Grass Pollen Allergic Patients Research Articles

Serum Fcεrii Receptor (SCD23) as an Evaluating Factor for Grass Pollen Immunotherapy

CD23 is a protein on the surface of certain hemopoietic cells and it is considered to be the low affinity receptor for immunoglobulin IgE, (FcεRll/CD23). The regulation of the expression of CD23 depends on the type of cell on which it is found. Like most of the FcR receptors, it is released in a soluble form (sCD23) in the extracellular fluid. This form is found in increased levels in the serum of allergic patients and in neoplastic diseases. We studied total IgE and sCD23 in the serum of 30 allergic patients undergoing immunotherapy, 15 allergic patients treated only symptomatically for grass pollen (GP) allergy, 15 healthy and subjects. We found that the mean values of total IgE and sCD23 after the course of hyposensitization were decreased compared to those before treatment as well as to those GP allergic patients under conventional therapy and to healthy adults. However, only the CD23 decrease was statistically significant. Therefore, we speculate that determination of sCD23 may be useful for (a) the general evaluation of allergic patients and (b) the immunological monitoring of patients under immunotherapy.

P226 Effect of single allergen immunotherapy on early skin reactivity and symptom scores in grass pollen-allergic patients

P226 Effect of single allergen immunotherapy on early skin reactivity and symptom scores in grass pollen-allergic patients

Sublingual versus injective immunotherapy in grass pollen allergic patients: a double blind (double dummy) study

Sublingual versus injective immunotherapy in grass pollen allergic patients: a double blind (double dummy) study

Sublingual versus injective immunotherapy in grass pollen allergic patients: a double blind (double dummy) study

Injective immunotherapy is a well-known and recognized treatment for allergic diseases, but its safety has been questioned during recent years. Alternative administration routes have been proposed and there is a growing interest and experience in sublingual therapy. The safety of alternative routes is nonetheless a real advantage, so long as it is not counterbalanced by a loss of clinical benefit. We have compared the efficacy of the same biologically standardized grass pollen extract administered through the injective or the sublingual route, in a group of 20 patients followed for two pollen seasons. Both therapies were administered for 12 months according to a double-blind (double-dummy) plan; at the end of the trial the cumulative dosage of the sublingual therapy was 2.4 times higher than that of the injective therapy. Data about skin reactivity, symptoms and drugs scores during the pollen season, as well as total specific IgG and specific IgG4, during and after the trial, were obtained. Our data show that sublingual and injective therapy are equally effective according to subjective clinical parameters, with a statistically highly significant reduction of symptoms and drugs (P = 0.002 for symptoms and drugs in SLIT-treated patients; P = 0.002 for symptoms and P = 0.0039 for drugs in patients given injections). On the other hand, objective parameters (total specific IgG, specific IgG4, skin reactivity) changed only in patients treated with active injective therapy, with P < 0.001, P < 0.001 and P = 0.021, respectively. The discrepancies observed could be interpreted as a consequence of different mechanisms of actin of the two therapies or to the lack of close relationships between the clinical and the objective parameters which were considered here.

Crystallization and Preliminary Diffraction Data of a Major Pollen Allergen: CRYSTAL GROWTH SEPARATES A LOW MOLECULAR WEIGHT FORM WITH ELEVATED BIOLOGICAL ACTIVITY

