Tfh cells in blood and spleen of immunized WAS KO and WT mice. (A) Flow cytometric analysis of B220⁻CD4⁺Foxp3⁻CXCR5⁺ cells in blood and spleen of WAS KO mice and WT mice after secondary immunization (immu). un, unimmunized control. Percentage of CXCR5⁺ cells within CD4⁺Foxp3⁻ T cells in blood (B) and spleen (C) of WT mice and WAS KO mice. (D) Number of Tfh cells in the spleen of WT and WAS KO mice. Percentage of CXCR5⁺CD44^hi cells within CD4⁺Foxp3⁻ T cells in blood (E) and spleen (F) of WAS KO mice and WT mice. (G) Percentage and (H) number of Tfr in the spleen of WT and WAS KO mice. (I) Flow cytometric analysis of CXCR5⁺ICOS⁺ cells in spleen and blood of WT and WAS KO mice. The percentage of CXCR5⁺ICOS⁺ T cells in blood (J) and spleen (K) of WT and WAS KO mice. (L) The number of CXCR5⁺ICOS⁺ T cells in spleen of WT and WAS KO mice. (M) Flow cytometric analysis of CXCR5⁺BCL6⁺ cells in spleen of WAS KO mice and WT mice. (N) Percentage and (O) number of CXCR5⁺BCL6⁺ cells within CD4⁺ T cells in the spleen of WAS KO mice and WT mice.