a, Illustration of viral glycoproteins facilitating EV uptake and fusion at either the plasma membrane or in the endosome. b, Uptake of dTomato-labeled VSV-G EVs by Jurkat T cells. c, Uptake of dTomato-labeled VSV-G EVs by primary human CD4+ T cells. d, Surface expression of SLAM on T cells. Unmodified Jurkats, Jurkats expressing transgenic SLAM, or primary human CD4+ T cells were evaluated for SLAM surface expression by flow cytometry. e, Uptake of dTomato-labeled measles viral glycoproteins H/F EVs by Jurkats (+/− SLAM). f, Uptake of dTomato-labeled measles virus glycoproteins H/F EVs by primary human CD4+ T cells. In all cases, EVs were incubated with cells for 16 h and trypsinized to remove surface-bound vesicles. Experiments were performed in biological triplicate, and error bars indicate standard error of the mean. Statistical tests comprise two-tailed Student’s t tests using the Benjamini-Hochberg method to reduce the false discovery rate. (*p < 0.05, **p < 0.01, ***p < 0.001). Exact p-values are shown in Supplementary Table 1. EV dTomato loading evaluations are in Supplementary Fig. 12.