Allergens in pepper and paprika

Mugwort and birch pollen allergy are frequently associated with IgEmediated hypersensitivity to celery and spices. We analyzed 22 sera from patients with the mugwort-birch-celery-spice syndrome for IgE binding to the spices pepper and paprika by immunoblotting. Immunoblot results revealed two major allergens of 28 and 60 kDa in pepper and a 23-kDa allergen together with allergens of higher molecular weight in paprika. In immunoblot-inhibition studies, crude mugwort, birch pollen, and celery extracts significantly reduced the IgE binding to pepper and paprika allergens. However, no inhibition was achieved with rBet v 1 and rBet v 2, suggesting that no homologs of these birch proteins act as allergens in pepper or paprika extracts, N-terminal sequence analysis of the 14- and 28-kDa pepper and 23-kDa paprika allergens revealed no homology to known allergens. The 28-kDa pepper allergen showed homology to a wheat germin protein, and the 23-kDa paprika allergen was identified as a homolog of a osmotin-like or pathogenesis-related protein in tomato. Therefore, we conclude that the IgE cross-reactivity in the mugwort-birch-celery-spice syndrome to the spices pepper and paprika is not caused by homologs of Bet v 1 and profilin, N-terminal amino acid sequence analysis of the main allergens in pepper and paprika indicate a relation to frequently occurring plant proteins.     

Allergenic cross-reactivity of olive pollen

BACKGROUND: Sera of patients allergic to olive (Olea europaea) pollen were used to analyze the IgE cross-reactivity between olive-pollen extract and other pollens obtained from phylogenetically unrelated species. METHODS: We used IgE immunostaining of pollen extracts blotted to nitrocellulose membranes after SDS-PAGE and inhibition analysis of this binding. RESULTS: A high inhibition of the IgE binding on olive-pollen extract was exhibited by birch, mugwort, pine, and cypress pollens, suggesting that these extracts contain proteins which share common epitopes and thus can be recognized by olive-allergic sera. IgE binding to Gramineae pollen extracts was not inhibited by olive-pollen extract, indicating a primary sensitization of the patients to these species. From the inhibition assays, the presence of an allergen of 45 kDa in the olive pollen, which has no homologous counterparts in other allergenic species, has been inferred. CONCLUSIONS: Olive pollen contains allergens which cross-react with pollens from unrelated species, a fact that could simplify the diagnosis and treatment of pollinosis.     

A human monoclonal IgM with autoantibody activities against heparan sulphate and the mitotic spindle.

A monoclonal IgM kappa from a patient with Waldenström''s macroglobulinaemia (IgM-Rod) was found to react at temperatures below 28 degrees C with all tissue basement membranes and the cell coat of non-haematopoietic cells. IgM-Rod antibody was directed against heparan sulphate side chains of heparan sulphate proteoglycans as shown by binding in a solid-phase ELISA to heparan sulphate glycosaminoglycans but not to other purified subcomponents of the extracellular matrix; and by specific inhibition of the observed reactivity by heparitinase treatment. IgM-Rod showed cross-reactivity by indirect immunofluorescence with an as yet unidentified structure expressed in the nucleus during cell division and becoming associated with the mitotic spindle apparatus. The co-existence of both binding activities for heparan sulphate and nuclei determinants in the same IgM molecule was deduced from adsorption-elution experiments and from the inhibitory effect of a mouse monoclonal anti-idiotypic antibody directed against the paratope of IgM-Rod.     

Evaluation of food-pollen cross-reactivity by nose-mouth cross-challenge in pollinosis with oral allergy syndrome

BACKGROUND: Oral allergy syndrome (OAS) is often associated with pollen-induced rhinitis, and there are preferential associations between causative substances. If OAS and rhinitis are both immunoglobulin (Ig)E-mediated and there are cross-reacting proteins, it is expected that similar reactions can be elicited in the nose and mouth. In order to test this hypothesis we performed a series of 'cross-challenges' with foods and pollens in both the nose and the mouth. METHODS: Nine patients with ascertained OAS due to vegetables and rhinitis due to pollens were studied. On the first day a nasal challenge with pollen extracts and an oral challenge with fresh food was carried out. After a week, washout nasal challenge with food and an oral challenge with pollens were performed. Immediate symptoms, mucosal tryptase and soluble eosinophil cationic protein (ECP) were assessed after each challenge. RESULTS: The administration of pollen into the nose and food into the mouth elicited symptoms as expected, but the cross-challenge had no clinical effect. In parallel, tryptase and ECP increased after nasal challenge with pollens, whereas foods did not elicit a measurable response. CONCLUSION: The cross-reactivity between foods and pollens, when evaluated at the shock organ, was not clinically evident. This data can be explained with a low concentration of cross-reagent epitopes in pollen extracts and food homogenized because of degradation. The different behaviour upon challenge suggests that different immunological mechanisms may act in the nose and mouth.     

