Rhinoconjunctivitis and asthma caused by vine pollen: a case report

BACKGROUND

The vine (Vitis vinifera) is a cultivated plant that is found in some European and American countries. Its pollen gathers in small quantities during a short pollination period in the months of May and June. Allergy to vine pollen has not been previously documented.

OBJECTIVE

We sought to describe a case report of allergy to vine pollen documented on the basis of anamnesis, cutaneous, provocation, and specific IgE determination tests.

METHODS

An allergenic extract was obtained from collected V vinifera pollens by aqueous standard procedures. Pollen counts and pollination periods of this and other common pollens in the area where the patient became symptomatic were studied. Cutaneous tests and the presence of specific IgE to the pollen extracts were performed by prick, CAP, and RAST techniques. Bronchial and conjunctival tests with the involved pollen extracts were also carried out to identify the sensitizing allergens. Five healthy subjects and 5 pollinic patients were used as control subjects and underwent the same tests.

RESULTS

Skin prick test responses with vine pollen at different concentrations were positive for the studied patient and negative for the control subjects. Patient serum revealed a total IgE titer of 334 IU/mL and a specific IgE value of 1.3 PRU/mL (RAST class 2) to vine pollen. Bronchial and conjunctival provocation test responses were also positive when the patient was challenged with V vinifera extract.

CONCLUSION

Exposure to the pollen of the vineyard plants (V vinifera) can induce immunologic sensitization and rhinoconjunctivitis/asthma.

Three replicons of Rhizobium sp. Strain NGR234 harbor symbiotic gene sequences

Rhizobium sp. strain NGR234 contains three replicons: the symbiotic plasmid or pNGR234a, a megaplasmid (pNGR234b), and the chromosome. Symbiotic gene sequences not present in pNGR234a were analyzed by hybridization. DNA sequences homologous to the genes fixLJKNOPQGHIS were found on the chromosome, while sequences homologous to nodPQ and exoBDFLK were found on pNGR234b.

[Fungemia in patients with HIV infection]

OBJECTIVE

To make an analysis of fungemia in HIV-infected patients in our hospital.

PATIENTS AND METHODS

We retrospectively (1989-1997) studied all HIV-infected patients with positive blood cultures for Candida sp., Cryptococcus neoformans or any other fungal infection.

RESULTS

C. neoformans was isolated in 11 patients (10 men and 1 woman): Six were treated with amphotericin B and 5 with fluconazole. 2 patients died during the acute phase and the infection relapsed in 3. Blood culture for Candida sp. were positive in 9 (8 men and 1 woman): only a case was nosocomial. Seven patients were intravenous drug users and the presenting manifestations were autolimited candidemia in 3, aortic and tricuspid endocarditis in 1 and 2 cases respectively and pneumonia in another one. Six C. albicans, 2 C. krusei and 1 C. glabrata were isolated. 3 patients received amphotericin B and 3 received fluconazole. 2 patients suffering from endocarditis died and so did the patient with C. glabrata infection. A patient, who denied having travelled to endemic areas, developed histoplasmosis; blood culture was positive for H. capsulatum. He initially had a good response to amphotericin B and itraconazole.

CONCLUSIONS

Fungemia is not frequent in HIV-infected patients. Cryptococcosis and histoplasmosis occur in advanced HIV-patients and candidemia is fundamentally associated with intravenous drug use.

Extracts from various mite species contain cross-reactive and noncross-reactive IgE epitopes. A RAST inhibition study

Previous studies have demonstrated the high incidence of Dermatophagoides, Euroglyphus, Blomia, Lepidoglyphus and Chortoglyphus spp. sensitizations in a mite-allergic population. The aim of this study was to evaluate immunological cross-reactivity among the above mentioned groups, using sera from a nonrural population allergic to mites, from a subtropical area (Canary Islands). RAST inhibition studies demonstrated significant cross-reactivity among Dermatophagoides and Euroglyphus species (> or = 65% of maximum theoretical inhibition), as also noted by other authors. Blomia kulagini demonstrated scarce cross-reactivity with Dermatophagoides, Lepidoglyphus and Chortoglyphus species (< or = 30% of maximum theoretical inhibition) and medium level with Euroglyphus maynei (45% of maximum theoretical inhibition). Chortoglyphus arquatus demonstrated high cross-reactivity levels with the other species studied. The results obtained in this study demonstrated the scarce immunological cross-reactivity between Pyroglyphidae and non-Pyroglyphidae mites, thus suggesting the polysensitization of the studied population to different mite species.

