Toll-like receptor-expressing cells for antiallergy compound screening

Background: Regulation of type 2 helper T cell (TH2) polarization by toll-like receptors (TLRs) has triggered great interest in new antiallergic therapeutics. In addition to being involved in the regulation of co-stimulation by antigen-presenting cells, they are expressed on other immune and non-immune cells. Objective: To review the expression and function of TLRs on these cells and their potential to regulate TH2-associated responses. Methods: We focused on human cells that can be used for in vitro testing of TLR agonists. Results/conclusion: Many cells involved in the allergic reaction have the capacity to respond to TLR agonists. Therefore, one needs to be cautious in extrapolating the antiallergic effect of a TLR agonist from the response analyzed in one cell type. Therefore, it is suggested that several cell types should be studied.