Histamine improves antigen uptake and cross-presentation by dendritic cells.

AMARAL MM, DAVIO C, CEBALLOS A, SALAMONE G, CAÑONES C, GEFFNER J, VERMEULEN M

JOURNAL OF IMMUNOLOGY

Año: 2007 p. 3425 - 3433

0022-1767

Previous studies have shown that histamine is able to modulate the function ofdendritic cells (DCs). Histamine seems to be required for the normaldifferentiation of DCs. Moreover, it is capable of stimulating the chemotaxis of immature DCs and of promoting the differentiation of T CD4+ cells into a Th2profile. In this study, we analyzed whether histamine was able to modulateendocytosis and cross-presentation mediated by immature DCs. Our results showthat both functions are stimulated by histamine. Endocytosis of soluble HRP andFITC-OVA and cross-presentation of soluble OVA were markedly increased byhistamine. Interestingly, stimulation of endocytosis and cross-presentationappeared to be mediated through different histamine receptors. In fact, theenhancement of endocytosis was prevented by the histamine2 receptor (H2R)antagonist cimetidine, whereas the stimulation of cross-presentation wasprevented by the H3R/H4R antagonist thioperamide. Of note, contrasting with theobservations made with soluble Ags, we found that histamine did not increaseeither the uptake of OVA-attached to latex beads, or the cross-presentation ofOVA immobilized on latex beads. This suggests that the ability of histamine toincrease endocytosis and cross-presentation is dependent on the Ag form and/orthe mechanisms through which the Ag is internalized by DCs. Our results supportthat histamine may favor cross-presentation of soluble allergens by DCs enabling the activation of allergen-specific T CD8+ cells, which appears to play animportant role in the development of allergic responses in the airway.