T cell response to grass pollen allergens: correlation with skin test reactivity and serum IgE levels

Inhibitory Activity of Allergic Contact Dermatitis and Atopic Dermatitis-Like Skin in BALB/c Mouse through Oral Administration of Fermented Barks of Alnus sibirica

Phytochemical isolation of fermented Alnus sibirica (FAS) which was produced by using Lactobacillus plantarum subsp. argentoratensis, exhibited multiple and different composition compared with the original plant. Anti-allergic contact dermatitis (anti-ACD)/anti-atopic dermatitis (anti-AD) activities (visual observation and regulation of Th₁/Th₂ cytokines and IgE in blood) of FAS and the barks of Alnus sibirica extract (AS) and the two diarylheptanoids, hirsutenone (1) and muricarpon B (2), which are major components of FAS, were measured in vitro and in vivo. FAS, AS and the two compounds showed potent anti-oxidative, anti-inflammatory, anti-ACD and anti-AD activity. In particular, FAS showed more potent biological activity than AS. Thus, fermentation might be a prominent way to enhance the biological activity compared with the original plant. In addition, compounds (1) and (2) might be developed as functional materials or herbal medicines for ACD and AD.

House dust and forage mite allergens and their role in human and canine atopic dermatitis

This article reviews the literature regarding the role of house dust and forage mite allergens in canine atopic dermatitis. The presence of immunoglobulin E (IgE) to these mites, especially to Dermatophagoides farinae, is common in both normal and atopic dogs. Exposure of dogs to the different mites is described both in the direct environment and in the coat of animals for house dust mites and in the food for forage mites. Allergens causing allergic disease in dogs seem to be different from those in humans. Dogs seem to react to high molecular weight allergens, compared to the low molecular weight group 1 and group 2 proteases that are commonly implicated in humans with atopic diseases. Despite numerous published studies dealing with this subject, a number of questions still need to be addressed to better understand the exact role of these mites in the pathogenesis of canine atopic dermatitis and to improve the quality of the allergens used in practice.

The combined effects of zafirlukast, prednisone, and inhaled budesonide on IL-13 and IFN-gamma secretion

Therapy for asthma often includes the combined use of glucocorticoids and leukotriene receptor antagonists. The short-term, combined effects of these drugs on cytokine secretion and lymphocyte proliferation are ill-defined. The aim of this study was to analyze allergen and mitogen-induced cytokine secretion and lymphocyte proliferation in asthmatics and to determine the effect of combined therapy on these immune responses. Peripheral blood mononuclear cells were isolated from mild, persistent adult asthmatics (n = 28) and analyzed for cat allergen (Fel d 1) and mitogen (phytohemagglutinin) induced IL-13 and IFN-gamma secretion and lymphocyte proliferation. Samples were analyzed before and after 10 days of therapy with oral zafirlukast, prednisone (0.5 mg/kg/day), and inhaled budesonide (1600 mcg/day). Both Fel d 1 and mitogen stimulation resulted in IL-13 and IFN-gamma secretion. Combination drug therapy resulted in a significant decrease in allergen-induced IFN-gamma secretion (p = 0.018) and allergen-specific lymphocyte proliferation (p = 0.02), while IL-13 secretion was unchanged (p = 0.109). This study indicates a role for Th1 cytokines as well as Th2 cytokines in the allergic response.

Characterization of the human T cell response to rye grass pollen allergens Lol p 1 and Lol p 5

BACKGROUND

Knowledge of dominant T cell epitopes of major allergens recognized by allergic individuals is required to improve efficacy and safety of allergen immunotherapy. Rye grass pollen (RGP) is the most important source of seasonal aeroallergens in temperate climates and Lol p 1 and Lol p 5 are the two major IgE-reactive allergens. This study aimed to characterize the T cell response to these allergens using a large panel of RGP-sensitive individuals.

METHODS

Short-term RGP-specific T cell lines (TCL) were generated from 38 RGP-sensitive subjects and stimulated with Lol p 1 and/or Lol p 5 allergens and synthetic 20-mer peptides. Proliferative responses were determined by 3H-thymidine uptake and IL-5 and IFN-gamma in culture supernatants analysed by ELISA.

RESULTS

Of 17 subjects tested for reactivity to both allergens 16 (94%) responded to Lol p 1 and/or Lol p 5, establishing these as major T cell-reactive allergens. Sites of T cell reactivity were spread throughout the allergen molecules but regions of high reactivity were found. For Lol p 1 these spanned residues 19-38, 109-128, 154-173, 190-209, and for Lol p 5 37-56, 100-119, 145-164, 154-173, 190-209, 217-236 and 226-245. IL-5 and IFN-gamma were produced by T cells cultured with proliferation-inducing peptides.

CONCLUSIONS

T cell responses to RGP major allergens have been extensively characterized, providing fundamental information for developing T cell-targeted immunotherapy for RGP allergy.

Expression of Th1, Th2 and immunosuppressive cytokine gene transcripts in canine atopic dermatitis

BACKGROUND

Atopic dermatitis is a common inflammatory skin disease of humans and dogs. Human atopic dermatitis is associated with Th2-type responses, although Th1 cytokines can be identified in chronic lesions. In contrast, tolerance to environmental allergens in healthy individuals is mediated by regulatory T cells.

OBJECTIVE

This study examined the expression of the immunosuppressive cytokines TGF-beta and IL-10, the Th2-type cytokines IL-4 and IL-6, and the Th1-type cytokines IFN-gamma, TNF-alpha, IL-2, IL-12p35 and IL-12p40, in canine atopic dermatitis.

MATERIALS AND METHODS

RNA was isolated from lesional atopic, non-lesional atopic and healthy canine skin samples. Semi-quantitative reverse transcriptase polymerase chain reactions (RT-PCRs) were carried out using specific primers and one-way analyses of variance used to compare cytokine expression in each group.

RESULTS

Canine atopic dermatitis was associated with over-expression of IL-4 mRNA and reduced transcription of TGF-beta compared with healthy skin (P < 0.05). Higher levels of IFN-gamma, TNF-alpha and IL-2 mRNA were seen in lesional compared with non-lesional and healthy skin (P < 0.05). There were no significant differences in IL-10, IL-6, IL-12p35 or IL-12p40 transcription between the three groups.

CONCLUSIONS

This is the first report to demonstrate that canine atopic dermatitis is associated with over-production of IL-4. Clinical tolerance in healthy individuals appears to be associated with TGF-beta, although it is unclear if this reflects an active mechanism or simply non-responsiveness of the immune system. Th1 cytokines may be induced by subsequent self-trauma and secondary infections in atopic skin. We believe that these results better characterize spontaneously occurring canine atopic dermatitis. We further propose that this should be investigated as a possible animal model of human atopic dermatitis.

Immunotherapy of allergy: anergy, deletion, and immune deviation

Decreased allergen-specific T cell proliferation and dysregulated cytokine synthesis accompany allergen immunotherapy, consistent with mechanisms of anergy and immune deviation. Recent studies emphasise the pivotal role of decreased T cell IL-4:IFN-gamma ratios. A landmark clinical trial of T cell epitope peptides for venom-immunotherapy shows efficacy and safety; murine models suggest intramolecular epitope-suppression inhibits responses to the whole allergen.