Adenovirus expressing TREM-1 infection of THP-1 cells up-regulates TREM-1 expression. THP-1 monocytic cells were collected after 72 h of infection. (A) Ad.TREM-1– and Ad.V-infected cell lysates (30 μg in each lane) were analyzed by immunoblot. β-Actin was used as a loading control. Results are representative of two independent experiments. (B) Ad.TREM-1– and Ad.V-infected THP-1 cells were performed by flow cytometric analysis. Results are representative of three independent experiments. Ad.TREM-1 = adenovirus expressing TREM-1; Ad.V = control adenovirus; PE = phycoerythrin; THP-1 = human acute monocytic leukemia cell line; TREM-1 = triggering receptor expressed on myeloid cells-1.