Fig. 6: Comparable Foxp3⁺ Treg response in both adults and children in response to malaria.

CD4⁺ T regulatory cell (Treg) frequency and surface marker expression in children (n = 6) and adults (n = 7) was measured after 5 days in vitro co-culture with trophozoite stage P. falciparum (Pf) red blood cells (pRBCs) and uninfected red blood cells (uRBCs). a Tregs were identified as CD25high CD127low and FoxP3⁺ CD4 T cells. b Treg frequency within CD4⁺ T cell compartment following stimulation. Surface marker frequency of inflammatory immune activation (c: CD38, ICOS and Ki67) and inhibition (d: CCR4, TNFR2 and PD−1) post stimulation of Treg frequency with uRBC, pRBC and Pf activated responses (quantified as expression in pRBC minus expression in uRBC cultured conditions). 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 the upper and lower limits. All p are two-sided. For all panels data is from children n = 6 and adult n = 7. Pf P. falciparum, uRBC uninfected red blood cells, pRBC parasitised red blood cells, TREG FoxP3+ regulatory T cells.