Ex vivo isolated memory Th cells express twist1. Cells were sorted by flow cytometry and restimulated for 3 h with PMA/ionomycin (A–C). (A) Cells were isolated from the spleen and lymph nodes of 8–12-wk-old DO11.10 mice (squares, each representing a pool of 15 individual mice) and the pooled inguinal and mesenteric lymph nodes of 4–6-mo-old nephritic MRL/lpr mice (circles, 1–2 mice each). Of note: 90% of the CD4⁺CD62L^hi cells in MRL/lpr mice represented activated (CD44⁺) cells (not depicted). (B) Twist1 mRNA in peripheral human Th lymphocytes. The mean expression of twist1 mRNA normalized to ubiquitin ligase H5 in total CD3⁺CD4⁺ cells was set to 1. Subpopulations were defined according to expression of the following surface markers: naive (CD4⁺CD45RA⁺CCR7⁺), CM (CD4⁺CD45RA⁻CCR7⁺), EM (CD4⁺CD45RA⁻CCR7⁻) with each data point representing one individual healthy donor. (C) Twist1 transcripts in CD3⁺CD4⁺ cells purified from patient material: blood (total peripheral CD3⁺CD4⁺ cells from healthy donors, see B), colon (noninflamed colon tissue), UC, and CD (endoscopic biopsies from UC and CD patients, respectively), RA, ReA, PsA, and AS (synovial fluid from rheumatoid arthritis, reactive arthritis, psoriatic arthritis, and ankylosing spondylitis patients, respectively) with each dot representing one individual patient. Mean twist1 mRNA expression is displayed from patients who were repeatedly sampled.