Figure 5.

The NH₂- and COOH-terminal serum amyloid A1 (SAA1) peptides are not directly chemotactic for neutrophils. The chemotactic activity of 100–3,000 ng/ml intact SAA1 (A,B), SAA1(1–51) (B), SAA1(52–104) (A), and SAA1(58–104) (A) was evaluated on human neutrophils in the Boyden microchamber assay. The chemotactic potencies are expressed as mean chemotactic index ± SEM from four (B) to six (A) independent experiments. Statistically significant differences compared with controls, determined by the Mann–Whitney U test, are indicated by asterisks (*p < 0.05 and **p < 0.01).