Allergenic cross-reactivity among pollens of Urticaceae

Common antigenic determinants have been observed between Parietaria and Urtica dioica pollen. The four Parietaria pollens selected (P. judaica, P. officinalis, P. lusitanica and P. mauritanica) are shown to possess a high allergenic homology. IgE-binding structures, homologous to the P. judaica main allergenic polypeptide (Pj10), were found in the other species by immunodetection. Monoclonal antibodies specific to the Pj10 polypeptide recognized proteins from the four Parietaria pollens. Skin prick test and RAST inhibition yielded results that also indicated a high allergenic cross-reactivity among these pollens, with homologous peptides bearing common antigenic and allergenic determinants. On the other hand, U. dioica pollen showed only a slight allergenic similarity to Parietaria. The potential allergenic activity of these pollens is discussed.     

Allergenic cross-reactivity between Callistemon citrinis and Melaleuca quinquenervia pollens

Aqueous extracts of both Callistemon citrinis (bottlebrush) and Melaleuca quinquenervia (melaleuca) were analyzed for allergenic cross-reactivity. Inhibition analysis using the radioallergosorbent test (RAST) was performed on the ammonium bicarbonate extracts of bottlebrush (NH4B) and melaleuca (NH4M) pollens. RAST inhibition analysis demonstrated that the extracts contained allergenically cross-reactive components. Sephadex G-100 column chromatography of NH4B and NH4M extracts resulted in at least 4 distinct peaks for each extract analyzed. These fractions were designated NH4B1-NH4B4 and NH4M1-NH4M4. A modified dot-blot assay for detection of allergenic components was utilized to show that the first elution peaks of bottlebrush and melaleuca, NH4B1 and NH4M1, respectively, contained allergenic components. These allergenic components, NH4B1 and NH4M1, had estimated molecular weights of 50,000 and 35,000 daltons, respectively.     

Allergenic cross-reactivity of yeasts

Yeast allergen extracts of Candida albicans, C. pseudotropicalis, C. krusei, C. parapsilosis, C. tropicalis, C. guilliermondi, C. humicola, C. norwegica, C. utilis, Cryptococcus albidus, Geotrichum candidum, Pityrosporon pachydermatis, P. ovale, Rhodotorula minuta, R. rubra, Saccharomyces cerevisiae, Torulopsis glabrata and Trichosporon cutaneum were investigated regarding their common allergenic properties. The enzyme immunoassay (EIA) using rabbit anti Candida albicans antiserum showed remarkable immunological cross-reactivity only between the Candida species. However, there was a significant multiple sensitivity to the extracts of C. albicans, C. utilis, Cr. albidus, R. rubra , and S. cerevisiae in skin prick testing in atopic patients, suggesting the possible presence of one or more common skin reactive allergens.     

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.     

Allergenic pollens and pollinosis in Italy: recent advances

The authors have mapped the occurrence of allergenic pollens throughout Italy and defined their most common clinical symptoms. To obtain an accurate aerobiological and clinical picture of such a geographically complex country as Italy, a detailed investigation was carried out involving 80 data-gathering stations and 40 clinical centers nationwide. Three main pollination periods can be distinguished: winter-pre-spring (January to March) for Betulaceae, Corylaceae, Cupressaceae, Salicaceae and Ulmaceae: spring-summer (April to June) for Gramineae, Urticaceae, Oleaceae, Plantago, Fagaceae, Pinaceae and Polygonaceae , and summer-autumn (August to September) for Urticaceae, Composilae and Chenopodiaceae. Examination of 49660 patients affected by pollinosis (conjunctivitis, rhinitis, asthma, with positive skin tests or IgE-specific serum determination: RAST, ELISA) throughout Italy revealed sensitivity to Gramineae in 64.6%, to Parietaria in 36.7% to Oka in 15.8%, to Compositae in 13.2%, to Betulaceae-Corylaceae in 7% and to Fagaceae-Cupressaceae-Plantago in 4%–10%; marked regional variations were observed. The patients suffered from rhino-conjunctivitis (55.7%), rhino-conjunctivitis plus asthma (31.6%) and asthma (12.7%). In monosensitised individuals, Parietaria was seen to be the main cause of the asthmatic syndrome (though our preliminary data also implicate Olea followed by Grawmeae.     

