Fig. 4: Malaria-naive adult Vδ2⁺ γδ T cells produce more inflammatory cytokines following malaria stimulation.

a Intracellular production of IFNγ and TNF by Vδ2⁺ γδ T cells following 24-h stimulation with P. falciparum (Pf) infected red blood cells (pRBCs) and uninfected red blood cells (uRBCs) (children n = 13, adults n = 12). b Proportion of Pf activated cytokine expressing Vδ2⁺ γδ T cells (cytokine positive frequency in pRBC condition subtracted by uRBC condition). c Co-expression of cytokines by Pf activated Vδ2⁺ γδ T cells. d Proportion of Cytokine positive pRBC stimulated Vδ2⁺ γδ T cells and age in years. LOESS regressions and Spearman’s rank correlation separated into age groups. Solid lines are LOESS fit curves with error bands of 95% confidence interval. e Vδ2⁺ γδ T cell memory subset frequency comparisons after pRBC stimulation: NAIVE (CD27⁺CD45RA⁺), CM (CD27⁺CD45RA^-), EM (CD27^-CD45RA^-) and EMRA (CD27^-CD45RA⁺). f Memory subset proportions of cytokine producing Vδ2⁺ γδ T cells during pRBC stimulation. g Cytokine producing proportion of Vδ2⁺ γδ T cell memory subsets. Lines represent paired observations. Wilcoxon signed rank test used for paired data. Mann–Whitney U test used for unpaired data. Centre line representing the median, box limits indicating the upper and lower quartiles, whiskers extending to 1.5 times the interquartile range. All p are two-sided. For all panels data is from children n = 13 and adults n = 12. uRBC uninfected red blood cells, pRBC parasitised red blood cells, Pf P. falciparum, EM effector memory, CM central memory.