Pollen responses

An allergen is usually an inert substance (e.g. pollen, house dust mite faeces) that in some individuals can trigger the generation of an (inappropriate) antigenic response. Mediated by TH2 lymphocytes, it causes B-Lymphocytes to produce lgE. Subsequent exposure of a sensitized individual to the allergen is therefore able to cross-link IgE antibodies on the surface of mast cells and trigger an immune response and histamine release. 

Extrinsic (also referred to as allergic asthma and caused in response to an allergen such as pollen, dust, and animal dander)... 

Among resurrection plants two seemingly very different kinds of response occur at the ultrastructural level. In many desiccation tolerant seeds, pollens, mosses and vascular plants, dehydration brings about rather... 

Francis JN, Till SJ, Durham SR Induction of 1L-10+CD4+CD25+ T cells by grass pollen immunotherapy. J Allergy Clin Immunol 2003 111 1255-1261. Jutel M, Akdis M, Budak F, Aebischer-Casaulta C. Wrzyszcz M, Blaser K, Akdis CA lL-10 and TGF-P cooperate in the regulatory T cell response to mucosal allergens in normal immunity and specific immunotherapy. Eur J Immunol 2003 33 1205-1214. 

Nouri-Aria KT. Wachholz PA. Francis JN. Jacobson MR, Walker SM. Wilcock LK. Staple SQ, Aalberse RC, Till SJ. Durham SR Grass pollen immunother-apyinduces mucosal and peripheral IL-10 responses and blocking IgG activity. J Immunol 2004 172 3252-3259. 

Pilette C. Nouri-Aria KT. Jacobson MR. Wilcock LK, Detry B. Walker SM. Francis JN. Durham SR Grass pollen immunotherapy induces an allergen-specific IgA2 antibody response associated with mucosal TGF-P expression. J Immunol 2007 178 4658-4666. 

Varney VA. Hamid QA. Gaga M. Ying S. Jacobson M, Frew AJ. Kay AB. Durham SR Influence of grass pollen immunotherapy on cellular infiltration and cytokine mRNA expression during allergen-induced late-phase cutaneous responses. J Clin Invest 1993 92 644-651. 

Larva Decreases worker response proboscis threshold to sucrose in a extension response increases number of pollen foragers Ten component blend of brood pheromone [123]... 

J Seasonal (hay fever) occurs in response to specific allergens (pollen from trees, grasses, and weeds) present at predictable times of the year (spring and/or fall blooming seasons) and typically causes more acute symptoms. Perennial (intermittent or persistent) occurs year round in response to nonseasonal allergens (e.g., dust mites, animal dander, molds) and usually causes more subtle, chronic symptoms. 

Pollen allelopathy is phenomenon when pollen chemicals (e.g., phenols, terpenoids, sesquiterpene lactones, etc.) inhibit sexual reproduction in heterospecific individuals due to influencing of fertilization (Murphy 1992). The phenomenon includes excretion of signaling compounds from the donor cell (pollens, pistil stigma), recognition of a specific signal, transmission of information (pollen), and the development of a characteristic response in the acceptor cell. The possible mechanism of the effect was described in Roshchina (2001). 

What is the specific term for the substance capable of triggering an inappropriate or harmful immune response to a harmless substance such as ragweed pollen ... 

Chronic inflammatory response is one of the hallmarks of allergic diseases. Over the course of pollen season, there might be even a tenfold increase in numbers of nasal epithelial submucosal mast cells. Histamine released from these cells might not only induce acute allergic symptoms but also be crucial for sustaining this response into a chronic phase, as increasing evidence suggests that it influences several immune/inftammatory and effector functions (table 2) [2]. 

Patients sensitized to pollen allergens often develop an IgE response to cross-reactive food allergens. Birch pollen-related food may lead to an exacerbation of eczema in a subpopulation of patients with atopic dermatitis and sensitization to birch pollen allergens. A birch pollen-specific T-cell response could be detected in lesional skin of these responding patients. T-cell cross-reactivity between Bet v 1 and related food allergens can occur independently of IgE cross-reactivity in vitro and in vivo. This has been shown in atopic dermatitis patients who developed late eczematous skin reactions to cooked food which was shown to elicit T-cell but not IgE-mediated responses [11]. 

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