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PubMed2006

How pollen tubes grow.

Sexual reproduction of flowering plants depends on delivery of the sperm to the egg, which occurs through a long, polarized projection of a pollen cell, called the pollen tube. The pollen tube grows exclusively at its tip, and this growth is distinguished by very fast rates and reaches extended lengths. Thus, one of the most fascinating aspects of pollen biology is the question of how enough cell wall material is produced to accommodate such rapid extension of pollen tube, and how the cell wall deposition and structure are regulated to allow for rapid changes in the direction of growth. This review discusses recent advances in our understanding of the mechanism of pollen tube growth, focusing on such basic cellular processes as control of cell shape and growth by a network of cell wall-modifying enzymes, molecular motor-mediated vesicular transport, and intracellular signaling by localized gradients of second messengers.

Arabidopsis↗
PubMed2002

Influence of natural exposure to pollens and domestic animals on airway responsiveness and inflammation in sensitized non-asthmatic subjects.

BACKGROUND: Atopy may be a risk factor in the development of asthma. Indoor allergens are considered to be more potent asthma inducers than outdoor ones such as pollens. Lower airway inflammation may be present in non-asthmatic subjects during natural exposure to relevant allergens and may eventually lead to the development of asthma. AIMS: To document seasonal variation in lower airway responsiveness and inflammation in sensitized non-asthmatic subjects, during natural exposure to allergens, and to determine whether it is more marked in those exposed to animals to which they are sensitized. METHODS: Twenty-two atopic subjects were seen during and out of the pollen season. All (but the controls) were sensitized to domestic animals, and to trees, grasses or ragweed. Eleven were not exposed to animals at home and 8 were exposed. They were compared with 3 normal controls. A respiratory questionnaire was administered, allergy skin prick tests, spirometry, methacholine challenge, blood and induced sputum with differential cell counts were obtained during the pollen season for all subjects. These tests were repeated out of the pollen season. RESULTS: Throughout the study, none of the subjects had asthma symptoms. Mean PC(20) was significantly lower in subjects exposed to animals compared with unexposed subjects or controls, both during and out of the pollen season. In season, subjects exposed to animals had significantly higher sputum eosinophil numbers than unexposed or normal control subjects. CONCLUSIONS: Non-asthmatic atopic subjects show variable degrees of airway responsiveness and inflammation. However, subjects exposed to animals show higher airway eosinophilia, which may suggest they are at increased risk of developing airway hyperresponsiveness and asthma.

Adolescent↗
PubMed1996

[Sugar beet pollen allergy as a rare occupational disease].

Although there are a few isolated reports in the literature suggesting that sugar beet pollen is highly antigenic, hypersensitivity to components of sugar beet is not a common disease. We report a 29-year-old man with a history of atopic dermatitis who developed both contact dermatitis and allergic rhinitis from sugar beet pollen through his job in a seed nursery.

Adult↗
PubMed2000

Pollen morphology, exine structure, and systematics of Acalyphoideae (Euphorbiaceae), part 3. Tribes Epiprineae (Epiprinus, Symphyllia, Adenochlaena, Cleidiocarpon, Koilodepas, Cladogynos, Cephalocrotonopsis, Cephalocroton, Cephalomappa), Adelieae (Adelia, Crotonogynopsis, Enriquebeltrania, Lasiocroton, Leucocroton), Alchorneae (Orfilea, Alchornea, Coelebogyne, Aparisthmium, Bocquillonia, Conceveiba, Gavarretia), Acalypheae pro parte (Ricinus, Adriana, Mercurialis, Leidesia, Dysopsis, Wetria, Cleidion, Sampantaea, Macaranga).

