FIG 3.

MHV3 exhibits higher tropism for BMECs than MHV-A59 and 51.6-MHV3 do. Mouse bEnd.3 immortalized brain microvascular endothelial cells (BMECs) were infected with MHV3, MHV-A59, or 51.6-MHV3 at an MOI of 0.1. (A) Kinetics of MHV infections up to 8 days p.i. (B) Metabolic activity of infected BMECs as determined by MTS-PMS colorimetric assay from 24 h to 72 h p.i. (C) Roles of CEACAM1a and TLR2 in MHV entry into BMECs. (D) Roles of caveolin-1 (CAV-1) and clathrin (CLT) in MHV endocytosis by BMECs. bEnd.3 cells were treated with specific siRNA to each molecule prior to infection for 24 h, and MHV nucleoprotein (N) mRNA expression was determined by qRT-PCR. All experiments were conducted in triplicate. Results are representative of two or three independent experiments. Values are means ± standard errors of means (error bars). Values that are significantly different are indicated by asterisks as follows: *, P < 0.05; **, P < 0.01; ***, P < 0.001. CTRL and Ctrl, control (uninfected cells).