Group V major allergen Phl p 5b of timothy grass pollen induces allergic rhinitis and bronchial asthma in 90% of grass pollen-allergic patients. In addition to its allergenicity ribonuclease activity has recently been attributed to this 29-kDa protein. The allergen was expressed in Escherichia coli and subsequently purified. Spontaneous conversion of these preparations to a mixture of various forms with molecular sizes between 10 and 29 kDa was consistently observed. Surprisingly, crystals could be grown from this heterogenous preparation. Single crystals, redissolved and analyzed by SDS-polyacrylamide gel electrophoresis and immunoblot, yielded one distinct low molecular weight protein, which was identified by amino acid sequencing as the C-terminal 13-kDa portion of the allergen. Histamine release assays with single crystal solutions using basophils of an allergic patient demonstrated allergenicity comparable with that of the holo-allergen. By contrast, RNase activity of the crystallized C-terminal form was 23 times higher than that of the full-length parent allergen. Crystals were used to collect preliminary diffraction data; the space group was evaluated to I4122 with cell dimensions of a = 87.7 A, b = 87.7 A, and c = 59.6 A. We conclude that preferential crystal growth of the 13-kDa form is indicative of a compact conformation of this particular C-terminal portion of the allergen. Thus, we show here that protein crystallization is not only a prerequisite for structural analyses, but it also can provide a unique separation technique to localize the functional domain of a major allergen.

Construction of a Combinatorial IgE Library from an Allergic Patient: ISOLATION AND CHARACTERIZATION OF HUMAN IgE Fabs WITH SPECIFICITY FOR THE MAJOR TIMOTHY GRASS POLLEN ALLERGEN, Phl p 5

To characterize human IgE antibodies with specificity for a major allergen at the molecular level, we have constructed an IgE combinatorial library from a grass pollen allergic patient. cDNAs coding for IgE heavy chain fragments and for light chains were reverse-transcribed and polymerase chain reaction-amplified from RNA of peripheral blood lymphocytes and randomly combined in plasmid pComb3H to yield a combinatorial library of 5 x 10(7) primary clones. IgE Fabs with specificity for Phl p 5, a major timothy grass pollen allergen, were isolated by panning. Sequence analysis showed that the 4 of the Fabs used the same heavy chain fragments which had combined with different kappa light chains. Soluble recombinant IgE Fabs were purified by affinity chromatography to Phl p 5 and, like natural IgE antibodies, cross-reacted with group 5 allergens from different grass species. The described approach should facilitate studies on the molecular interaction between IgE antibodies and allergens and encourages the consideration of specific IgE Fabs that are capable of interfering with allergen-IgE binding as potential therapeutic tools.

Expression of Zm13, a pollen specific maize protein, in Escherichia coli reveals IgE-binding capacity and allergenic potential

Plant proteins belong to the most frequent elicitors of type I allergic symptoms in industrialized countries. Several relevant plant allergens have been found to be either specifically expressed or highly upregulated in mature pollen. The cDNA coding for a pollen specific maize protein, Zm13, shows significant sequence homology with a number of pollen or anther specific proteins from monocot and dicot plants as well as with recently described allergens from olive and rye grass. To test whether the Zm13 protein might possess IgE-binding capacity, Zm13 was expressed in E coli. The coding region of Zm13 was PCR amplified from a genomic clone and expressed as as a glutathione- S-transferase fusion protein. The recombinant Zm13 fusion protein bound a Zm13 specific rabbit antiserum and reacted with serum IgE from grass pollen allergic patients indicating that Zm13 and homologous proteins represent a family of conserved plant allergens.

Common IgE-epitopes of recombinant Phl p I, the major timothy grass pollen allergen and natural group I grass pollen isoallergens

Grass pollen allergens are potent elicitors of Type I allergy. More than 95% of grass pollen allergic patients display IgE-cross-reactivity to group I grass pollen allergens of different grass species. A cDNA coding for the major timothy grass pollen allergen, Phl p I, was isolated previously. To investigate the presence of common IgE-epitopes among naturally occurring group I grass pollen isoallergens, Phl p I was expressed in Escherichia coli and used for IgE-absorption experiments. Recombinant Phl p I was able to inhibit IgE-binding to most of group I isoallergens from seven grass species as identified by two dimensional electrophoresis. When tested in competitive ELISA experiments, recombinant Phl p I bound a high percentage of grass pollen specific IgE. The results indicate that recombinant Phl p I shares many of the IgE-epitopes with natural group I grass pollen allergens and hence may represent a useful tool for specific diagnosis and therapy of grass pollen allergy.