This is the third paper of an extensive study of pollen morphology and exine structure of Acalyphoideae (Euphorbiaceae) following the most recent system of Webster. Pollen from 120 collections representing 96 species and 30 genera is described and illustrated with light microscopy, scanning and transmission electron microscopy. These taxa are from tribes Epiprineae, Adelieae, Alchorneae, and Acalypheae pro parte. Pollen of eight genera, Epiprinus, Symphyllia, Adenochlaena, Cleidiocarpon, Koilodepas, Cladogynos, Cephalocrotonopsis and Cephalocroton, of the nine assigned to Epiprinae share 3-colporate apertures, microreticulate, punctate or deeply punctate tecta, well developed or prominent columellae (Koilodepas excepted) and thin foot layers; pollen of the ninth genus, Cephalomappa, has porelike colpi, a coarsely reticulate exine, irregular columellae and an irregular foot layer. Of the five genera assigned to Adelieae, pollen of Adelia, Lasiocroton and Leucocroton is similar: 3-colp(oroid)ate with stratified opercula, crotonoid tecta and thin foot layers; grains of Enriquebeltrania and Crotonogynopsis lack opercula and the latter has a distinctive infratectum of poorly differentiated columellae. All genera examined of tribe Alchorneae, seven of the nine, have exines with unstratified opercula and elongated columellae near the endoaperture. Exines of subtribe Alchorneinae (Orfilea, Alchornea, Coelebogyne, Aparisthmium, Bocquillonia) have complex infratecta of poorly differentiated columellae, whereas pollen of Conceveiba and Gavarretia, the two genera examined of the three assigned to subtribe Conceveibinae, has a single layer of short columellae and almost identical tectal morphology. In the large tribe Acalypheae, pollen of the first six of the 11 subtribes was examined. Pollen of Ricinus (Ricininae) and Adriana (Adrianinae) share indistinguishable exine structures and tecta. Pollen of Mercurialis and Leidesia of subtribe Mercurialinae and pollen of Dysopsis of subtribe Dysopsidinae are almost identical: finely reticulate tecta, very thin apertural endexines, elongate columellae, and channeled/perforate foot layers. All three genera of subtribe Cleidiinae have grains that are 3-colporate and have complete tecta; pollen of Wetria has a tectum morphology very similar to that of Ricinus and Adriana; pollen of Cleidion is 3-brevicolporate with microrugulose or punctate tecta, and has threadlike non-apertural endexines and foot layers, and thick tecta; exines of Sampantaea have an endexine throughout the grain, thin foot layers, very short columellae and a thick continuous tectum. Pollen of Macaranga of subtribe Macaranginae is small, 3-colporate with poorly defined endoapertures, and an exine structure characterized by thin foot layers, short columellae, and thick tecta. Pollen data support: the concept of the subtribe Epiprininae, but indicate that subtribe Cephalomappinae (Cephalomappa) is not related and should be considered for separate tribal status; a close relationship among Adelia, Lasiocroton and Leucocroton, but not with the two remaining members of Adelieae, Enriquebeltrania and Crotonogynopsis, which do not appear to be closely related to each other; the present concept of Alchorneae and subtribes Alchorneinae and Conceveibinae. Within the genera examined of the first six subtribes of Acalypheae, the pollen data: support a close relationship between the monogeneric subtribes Ricininae and Adrianinae; indicate a close relationship between subtribes Mercurialinae (Mercurialis, Leidesia) and Dysopsidinae (Dysopsis); suggest that Wetria is not closely related to Cleidion or Sampantaea (Cleidiinae); tentatively support the concept of Macaranginae as comprising only Macaranga.

Journal Article↗
PubMed1999

Seed abortion in Pongamia pinnata (Fabaceae).

In Pongamia pinnata only one of the two ovules develops into a seed in most of the pods. Since pollen was not found to be limiting and reduced fertilization could not completely explain the observed frequency of seed abortion, it implied an effect of postfertilization factors. Aqueous extracts of developing seeds and maternal tissue (placenta) did not influence abortion in vitro, suggesting that abortion may not be mediated by a chemical. Experimental uptake of (14)C sucrose in vitro indicated that both the stigmatic and the peduncular seed have similar inherent capacities of drawing resources, but the peduncular seed is deprived of resources in the presence of the stigmatic seed. This deprivation of the peduncular seed could be offset by supplying an excess of hormones leading to the subsequent formation of two seeds in a pod. The prevalence of single-seeded pods in P. pinnata seems therefore to be a result of competition between the two seeds for maternal resources. The evolutionary significance of single-seeded pods in P. pinnata is discussed with respect to possible dispersal advantage enjoyed by such pods.

Journal Article↗
PubMed2005

[Palynological evidence of anthropogenic pressure: effect on pollination dynamics in the Evian area since the middle Neolithic: the pollen record of La Beunaz (971 m a.s.l., northern Alps, France)].

This paper presents a pollen diagram from La Beunaz peat-bog (southeast of Evian, Haute-Savoie, France), which provides the first detailed record of human impact on vegetation of the southern bank of Lake Geneva since the Middle Neolithic. The radiocarbon-dated pollen profile is correlated with micro-charcoal record and archaeological data. The results suggest that several phases of deforestations since 4615+75/-70 years BP occurred, in relation to human activities (agriculture, pastoralism). Tombs and vestiges of lacustrine villages indicate that the region was intensively and recurrently occupied by man during at that time.

