Expansion of T regulatory lymphocytes by murine bone marrow dendritic cells previously stimulated with Anisakis simplex larval antigens.

BACKGROUND: Anisakis simplex antigens present immunomodulatory properties by the induction of tolerogenic dendritic cells (DCs) in mice. OBJECTIVES: To study the capacity of DCs stimulated with A. simplex excretory-secretory (ES) or crude extract (CE) to generate Tregs. To investigate in vitro effects of antigens on the metabolic activity of splenocytes induced by LPS or CpG. METHODS: Phenotypic and functional characterization of T cells co-cultured with A. simplex-pulsed DCs was performed by flow cytometry. Lymphocyte mitochondrial respiratory activity was estimated by the Alamar Blue® Assay. FINDINGS: In C57BL/6J, CD4+CD25-Foxp3+ and CD8+CD25-Foxp3+ populations increased by CE-stimulated-DCs. In BALB/c, CE-stimulated-DCs caused the expansion of CD4+CD25+Foxp3+IL-10+ and CD8+CD25+Foxp3+IL-10+. IFN-γ expression raised in BALB/c CD4+CD25+ and CD4+CD25- for CE and ES, respectively. ES-stimulated-DCs increased CD4+CD25+ Foxp3+ and CD8+CD25- Foxp3+ expression in T cells. The association of ES or CE with LPS produced the increase in splenocyte activity in C57BL/6J. The association of CE with CpG decreased the proliferation caused by CpG in C57BL/6J. MAIN CONCLUSIONS: A. simplex increase the frequency of Tregs, which in turn produce IL-10 and IFN-γ. The host genetic base is essential in the development of anti-Anisakis immune responses (Th2, Th1, Treg).