CD27 blockade compromises CXCR5⁺EOMES⁺CD8⁺T-cell accumulation during EBV infection. (A) Cytokine production from serum samples harvested at termination of the experiment. Each individual cytokine is presented in the separate transfer conditions in the upper panel. In the lower panel, pooled data of α-CD27 blocking antibody–treated or isotype control antibody–treated groups is shown. (B) Frequency of CXCR5 expression on CD8⁺ T cells in the respective groups in blood, spleen, and liver. (C) Frequency of EOMES bright T-bet dim and EOMES dim T-bet bright populations in the respective group in blood. (D) Frequency of CD69 expression on CD8⁺ T cells in spleen. (E) Frequency of 2B4 (left) and PD1 (right) expression on CD8⁺ T cells in spleen. (F) Representative ChipCytometry immunofluorescence images for CD20, EBNA2, CD8, CD69, and PD1 in splenic sections of the respective treatment groups. Scale bars, 50 μm. (G) Quantification of the CD8⁺/EBNA2⁺CD20⁺ ratio, as well as the frequency of CD8⁺CD69⁺ and CD8⁺PD1⁺ cells in 5 to 7 randomly selected fields in splenic sections of isotype control or CD27 blocking antibody–treated animals. Data (n = 14-16 per group) pooled from 2 independent mouse experiments were graphed (A,B,D-F) and displayed with median and interquartile range. The Mann-Whitney U test was used to assess P values (A-E,G). *P < .05, **P < .01, ***P < .001. IFN, interferon; IL, interleukin; TNF, tumor necrosis factor.