Adhesion of conventional and CXCR5⁺CD4⁺T cells to LPS-activated hDMVECs. (A) Human peripheral blood CD4⁺/CXCR5⁻ (conventional) or CD4⁺/CXCR5⁺ (cTf) T cells flow sorted. Equal numbers of CD4⁺/CXCR5⁻ and CD4⁺/CXCR5⁺ T cells were then incubated for 1 hour on hDMVECs that were pretreated for 24 hours with LPS (10 ng/mL) in the absence and presence of 20 μg/mL function-blocking anti-CXCL13 antibody. Samples were then subjected to brief washing with warm media, fixation, staining for CD4, and imaging. (B) Representative fields of view showing phase and fluorescence images overlaid. T cells were labeled with anti-CD4-Alexa488 antibody, shown in green. Scale bar, 20 μm. (C) Quantitation of average number of cells per field of view (10 images per condition for 2 separate experiments).