KSHV up-regulates CCL20 expression in HUVEC and PEL cell lines. (A) HUVECs were infected with KSHV for 48 hours, and expression of CCL20 was measured by quantitative RT-PCR analysis and normalized to GNB2L1 (housekeeping control). PCRs were performed in triplicate and the data presented as fold change in target gene expression (mean ± SE). The results of the quantitative RT-PCR analysis were confirmed by separating the products (5.0 μL) on a 1.5% agarose gel followed by staining with ethidium bromide (bottom panel). (B,C) Cellular supernatants from KSHV-infected HUVECs were collected 3 days (B) and 6 days (C) after infection and used to measure the secretion of CCL20 by ELISA. The values shown are averages (mean ± SE) of 1 representative experiment of 3 in which the level of CCL20 secretion was measured in duplicate. (D) Kinetics of CCL20 up-regulation in KSHV-infected iHUVEC as measured by ELISA. (E) Level of CCL20 mRNA expression, as measured by quantitative RT-PCR, in PEL cell lines naturally infected with KSHV (BC-1, BCBL-1, and JSC-1). The KSHV-negative BJAB cell line was used as negative control.