Isotypic Analysis of Grass Pollen-Specific Immunoglobulins in Human Plasma

Abstract

The specificity and isotypic profile of humoral immune responses to Dactylis glomerata (Cocksfoot) pollen was studied by isoelectric focusing (IEF)-immunoprint analysis using 26 human plasma samples with high levels of Dactylis pollen-specific IgG4 (IgG4+ plasma) and 25 human plasma samples with low levels of specific IgG4 (normal plasma). Over 60 individual protein components in an aqueous pollen extract were separated by IEF and immunoprinted onto nitrocellulose (NC). Following plasma incubation, bound IgE, IgG1–4, IgA1, IgA2 and IgM antibodies were detected on separate immunoprints with isotype-specific antibodies. Binding patterns of IgG4 and the majority of IgG1 and IgA2 antibodies in the IgG4+ plasma group very closely paralleled the binding patterns produced by the IgE antibodies from the same plasma and are described as the ‘allergen repertoire’. In contrast, IgE, IgG4, IgG1 and IgA2 antibody reactivities to the ‘allergen repertoire’ were insignificant in the normal plasma group. These results suggest a qualitative, as well as a quantitative relationship between the immune responses which involve these 4 isotypes. Characteristic IgG2 and IgM antibody binding patterns, predominantly to non-allergenic antigens, were shared by the plasma from both groups, while IgG3 and IgA1 antibody binding patterns were highly variable from one plasma to another in both groups. One possible origin of the allergic diseases at the immunoglobulin heavy chain gene level is discussed.

Abnormal lgG4 Antibody Response to Aeroallergens in Allergic Patients

“…grass pollen, or cat dander had anti-D/;/, anti-grass pollen, or anti cat dander IgG4 Ab levels, respectively, significantly higher than in controls; nevertheless, controls also had significant levels of lgG4 Ab to aeroallergens (low levels except for cat dander). Similar data demonstrating antisensitizing aller gen IgG4 Ab levels higher in allergies than in controls have been reported [3,11,14]. In these studies, the high values sometimes observed in the control group could be related to their way of selection: as we observed that patients could present IgG4 Ab to allergens they were not sensitive to, our healthy subjects were drastically selected as nonallergic.…”

Modifications of <i>Phleum pratense</i> Grass Pollen Allergens following Artificial Exposure to Gaseous Air Pollutants (O₃, NO₂, SO₂)

“…10, 12 and 25 were selected from a group of 26 grass pollen-allergic donors for their ability to recognise a great number of grass pollen allergens after blotting [32]. …”

CD14 Promoter Polymorphisms in Atopic Families: Implications for Modulated Allergen-Specific Immunoglobulin E and G1 Responses

“…Aside from the clinical implications, aeroallergens are non-infectious environmental antigens to which most people will mount a minimal T-cell-dependent and allergen-specific humoral response involving the IgA and IgG isotype classes [5, 6]. We have shown that atopic and non-atopic humans can mount equally vigorous humoral responses to these challenges [7, 8].…”