A mimotope defined by phage display inhibits IgE binding to the plant panallergen profilin

Birch pollen and mugwort pollen allergies are often associated with hypersensitivity to plant foods. This clinical and serological cross-reactivity is mediated by IgE antibodies reacting with homologous proteins in pollen and food. Cross-reacting homologs of the important birch pollen allergen Bet v 2 (profilin) could be detected in other pollen, fruits, nuts, and vegetables, such as celery tuber. We purified IgG/IgE antibodies from the serum of an exclusively profilin-allergic patient using affinity columns either coupled with protein extracts from mugwort pollen, birch pollen, or celery tuber. Constrained and unconstrained random nonapeptide libraries were pooled and screened with the anti-profilin antibody preparations to define cross-reactive ligands. Specific ligands were enriched by successive panning rounds using the profilin-specific antibodies in series. After the last panning round enriched phage clones were screened with purified profilin-specific antibodies and IgE-binding clones were sequenced. Five out of eight positive clones (62.5 %) displayed the same circular peptide CAISGGYPVC. This peptide was synthesized and examined for its ability to inhibit IgE binding to blotted mugwort pollen, birch pollen, or celery tuber profilin. Inhibition studies showed reduction of IgE binding to profilins in all three protein extracts. As the sequence of the mimotope did not show any homology to the known birch profilin sequence this peptide is considered to mimic a common conformational IgE epitope for these examined profilins.     

黑胸大蠊与美洲大蠊交叉抗原成分比较

对黑胸大蠊与美洲大蠊体部浸出液交叉抗原成分进行分析 ,为利用有关美洲大蠊分子克隆的资料进行黑胸大蠊主要变应原的克隆、测序和重组表达做前期工作。制备纯种黑胸大蠊及美洲大蠊的体部浸出液 ,采用SDS PAGE (12 %分离胶 )分离蛋白成分 ,用Coomassi亮蓝染色 ,比较两种来源蛋白成分的差异。然后将蛋白电转至PVDF膜 ,以兔抗黑胸大蠊体部浸出液 (WBE )抗体作为第一抗体 ,进行Western免疫印迹检测 ,以判断两种蟑螂的交叉抗原成分。两种蟑螂体部浸出液蛋白成分的SDS PAGE带型略有差异 ,主要是条带密度不一致 ,而从其疏密分布 (分布型式 )上看 ,两者间存在相当多的分子量相同或相近组分。经SDS PAGE分离的条带多达近 30条 ,分子量相同的组分多达 2 0余条。免疫印迹表明 ,针对兔抗黑胸大蠊体部浸出液 (WBE )抗体 (IgG )有交叉反应的抗原成分多达 10几条。黑胸大蠊与美洲大蠊体部浸出液的蛋白成分或变应原组分间存在交叉反应成分。提示 ,利用有关美洲大蠊分子克隆的资料进一步对黑胸大蠊主要变应原进行克隆、测序或重组表达等分子生物学研究具备一定的可行性。     

Cross-reacting IgE and IgG antibodies to Pityrosporum ovale mannan and other yeasts in atopic dermatitis.

Atopic dermatitis (AD) patients often demonstrate positive skin prick test results and serum IgE antibodies to a range of different yeasts. This has been thought to be due to cross-reactivity. In this study, the cross-reactivity of IgE and IgG antibodies between mannan and crude antigens of Pityrosporum ovale, Candida albicans, and Saccharomyces cerevisiae and crude antigens of Cryptococcus albidus and Rhodotorula rubra was examined by RAST and ELISA inhibition with two serum pools of AD patients. We found cross-reacting IgE and IgG antibodies. In the IgE response, the main cross-reacting pattern was the mannan region, although inhibition could be achieved also with crude antigens of C. albicans, S. cerevisiae, and, to some extent, C. albidus. P. ovale was the most potent inhibitor of IgE-binding components, and against it the highest IgE antibody levels were detected in AD serum pools. In contrast, C. albicans was found to be the most important inducer of IgG antibodies, since the IgG level against P. ovale mannan in both AD serum pools was very low. Cross-reacting antibodies were also seen in ELISA inhibition with both crude and mannan antigens, but since the IgG antibody level of P. ovale mannan in AD serum pools was low, further studies are needed to confirm the IgG results.