Figure 8.
Chemotactic activity associated with the activation of platelets. (A) Platelets were isolated from normal mice and incubated with L. major promastigotes in the presence or absence of plasma as a source of complement. The release of PDGF from activated platelets after 30-min incubation was measured by ELISA. (B) CCL2 (MCP-1) production by MEF exposed to activated platelets was measured by ELISA. MEFs were incubated in culture medium alone, medium containing L. major, or medium containing L. major and fresh plasma for 30 min. (C and D) Mice were injected in the footpad with 25 µl saline alone (filled triangles) or saline containing 2 × 106 L. major parasites (filled circles). 24 h before infection some mice received 2 µg anti-CD41 antibody i.p. to deplete platelets (open circles). The production of PDGF (C) or CCL2/MCP-1 (D) was measured by ELISA and normalized to the total protein. Data represent the mean ± SE of the mean, from 3 independent experiments using a total of 15 mice. Data on platelet depletion was performed on five mice.