Detection of allergen-specific IgE in tears of grass pollen-allergic patients with allergic rhinoconjunctivitis.

Allergic conjunctivitis is a common symptom amongst Type I (IgE-mediated) allergic diseases; and most frequently seen as rhinoconjunctivitis. However, the site of production and the significance of allergen specific IgE needs further elucidation. We investigated whether the presence of IgE in tears of grass pollen allergic patients correlated with disease and clinical symptoms, whether the IgE binding pattern to the different grass pollen antigens was different in sera and tears, and whether IgA antibodies to grass pollen allergens were present in tears. Finally, we looked whether specific IgE was produced locally or was exudated from serum. Sera from 44 grass pollen allergic patients suffering from either allergic rhinitis (n = 11) or allergic rhinoconjunctivitis (n = 33) and from healthy controls (n = 7) were used for the experiments. Binding of specific IgE and IgA antibodies to the different groups of grass pollen allergens (Phleum pratense) was evaluated by means of immunoblotting. Specific IgE was detected in sera as well as in tears of allergic patients, whereby tear-derived allergen-specific IgE exerted similar specificities to the corresponding IgE from serum. The correlation between symptoms of ocular allergy and the presence of allergen-specific IgE in tears was highly significant (P < 0.0001). In contrast, only a poor correlation was found between specific and/or total IgE in sera and the manifestation of ocular allergy (P = 0.73). Allergen-specific IgE antibodies in tears seem to be produced locally rather than exudated from serum. IgE in tears seems to be responsible for allergic conjunctivitis. IgA in tears cannot exert a protective function since the IgA antibodies recognize different antigens in a grass pollen (Phleum pratense) extract than IgE antibodies. The highly significant correlation between allergic conjunctivitis and the presence of specific tear IgE emphasizes the diagnostic value of immunoblots with tear IgE, especially in cases in which serum provides inconclusive results.

Cloning, expression and immunological characterization of Ory s 1, the major allergen of rice pollen

We have isolated and characterized a cDNA clone, Ory s 1, encoding a group-1 allergen of rice pollen. The Ory s 1 protein shows significant sequence identity to the major allergen of rye-grass pollen, Lol p 1. RNA gel blot analysis shows that the Ory s 1 gene is expressed in mature anthers, but not in vegetative or other floral tissues tested. Southern blot analysis indicates that this clone represents a member of a small gene family in rice. Western blot analyses of total rice pollen proteins with the group-1 allergen-specific monoclonal 3A2 and IgE antibodies from grass pollen-allergic patients, revealed the presence of cross-reactive antigenic and allergenic epitopes in Ory s 1.

Isolation of an immunodominant IgE hapten from an epitope expression cDNA library. Dissection of the allergic effector reaction.

An epitope expression cDNA library was constructed from the randomly fragmented cDNA coding for Phl p I, the major grass pollen allergen. Using IgE from allergic patients, epitope clones were isolated and immunodominant fragments were selected. Among three epitope clones coding for a similar region of Phl p I, one clone expressed a 15-amino-acid epitope which was target for IgE antibodies from approximately 30% of grass pollen allergic patients. According to the prevalence of grass pollen allergy, 22% of all allergic patients are expected to display IgE reactivity with this epitope. Although the purified recombinant epitope specifically bound IgE, it did not release histamine from basophiles of most grass pollen allergic patients and thus represents an IgE hapten. Immunodominant IgE haptens may be useful as therapeutic agents to saturate mast cell-bound IgE prior to allergen exposure and may represent candidates for a safe immunotherapy of allergic diseases by reducing anaphylactic side effects.

