Analysis of sHSP70 uptake by T-cell subsets using fluorescent microscopy. Representative results of fluorescent microscopic images of isolated CD3⁺ and CD4⁺ T cells, respectively, incubated with sHSP70-FITC. CD3-PE–stained isolated CD3⁺ T cells (A) and isolated CD4⁺ T cells (D) and internalized sHSP70-FITC (B,E) are depicted separately, as well as with the merged images (C,F). Incubation of CD4⁺ T cells (G) with unlabeled sHSP70 resulted in a decrease of the uptake of the sHSP70-FITC as shown separately (H) and in the overlay (I).