th2 and IgE in the early (24 h) and Th1 predominance in the late (96 h) phase.

Sublingual immunotherapy in children modulates allergen-induced in vitro expression of cytokine mRNA in PBMC.

BACKGROUND: During subcutaneous immunotherapy (SCIT), there is a local mucosal shift from Th2 to Th1 type cytokine predominance and downregulation of interleukin (IL)-5 and eosinophilia. According to recent studies IL-10- and transforming growth factor (TGF)-beta-induced tolerance is another key phenomenon in SCIT. Few data to date is available on mechanisms and roles of these cytokines in sublingual immunotherapy (SLIT). SCOPE: This study was undertaken to analyse the allergen-induced in vitro mRNA expression of IL-4, IL-5, IL-10, TGF-beta and interferon (IFN)-gamma during SLIT in peripheral blood mononuclear cells (PBMC) of children with allergic rhinitis (AR). METHODS: Ten patients with AR undergoing pollen SLIT with a weekly dose of 200,000 SQ-U, 10 with a weekly dose of 24,000 SQ-U of glycerinated mixture of Betula verrucosa, Corylus avellana and Alnus glutinosa and 10 with placebo were included in the study. Peripheral blood mononuclear cell samples were collected and stimulated with pollen allergen extract prior to the treatment, after 1 and 2 years of the treatment. The cytokine mRNA expression was assessed using kinetic real time reverse transcription polymerase chain reaction (RT-PCR; TaqMan). RESULTS: The in vitro allergen-induced mRNA expression of IL-5 by PBMC in the placebo group at 1 (P = 0.0065) and 2 (P = 0.013) years of therapy were increased in comparison with the highest dose. The expression of IL-10 mRNA was increased in the highest dose group (P = 0.0016) and the lower dose group (P = 0.034) at 2 years of therapy when compared with placebo. The change in the expression of allergen-induced TGF-beta had an inversed correlation with the change of IL-5 (r = -0.38, P = 0.036) and positive correlation with the change of IL-10 (r = 0.58, P = 0.0019). CONCLUSIONS: Sublingual immunotherapy induced a dose-dependent systemic allergen-specific immunological response in children with AR. During high-dose SLIT, there was activation of regulatory cytokine IL-10 and an inhibitory effect on IL-5 expression increase that was associated with TGF-beta.

Clinical effects of probiotics are associated with increased interferon-gamma responses in very young children with atopic dermatitis.

BACKGROUND: We recently demonstrated that administration of probiotics resulted in significant clinical improvement in very young children with moderate-to-severe atopic dermatitis (AD). The purpose of this study was to determine the underlying immunological effects that are associated with these apparent clinical benefits. METHODS: Peripheral blood mononuclear cells (PBMC) were isolated from children (n = 53) at baseline and at the end of an 8-week supplementation period during which they received a probiotic (Lactobacillus fermentum PCCtrade mark) (n = 26) or a placebo (n = 27). A further sample was collected at 16 weeks (8 weeks after ceasing the supplement). Cytokine (IL-5, IL-6, IL-10, IL-13, IFN-gamma and TNF-alpha) responses to allergens (egg ovalbumin (OVA), beta lactoglobulin (BLG), house dust mite (HDM)), vaccines (tetanus toxoid (TT)), diphtheria toxoid (DT)), intestinal flora (heat-killed Lactobacillus (HKLB)), heat-killed Staphylococcus aureus (HKSA), Staphylococcus aureus enterotoxin B (SEB) and mitogen (phytohaemaglutinin (PHA)) were compared. RESULTS: The administration of probiotics was associated with a significant increase in T-helper type 1(Th1-type) cytokine IFN-gamma responses to PHA and SEB at the end of the supplementation period (week 8: P = 0.004 and 0.046) as well as 8 weeks after ceasing supplementation (week 16: P = 0.005 and 0.021) relative to baseline levels of response. No significant changes were seen in the placebo group. The increase in IFN-gamma responses to SEB was directly proportional to the decrease in the severity of AD (r = -0.445, P = 0.026) over the intervention period. At the end of the supplementation period (week 8) children receiving probiotics showed significantly higher TNF-alpha responses to HKLB (P = 0.018) and HKSA (P = 0.011) but this was no longer evident when supplementation ceased (week 16). Although IL-13 responses to OVA were significantly reduced in children receiving probiotics after 8 weeks (P = 0.008), there were no other effects on allergen-specific responses, and this effect was not sustained after ceasing supplementation (week 16). There were no effects on vaccine-specific responses, or on responses to any of the stimuli assessed. CONCLUSION: The improvement in AD severity with probiotic treatment was associated with significant increases in the capacity for Th1 IFN-gamma responses and altered responses to skin and enteric flora. This effect was still evident 2 months after the supplementation was ceased. The lack of consistent effects on allergen-specific responses suggests that the effects of probiotics may be mediated through other independent pathways, which need to be explored further.

