The accessory roles of Lipopolysaccharide-activated murine B cells in T cell polarization

Abstract

Environmental factors lipopolysaccharide (LPS) and mite allergens stimulate immune responses to develop Th2-mediated allergic diseases; the underlining mechanisms remain ambiguous. The importance of the direct effects of environmental factors on antigen presenting cells (APCs) such as dendritic cells (DCs) has been addressed. The objective of this study is to address the question from B cell perspective. Results indicated that low doses (0.1-100ng/mL) of LPS-stimulated B cells were capable of driving Th2 polarization, whereas high doses (1,000-10,000ng/mL) of LPS-stimulated B cells polarized T cells into Tr1 phenotype. B cells co-cultured with low dose of LPS-containing Der p 1 or Der p 2 could also drive Th2 polarization. In conclusion, LPS-activated B cells acquire differential modulatory effects on antigen specific T-cell polarization, which is dependent on the stimulation of LPS in a dose-dependent manner. These observations may provide mechanistic explanation for the influence of environmental factors on the development of allergic diseases.