Agata Szymkiewicz

Peanut Allergenicity and Cross-Reactivity with Pea Proteins in the In Vivo Model

The aim of the study was to analyse the potential pea-peanut cross-reactivity using the mice BALB/c as a biological in vivo model in the research on immune response to peanut proteins (PnE). BALB/c mice were three-fold sensitised (on days 1, 7, and 21) by oral or intraperitoneal (IP) administration of PnE in 0.5 mg or 1 mg dose, with or without adjuvant - aluminum hydroxide gel (Alum). Serum immunoglobulins (IgE, IgG, IgG1 and IgG2a) and level of cytokines (IL-4, IL-10, IFN- γ), secreted by the isolated lymphocytes were examined. The highest increase in total IgE and peanut-specific IgG1 was noted in the group sensitised by IP administration of PnE in the presence of Alum. Lymphocytes from peanut-sensitised (with and without Alum) mice showed a significantly high level of IL-4 and this cytokine was secreted to a much higher extent as compared to IFN-γ. Stimulation of a culture of lymphocytes with pea proteins resulted in high IFN-γ secretion. A weak reaction of peanut-specific IgG1 present in mice serum with pea globulins (vicilin - PV and legumin - PL) can suggest that the cross-reactivity between peanut and pea proteins results from the presence of proteins other than 7S and 11S globulins. Due to the demonstrated low cross-reactivity between peanut proteins and pea globulins, the possibility of applying pea proteins in peanut-allergy immunotherapy may be suggested.

A simultaneous two-colour detection method of human IgG- and IgE-reactive proteins from lactic acid bacteria

Whole cell extracts of two Lactobacillus strains were tested with primary antibodies from two pooled sera from allergic patients. Fluorescently labelled anti-human IgG and anti-human IgE secondary antibodies applied in Western blotting, together with an appropriate image acquisition protocol facilitated imagining bacterial proteins that reacted with human IgG and IgE.