Development of a novel mouse model to study tick-borne onset of red meat allergy

Abstract

Abstract Bites from Amblyomma americanum, also known as the lone star tick, cause a life-threatening food allergy that induces IgE-mediated allergic reactions in affected individuals after eating dietary ‘red’ meat such as beef, pork, and lamb. Currently, there is no treatment to prevent or cure red meat allergy. Thus, establishing how lone star ticks cause red meat allergy is important for protecting individuals against this allergy. Our lab has successfully developed a novel mouse model of hypersensitivity to tick exposure to better understand how bites from the lone star tick sensitize the host to produce and maintain allergic IgE. Using this model, we identified increased T follicular helper cell and germinal center B cell responses and elevated serum titers of tick-specific IgE and IgG1 in mice exposed to lone star ticks subcutaneously. Furthermore, these mice generate a hypersensitivity response after oral challenge with red meat, as measured by basophil activation. Finally, we found that both the formation of inflammatory skin lesions at the site of tick exposure and the production of IgE were dependent on CD4+ helper T cells. These findings suggest that contained within the tick are factors that markedly influence priming of CD4+ T cells leading to the production of allergic IgE. Based on these data, we propose that manipulation of the factors within lone star ticks that drive CD4+ helper T cell activity could be used locally in the skin at the tick bite site to prevent the onset of meat allergy and systemically to stop an allergic reaction from progressing to a state of severe hypersensitivity.