Fig 3. Granzyme B and perforin expression in circulating CD38⁺ CD8⁺ T cells following P. vivax blood-stage infection.

Blood samples were collected from malaria-naive volunteers prior to and post-infection with P. falciparum or P. vivax infected erythrocytes, as described in legend to Fig 1. The expression of granzyme B and perforin within CD38⁺ CD8⁺ T cells and CD38^- CD8⁺ T cells was determined by flow cytometry. (A) Representative staining of granzyme B and perforin in CD38⁺ and CD38^- CD8⁺ T cells from one P. vivax infected volunteer. (B) The frequency of cells expressing granzyme B and perforin in CD38⁺ or CD38^- CD8⁺ T cells circulating pre- and post-infection with P. vivax. (C) Representative staining of granzyme B and perforin in circulating CD38⁺ CD8⁺ T cells from one P. falciparum infected volunteer and one P. vivax infected volunteer. (D) The frequency of cells expressing granzyme B and perforin in circulating CD38⁺ CD8⁺ T cells pre- or post-infection in P. vivax or P. falciparum infected volunteers. Graphs show mean data from 6 volunteers (P. falciparum) or 2 volunteers (P. vivax); error bars indicate SD.