001581 - Inflammatory Responses to Ole e 7 and Pru p 3 in Pollen-Food Syndrome: Insights from ex vivo Blood Culture Models

Cross-reactivity between nonspecific lipid transfer proteins (nsLTPs) has been identified as a significant factor in allergic reactions, including anaphylaxis. Specifically, nsLTPs such as Ole e 7 from olive pollen and Pru p 3 from peach, are believed to play a pivotal role in the development of pollen-food syndrome. A comprehensive molecular understanding of the underlying mechanisms driving these cross-reactions remains to be achieved, therefore further investigation is necessary.

In this study, we employed an ex vivo blood culture model to investigate the inflammatory response of patients with confirmed allergies to either or both Ole e 7 and Pru p 3 allergens. Blood samples from these allergic patients were exposed to the respective allergens (Ole e 7 and Pru p 3) or both of them together, at concentrations of 1 µg, 5 µg, and 10 µg for 12 h. Subsequent immune responses were assessed by ELISA assays measuring a broad spectrum of inflammatory cytokines in plasma, specifically IL-1β, IL-17, IL-10, and TNF-α.

We observed a strong correlation between the levels of the specific Ole e 7 and Pru p3 IgE levels present in the patients, and the increase of the measured inflammatory cytokines (IL-1β, TNF-α) after allergen exposure. Such increase in the measured cytokines seemed to reach a plateau phase with the three concentrations of allergen tested, suggesting that lower concentrations (< 1 µg) should be tested in order to detect possible microsensitivities without compromising the sensitivity of the assay. These findings underscore the potential of the ex vivo blood culture model as a reproducible and effective tool for investigating the immune responses triggered by allergens. Notably, the inflammatory reactions observed in patients confirmed their allergy to the respective allergens, further validating this approach as an effective means of diagnosing pollen-food syndrome.

This experimental framework holds significant potential for advancing our understanding of the molecular inflammatory mechanisms behind cross-reactivity in pollen-food syndromes. Ultimately, the insights gained from this study may contribute to improved diagnostic and therapeutic strategies for patients affected by these complex allergic conditions. The present model of study can be implanted to assess many other poorly characterized allergenic responses.