Study of a case of hypersensitivity to lettuce (Lactuca sativa)

BACKGROUND

Allergic reactions to lettuce (Lactuca sativa) are not too frequent and few cases of systemic adverse reactions after its ingestion have been described.

OBJECTIVE

We report a case of clinical sensitization to lettuce on a patient who presented mucocutaneous manifestations after its ingestion, with positive skin tests, histamine release test and serum specific-IgE to lettuce. The allergens responsible for this sensitization were also characterized by means of SDS-PAGE immunoblotting.

MATERIALS AND METHODS

We performed skin tests, histamine release test, serum specific IgE determination and CAP inhibition with lettuce and mugwort (Artemisia vulgaris) extracts. An aqueous and enriched lettuce (from loose leaf type) extract was subjected to SDS-PAGE immunoblotting for determination of its IgE-binding components.

RESULTS AND CONCLUSIONS

CAP inhibition showed antigenic community between lettuce and mugwort. Four protein bands from the lettuce extracts with molecular weights of 50, 43, 39 and 16 kDa exhibited IgE-binding properties.

Influence of mite growth culture phases on the biological standardization of allergenic extracts

House dust mites are a well known cause of asthma and other respiratory allergies. In order to improve the standardization of allergenic extracts for diagnosis and immunotherapy, it is important to determine the frequency and concentration of the components, both the major and the minor allergens during the growth period of the mite population. In a previous paper we demonstrated that the laboratory cultures of Dermatophagoides pteronyssinus and Dermatophogoides farinae exhibited three well differentiated growth phases: latency, exponential growth, and death of the culture. Biological standardization of extracts from the two mite species were carried out by skin prick tests in a group of 20 patients, using different concentrations of the extracts at the three growth phases. The patient sera were also studied by means of the RAST technique to determine the levels of specific IgE for each phase. The extracts produced from the exponential growth phase of the cultures revealed six times more relative allergenic activity in in vivo studies, and average RAST values were approximately three times higher than those extracts from latency and death phases. The reproducibility of the extract production method was assessed by comparing different batches obtained in similar conditions. The results showed batch-to-batch homogeneity allergenic activity. In conclusion, it was demonstrated that extracts obtained from cultures with the highest concentration of live mites (maximum growth phase) render the best diagnostic results in vivo and in vitro.

Genes essential for nod factor production and nodulation are located on a symbiotic amplicon (AMPRtrCFN299pc60) in Rhizobium tropici

Amplifiable DNA regions (amplicons) have been identified in the genome of Rhizobium etli. Here we report the isolation and molecular characterization of a symbiotic amplicon of Rhizobium tropici. To search for symbiotic amplicons, a cartridge containing a kanamycin resistance marker that responds to gene dosage and conditional origins of replication and transfer was inserted in the nodulation region of the symbiotic plasmid (pSym) of R. tropici CFN299. Derivatives harboring amplifications were selected by increasing the concentration of kanamycin in the cell culture. The amplified DNA region was mobilized into Escherichia coli and then into Agrobacterium tumefaciens. The 60-kb symbiotic amplicon, which we termed AMPRtrCFN299pc60, contains several nodulation and nitrogen fixation genes and is flanked by a novel insertion sequence ISRtr1. Amplification of AMPRtrCFN299pc60 through homologous recombination between ISRtr1 repeats increased the amount of Nod factors. Strikingly, the conjugal transfer of the amplicon into a plasmidless A. tumefaciens strain confers on the transconjugant the ability to produce R. tropici Nod factors and to nodulate Phaseolus vulgaris, indicating that R. tropici genes essential for the nodulation process are confined to an ampliable DNA region of the pSym.

Anaphylactic reaction to ingestion of Quercus ilex acorn nut

BACKGROUND

A patient experienced an anaphylactic reaction after eating acorn nuts, fruit of the holm oak (Quercus ilex), one of the most abundant trees in Spain. Several urticaria episodes upon ingestion of peanuts were also referred.

