Disease relevance of Phleum

• Group V major allergen Phl p 5b of timothy grass pollen induces allergic rhinitis and bronchial asthma in 90% of grass pollen-allergic patients [1].
• CONCLUSION: Phl p 4 represents a trypsin-resistant major timothy grass pollen allergen with immunologic similarities to the major ragweed allergen Amb a 1 and therefore must be considered an important cross-reactive component in grass pollen and weed pollen allergy [2].
• METHODS: Proof of the AT principle was shown by using a human ex vivo system in which EBV was used to transform human B cells specific for the timothy grass pollen allergen Phl p 5b [3].
• Phage display has been used to clone human IgE to timothy grass pollen allergen Phl p 5, to characterize the epitopes for murine and human antibodies to a birch pollen allergen Bet v 1, and to elucidate the epitopes of a murine mAb to the house dust mite allergen Der p 1 [4].
• RESULTS: Of all subjects studied, 19.9% suffered from rhinoconjunctivitis, 4.1% rhinoconjunctivitis plus asthma, 3.1% asthma alone, and 0.8% atopic dermatitis; 46.4% had a positive skin test to at least one allergen (28.2% to D. pteronyssinus, 20.4% to Olea, 13.8% to Phleum); and 43% had total IgE > 100 kU/L and 44.7% a family history of atopy [5].

High impact information on Phleum

• An IgE inhibition experiment performed with recombinant birch profilin and purified natural profilins from timothy grass and mugwort indicates common IgE epitopes [6].
• We have used the major timothy grass pollen allergen Phl p 1, which cross-reacts with most grass-, corn-, and monocot-derived group 1 allergens to develop a generally applicable strategy for the production of hypoallergenic allergy vaccines [7].
• B cell epitopes of the major timothy grass pollen allergen, phl p 1, revealed by gene fragmentation as candidates for immunotherapy [8].
• Local and systemic IL-10 responses and serum Ab concentrations were measured before/after a double-blind trial of grass pollen (Phleum pratense, Phl P) immunotherapy [9].
• "Allergen engineering": variants of the timothy grass pollen allergen Phl p 5b with reduced IgE-binding capacity but conserved T cell reactivity [10].

Chemical compound and disease context of Phleum

• In Switzerland the birch tree (Betula verrucosa) major allergen Bet v 1 and the grass (Phleum pratense) pollen major allergen Phl p 5 are of particular relevance for inducing pollinosis [11].
• Treponema saccharophilum utilized Timothy grass fructan, inulin and sucrose but not free fructose [12].
• SETTING: Hospital in Hampshire. PARTICIPANTS: 183 participants aged between 18 and 64 with a history of severe summer hay fever for at least two years; all were skin prick test positive to timothy grass pollen [13].

Biological context of Phleum

• We report the isolation of a cDNA coding for a 8.6 kDa two EF-hand calcium binding allergen, Phl p 7, from a timothy grass (Phleum pratense) pollen expression cDNA library, using serum IgE from a grass pollen allergic patient [14].
• Calcium-dependent immunoglobulin E recognition of the apo- and calcium-bound form of a cross-reactive two EF-hand timothy grass pollen allergen, Phl p 7 [14].
• Mutual boosting effects of sensitization with timothy grass pollen and latex glove extract on IgE antibody responses in a mouse model [15].
• Post-translational modifications influence IgE reactivity to the major allergen Phl p 1 of timothy grass pollen [16].
• In this study we reinvestigated the kinetics of allergen release from birch pollen (Betula verrucosa) and timothy grass pollen (Phleum pratense) using different protein extraction procedures, immunoblotting with specific antibodies and immune electron microscopy [17].

