The role of HA in TSN-induced monocyte dysfunction. (A) Human monocytes were left untreated (open bars) or were pretreated with INT-HA (shaded bars) or TSN from U251 (solid bars) cells for 10 hours, and the cells were then washed and recultured in medium alone or with INT-HA or the indicated TSN for 18 hours. (B) Monocytes were preincubated for 4 hours in medium alone (open bars) or with 10 μg/mL CD44-blocking Ab (solid bars) or control mAb (IgG1, shaded bars), after which they were left untreated (Med) or stimulated with 15% TSN or 50μg/mL INT-HA for 18 hours. (C) Cells were pre-incubated for 4 hours in medium alone (open bars) or with 100 μg/mL Pep-1 (solid bars) or control peptide (shaded bars) and then stimulated with TSN or INT-HA for 18 h. Levels of TNF-α and IL-10 in the culture supernatants were determined by enzyme-linked immunosorbent assay, and the illustrated values represent the mean (± SE) of 4 separate experiments; *P < .05 and **P < .01, compared with monocytes pre-incubated in medium alone.