CD69 prevents PLZF innate precursors from prematurely exiting the thymus and aborting NKT2 cell differentiation.

While CD69 may regulate thymocyte egress by inhibiting S1P expression, CD69 expression is not thought to be required for normal thymocyte development. Here we show that CD69 is in fact specifically required for the differentiation of mature NKT2 cells, which do not themselves express CD69. Mechanistically, CD69 expression is required on CD24 PLZF innate precursors for their retention in the thymus and completion of their differentiation into mature NKT2 cells.

Effect of antioxidants, oxidants, metals and saliva on cytotoxicity induction by sodium fluoride.

We have recently found that millimolar concentrations of sodium fluoride (NaF) induced apoptotic cell death, characterized by caspase activation and DNA fragmentation, in tumor cell lines. This finding paved the way to investigating the interaction between NaF and the oral environment. As an initial step, we investigated redox compounds, metals and saliva, which may modify the cytotoxic activity of NaF against a human oral squamous cell carcinoma cell line (HSC-2).