Figure 4.

In vitro induction of respiratory burst by neutrophil activation by anti-MPO IgG is not dependent on B1R. (A) Superoxide anion production in TNF-α–primed neutrophils derived from WT B6 (black triangles), B1R^+/+ littermates (black circles), and B1R^−/− (black squares) as measured by the SOD inhibitable ferricytochrome C assay. Anti-MPO IgG induces similar superoxide anion production in these three groups. (B) TNF-α–primed B1R^+/+ and B1R^−/− neutrophils incubated with B1R agonist LDBK and anti-MPO IgG showed comparable levels of activation. Negative controls include neutrophils from WT B6 (white triangles), B1R^+/+ littermates (white circles), and B1R^−/− (white squares) treated only with LDBK (no anti-MPO IgG).