The kinetics of T cell–DC interaction is similar in mice after chemotherapy or in BALB/c to CD11c-YFP mice. (A-C) Intravital imaging of donor T cells (labeled with CMTPX) and host DCs in the popliteal LNs of CD11c-DTR-EGFP mice (BALB/c background) conditioned by chemotherapy (cyclophosphamide 200 mg/kg intraperitoneal 1 day before transplant). (A) Instantaneous velocity of T_cons at 2 and 8 hours (hr) posttransplant compared with T_cons in mice conditioned with irradiation. (B) Mean velocity of T_cons at various time points. (C) Contact time between donor T_cons and host DCs at various time points after chemotherapy. (D-F) Median values for instantaneous velocity are indicated by blue or gray colored arrows. Intravital imaging of BALB/c donor T cells (labeled) and host DCs in the LNs of CD11c-YFP mice (C57BL/6 background). (D) Instantaneous velocity of T_cons at 2 and 8 hours posttransplant in YFP mice compared with those of CD11c-DTR-EGFP mice. (E) Mean velocity of T_cons in YFP mice. (F) Contact time between T_cons and DCs. Each line represents a different time point. The bars in all graphs represent median values. Data are representative of 2 separate experiments, with 1 mouse imaged per condition per experiment.