Carbon Radioisotopes↗
PubMed2006

A sensitive monoclonal antibody-based enzyme-linked immunosorbent assay to quantify Parietaria judaica major allergens, Par j 1 and Par j 2.

BACKGROUND: Parietaria pollen is one of the most important causes of pollinosis in Mediterranean countries. Parietaria judaica pollen extract presents two major allergens, Par j 1 and Par j 2, that belong to the lipid transfer protein family. OBJECTIVE: To develop an ELISA for quantification of both major allergens of P. judaica pollen extracts, and to assert correlation of these allergens content with the allergenic activity of extracts. METHODS: Natural Par j 1-Par j 2 allergens were purified by gel filtration, ion exchange, and affinity chromatography and identified by mass spectrometry. Rabbit antisera were obtained using this protein preparation as antigen and used for immunoaffinity purification of nPar j 1-Par j 2. BALB/c mice were immunized with the immunopurified nPar j 1-Par j 2 and after fusion and screening by direct ELISA, 5D4 monoclonal antibody was selected as capture antibody to develop a quantitative two-site ELISA. Bound proteins were detected by a biotinylated Par j 1-Par j 2-specific polyclonal antibody. RESULTS: The optimized ELISA was developed from 25 to 8000 pg/mL of purified Par j 1-Par j 2, and a linear portion of 200-1000 pg/mL. The intraassay and interassay coefficients of variation were lower than 7% and 14% respectively. The assay was very sensitive and specific as it had a detection limit of 25 pg/mL and did not detect reactivity with the same family plants, as Urtica. Par j 1-Par j 2 allergens content was measured in 14 P. judaica and two P. officinalis pollen extracts showing a significant correlation with their allergenic activity measured by enzyme allergosorbent test inhibition. CONCLUSIONS: The results proved the usefulness of the two-sandwich ELISA for the standardization of Parietaria pollen extracts intended for clinical use, because of its good correlation with allergenic potency.

Allergens↗
PubMed2005

Space mediates coexistence of females and hermaphrodites.

In gynodioecious populations of flowering plants females and hermaphrodites coexist. Gynodioecy is widespread and occurs in both asexual and sexual species but does not admit a satisfactory explanation from classical sex ratio theory. In sexual populations male fertility restoring genes have evolved to counter non-nuclear male sterility mutations. In pseudogamous asexual populations pollen retention and increased self-fertilization can make male sterility costly. Both of these mechanisms can promote coexistence. However, it remains unclear how either of these mechanisms could evolve if coexistence was not initially possible. In the absence of these adaptations non-spatial models predict that females either fail to invade hermaphrodite populations or else displace them until pollen shortage drives the population to extinction. We develop a pair approximation to a probabilistic cellular automata model in which females and hermaphrodites interact on a regular lattice. The model features independent pollination and colonization processes which take place on different timescales. The timescale separation is exploited to obtain, with perturbation methods, a more manageable aggregated pair approximation. We present both the mean field model which recreates the classical non-spatial predictions and the pair approximation, which strikingly predicts different invasion criteria and coexistence under a wide range of parameters. The pair approximation is shown to correspond well qualitatively with simulation behaviour.

Models, Biological↗
PubMed2000

Allergen-specific immunotherapy in birch- and grass-pollen-allergic rhinitis. I. Efficacy estimated by a model reducing the bias of annual differences in pollen counts.

BACKGROUND: Evaluation of the efficacy of allergen-specific immunotherapy (IT) with pollen extracts is complicated by annual variation in pollen intensity. Our study aimed to evaluate the efficacy of birch and grass IT, taking into consideration these variations. METHODS: After 1 year of observation, 52 patients with rhinoconjunctivitis and allergy to birch as well as grass pollen were allocated to double-blinded clustered IT with aluminum-adsorbed extract produced from either birch (Betula verrucosa) pollen or grass (PIleum pratense) pollen. After 1 year of treatment, the patients continued IT with their original extract and also received the other extract. During the three consecutive pollen seasons, the rhinoconjunctivitis symptom score and the use of antihistamines, eye-drops, and oral prednisolone were recorded. Longitudinal data analysis was used to investigate the relation between different pollen counts and the magnitude of clinical efficacy. RESULTS: An effect of IT was found on symptom score, antihistamine intake, and eye-drop use for both birch and grass (P values <0.05). The mean reduction in symptom score/medication by IT ranged from 24% to 95%, depending on mean seasonal pollen counts. A minimum mean seasonal grass-pollen count of 20-30 pollen grains m3 was required for the efficacy of grass IT to emerge. CONCLUSIONS: A model was developed for evaluation of efficacy in longitudinal IT studies, taking the differences in annual pollen counts into consideration. The model showed a significant beneficial role of pollen IT in rhinoconjunctivitis patients allergic to birch and grass pollen.

