Fig. 4

Metformin regulates the balance between Tfh cells and Tfr cells in vitro. a Splenocytes from NOD/ShiLtJ mice were cultured for 3 days with anti-CD3 and anti-CD28 antibodies in the presence or absence of 1 mM metformin (n = 3 per group). The cells were next reacted with antibodies against CD4, CXCR5, Bcl-6, IL-17, or Foxp3. The frequencies of Tfh cells (Bcl6⁺IL-17⁺ cells gated on CD4⁺CXCR5⁺ T cell population) and Tfr cells (Bcl6⁺Foxp3⁺ cells gated on CD4⁺CXCR5⁺ T cell population) are shown. Numbers in the plots indicate percentages of gated cells. The data were pre-gated on live single cells. b Data are means ± SEMs. Data are representative of three independent experiments (*p < 0.05, **p < 0.01)