Allergenic cross-reactivity of Curvularia lunata with other airborne fungal species

BACKGROUND: Curvularia lunata is an important fungus for respiratory allergic disorders. Previous studies indicated cross-reactivity of Curvularia with other fungi. However, the cross-reactive allergenic component (s) were not identified. The present work was carried out to study the shared allergenic components of C. lunata and others. METHODS: Cross-reactivity studies were performed using pooled hypersensitive patient sera to C. lunata by ELISA, immunoblot, immunoblot inhibition and ELISA inhibition. RESULTS: Many C. lunata sensitive patients showed positive skin test to five other fungi. Alternaria alternata exhibited maximum (68%) whereas Cladosporium herbarum showed the least (17%) skin reactivity. Immunoblots of fungal extracts with pooled sera showed common proteins. Fusarium solani and C. herbarum showed negligible IgE binding. IgE ELISA inhibition with C. lunata showed 92% inhibition whereas A. alternata and E. nigrum showed 84% and 63%, respectively. Immunoblot inhibition with self protein showed complete loss of IgE-binding activity. Proteins of 26, 31, 38, 45 and 50 kDa of C. lunata were inhibited by A. alternata and E. nigrum, whereas A. fumigatus inhibited 26, 45 and 50 kDa proteins. CONCLUSIONS: Significant allergenic cross-reactivity exists among proteins of C. lunata, A. alternata and E. nigrum. Proteins of 26, 31, 38, 45 and 50 kDa are shared allergens in these fungi.     

Allergenic composition of the mite Suidasia medanensis and cross-reactivity with Blomia tropicalis

BACKGROUND: Mites of the genus Suidasia are commonly found in house dust and may play an allergenic role in exposed populations. However, the allergenic potential and clinical impact of this genus has not been well established. The main objective of this project was to evaluate the allergenic role of the mite Suidasia medanensis. METHODS: An extract of S. medanensis was prepared and the allergen composition determined by immunoblot. Specific IgE antibody levels to S. medanensis and Blomia tropicalis were evaluated by radioallergosorbent (RAST) in the sera of 97 allergic asthmatic patients and 50 nonallergic subjects. Cross-reactivity between S. medanensis and the mite species B. tropicalis and Dermatophagoides farinae was investigated by RAST and immunoblot inhibitions. RESULTS: Seventy-one asthmatic patients sera (73.2%) had positive IgE reactivity to S. medanensis; 14 allergens with molecular weights ranging from 7.5 to 105 kDa were detected. The most frequently detected had molecular weights of 30-31 (54.8%), 24.5 (42%), 21 (38.7%), 47 (35%) and 58 kDa (35.5%). Blomia tropicalis extract inhibited IgE binding to nine of these identified allergens. Four B. tropicalis allergens were inhibited by S. medanensis extract. RAST inhibition results demonstrated a high degree of inhibition by B. tropicalis (87.2%) and D. farinae (90.9%) than by S. medanensis (32%). CONCLUSIONS: Sensitization to S. medanensis is common in asthmatic allergy patients in Cartagena. An important degree of cross-reactivity was established between S. medanensis and B. tropicalis, and D. farinae.     

Allergenic properties of kiwi-fruit extract: cross-reactivity between kiwi-fruit and birch-pollen allergens

Our investigation aimed to produce and characterize a kiwi extract and to use this extract to investigate a possible cross-reactivity with birch pollen. Kiwi was extracted in two buffers: phosphate-buffered saline (PBS) and borate-buffered saline (BBS). Extraction in BBS produced a double amount of protein, and a more stabile extract. Tandem crossed-immunoelectrophoresis showed that the BBS and PBS extracts had several common, but also a few individual, proteins. The mixture of both extracts was assumed to represent the most complete allergen extract. The allergenic properties of the kiwi extract were investigated by immunoblotting (IB), RAST, and histamine-release (HR) test in 15 birch-pollen-allergic patients (eight of them with clinical kiwi allergy) and one with clinical monoallergy to kiwi. All eight birch-pollen-allergic patients with kiwi allergy and the kiwi-monoallergic patient were positive in kiwi IB binding most frequently to proteins of 10-12 and 20-25 kDa. With our extract, RAST was positive in four kiwi-allergic and one non-kiwi-allergic patient, whereas the HR test was positive in five kiwi-allergic patients and negative in all non-kiwi-allergic patients. RAST and IB inhibition demonstrated cross-reactivity between birch-pollen and kiwi allergens due to a 10-12 kDa protein. In conclusion, a kiwi extract with allergenic properties was produced, and, by the methods used, cross-reactivity was demonstrated between birch-pollen and kiwi allergens.     

