Dynamic of T regulatory, Th17, and Tc17 cells and their related cytokines during Nocardia brasiliensis infection in BALB/c mice (99.1)

Abstract

Actinomycetoma caused by Nocardia brasiliensis induces an inflammatory response with multiple microabscesses and granuloma formation with abundant large cells and mononuclear infiltration. Th1 and Th2 lymphocytes response have been evaluated in N. brasiliensis infection. T regulatory, Th17, and Tc17 lymphocytes are being studied to evaluate their role in several infectious diseases, but there are not data in N. brasiliensis infection. In this study, we evaluated the levels of Treg, Th17 and Tc17, as well as their related cytokines during N. brasiliensis infection in BALB/c mice. Methodology: Mice infected with N. brasiliensis in the footpad were sacrificed at 0, 3, 7, 15, 30, 60 days after infection and levels of Treg, Th17 and Tc17 cells in footpad and spleen were measured by flow cytometry, and their related cytokines (IL-6, IL-10, IL-17A, IL-23 and TGF-β) in the homogenized tissue were measured by ELISA. Results: In footpad, Th17/Tc17 lymphocytes were increased at day 3 (P<0.01), while Treg cells at day 7 (P<0.01). In spleen, Treg cells reached its peak at day 15 (P<0.01) meanwhile Tc17/Th17 at day 3 (P<0.05). Anti-inflammatory cytokines were higher, TGF-β at day 7 and 30 (P<0.01), while IL-10 at day 15. IL-17A and IL-23 were increased gradually during the infection (P<0.01). Finally, IL-6 was increased at day 3 (P<0.01). In conclusion, there is an imbalance of Treg, Th17 and Tc17 in the early stage of N. brasiliensis that could favor chronic disease.