Adolescent↗
PubMed2005

Enhanced fixation reveals the apical cortical fringe of actin filaments as a consistent feature of the pollen tube.

The actin cytoskeleton plays a crucial role in the growth and polarity of the pollen tube. Due to inconsistencies in the conventional preservation methods, we lack a unified view of the organization of actin microfilaments, especially in the apical domain, where tip growth occurs. In an attempt to improve fixation methods, we have developed a rapid freeze-whole mount procedure, in which growing pollen tubes (primarily lily) are frozen in liquid propane at -180 degrees C, substituted at -80 degrees C in acetone containing glutaraldehyde, rehydrated, quenched with sodium borohydride, and probed with antibodies. Confocal microscopy reveals a distinct organization of actin in the apical domain that consists of a dense cortical fringe or collar of microfilaments starting about 1-5 microm behind the extreme apex and extending basally for an additional 5-10 microm. In the shank of the pollen tube, basal to the fringe, actin forms abundant longitudinal filaments that are evenly dispersed throughout the cytoplasm. We have also developed an improved ambient-temperature chemical fixation procedure, modified from a protocol based on simultaneous fixation and phalloidin staining. We removed EGTA, elevated the pH to 9, and augmented the fixative with ethylene glycol bis[sulfosuccinimidylsuccinate] (sulfo-EGS). Notably, this protocol preserves the actin cytoskeleton in a pattern similar to that produced by cryofixation. These procedures provide a reproducible way to preserve the actin cytoskeleton; employing them, we find that a cortical fringe in the apex and finely dispersed longitudinal filaments in the shank are consistent features of the actin cytoskeleton.

Actins↗
PubMed1986

A multicenter trial of immunotherapy with alginate--conjugated grass pollen extract.

Conjuvac, a new generation of allergen extracts, has been developed to meet the need for improved characterization, purification, and standardization. Conjuvac consists of a dialyzed, standardized aqueous allergen extract chemically conjugated to a sodium alginate carrier and lyophilized in single-dose vials, thus ensuring stability until reconstituted with sterile water just before each injection. A preliminary study of Conjuvac 2 Grass by Pegelow (1984) involving a small number of patients showed this extract to have potential advantages. Accordingly, a study involving more patients was undertaken: two different maintenance dose levels of Conjuvac 2 Grass were investigated and compared to a pyridine-extracted, alum-precipitated two-grass extract called Allpyral, which in previous double-blind trials has been shown to be effective. The trial, which included 125 patients with hay fever and which extended over 2 years, involved ten allergists from seven European countries. Overall, the Conjuvac high-dose regimen proved slightly superior to Allpyral without any increased incidence of side effects, and all treatments stimulated marked increases in specific IgG levels without raising IgE levels.

Adolescent↗
PubMed2004

Context-dependent autonomous self-fertilization yields reproductive assurance and mixed mating.

The evolution of self-fertilization in hermaphrodites is opposed by costs that decrease the value of self progeny relative to that of outcross progeny. However, self-fertilization is common in plants; 20% are highly selfing and 33% are intermediate between selfing and outcrossing. Darwin proposed an adaptive benefit of self-pollination in providing reproductive assurance when outcrossing is impossible. Moreover, if outcross pollen receipt is inconsistent within or between years, these conditions likewise favour self-pollination, and this can result in a mixture of self and outcross seed production (mixed mating). Despite wide acceptance, the reproductive assurance hypothesis has lacked the support of complete empirical evidence to show that variable pollination can create both the ecological and genetic conditions favouring self-pollination. We recently showed in Collinsia verna that during periods of infrequent pollinator visits, autonomous self-pollination boosted seed output per flower, the key ecological condition. Here we show low inbreeding depression and marker-based estimates of selfing, demonstrating that when the pollination environment in wild populations necessitates reproductive assurance, selfing rates increase. We provide a complete demonstration of reproductive assurance under variable pollination environments and mechanistically link reproductive assurance to intermediate selfing rates through mixed mating.

