Figure 6. Engagement of integrin α_Dβ₂ triggers expression of inflammatory chemokines and cytokines by human monocytes.

Integrin α_Dβ₂ was engaged by immobilized activating mAb and supernatants for mediator analysis were collected as outlined in Figure 5. In (A) the concentration of anti-α_D mAb, mAb against other leukocyte integrin α subunits, or control proteins used to coat the wells was 10 µg/ml, and in (B) the concentrations were 20 µg/ml. A. Engagement of integrin α_Dβ₂ (8 hr) triggered release of MCP-1 that was much greater than that induced by immobilized mAb against other leukocyte integrin α subunits or release from monocytes incubated on control surfaces. Two activating anti-α_D mAb, 169B and 217I, were studied. This result is representative of the pattern seen in eight separate experiments using monocytes from different donors, as shown in detail in Table S5. B. Engagement of integrin α_Dβ₂ induced time-dependent release of IL-1β by monocytes. Two activating anti-α_D mAb were examined, as in (A). In five additional experiments using monocytes from different donors, IL-1β protein was induced in monocyte lysates and released into the supernatants when integrin α_Dβ₂ was engaged for 8 hr., and was greater than that in samples from monocytes incubated on control surfaces (Table S6).