The rAAV-induced IL2 persistent release that we used here, before and during the course of S. aureus arthritis, is known to robustly expand CD4+CD25+FoxP3+ Tregs in both blood and spleen [31]; we have confirmed this effect and found it to be sustained for the duration of the infection, without a major impact on the Teffs. This evidence concerns the gene IL2RA and infection.