OBJECTIVE

To assess the hypersensitivity reaction to acorn and to characterize the allergenic proteins involved.

METHODS

Cutaneous tests were performed using the skin-prick technique, using a large variety of grass, tree and weed pollens as well as fresh nuts and nut extracts. Specific IgE determination was assessed by RAST. IgE binding bands were determined by SDS-PAGE immunoblotting.

RESULTS

Skin-prick tests were strongly positive with acorn and peanut. Olea europaea, Quercus alba, Quercus ilex and grass pollens also elicited a weal higher than negative control. Patient serum had measurable levels of IgE antibodies especially to acorn, peanut and grass pollens. Only one protein band, of 17.9 kDa molecular mass, showed IgE-binding properties in the acorn extract. The possible homology of this strong allergenic protein with the group 1 tree pollen allergens was evidenced by the partial inhibition of the western blot with Bet v 1.

CONCLUSIONS

We present a case of anaphylaxis to acorn ingestion as demonstrated by in vivo and in vitro results. A 17.9 kDa IgE-binding band, showing some homology to group 1 pollen tree allergens, was recognized by patient serum.

Cloning and immunological characterization of the allergen Hel a 2 (profilin) from sunflower pollen

Sunflower (Helianthus annuus) sensitization is not always related with occupational allergy. We have isolated the allergen profilin (Hel a 2) from this Compositae plant, cloned and sequenced five cDNAs encoding for full-length or partial Hel a 2. Natural sunflower profilin reacted with specific IgE in the 121 sera tested, at a frequency of 30.5%. Expression of the cDNA encoding Hel a 2 in Escherichia coli and a simple purification procedure by poly-L-proline chromatography allowed immunological characterization of the recombinant allergen. Binding of monoclonal antibodies against sunflower profilin revealed that some epitopes responsible for antigen-specific IgG production were not present in the recombinant allergen. High cross-reactivity has been found between recombinant Hel a 2 and profilins from other Compositae plants and also from botanically distant plants.

Comparative allergenic study of Tetranychus urticae from different sources

Tetranychus urticae is a macroscopic mite known as "red spider mite". It is a cosmopolitan and polyphagous mite which parasitizes both fruit trees and herbaceous plants, particularly in greenhouses. Contribution of T. urticae to occupational asthma among greenhouse workers has been studied to identify and describe the main T. urticae allergens. In this study we described and compared the physiochemical characteristics of the main. T. urticae allergens from three different sources, carnation, cucumber and vegetable marrow. Forty-two green-house workers with occupational T. urticae allergy were included. Extracts were prepared from mite bodies collected from the three different sources; skin prick tests, specific IgE, SDS-PAGE and SDS-PAGE immunoblotting were carried out with the three T. urticae extracts. Cross-reactivity was measured by RAST inhibition. These assays were done with each of the three extracts in solid and fluid phases. All patients showed a positive prick test to T. urticae extracts from carnation, 39 (93%) to those from cucumber, and 34 (81%) to those from vegetable marrow. Specific IgE was positive in 80% of patient sera from T. urticae extract from carnation, 58% and 63% in that from cucumber and vegetable marrow, respectively. SDS-PAGE immunoblotting of the extracts showed coincident and relevant allergens. The similar curve obtained by RAST inhibition assays revealed the high epitope similarity from the three extracts. In conclusion, T. urticae extracts from parasitic carnation, cucumber and vegetable marrow cultures showed a high epitope similarity with three relevant allergens with molecular mass of 25, 19 and 15 to 17 kDa.

Sequencing and high level expression in Escherichia coli of the tropomyosin allergen (Der p 10) from Dermatophagoides pteronyssinus

The cDNA encoding an allergen from the dust mite Dermatophagoides pteronyssinus has been cloned and sequenced. The allergen (Der p 10) is a tropomyosin that shared more than 65% identical residues with other invertebrate tropomyosins. The final recovery of recombinant Der p 10 from the culture media after a single purification step was as much as 26 mg/l. The recombinant allergen is reactive to shrimp antitropomyosin IgG antibodies and has a 5.6% frequency of IgE reactivity in sera from mite-allergic patients.

Characterization of recombinant Mercurialis annua major allergen Mer a 1 (profilin)

BACKGROUND

Two major allergens (Mer a 1A and Mer a 1B), tentatively identified as profilin, have been described in the euphorbiacea, Mercurialis annua.

