Figure 4.

CD28 co-stimulation enhances the expression of co-stimulatory molecules

Univariate analyses of co-stimulatory marker expression in CD4⁺ and CD8⁺ T cells after 15h of stimulation of purified T cells from UD participants, using aCD3 aAPCs or aCD3 aCD28 aAPCs.

(A and B) Representative flow cytometry plots of purified CD4⁺ T cells stimulated with indicated aAPCs. (A) CD69 expression. (B) Co-expression of CD69 and other activation molecules.

(C–F) Background-subtracted net responses of CD4⁺ and CD8⁺ T cells expressing co-stimulation molecules (CD40L, OX40, 4-1BB, ICOS). Global responses (OR-gate identified cells expressing one or more co-stimulation molecules) for (C) CD4⁺ and (D) CD8⁺ T cells are shown, then subdivided individually for each tested co-stimulation molecule for (E) CD4⁺ and (F) CD8⁺.

(G and H) Percentage of residual cytokine⁺ signal, representing the quotient between the 1:0:4 (aCD3:aCD28:IgG; aCD3 aAPCs) and 1:4:0 (aCD3:aCD28:IgG; aCD3+aCD28 aAPCs) conditions in (G) CD4⁺ and (H) CD8⁺ T cells. In (C–H), n = 11. Friedman tests are shown below the histograms in (C, D, G, H). In (C–H), error bars represent the interquartile range. Gray borders represent responses <0.1% (in C and D) or <0.01% (in H) that could not be represented on the logarithmic scale and hence were given arbitrary values of 0.1% or 0.01% respectively.