CD4 and type 2 diabetes mellitus: First, to determine whether IFNγ production by T cells differed between Lepr-deficient, T2DM and lean mice at baseline, we stimulated splenocytes from mock-infected Lepr-deficient, T2DM and lean mice with a mixture of Phorbol 12-Myristate 13-Acetate (PMA) and ionomycin for 5 hours (h), and subsequently analyzed IFNγ-producing CD8+ and CD4+ T lymphocytes by flow cytometry.