Fig 1: eLFs of brain and spinal cord exhibit more CD4+CD69+ cells. (A–D) Consecutive IF co-staining of CD4 and CD69 in follicle-like structures of SPMS brains and spinal cords. Inserts show co-localization of CD4+ cells with CD69 suggesting tissue-resident T cells in a representative meningeal eLF of SPMS spinal cord (same region as Figures 3, 4E–H, 5). Scale bar indicate 100 µm, scale bars of the inserts indicate 10 µm. (E) Percentage of tissue-resident cells defined as CD4+CD69+ cells of CD4+ cells in follicle-like structures (F+) and less defined infiltrates (F-) in SPMS brains and spinal cords. F-, 5.70, SD = 10.67, n = 38; F+, M = 7.92, SD = 9.39, n = 32; Mann Whitney test, U = 434.0, p = 0.028.