Green pea (Pisum sativum) is a component of European cuisine; however, an estimated 0.8% of Europeans suffer from allergies to pea proteins. We examined the immunoreactive potential of pea albumins (PA) in BALB/c and C57BL/6 mice. Mice were orally gavaged with PA or glycated pea albumins (G-PA) for 10 consecutive days, in combination with an adjuvant. Both PA and G-PA increased PA-specific serum antibody titers to about 2 12 for anti-PA IgG, ∼2 7 for anti-PA IgA, and ∼2 7.8 for anti-PA IgA in fecal extracts (p < 0.001). On day 42 postexposure, the antibodies titers decreased and were greater in BALB/c compared to C57BL/6 mice (p < 0.05). Distribution of CD4 + and CD8 + T cells in lymphoid tissues presented strain-specific differences. PA was found to induce lymphocyte proliferation; however, G-PA did not. Both PA and G-PA changed CD4 + and CD8 + T cells percentages in some lymphoid tissues; however, this did not impact cytokines production by splenocyte cultures evidenced by the stimulation of Th1, Th2, and Th17 cells. The observed immunomodulatory properties of PA and G-PA and lack of a sign of allergic reaction render them suitable for supplements in personalized diets, but further research is needed to precisely understand this activity.

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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.

Mice (Balb/c), with peanut allergy induced, were subjected to desensitization therapy with the use of pea protein extract (PE) or isolated globulin fractions: legumin (PL) and vicilin (PV). B-and T-cell responses to peanut proteins were analysed by determination of the IgE, IgG1, and IgG2a antibody levels in plasma and the concentration of IL-4, IFN-gamma and IL-10 cytokines secreted by isolated splenocytes.Conducted studies have demonstrated that immunotherapy with proteins resulted in the decrease of total IgE and peanut-specific IgG1 levels and significantly enhanced synthesis of peanut-specific IgG2a in plasma (ELISA method) and at the cellular level (ELISPOT type B). A successful and effective immunotherapy is related to the shift in profile of lymphocytes from Th2 subpopulation towards Th1 subpopulation. In our studies significant increase in the activity of Th1 lymphocytes was observed in groups desensitized with pea protein extracts (PE) and pea legumin fraction (PL). In these groups, significant statistic decrease in IL-4 secreted and increase in IL-10 level were found.Desensitization method with the use of pea proteins being suggested in the presented studies can be an alternative method for specific immunotherapy for people, especially with strong allergic reaction to peanuts; however, this method needs further studies with mouse model. Keywords: peanut hypersensitivity, specific immunotherapy, cross-reactivity, pea proteins, animal modelPeanut allergy is one of the most serious disorders among the immediate hypersensitivity reactions and it appears to be a growing problem. The most common treatment of food allergy is exclusion of the component causing hypersensitivity from diet. However, in case of allergy to peanuts, this method is not suitable due to the possible occurrence of peanuts in foods, cosmetics and pharmaceutical products. Another problem is that traces of peanut allergens are sufficient to induce strong reaction (HouriHAne et al., 1997;BlumcHen et al., 2010). Mechanism of peanuts allergy is the subject of extended studies; however, there are still more questions than answers related to this aspect. Recent studies have proven that extracts from peanuts and nuts, contrary to milk or eggs, were able to activate complement system both in mice and people, which increased their ability to induce anaphylaxis (kHodoun et al., 2009). However, lack of definitive explanation of the mechanism of food hypersensitivity to peanuts limits therapeutic applications (THyAgArAjAn et al., 2010). Recently, a lot of attention has been focused on novel specific immunomodulatory therapies for food allergy, including oral immunotherapy (OIT) and sublingual immunotherapy (SLIT) (BlumcHen et al., 2010;Frew, 2010). Allergen-specific immunotherapy (ASIT) has been reported to modify different aspects of the immune system, inducing shift of allergy-promoting Th2 cells to Th1 cells, epitope-specific T-cell anergy, and allergen-specific regulatory T cells that suppress the responses of effector T cells (ArpS et al., 1998...