Topical corticosteroid inhibits interleukin-4, -5 and -13 in nasal secretions following allergen challenge.

BACKGROUND: Cytokines and chemokines produced by allergen-reactive T-helper type 2 (Th2) cells may be pivotal to the pathophysiology of allergic disorders. OBJECTIVE: This study was performed to assess the effect of 7 days of topical corticosteroid on nasal allergen challenge (NAC) in terms of eosinophils, cytokines and chemokines obtained by nasal lavage and filter paper methods. METHODS: Patients with grass pollen seasonal-allergic rhinitis (n = 13) out of season received nasal challenge following matched placebo (twice daily into each nostril for 7 days) and fluticasone propionate (100 microg twice daily into each nostril for 7 days). Chemokine and cytokine levels were analysed using a sensitive automated bead immunoassay system at intervals up to 8 h after NAC. RESULTS: Levels of cytokines and chemokines from filter paper were generally higher than from nasal lavage. Fluticasone propionate caused a reduction in symptoms, total leukocyte counts and eosinophils, and abrogation of IL-4, IL-5, IL-6 and IL-13 responses in the filter paper taken in the late phase (P < 0.05 for IL-4 and IL-13, P < 0.01 for IL-5 and IL-6). Levels of chemokines (eotaxin, RANTES, MCP-1, MIP-1alpha, IL-8 and IP-10) were also reduced in the late phase (P < 0.01 at 8 h). However, levels of IL-2, IL-3, IL-7, IL-12 (p40 and p70), -15, TNF-alpha, IFN-gamma and GM-CSF were not affected. CONCLUSION: Fluticasone propionate has selective inhibitory effects on Th2 cytokine synthesis following nasal challenge, while also decreasing release of chemokines, but not affecting levels of Th1 cytokines.

Pre-clinical evaluation of the malaria vaccine candidate P. falciparum MSP1(42) formulated with novel adjuvants or with alum.

We compared the safety and immunogenicity of the recombinant Plasmodium falciparum MSP1(42) antigen formulated with four novel adjuvant systems (AS01B, AS02A, AS05 and AS08) to alum in rhesus monkeys. All five formulations of MSP1(42) were safe and immunogenic. Whereas, all MSP1(42) formulations tested generated high stimulation indices for lymphocyte proliferation (ranging from 27 to 50), the AS02A and AS01B formulations induced the highest levels of specific anti-MSP1(42) antibody. ELISPOT assays showed that the AS02A and AS01B vaccine formulations-induced different cytokine response profiles. Using the ratio of IFN-gamma/IL-5 secreting cells as the metric, the AS01B formulation induced a strong Th1 response, whereas the AS02A formulation induced a balanced Th1/Th2 response. The IFN-gamma response generated by AS02A and AS01B formulations persisted at least 24 weeks after final vaccination. The notable difference in Th1/Th2 polarization induced by the AS02A and AS01B formulations warrants comparative clinical testing.

Reduction of allergic airway eosinophilia by dietary raffinose in Brown Norway rats.

Oral administration of raffinose, a naturally occurring indigestible oligosaccharide, has reportedly ameliorated atopic dermatitis in human subjects although the mechanism is unknown. The present study investigated the effect of dietary raffinose on allergen-induced airway eosinophilia in ovalbumin-sensitised Brown Norway rats as an atopic disease model. Brown Norway rats were immunised by subcutaneous injection with ovalbumin on day 0 and fed either a control diet or the diet supplemented with raffinose (50 g/kg diet). The rats were exposed to aerosolised ovalbumin on day 20, and broncho-alveolar lavage fluid was obtained on the next day. The number of eosinophils in the fluid was significantly lower in the rats fed the raffinose diet than in those fed the control diet. Dietary raffinose significantly reduced IL-4 and IL-5 mRNA levels in lung tissue and tended to lower ovalbumin-specific Ig E levels. Suppression of eosinophilia by dietary raffinose was still observed in caecectomised and neomycin-administered rats, suggesting little contribution by the colonic bacteria to the effect of raffinose. Intraperitoneal administration of raffinose also suppressed eosinophilia. Significant concentrations of raffinose were detected in portal venous and abdominal arterial plasma after the intragastric administration of raffinose. Overall, the findings suggest that dietary raffinose ameliorates allergic airway eosinophilia at least partly via post-absorptive mechanisms in Brown Norway rats.