Molecular characterization of Phl p II, a major timothy grass ( Phleum pratense) pollen allergen

Grass pollen allergens belong to the most important and widespread elicitors of pollen allergy. Using serum IgE from a grass pollen allergic patient, a complete cDNA encoding a group II allergen was isolated from a timothy grass ( Phleum pratense) pollen expression library. The deduced amino acid sequence of the Phl p II allergen shows an average sequence identity of 61% with the protein sequences determined for group II/III allergens from rye grass ( Lolium perenne) and a sequence identity of 43% with the C-terminal portion of group I grass pollen allergens from different species. A hydrophobic leader peptide similar to leader peptides found in other major grass pollen allergens heads the deduced amino acid sequence, indicating that group II/III grass pollen allergens belong to a family of secreted proteins. Serum IgE specific for Phl p II, detected the protein exclusively in pollen and not in other plant tissues. The recombinant Phl p II was expressed in Escherichia coli and showed similar IgE-binding capacity as the natural allergen.

CDNA cloning of a major allergen from timothy grass (Phleum pratense) pollen; characterization of the recombinant Phl pV allergen.

We isolated a cDNA encoding a major grass pollen allergen from a timothy grass (Phleum pratense) pollen expression cDNA library using allergic patients' IgE. The complete cDNA encoded an allergen that binds IgE from about 80% of grass pollen-allergic patients. Significant sequence homology was found to other major grass pollen allergens from Kentucky bluegrass (Poa pratense) as well as from rye grass (Lolium perenne) which originally were believed to form different identities. Using different monoclonal and polyclonal antibodies raised against group V allergens we identified the recombinant protein as a group V allergen from timothy grass, Phl p V. In IgE-binding studies it is demonstrated that the rPhl p V allergen can be used to block binding of patients' IgE to natural group V isoallergens on two-dimensional immunoblots. IgE inhibition experiments show that up to 60% of grass pollenspecific IgE can be preadsorbed with the rPhl p V allergen from patients sera. The purified rPhl p V induced specific histamine release of blood basophils from grass pollen-allergic patients. This emphasizes the usefulness of the rPhl p V for diagnostic and therapeutic purposes and corroborates the view that specific diagnosis and therapy of type l allergy could be performed with a limited panel of relevant recombinant allergens.

Fungal spores enhance basophil histamine release

The effects of whole spores from moulds were examined concerning histamine release using leukocyte suspensions from normal (non-atopic) individuals and grass pollen-allergic patients. Spores fromChaetomium globosum, Mucor racemosus andAspergillus terreus caused no histamine release in concentrations up to 0.1 or 1 mg/ml, but they enhanced mediator release triggered by both IgE-dependent stimuli (grass-pollen allergen and anti-IgE antibody) and non-immunological stimuli (Staphylococcus aureus and calcium ionophore). Organic dust contains microfungi as well as bacteria and endotoxins. Earlier we have shown that bacteria release mediators from human lung cells and that bacteria and their endotoxins potentiate mediator release. It is now demonstrated that fungal spores also have potentiating ability. The content of all these microorganisms in dust may therefore be responsible for the symptoms observed after occupational exposure to organic dusts.

Efficacy of an oral antihistamine, loratadine, as compared with a nasal steroid spray, beclomethasone dipropionate, in seasonal allergic rhinitis

The aim of the study was to compare the efficacy and side-effects of oral antihistamine and nasal glucocorticoid therapy in seasonal allergic rhinitis. In a double-blind, double-dummy, group-comparative study, 60 birch and grass pollen allergic patients were treated with either loratadine (10 mg daily) or beclomethasone dipropionate (BDP) (100 micrograms in each nostril twice daily) during a 3 weeks' study period. Grading of 4 nasal and 3 non-nasal symptoms was performed at 4 weekly visits, and patients recorded daily symptoms and possible adverse experiences in a diary. Patients treated with BDP showed significantly less nasal blockage than those receiving loratadine (P less than 0.05), but there was no difference (P greater than 0.05) in other nasal symptoms (sneezing, itching and discharge). Patients treated with loratadine showed a statistically significantly greater relief in eye symptoms as compared with BDP (P less than 0.05). The side-effects caused by the 2 treatments were few and insignificant. We conclude that loratadine and intranasal BDP were effective in the treatment of seasonal allergic rhinitis, but the spectrum of individual symptoms controlled was different for the 2 drugs.

