Fig. 1

Characterization of CD4+ T cells from telomerase-deficient mice under steady state conditions. A Schematic representation of the different generations of mTerc−/− mice and validation of the telomere loss. Generation 2 (G2) animals were obtained by crossing mTerc−/− G1 animals, G3 animals are offspring of mTerc−/− G2 mice. Telomere length was quantified by a qPCR-based method in Terc+/+, Terc−/− G1 and Terc−/− G3 mice (n = 3 per group, except thymus of Terc−/− G3: n = 2). B Flow cytometric analysis of CD4+ and CD8a + cells from blood and lymphoid organs of mTerc−/− mice (n = 3) under steady-state conditions. C Immunohistochemical stainings of CD4+ T cells (red) in mesenteric lymph node (mLNs, n = 3 except Terc −/− G2: n = 2) and spleen (n = 3) of mTerc−/− mice. Nuclei were counterstained with DAPI (blue). Quantification was done with ImageJ software by calculation of the area of positive CD4 staining relative to the area of DAPI staining from non-overlapping pictures (≥ 5 pictures per mLN and ≥ 7 pictures per spleen). D Composition of the CD4+ T cell pool with regards to memory populations. Cells were defined as naïve (CD44- CD62L+), central memory (CD44+ CD62L+) and effector/effector memory (CD44+ CD62L-). E Relative numbers of CD4+ T cells expressing costimulatory molecules CD28 and CD27 in lymphoid organs from telomerase-deficient mice. If not otherwise indicated, the experiment was performed with n = 3 mice from each generation. Graphs show the mean ± SD, * adjusted p ≤ 0.05, ** adjusted p ≤ 0.01, *** adjusted p ≤ 0.001