Thiol peroxiredoxin, a novel allergen from Bombyx mori, modulates functions of macrophages and dendritic cells

Bombyx mori (B. mori, also known as silkworm) plays a role in the pathogenesis of allergic diseases. However, its allergens are to be characterized. The aim of this paper is to identify new silkworm allergens. Two dimensional gel electrophoresis (2-DE) and mass spectrometry were employed to separate and identify potential allergens from silkworm pupa. Six potential allergens were identified in this study. Thiol peroxiredoxin (TP), one of the 6 allergens, reacted to serum IgE from patients sensitized to silkworm. By sensitizing with TP allergic asthma like symptoms were induced in mice, including elevation of the levels of serum IgE, IL-4 from bronchoalveolar lavage fluid and culture supernatant of spleen cells. In vitro experiments showed that TP significantly induced RAW264.7 cells (a macrophage cell line) apoptosis via modulating the BCL2 and Caspase9 pathways. The levels of CD80, CD40, CD83 and TNF-alpha in DC2.4 cells (a dendritic cell line) were increased in the culture after exposure to TP. In summary, TP is an allergic component of silkworm. It induces allergic asthma, and modulates the functions of macrophages and dendritic cells.