Differences in clinical and immunologic reactivity of patients allergic to grass pollens and to multiple-pollen species: II. Efficacy of a double-blind, placebo-controlled, specific immunotherapy with standardized extracts

The IgE response of patients only allergic to grass pollens differs from response of patients allergic to multiple-pollen species. The IgE immunoblots to orchard-grass pollens confirmed that poly sensitized patients had more proteins revealed than patients only allergic to grass pollens. To determine if both groups of patients present a different response toward specific immunotherapy (IT), a double-blind, placebo-controlled study was performed in 70 patients. Patients receiving the active treatment had a rush IT with either a standardized orchard grass-pollen extract or with a standardized mixed-pollen extract prepared, depending on the sensitivity of the patients. The maintenance dose was defined as that dose effective in grass-pollen IT in previous experiments. The same equipotent maintenance dose was administered for all pollen species. Symptom-medication scores during the pollen season and nasal challenge with orchard grass-pollen grains demonstrated that grass pollen-allergic patients had a significantly improved efficacy by comparison to placebo treatment, whereas polysensitized patients had a nonsignificant improvement. Serum grass-pollen IgG was significantly increased after IT in both treated groups. This study demonstrate that the response toward specific IT differs in patients only allergic to grass pollens by comparison to polysensitizied patients.

Nucleotide sequence analysis of three cDNAs coding for Poa p IX isoallergens of Kentucky bluegrass pollen.

Grass pollen allergens are one of the major causes of type I allergic reactions (allergic rhinoconjunctivitis, allergic bronchial asthma, and hayfever) in temperate climates afflicting 15-20% of a genetically predisposed population. Workers have found considerable physico- and immunochemical heterogeneity within the grass pollen allergens which has made them difficult to purify for both therapeutic uses and further biochemical study. We recently reported the construction of a cDNA library in lambda gt11 using mRNA extracted from dehydrated Kentucky bluegrass (KBG, Poa pratensis). Here, we present the nucleotide and deduced amino acid sequences for three KBG pollen allergen cDNA clones, KBG 41, 60, and 31, which were isolated from the above library using a pool of six sera from grass pollen allergic patients. These clones exhibit an exceptionally high degree of sequence similarity to one another, only minor similarity to other known allergens, and no homologies to other known proteins or genes. The predicted molecular mass for the cloned proteins range from 28.3 to 37.8 kDa with pI values of 9.6-10.2. All three clones appear to possess leader peptides and lack asparagine sequons required for N-glycosylation. Therefore, the molecular mass of the post-translationally modified proteins were calculated to be 28.4-34.9 kDa, which is consistent with the size of the polypeptides revealed in Western blots of pollen proteins using an antiserum to a recombinant peptide encoded by the partial cDNA clone KBG 8.3. Northern blotting analysis indicates that expression of the genes corresponding to these clones is confined to pollen tissue. The results suggest that the clones code for a group of proteins that represent a new and previously uncharacterized group of grass pollen isoallergens, which have been hereby designated as Poa p IX.

Isolation and Characterization of a cDNA Clone Encoding an IgE-Binding Protein from Kentucky Bluegrass &lt;i&gt;(Poa pratensis)&lt;/i&gt; Pollen

