Chronic production of chemokines and cytokines in CCF-STTG1 cells persistently infected with CVB3. CCF-STTG1 cells were infected with CVB3, EV71, or CVA9 at an MOI of 1 for the indicated times. The release kinetics of VCAM-1 (A), IL-6 (B), IL-8 (C), and MCP-1 (D) in cell culture supernatants were measured by ELISA. Bars represent the means ± standard deviations of three independent experiments.