Arsenic-induced dose-dependent modulation of the NF-κB/IL-6 axis in thymocytes triggers differential immune responses

•We for the first time explicitly show that arsenic exposure causes morphological damage to the thymus and results in heightened death of thymocytes.•Our data suggests that arsenic-induced apoptosis occurs due to increase in cellular oxidative and nitrosative stress.•We have for the first time established a non-classical role of NF-κB, correlating it with increase in FoxP3 expression.•The % of CD4+ CD25+ T cells were high and expression of FoxP3 has also increased at higher doses of arsenic indicating an nTreg bias.