OBJECTIVES

We sought to clone and characterize these major allergens from M. annua pollen and to obtain the immunologically active and soluble recombinant allergen, which could then be used for diagnostic procedures and therapy.

METHODS

Isolation of cDNA clones was performed by polymerase chain reaction amplification with degenerate primers. Expression in Escherichia coli BL21 (DE3) was carried out with a vector based in the T7 expression system, and the recombinant allergen was isolated by affinity chromatography on poly-(L-proline)-Sepharose. Electrophoretic (sodium dodecylsulfate-polyacrylamide gel electrophoresis, isoelectric focusing, and 2-dimensional polyacrylamide gel electrophoresis) and immunochemical methods (Western blot and ELISA) were used for the characterization of the recombinant allergen.

RESULTS

Two cDNA inserts coding for M. annua pollen profilin (Mer a 1) were cloned and sequenced. Full-length Mer a 1 cDNA was expressed in E. coli as nonfusion protein. The final yield of recombinant Mer a 1 from the culture media after a single purification step on poly-(L-proline)-Sepharose was as much as 5 mg per liter. The reactivity of recombinant Mer a 1 with IgE antibodies present in sera from patients allergic to M. annua, Olea europaea, and Ricinus communis pollens was comparable to that of the natural counterparts, but latex profilin had no cross-reactivity with M. annua profilin. Recombinant Mer a 1 was shown to share B-epitopes with sunflower profilin.

CONCLUSION

This approach is suitable for the production of defined and purified recombinant allergens, which could allow more detailed immunologic characterization of these proteins and the development of much more accurate diagnostic measures and specific anti-allergic treatments.

Gene amplification and genomic plasticity in prokaryotes

Gene amplification is a common feature of the genome of prokaryotic organisms. In this review, we analyze different instances of gene amplification in a variety of prokaryotes, including their mechanisms of generation and biological role. Growing evidence supports the concept that gene amplification be considered not as a mutation but rather as a dynamic genomic state related to the adaptation of bacterial populations to changing environmental conditions or biological interactions. In this context, the potentially amplifiable DNA regions impose a defined dynamic structure on the genome. If such structure has indeed been selected during evolution, it is a particularly challenging hypothesis.

Cloning and high level expression of Cynodon dactylon (Bermuda grass) pollen profilin (Cyn d 12) in Escherichia coli: purification and characterization of the allergen

BACKGROUND

Profilin, an actin-binding protein, was previously described as a panallergen which is involved in about 20% of the crossreactivity found among pollen and food allergic patients. This allergen is usually under-represented in natural extracts used for allergy diagnosis.

OBJECTIVES

To obtain an immunologically active and soluble recombinant profilin from Cynodon dactylon pollen which could be used for diagnostic and therapy.

METHODS

Isolation of cDNA clones was performed by polymerase chain reaction amplification using degenerate primers. Expression in Escherichia coli BL21 (DE3) was carried out using vector pKN172, and the expressed product was isolated by affinity chromatography on poly L-proline-Sepharose.

RESULTS

Four cDNA inserts coding for Cynodon dactylon (Bermuda grass) pollen profilin (Cyn d 12) were cloned and sequenced. Full-length C. dactylon profilin gene was expressed in Escherichia coli as non fusion protein. Induced cells could produce high amounts of recombinant Cyn d 12, and after a single purification step on poly (L-proline)-Sepharose, up to 45 mg of pure allergen per litre culture could be obtained. The reactivity of recombinant Cyn d 12 with IgE antibodies present in sera from Bermuda grass-allergic patients is comparable to that of the natural Bermuda grass allergen. Recombinant Bermuda grass pollen profilin was shown to share B-epitopes with sunflower profilin.

CONCLUSIONS

Our results showed that this heterologous expression system and purification procedure are suitable for the production of large amounts of pure allergen which can be used for the characterization of allergenic epitopes recognized by T and B cells and finally for diagnostic and therapeutic purposes.

