Supplementary Figure 6: Establishment of and characterization of the Il21^ΔT mice

(a) Construction of the LoxP-flanked Il21 allele (Il21^f/f) mice. Exons 1 and 2 of the Il21 gene locus were flanked by LoxP sites (open triangles) by homologous recombination. The flanked region was removed from the mouse germline by crossing with Cd4-cre mice. Arrows show binding sites of PCR primers. (b) Electrophoretic analysis of PCR fragments of DNA in the Il21 locus of the sorted CD4⁺ T cells from WT and Il21^ΔT mice. Arrows indicate PCR products derived from the Il21 locus. (c) Percentage of CD8⁺ and CD4⁺ T cells in thymus of Il21^ΔT mice. (d) The expression of Il21 mRNA in splenic CD4⁺ T cells and Peyer’s patches. Il21 mRNA expression was measured in CD4⁺ T cells from Il21^ΔT mice by qPCR. (e) Expression of GL-7 and Fas were analyzed in B220⁺ B cells from WT or Il21^ΔT mice immunized with Narita. The bar graph shows the percentage of GC B cells in the B220⁺ population (n=5).