We reported previously on the isolation and characterization of several allergens from Kentucky bluegrass (KBG) (Poa pratensis L.) pollen with the aid of the corresponding murine monoclonal antibodies (Mabs). In the present study, (1) an analysis of various tissues of this grass revealed that the allergenic components recognized by these Mabs were confined to the pollen; (2) intact translatable mRNA was isolated from the KBG pollen, and (3) a cDNA library was constructed with this mRNA in the lambda gt11 expression vector. Screening of this library with a pool of six sera from KBG-allergic patients, in combination with enzyme-labeled antibodies to human IgE, led to the isolation of a cDNA clone, referred to as KBG7.2. The nick-translated cDNA probe of KBG7.2 hybridized to a 1.5-kbp RNA transcript from KBG pollen. Moreover, transcripts corresponding to KBG7.2 were found in pollens of eight other grasses, indicating that the proteins similar to the one encoded by this cDNA may be present in these grasses. The nucleotide sequence of KBG7.2 was determined; interestingly, the corresponding derived amino acid sequence did not match any other sequence recorded in the protein data banks. The peptide encoded by KBG7.2 was expressed as a fusion protein utilizing the plasmid vector pWR590.1. Whereas none of the above allergen-specific Mabs bound to the fusion protein, all the 15 individual sera from grass pollen allergic patients recognized the fusion protein.(ABSTRACT TRUNCATED AT 250 WORDS)

Double-blind, placebo-controlled immunotherapy with mixed grass-pollen allergoids: III. Efficacy and safety of unfractionated and high-molecular-weight preparations in rhinoconjunctivitis and asthma

Specific immunotherapy with unmodified formalinized allergoids is effective in grass-pollen allergy, but systemic reactions have been observed. A high-molecular-weight formalinized allergoid (HMW-GOID) was fractionated by gel filtration, retaining molecules of >85,000 daltons in the expectation of improving safety without sacrificing efficacy. HMW-GOID and unfractionated allergoid (GOID) had a similar allergenic activity assessed by RAST inhibition, but the HMW-GOID preparation was 65 times less reactive when it was tested by skin prick test than the GOID preparation. A double-blind, placebo-controlled study was carried out in grass pollen-allergic patients with placebo (14 patients), GOID (15 patients), and HMW-GOID (13 patients). An additional group of 18 patients was treated by a rush schedule with a standardized orchard grass-pollen extract. A similar mean cumulative dose was administered with both allergoids. The fractionated allergoid only elicited minor systemic reactions similar to reactions elicited by placebo, whereas 20% of patients treated by GOID and 5.5% of patients receiving the standardized extract had a severe systemic reaction. For rhinitis, conjunctivitis, and asthma, the HMW-GOID and the standardized extract had a similar efficacy, significantly greater than placebo. GOID was less effective than the other two active treatments but was significantly more effective than placebo treatment for asthma and conjunctivitis.

Epidemiology of emergency room asthma in northern California: Association with IgE antibody to ryegrass pollen

To examine the relationship between allergy and acute attacks of asthma, we have examined adult patients with acute asthma presenting during a defined pollen season. Sera from 59 patients presenting with acute asthma to the David Grant Medical Center emergency room at Travis Air Force Base during the spring “epidemic” of asthma were assayed for IgE antibody (Ab) to five allergens (mite, cat, cockroach, ryegrass pollen, and ragweed) with RAST. Control sera were obtained from 34 patients without asthma and 25 employees. The results demonstrate that 92% of the patients with asthma had >200 units of IgE Ab to ryegrass pollen (~20 ng of IgE Ab per milliliter) compared to 14% of the control subjects (x 2 = 69; p < 0.0001; odds ratio = 69). Some of the grass pollen-allergic patients also had increased levels of IgE Ab to ragweed, but only 25% had >200 units. In contrast, there was no significant difference between subjects with asthma and control subjects in the prevalence of IgE Ab to the three indoor allergens (mite, cockroach, and cat). Twelve percent of the patients with asthma compared to 5% of the control subjects had >200 units of IgE Ab to one of these three (x 2 = 0.98; p > 0.1; odds ratio = 2.5). Dust samples from the homes of 15 of the patients with asthma demonstrated very high levels of grass pollen ( 13 15 houses with >10 μg of allergen per gram of dust), low levels of mite ( 13 15 homes with <2 μg of allergen per gram of dust), and no detectable cockroach allergen. These results demonstrate that the development of IgE Ab to an inhalant allergen (i.e., grass pollen) increased the patients' odds of developing acute asthma during a period of increased exposure.