Kinetics of allergen expression in cultures of house dust mites, Dermatophagoides pteronyssinus and D. farinae (Acari: Pyroglyphidae)

Laboratory cultures of house dust mites Dermatophagoides pteronyssinus (Trouessart, 1897) and Dermatophagoides farinae Hughes, 1961 were used to study the population dynamics of the mites and the kinetics of antigen appearance. The analysis of extracts obtained after different incubation periods, carried out by SDS-PAGE, immunoblotting, and enzyme-linked immunosorbent assay, allows for the definition of 3 different growth phases: the latency phase (F1); the exponential growth phase (F2) during which the allergenic proteins, including the Der 1 and Der 2 major allergens, were expressed more intensely and in larger quantities; and a final phase (F3), death, in which the lowest rates of allergenic components with a clearly different pattern were seen. The data obtained from this work demonstrates that mite cultures during the maximum growth phase (F2) contain the largest amount of allergenic components as well as the highest major allergen concentrations.

Cloning and expression of the panallergen profilin and the major allergen (Ole e 1) from olive tree pollen

BACKGROUND

Olive tree (Olea europaea) pollen allergy is one of the main causes of allergy in Mediterranean countries and some areas of North America.

OBJECTIVE

To clone olive allergens and to characterize immunologically the purified recombinant allergens.

METHODS

Full-length complementary deoxyribonucleic acid (cDNA) strands encoding olive allergens (Ole e 1) were cloned by polymerase chain reaction amplification and sequenced. Recombinant proteins were produced in Escherichia coli by the use of two different expression systems. Immunoreactivity of the recombinant proteins was tested by ELISA and Western blot with serum from patients with allergy to olive.

RESULTS

Significant sequence polymorphism was found in both allergens. The panallergen profilin was expressed as a nonfusion protein and was purified to homogeneity after a single step of affinity chromatography with a poly-L-proline Sepharose column. One cDNA encoding an Ole e 1 isoform was expressed as a fusion protein consisting of the glutathione S-transferase of Schistosoma japonicum and Ole e 1. The fusion protein was purified to homogeneity by gel filtration chromatography and affinity chromatography with a glutathione-Sepharose column, and digested with thrombin. Both recombinant allergens shared B cell epitopes with the corresponding natural allergens.

CONCLUSION

IgE-reactive Ole e 1 and olive profilin expressed in bacteria were purified after simple chromatographic procedures and may be useful for diagnostic purposes.

Sequence polymorphism and structural analysis of timothy grass pollen profilin allergen (Phl p 11)

Three cDNA clones encoding timothy grass pollen profilin (Phl p 11) were newly isolated. Comparison of the sequences of four cDNA clones, including a previously isolated clone, showed a low level of polymorphism. Isoelectrofocusing of highly purified timothy grass profilin indicated the existence of at least five isoforms. One recombinant profilin showed similar immunological properties to natural timothy grass profilin. Tertiary structure of Phleum pratense profilin was obtained by homology-based molecular modeling.

Occupational allergy in greenhouse workers: sensitization to Tetranychus urticae

BACKGROUND

Tetranychus urticae (TU) is a macroscopic mite which is found infesting a large number of plants of economic interest. It has rarely been described as a cause of occupational allergic disease in agricultural workers.

OBJECTIVE

To describe TU sensitization in greenhouse workers attending the outpatient allergy unit and its clinical associations, and to characterize the allergens involved.

MATERIALS AND METHODS

Twenty-four consecutive carnation greenhouse workers with allergy-related symptoms, referred to our outpatient clinic during a 6-month period, were included. We made the diagnostic extract from carnation leaves heavily infested with TU. Skin-prick test, specific IgE measurement and bronchial provocation test with TU extract were carried out in all subjects. Allergen characterization was achieved by SDS-PAGE (sodium dodecylsulfate-polyacrylamide gel electrophoresis) and immunoblotting.

RESULTS

Sixteen patients (66%) presented positive skin-prick test and specific IgE and were diagnosed allergic to TU. Fifteen patients suffered from bronchial asthma, 14 rhinitis and five urticaria. Twelve exhibited positive bronchial provocation test to the TU extract. On RAST-inhibition studies, there was no evidence of crossreactivity between TU extract and D. pteronyssinus. An allergen at 19 kDa was determined in the TU extract by SDS-PAGE immunoblotting studies.

CONCLUSION

TU could be an important occupational allergen in greenhouse workers showing allergic symptomatology. There is no crossreactivity between this mite and the house dust mite D. pteronyssinus.

