AR is produced in response to antigen stimulation. We next tested whether human CD4 T cells expressed AR during antigen/APC stimulation in response to influenza peptides, allergens or tetanus antigens to stimulate Type 1, Type 2 and Thpp-biased recall responses, respectively [6] . PBMCs were stimulated with antigens for 10 hours, and AR and other cytokines measured by ICS.