Breeding↗
PubMed1998

Guidance in vitro of the pollen tube to the naked embryo sac of torenia fournieri

The precise guidance of the pollen tube to the embryo sac is critical to the successful sexual reproduction of flowering plants. We demonstrate here the guidance of the pollen tube to the embryo sac in vitro by using the naked embryo sac of Torenia fournieri, which protrudes from the micropyle of the ovule. We developed a medium for culture of both the ovule and the pollen tube of T. fournieri and cocultivated them in a thin layer of solid medium. Although pollen tubes that had germinated in vitro passed naked embryo sacs, some pollen tubes that grew semi-in vitro through a cut style arrived precisely at the site of entry into the embryo sac, namely, the filiform apparatus of the synergids. When pollen tubes were unable to enter the embryo sac, they continuously grew toward the same filiform apparatus, forming narrow coils. Pollen tubes selectively arrived at complete, unfertilized embryo sacs but did not arrive at those of heat-treated ovules or those with disrupted synergids. These results convincingly demonstrate that pollen tubes are specifically attracted to the region of the filiform apparatus of living synergids in vitro.

Journal Article↗
PubMed1993

Monoclonal antibody immunoassay for quantitative analysis of group V allergens in grass pollen extracts.

A two-site monoclonal antibody (MoAb) ELISA has been developed for the quantification of the Phleum pratense major allergen, Phl p V. The assay is based on two MoAbs which recognize different non-overlapping epitopes on the Phl p V molecule; one antibody (1D11) was immobilized on the solid phase and the other (3B2) was biotinylated. An affinity-purified Phl p V preparation (purity of 95%) was used as standard. The assay has a sensitivity of 10 ng/ml of allergen and is suitable for the detection of group V allergen in aqueous grass extracts. The specificity of the assay was investigated with 14 grass pollen and five non-grass pollen extracts. Different levels of group V allergen were detected in extracts of grasses, but not in non-grasses. The assay gives a good correspondence with allergenic activity of extracts as determined by ELISA inhibition using serum pool of allergic patients. The results indicate that the two-site MoAb ELISA could be very useful in the standardization of allergenic extracts from grass pollen.

Allergens↗
PubMed2006

Brassica oleracea pollen, a new source of occupational allergens.

BACKGROUND: Vegetable pollen is a rare source of occupational allergens. Occupational allergy has only been described in the case of paprika pollen and tomato pollen. We describe a new source of occupational pollen allergy. AIM: To study the incidence and the impact of broccoli and cauliflower pollen allergy in employees involved in classical plant breeding. METHODS: Fifty-four employees of five companies working with cauliflower (Brassica oleracea botrytis) and broccoli (B. oleracea italica/cymosa) pollen were eligible for complete evaluation. Allergy to cauliflower and broccoli pollen was evaluated by questionnaire and determination of sensitization by radioallergosorbent test (RAST) and skin-prick tests (SPT). SPT and RAST were performed with a panel of commercial and homemade extracts from cauliflower and broccoli pollen. RESULTS: Work-related symptoms such as rhinitis, conjunctivitis, asthma and urticaria caused by B. oleracea pollen were reported by 44% of the participants (24/54), of whom all but one had positive SPT for cauliflower- and/or broccoli-pollen/flower extracts and 58% (14/24) had positive RAST results. Symptoms had developed within the first 2 years in 33% of the patients. Six patients had to stop or change work. CONCLUSIONS: Brassica oleracea pollen is a new source of occupational allergen with strong allergenic potential leading to symptoms in almost half of the exposed employees.

Adult↗
PubMed2006

Style-by-style analysis of two sporadic self-compatible Solanum chacoense lines supports a primary role for S-RNases in determining pollen rejection thresholds.