[A new method of administration of budesonide powder for the treatment of allergic rhinitis]

The efficacy and safety of a new device for administering powdered budesonide in allergic rhinitis was evaluated. This method eliminates the disadvantages of traditional preparations and improves dosing and administration, even at low nasal flow rates. A randomized, controlled, single-blind study was made in 66 patients with allergic rhinitis, half of whom were assigned to the experimental treatment (powdered budesonide) and half to a standard aerosol. Results showed that both preparations were very effective (p < 0.01) in controlling rhinitis symptoms and not significantly different. However, the overall patient evaluation was significantly better (p < 0.01) in the group treated with powdered budesonide. Both treatments elicited a similar tolerance, although tolerance of powdered budesonide was slightly better. To conclude, treatment with the new powdered budesonide dispenser was as effective and well-tolerated as standard treatment, and better accepted by patients.

Occupational allergy in saffron workers

Sensitization to the flower of saffron, a plant commonly grown in Spain for commercial purposes, and its clinical significance as an occupational allergen were studied. The prick test and RAST, with saffron pollen, stamen, and pistil extracts, were used to evaluate the cutaneous and specific antibody responses in the studied population. Provocation tests in patients with clinical findings were used to verify the implication of saffron components in these symptoms. Fifty saffron workers were evaluated. Three of them were sensitized to saffron pollen and stamen proteins, giving prick and RAST positive values. One patient presented asthma, showing a positive bronchial provocation test, and two patients rhinoconjunctivitis, showing positive conjunctival provocation tests. Of a general allergic population of 237, 10 patients also presented cutaneous test and IgE positive to saffron. Saffron allergens (from pollen and stamens) were characterized by SDS-PAGE immunoblotting. A relevant allergen of 15.5 kDa with profilinic nature was detected and further purified by high-resolution gel filtration chromatography. No allergenic components were demonstrated in pistils. Cross-reactivity of saffron extracts was evaluated by RAST inhibition with respect to other pollen species commonly causing sensitization in the same area of study. A significant degree of cross-reactivity was demonstrated between saffron and Lolium, Salsola, or Olea. The identification of the protein components involved in the cross-reactions was investigated by blot inhibition.

Generation of Rhizobium strains with improved symbiotic properties by random DNA amplification (RDA)

To select for bacterial strains with enhanced phenotypes, random fragments of a whole genome, or a defined region of the genome, are cloned in a nonreplicating vector. The resulting plasmids are integrated by recombination into the homologous DNA region of the original strain. Integration gives rise to a nontandem direct duplication of the corresponding DNA region separated by the vector moiety of the plasmid. Recombination between the direct repeats leads to tandem duplication and further amplification of the entire integrated DNA, including the vector. Bacteria harboring the amplified DNA are selected by increasing the dosage of an antibiotic corresponding to a resistance marker of the integrated vector. Pooled strains carrying amplifications are then challenged with a selective pressure for the desired phenotype. After repeated selection cycles, the most fit strains are isolated. We used this process, which we called random DNA amplification, to select Rhizobium strains with increased competitiveness for nodule formation. Derivatives containing randomly amplified DNA regions of the symbiotic plasmid of Rhizobium tropici CFN299 strain were generated. Pools of amplified strains were inoculated onto various tropical legumes. After several cycles of selection through plants, amplified derivatives showing an increased competitiveness for nodule formation with the leguminous plant Macroptilium atropurpureum were obtained.

Production and characterization of profilin monoclonal antibodies

Profilins have been identified as a pan-allergen of different plant pollens and foods. In this paper, we describe the generation of monoclonal antibodies (MAbs) by immunizing BALB/c mice with Helianthus annuus purified profilin in order to characterize this important and common allergen. A panel of forty MAbs has been obtained, and twenty of them were used to map antigenic determinants in this molecule. At least two different antigenic determinants were recognized in H. annuus profilin by immunoblotting. Using the purified MAbs produced against sunflower profilin, we have analyzed the common epitope determinants in pollens of different plants: Olea europaea, Cynodon dactylon, Mercurialis annua, Phleum pratense, Parietaria judaica and Betula verrucosa. These experiments showed different cross-reactivity patterns.