Allergenic cross-reactivity of egg-white and egg-yolk proteins. An in vitro study

The radioallergosorbent test (RAST) and RAST inhibition test were used to examine cross-allergenicity amongst the major hen's egg-white and egg-yolk proteins. Using ovalbumin as a reference allergen to compare cross-reactivity, it was apparent that the proteins conalbumin, ovomucoid and lysozyme substantially inhibited binding to ovalbumin discs of IgE in the sera of patients clinically hypersensitive to egg. The converse situation with conalbumin, ovomucoid and lysozyme on the discs and ovalbumin as the inhibitor also resulted in significantly decreased levels of IgE binding to the proteins on the discs. It was also demonstrated that cross-reactions occurred between ovalbumin and the yolk protein, apovitellenin I. Cross-reaction was also observed surprisingly when egg lysozyme was on the disc and the milk protein allergen alpha-lactalbumin was used as the inhibitor. The demonstration of cross-reaction between all of these proteins may signify that there are a number of common allergenic determinants on these egg proteins, thus providing a molecular basis for the phenomenon of cross-reactivity.     

Immunologic characterization of a recombinant Kentucky bluegrass (Poa pratensis) allergenic peptide

A recombinant peptide of Kentucky bluegrass (KBG) pollen was synthesized as a fusion protein (FP) in Escherichia coli by recombinant DNA procedures and was compared with its natural counterparts with respect to its allergenic properties. The FP was demonstrated to bind to the IgE antibodies (Abs) of greater than or equal to 95% of 55 individual sera examined. A positive correlation (r = 0.90) was observed between the levels of IgE Abs corresponding to the FP and the grass-pollen extract(s). With sera of five allergic patients, the IgE binding of three different protein preparations were compared, namely, KBG pollen proteins, 27 to 35 kd gel-purified pollen proteins, and the FP. Results indicated that about 50% of the total IgE binding of KBG pollen proteins was due to the IgE Abs specific to FP. Comparison of the above protein preparations with respect to their abilities to specifically stimulate murine popliteal lymph node cells in vitro indicated that the total pollen proteins stimulated the highest proliferation of lymph node cells. Interestingly, the FP supported higher proliferation of lymph node cells than the gel-purified proteins. Collectively, these results suggest that the recombinant peptide constitutes a major allergenic constituent of grass pollens and may be of diagnostic and therapeutic value.     

Allergy to Diplotaxis erucoides pollen: occupational sensitization and cross-reactivity with other common pollens

BACKGROUND: Diplotaxis erucoides is a common weed of the Brassicaceae family widespread in southern and central Europe. METHODS: A total of 410 consecutive patients referred for allergy study of rhinoconjunctivitis and/or asthma were skin tested with D. erucoides pollen, 14 proving positive. A purified D. erucoides pollen extract was prepared to perform quantitative skin tests, provocation tests, immunoblotting, and EIA inhibition in the 14 sensitized patients. RESULTS: Three patients, directly involved in viniculture, had rhinoconjunctivitis related to D. erucoides pollen. No D. erucoides-related symptoms were observed in most patients, who were also sensitized to Artemisia pollen. RAST was positive in 12/14 patients and nasal provocation tests in 9/12. The molecular masses of the most prevalent IgE-binding proteins ranged from 26 to 27.5 and from 31 to 34 kDa. D. erucoides pollen inhibited the IgE-binding of other sensitizing pollens in the three viniculture workers, whereas both Artemisia and D. erucoides pollen produced similar heterologous inhibition in the pooled serum of the remaining, nonclinically affected, D. erucoides-sensitized patients. CONCLUSION: D. erucoides pollen may be an important prevalent aeroallergen, particularly in rural areas. It may act as an occupational allergen in vineyard workers, in whom it seems to be the primary sensitizing agent, playing a secondary cross-reactive role in other sensitized patients.     

