Allergenic and Antigenic Cross-Reactivities of Group IX Grass Pollen Allergens

Abstract

The allergenic and antigenic cross-reactivities between a major recombinant Poa pratensis(Poa p) IX allergen, rKBG8.3, and its corresponding proteins of different grass pollens were examined. Immunoblotting of the proteins of thirteen different grass pollens using anti-rKBG8.3 antibodies indicated that Poa p IX-like proteins are present in ten other grass pollens, albeit in variable amounts and polymorphic forms. These proteins ranged in size from 20 to 88 kDa in different grass pollens. The percent relative binding determined for each grass pollen extract using allergic human sera showed a significant correlation (r = 0.891) with that of anti-rKBG8.3 antiserum. Moreover, there was a strong association (r = 0.901) between the Kentucky bluegrass extract and rKBG8.3 with respect to their inhibition of the binding of human IgE antibodies to allergens in grass pollen extracts. Taken together, these results suggest that the allergenic and antigenic epitopes of the Poa p IX-related proteins in some but not all grass pollens are similar in structure and specificities. It is concluded that the group IX allergens constitute a major family of homologous proteins in several grass pollens.

Pollen allergen homologues in barley and other crop species

“…It has previously been demonstrated by several investigators that monoclonal antibodies can be employed to identify crossreactive allergens in a variety of grass species [7.35]. Group IX proteins in wild grass species have been examined previously [5]. Now.…”

“…Recombinant allergens provide a reliable and inexhaustible supply of purified antigen which can be used for diagnosis and therapy of atopic allergies [4]. In addition, antibodies to purified antigens facilitate the analysis of potential antigens expressed by other wild plant species [5]. Since pollens of agricultural species represent a small fraction of the aeroallergenie substances routinely detected by mechanical surveys [6], they are widely assumed to be minor agents of pollinosis.…”

Comparison of IgE and IgG antibody responses of atopic individuals with sensitization to tree and grass pollens

“…The last few years have seen monumental progress in our knowledge of the molecular structure of allergens (23). Studies in our laboratory (12)(13)(14)18) and those of others (24)(25)(26) have revealed that certain epitopic sequences appear to be conserved among diverse allergens, leading to the widespread cross-reactivities at the level of recognition by both T and B cells. Moreover, both atopic and NA individuals are known to produce allergen-specific antibodies of different isotypes (4,5) and, in the presence of IL-4, B lymphocytes from both atopies and NAs produce IgE antibodies (6)(7)(8)(9).…”

“…In an effort to shed light on antibody responses to related antigens involved in the development of the atopic condition and to understand the basis of the effectiveness of specific therapies, we undertook a comprehensive study of the allergenspecific antibody responses of IgE and IgG4 isotypes in selected individuals of a large pollen-allergic population. In this study, we have used the recombinant allergen, rKBG8.3, which constitutes the conserved fragment of the Poa p IX allergens (16)(17)(18), and the proteins present in the Kentucky bluegrass (KBG) pollen extract to examine the magnitude and isotypes of specific antibodies produced in a defined group of allergic individuals who were predominantly allergic to either tree pollen (TAs) or to several aeroallergens including both tree and grass pollen (TGAs). Our results demonstrate that the antibody response to the grass pollen extract is more complex in TGAs than in TAs and nonatopic subjects (NAs).…”

Therapeutic Potential of Recombinant Allergens

“…Determination of primary structures of allergenic mol ecules has intensified the investigations of cross-reactiv ities among different allergens [14,[27][28][29][30]. On the basis of taxonomical relationships, these cross-reactivities can be categorized as intergeneric, inter-and intra-species.…”