Anatomical context of Phleum

• In addition, the purified recombinant timothy grass pollen allergens induced dose-dependent and specific histamine release from patients' blood basophils [18].
• Our group reported papain-like properties of beta-expansin of Timothy grass (Phleum pratense) pollen, Phl p 1, and suggested that cleavage of cell wall structural proteins may be the underlying mechanism of expansin-mediated wall extension [19].
• Leukocytes were challenged in vitro with extracts of Phleum pratense (timothy) and the release of histamine was determined indirectly as the residual histamine in the cell sediment [20].
• Blood serum tocopherol was determined in 44 calves born in the spring from cows that had been fed either timothy grass silage or timothy hay produced in Norther Ontario. On all sampling dates (at birth and at eight, 21, 35 and 60 days of age), calves from the silage group had higher average tocopherol levels than those from the hay group [21].
• Total IgE determination, antigen-specific histamine release test against two concentrations of Phleum pratense, and quantification of beta 2-adrenergic receptor numbers in lymphocyte membrane of peripheral blood were done on all patients [22].

Associations of Phleum with chemical compounds

• In the present study we immunized mice with aluminum hydroxide-adsorbed purified recombinant major timothy grass pollen allergens (rPhl p 1, rPhl p 2, rPhl p 5), dog albumin, a major animal dander allergen, and proteins with low (beta-lactoglobulin) or no (ribulose diphosphate carboxylase) allergenic potential in humans [23].
• METHODS: Aqueous and lipid extracts from Phleum pratense L and Betula alba L pollen were analyzed by means of HPLC [24].
• Although preincubation with recombinant Bet v 1 and Bet v 2 did not significantly inhibit IgE binding to latex proteins, weed and, in particular, timothy grass pollen extract strongly inhibited IgE binding to latex allergens [25].
• METHODS: The patients received cluster immunotherapy with a standardized birch (Betula verrucosa) or grass (Phleum pratense) pollen extract adsorbed to aluminum hydroxide [26].
• METHODS: CAP inhibition experiments were performed with crude oilseed rape (OSR) and timothy grass pollen extracts and a neoglycoprotein construct displaying a MUXF glycan, as present in pineapple-stem bromelain (MUXF-BSA) [27].

Gene context of Phleum

• We report for the first time the successful measurement of IL-4 secreted by CBMC stimulated by the allergens timothy grass pollen and house dust mite extract [28].
• Sequence analysis of the insert shows 87% similarity to tobacco ntPro2, 78% to timothy grass profilin, 77% to Arabidopsis AthPRF4, 77% to maize ZmPro3, and 73% to birch profilin [29].
• Fluids from blister chambers after either Ag (timothy grass, orchard grass, or ragweed) or vehicle control challenge were collected hourly for 12 h from nine patients with allergic rhinitis [30].
• The NMR analyses of the birch and the nonreactive timothy grass profilin peptides showed that the loss of binding was not due to major structural differences [31].
• A panel of 60 cDNA clones coding for IgE-binding proteins from timothy grass pollen was immunocharacterized with sera from 30 patients allergic to grass pollen and antibodies raised against natural grass pollen allergens [32].

Analytical, diagnostic and therapeutic context of Phleum

• The percentage of grass pollen-specific IgE that was preabsorbed with a combination of recombinant timothy grass pollen allergens (Phl p 1, Phl p 2, and Phl p 5) and recombinant birch profilin (Bet v 2) was determined by ELISA in sera from 193 European, American, and Asian subjects [33].
• Group I had a history of seasonal allergic rhinitis, negative skin prick test responses to timothy and Bermuda grass, but positive intradermal skin test responses to timothy grass [34].
• By immunoelectron microscopy Phl p 4 was localized in the exine, cytoplasm, and amyloplast of timothy grass pollen. significant sequence similarities of a Phl p 4 10 amino acid peptide with Amb a 1, the major ragweed allergen, could be found [2].
• By RNase activity gel of natural pollen extract of timothy grass and consecutive Western blot analysis of the excised proteins, the RNase active bands were shown to be group V allergens [35].
• OBJECTIVE: The aim of this study was to identify and characterize an allergen of the high molecular mass fraction of Phleum pratense pollen by N-terminal protein sequencing and molecular cloning [36].

References