Pollen immunotherapy inhibits T helper 1 and 2 cell responses, but suppression of T helper 2 cell response is a more important mechanism related to the clinical efficacy.

OBJECTIVES: To investigate the allergen-induced IgE synthesis and cytokine production by peripheral blood mononuclear cells from patients with seasonal allergic rhinitis due to Japanese cedar (Cryptomeria japonica) pollens and to elucidate the immunological mechanisms related to the clinical efficacy of immunotherapy (IT) for seasonal allergic rhinitis. DESIGN: This study included 51 patients with seasonal allergic rhinitis due to the pollen and 8 nonatopic healthy volunteers (nonatopic group). Thirty-nine patients had been undergoing IT using the pollen extracts for various lengths of time (IT group). The remaining 12 patients had never been treated with IT (untreated group). Peripheral blood mononuclear cells (3.3 x 10(6) cells per milliliter) from each individual were cultured with Cry j 1, 4.17 microg/mL. After 96 hours, culture supernatants were harvested to determine the concentrations of IgE, interleukin (IL) 5, interferon gamma (IFN-gamma), and tumor necrosis factor alpha (TNF-alpha). RESULTS: The levels of IgE (P = .02), IL-5 (P<.01), and TNF-alpha (P = .05) were significantly higher in the untreated group than in the nonatopic group. The levels of IFN-gamma did not differ significantly between the untreated and the nonatopic groups (P = .19). The levels of IgE, IL-5, and IFN-gamma, but not of TNF-alpha, were inversely correlated with the duration (in years) of IT, and none of the levels of IgE (P = .74), IL-5 (P = .15), IFN-gamma (P = .61), and TNF-alpha (P = .55) differed significantly between the nonatopic group and those who had been treated with IT for 10 years or more. The levels of IL-5 were significantly lower in the good responders than in the poor responders to IT (P<.001), whereas the levels of total IgE (P = .20), IFN-gamma (P = .16), and TNF-alpha (P = .14) did not differ significantly between them. CONCLUSION: The mechanisms responsible for the clinical efficacy of pollen IT are principally related to the tolerance or anergy of T helper 2 cells.

Interleukin-5 and interleukin-8 in relation to eosinophils and neutrophils in nasal fluids from school children with seasonal allergic rhinitis.

The objectives of this study were to measure interleukins 5 and 8 (IL-5 and IL-8) in relation to eosinophils and neutrophils, in nasal lavage fluids from 60 school children with allergic rhinitis, and to determine the influence of treatment with a topical steroid (budesonide) on the levels of the two cytokines. Highly sensitive enzyme immunoassays were used to analyze IL-5 and IL-8. IL-5 levels and relative eosinophil counts in nasal lavage fluid increased significantly in patients with allergic rhinitis during the pollen season, compared with values obtained before the start of the season, and decreased significantly after treatment with budesonide. By contrast, no significant changes in IL-8 or neutrophils were found during the pollen season, nor did they decrease following treatment. In the untreated patients, IL-5 levels correlated significantly with eosinophil counts but not with neutrophil counts, whereas IL-8 levels correlated with neutrophil counts but not with eosinophil counts. After budesonide treatment, the correlation between IL-8 and neutrophils remained, and a correlation between IL-8 and eosinophils emerged. These findings support the concepts that IL-5 has a key role in regulating eosinophils and that IL-8 is important for the regulation of neutrophils. Whereas IL-5 and relative eosinophil counts are profoundly affected by topical steroid treatment, IL-8 and neutrophils are not demonstrably affected by such treatment. It is possible that neutrophils, through the release of IL-8, could be chemotactic for eosinophils in steroid-treated patients.

Reactivity of T cells with grass pollen allergen extract and allergoid.

