T_FH kinetics and CD73 expression.

<p>At the indicated days post i.p. immunization with NP-CGG in alum, spleens from B6 WT and CD73KO control mice were stained and analyzed by flow cytometry. T_FH were identified as TCRbeta⁺ CD4⁺ CD44^hi ICOS^hi PD-1^hi. Similar results were observed with additional PSGL1^low gating. 3 million events were collected per sample. (<b>A</b>) Representative histogram showing high expression of CD73 on T_FH cells 11 days post immunization (shaded dark gray). For comparison, low expression on naive splenic CD19⁺ CD38⁺ CD95⁻ B cells (shaded medium gray), GC B cells (CD95⁺ CD38⁻ NIP⁺ CD19⁺ day 20 post-immunization, shaded light gray), total CD4⁺ T cells (solid black) and CD4⁻ (CD8⁺) T cells (dashed gray) is shown. (<b>B</b>) Kinetics of T_FH cell expansion post immunization. (<b>C</b>) Relative intensity of CD73 staining among T_FH cells at different times post immunization. Each point represents an individual mouse and bars are means.