Cytochrome c mRNA levels decrease in senescent rat heart

The concentration of mitochondria decrease in the heart as rodents age from maturity to senescence. The reason for this change is not known. One purpose of the present study was to determine if cytochrome c mRNA, representative of proteins of the inner mitochondrial membrane, decreased in the hearts of Fischer 344 rats as they aged from 12 to 24 months. Twenty-two percent less cytochrome c mRNA existed per given quantity of extracted RNA from the heart in 24-month-old rats as compared with the 12-month-old group. No change in the quantities of cardiac α-actin mRNA, Ca²⁺/calmodulin protein kinase II mRNA or 18S rRNA was noted between 12- und 24-month-old hearts. Thus, the decrease in cytochrome c mRNA suggests that decreased in mRNAs for proteins of the inner mitochondrial membrane could play some role in the diminished concentration of mitochondria that exists in the senescent heart.     

Allergenic fragments of ryegrass (Lolium perenne) pollen allergen Lol p IV

To facilitate studies on establishing the nature of structure/function relationships of allergens, ryegrass pollen allergen, Lol p IV, was cleaved into smaller fragments by cyanogen bromide (CNBr) and the resulting peptides were further digested with trypsin. The resulting peptides were then fractionated by high performance liquid chromatography (HPLC) on a C-18 reverse phase column. The allergenic activity of the HPLC fractions was evaluated in terms of their ability to inhibit the binding of 125I-Lol p IV to serum IgE antibodies of a grass-allergic patient. Many of these fractions inhibited the binding between the native allergen and IgE antibodies in a dose-dependent manner. The inhibitions were specific, i.e., the fractions did not inhibit the binding between 125I-Lol p I (a group-I ryegrass pollen allergen) and the IgE antibodies present in the allergic human serum. The possibility that the allergenic peptide fractions were contaminated by the native undegraded allergen, which might have accounted for the observed inhibition, was ruled out by the fact that the native allergen could not be detected by SDS-PAGE and the elution profiles of allergenically active peptides did not coincide with that of native allergen. One of the allergenic sites recognized by monoclonal antibody (Mab) 90, i.e., site A, was located in HPLC fractions 90-100 while another allergenic site B (recognized by Mab 12) appeared to be lost following the sequential digestion of Lol p IV with CNBr and trypsin.     

Allergenic components of Indian jujube (Zizyphus mauritiana) show IgE cross-reactivity with latex allergen

BACKGROUND: 'Latex-fruit syndrome' has been well documented. A prevalence of latex allergy among medical workers of 6.8-8.6% had been reported in Taiwan. However, there has been no study to determine the importance and type of fruit hypersensitivity in latex-allergic patients in Taiwan. This study aimed to identify the allergenic components of Indian jujube (Zizyphus mauritiana) and characterize the cross-reactivity of specific IgE antibodies to latex allergen. METHODS: Crude extracts were prepared from Indian jujube and from ammoniated natural rubber latex, and six medical workers and one patient with a history of fruit allergy underwent skin testing with routine allergens, latex, Indian jujube and other fruits. Sera from two Indian jujube skin test-positive latex-allergic subjects were used for allergen-specific IgE, immunoblotting, immunoblot inhibition and enzyme-linked immunosorbent assay (ELISA) inhibition studies. RESULTS: Both patients had positive skin test responses and specific IgE assays to Indian jujube and latex extracts. Immunoblotting revealed that IgE from both subjects bound to a 42-kD latex protein and a 42-kD Indian jujube protein. In addition, IgE from one subject bound to a 30-kD Indian jujube protein. Preincubation of atopic sera with Indian jujube or latex extract demonstrated absent and/or marked inhibition of IgE binding. Moreover, anti-Indian jujube protein antibody-based ELISA was able to detect latex extracts. CONCLUSIONS: Our results add to findings regarding the 'latex-fruit syndrome' described in the literature, and further study of the cross-reacting allergens identified in Indian jujube may help to elucidate the mechanisms underlying this syndrome.     

Allergenic cross-reactivity of several strains of Trichinella in mice and rats by the passive cutaneous anaphylaxis technique

The cross-reactivity of antiparasite IgE antibody responses induced by allergenic antigens obtained from Trichinella spiralis and Trichinella pseudospiralis was determined by the passive cutaneous anaphylaxis (PCA) technique in BCF1 mice infected with T. spiralis, Trichinella nelsoni, Trichinella nativa, and T. pseudospiralis and in rats infected with T. spiralis and T. pseudospiralis. Our results demonstrate that when the antigen used for the PCA challenge is derived from muscular L1 larvae of T. spiralis, high IgE antibody titres can be detected from sera of animals infected with T. spiralis, T. nelsoni, or T. nativa, but not with T. pseudospiralis, during the entire life cycle of the parasite. However, when homologous antigens are used in the PCA test, we obtained comparable values of IgE titres in rats and mice infected with both T. spiralis and T. pseudospiralis strains. These results suggest the existence of a high degree of immunologic identity between the allergenic antigens of T. spiralis, T. nelsoni, and T. nativa strains, but not T. pseudospiralis.     