A method for the quantification of S-RNase levels in single styles of self-incompatible Solanum chacoense was developed and applied toward an experimental determination of the S-RNase threshold required for pollen rejection. It was found that, when single style values are averaged, accumulated levels of the S(11)- and S(12)-RNases can differ up to 10-fold within a genotype, while accumulated levels of the S(12)-RNase can differ by over 3-fold when different genotypes are compared. Surprisingly, the amount of S(12)-RNase accumulated in different styles of the same plant can differ by over 20-fold. A low level of 160 ng S-RNase in individual styles of fully incompatible plants, and a high value of 68 ng in a sporadic self-compatible (SSC) line during a bout of complete compatibility was measured, suggesting that these values bracket the threshold level of S-RNase needed for pollen rejection. Remarkably, correlations of S-RNase values to average fruit sets in different plant lines displaying sporadic self-compatibility (SSC) to different extents as well as to fruit set in immature flowers, are all consistent with a threshold value of 80 ng S(12)-RNase. Taken together, these results suggest that S-RNase levels alone are the principal determinant of the incompatibility phenotype. Interestingly, while the S-RNase threshold required for rejection of S(12)-pollen from a given genetic background is the same in styles of different genetic backgrounds, it is different when pollen donors of different genetic backgrounds are used. These results reveal a previously unsuspected level of complexity in the incompatibility reaction.

Flowers↗
PubMed1999

Identification of a highly promiscuous and an HLA allele-specific T-cell epitope in the birch major allergen Bet v 1: HLA restriction, epitope mapping and TCR sequence comparisons.

BACKGROUND: Allergen-specific CD4+ T cells play an important regulatory role in atopic allergy. OBJECTIVE: To investigate the human leucocyte antigen (HLA) restriction and T-cell receptor (TCR) usage of allergen-specific T-cell clones (TCCs) that react with defined epitopes of Bet v 1, the major birch pollen allergen. METHODS: Five Bet v 1-specific TCCs derived from two birch pollen-allergic individuals and specific for Bet v 1, were epitope-mapped with overlapping synthetic peptides. In addition, HLA-restriction and TCR CDR3 sequences were determined. RESULTS: Three TCCs reacted with a Bet v 1 peptide containing amino acid residues 21-33 (BP21), the other two TCCs reacted with a minimal peptide comprising residues 37-45 (BP37). Studies using neutralizing anti-HLA-monoclonal antibodies and HLA-typed APCs showed that the BP37-specific TCCs were restricted by a HLA-DQA1*0301/DQB1*0603 heterodimer. In contrast, BP21 was recognized in a highly promiscuous manner. TCCs recognizing this sequence were restricted by HLA-DPB1*0201, a HLA-DQA1*0201/DQB1*0201 heterodimer, or HLA-DRB3*0101. Reverse transcription-polymerase chain reaction with primers for all known TCRAV and TCRBV gene segments, followed by CDR3 region sequencing, revealed the usage of five different TCRAV and four different TCRBV gene segments by the TCCs, as well as diversity in the joining region. All BP21-specific TCCs contained a negatively charged residue in their CDR3alpha regions, the CDR3beta regions showed a high concentration of polar and OH-group bearing residues. BP37-specific TCCs shared the amino acid combination LY in the middle of their CDR3alpha regions, the CDR3beta regions showed high concentration of OH-group bearing or charged residues. CONCLUSIONS: This study shows the existence of a highly promiscuous T-cell epitope in Bet v 1. The presence of additional T-cell epitopes in Bet v 1 may, however, hamper the clinical applicability of the epitope. Likewise, the diversity in TCR usage by T cells recognizing the epitope does not support the development of TCR-directed immunotherapy for birch pollen allergy.

Alleles↗
PubMed1992

[Immunological study of the HLA class II antigen associated with birch pollen allergy].

Pollinosis is known as a hereditary disease. Recently, association of HLA antigens and pollinosis caused by several pollen allergens has been reported. Furthermore, HLA antigens are considered to have a very important role in the development of pollinosis. We performed an HLA population study and tested the lymphocyte proliferative response (LPR) to birch pollen allergens with birch pollen allergic patients and healthy control subjects. The results of the HLA population study indicated that HLA-DR9 and HLA-DQw3 correlated with the development of birth pollinosis (relative risk [R. R] = 6.37 for DR9 and R. R = 7.92 for DQw3). DNA typing revealed that serotype DQw3 in patients were DQw9 specific. Two sources of birch pollen allergens, betula pendula and betula platyla var. japonica, were used in LPR. Lymphocytes from the patients, but not from the healthy control subjects, proliferated in response to these two allergens. Anti-HLA-DR antibody, but not anti-HLA-DQ antibodies, inhibited the patients' LPR. These results suggest that the HLA-DR molecules are responsible to present the pollen specific antigen to T lymphocytes inducing LPR in the patients. Furthermore, in some of the healthy control subjects, anti HLA-DQ antibodies enhanced this LPR almost to the same level as that of the patients'. This result indicates that HLA-DQ molecules might be associated with the suppression of T cell proliferation.

HLA-DQ Antigens↗