Induction of chemokine release in NK cells by engagement of CD43. (A) Kinetics of the chemokine production induced by the pro-activatory anti-CD43 TP1/36 MoAb in NK cells. IL-2–activated NK cells were incubated in complete medium for different periods of time in the absence or presence of anti-CD43 TP1/36 MoAb (5 μg/mL). Cell supernatants were then assayed for different chemokines as described in Materials and Methods. This is a representative experiment of 2 independent experiments. (B) Secretion of RANTES and MIP-1β by NK cells stimulated with different MoAb. IL-2–activated NK cells were incubated in complete medium for 4 hours in the absence or the presence of the following MoAbs (5 μg/mL): anti-CD44 (HP2/9, IgG1); anti-CD43 (TP1/36 and HP2/21, IgG1 and IgM, respectively); and anti-CCR5 (IgM). Chemokines present in cell supernatants were then measured as described in Materials and Methods. In the absence of NK cells, the presence of chemokines was undetectable in complete medium (medium). The arithmetic mean ± SE of 6 independent experiments performed with cells from 6 different donors are shown. (C) The divalent F(ab′)₂fragments of anti-CD43 MoAb induce RANTES and MIP-1β production in NK cells. IL-2–activated NK cells were allowed to adhere on dishes precoated with saturating concentrations of different MoAbs for 4 hours in complete medium. Chemokines present in cell supernatants were then measured. Chemokines were undetectable in complete medium (medium). The arithmetic mean ± SE of 3 experiments performed with cells from different donors are shown.