Cytochrome c oxidase defects of the human substantia nigra in normal aging

Based on morphological, biochemical, and molecular biologic analyses, degeneration of the dopaminergic nigrostriatal system has been reported to occur with normal aging. In the present study, the substantia nigra of 36 human brains with normal aging was investigated by means of morphometry and immunohistochemistry. The anteromedial (Am), anterointermediolateral (Ail), posteromedial (Pm), and posterolateral (Pl) nuclei of the substantia nigra were analyzed using antibodies directed against the subunits II/III of cytochrome c oxidase (COX), the complex IV of the respiratory chain. The numerical density of melanin-positive neurons with COX defects was significantly increased in the four investigated nuclei, namely Am, Ail, Pm, and Pl. These cells did not show any histologic signs of degeneration. The numerical density of melanin-positive neurons without COX defects was decreased with aging. The data of the present study indicate that complex IV defects of neurons in the substantia nigra might be one cause of neuronal dysfunction occurring during aging.     

Analysis of IgE binding proteins of mesquite (Prosopis juliflora) pollen and cross-reactivity with predominant tree pollens

Pollen from the mesquite tree, Prosopis juliflora, is an important source of respiratory allergy in tropical countries. Our aim was to partially characterize the IgE binding proteins of P. juliflora pollen extract and study cross-reactivity with prevalent tree pollen allergens. Intradermal tests with P. juliflora and five other tree pollen extracts were performed on respiratory allergy patients from Bikaner (arid) and Delhi (semi arid). Prosopis extract elicited positive skin reactions in 71/220 of the patients. Sera were collected from 38 of these 71 patients and all demonstrated elevated specific IgE to P. juliflora. Immunoblotting with pooled patients' sera demonstrated 16 IgE binding components, with components of 24, 26, 29, 31, 35, 52, 58, 66 and 95 kDa recognized by more than 80% of individual patients' sera. P. juliflora extract is allergenically potent requiring 73 ng of self-protein for 50% inhibition of IgE binding in ELISA inhibition. Cross-inhibition assays showed close relationship among P. juliflora, Ailanthus excelsa, Cassia siamea and Salvadora persica. IgE binding components of 14, 41, 52 and 66 kDa were shared allergens whereas 26 and 29 kDa were specific to P. juliflora. The findings suggest that purification of cross-reactive allergens will be helpful for diagnosis and immunotherapy of tree pollen allergic patients.     

Isolation and characterization of Poa p I allergens of Kentucky bluegrass pollen with a murine monoclonal anti-Lol p I antibody

The Poa p I allergens were isolated from the retentate fraction of a dialyzed preparation of an aqueous extract of Kentucky bluegrass pollen by means of a reverse immunosorbent prepared with a murine anti-Lol p I monoclonal antibody, Mab 290-A-167. By sodium dodecyl sulphate-polyacrylamide gel electrophoresis and preparative isoelectrofocusing, Poa p I was found to consist of a 35.8-kD component with an isoelectric point of 6.4 and a 33-kD component with one of 9.1 and designated as Poa p Ia (acidic) and Poa p Ib (basic), respectively. The relative protein content of these components was estimated from the intensity of the stained bands following sodium dodecyl sulphate-polyacrylamide gel electrophoresis. Thus, Poa p Ia appeared to be the major protein constituent, and on Western immunoblot it also bound the monoclonal antibody to a greater extent than Poa p Ib. On the other hand, Poa p Ib was shown by Western immunoblot and autoradiographic analysis, to bind to a greater extent the IgE antibodies present in a pool of sera from grass-allergic individuals. Therefore, Poa p Ib was considered as the major allergenic component of Poa p I. By competitive inhibition of the radioallergosorbent test, it was demonstrated that the Mab inhibited the binding of Poa p I allergens to human IgE antibodies to the extent of 70%. Hence, it is suggested that Mab and human IgE antibodies recognize identical or closely related determinants of Poa p I allergens.