BACKGROUND: Successful allergen-specific immunotherapy is achieved with progressively increasing doses of allergen or allergoid. In order to gain further insight into the mechanism of action of allergoids several in vitro investigations were conducted. METHODS: Peripheral blood mononuclear cells (PBMC) from grass pollen allergic and nonallergic subjects were stimulated with either grass pollen extract or allergoid and the proliferation and cytokine production (IL-5, IFN-gamma) were measured. Similar investigations were performed with Phl p 5-specific T cell lines (TCL) and clones (TCC). Dendritic cells and PBMC were compared in terms of their relative efficacies as antigen-presenting cells. RESULTS: Both allergen and allergoid induced proliferation and Th2 and Th1 cytokine synthesis by PBMC of allergic subjects, whereas PBMC of nonallergic subjects did not produce IL-5. The maximum level of IL-5 was obtained with a lower concentration than was necessary for maximal IFN-gamma production. Higher stimulation doses of allergen and allergoid shifted the cytokine profiles towards a Th1 phenotype. TCL and TCC clearly showed reactivity with both allergen and allergoid when using autologous PBMC for antigen presentation, but compared with the native allergen the reactivity of the allergoid was reduced with most of the TCC. Using dendritic cells for antigen presentation a pronounced increase of stimulation of the TCC especially for the allergoids becomes obvious. CONCLUSION: In common with grass pollen allergen the corresponding allergoids possess a strong allergen-specific T cell-stimulating capacity. However, the degree of T cell stimulation by the allergoid seems to be dependent on the type of the antigen-presenting cell. Both, allergen and allergoid, can modulate T cell responses in a dose-dependent manner.

The immediate and late allergic response to segmental bronchopulmonary provocation in asthma.

The response to antigen is an important factor in the development of airway inflammation. Segmental bronchoprovocation (SBP) with antigen and subsequent bronchoalveolar lavage (BAL) have provided valuable insight into the mechanisms of allergic inflammation. To determine the features of allergic airway response in asthma, 19 subjects with mild asthma underwent antigen SBP in a dose-dependent manner. The amount of antigen used in SBP was 0 (saline), and 1, 5, or 20% of the antigen dose required to drop the FEV1 by 20% (APD20). BAL was done at 5 min and 48 h after SBP. BAL histamine levels increased modestly 5 min after antigen SBP. At 48 h, there was a marked increase in eosinophils and IL-5 concentration even in airway segments where the release of histamine was small. Moreover, eosinophils correlated with IL-5 levels at 48 h (r = 0.63; p < 0.001), but not with BAL histamine concentrations at 5 min. GM-CSF levels did not increase after antigen SBP and did not correlate with eosinophils. These observations indicate that asthmatic subjects can develop a dose-dependent response to antigen SBP that is characterized by a modest increase in histamine immediately after antigen exposure, and marked eosinophilia, which appears proportionately greater than the histamine response and relatively greater than what is seen in allergic nonasthmatic subjects. This feature might be important to the eventual development of airway inflammation in asthma.

Nasal messenger RNA expression of interleukins 2, 4, and 5 in patients with allergic rhinitis.

In nasal biopsies from 17 adult patients with seasonal allergic rhinitis and from 10 healthy controls, cytokines were analyzed by reverse-transcriptase polymerase chain reaction (RT-PCR). The time-course study during winter included repeated local allergen provocation with subsequent nasal biopsies as well as biopsies taken during pollen season. The RT-PCR for CD44 yielded positive bands in 65 of 71 cases, in which cases mRNA for interleukins 2, 4, and 5 (IL-2, IL-4, and IL-5) were thus investigated by means of seminested PCR. IL-4 mRNA was found almost exclusively in the allergic patients. During provocation a significant increase in IL-4 was noticed compared with controls (p = 0.043). Equally, during the natural pollen season, IL-4 mRNA expression was significantly higher in patients not using nasal corticosteroids compared with those who did (p = 0.011). No differences in IL-2 or IL-5 were observed between the groups. These findings also indicate, together with earlier observations of T-cell activation, a phenotype switch toward T-helper 2 (Th2) cells, and the accumulation (homing) of these T cells in the nasal mucosa, that T cells constitute the main source for IL-4 in the nasal mucosa. Therefore, allergic patients have an increased synthesis of IL-4 when provoked with the allergen, and during natural pollen season this synthesis can be downregulated by corticosteroids. Furthermore, this study exemplifies the versatility of molecular biology in surgical pathology and that even low-copy-number cytokine mRNA can be examined in routinely snap-frozen surgical specimens.