CCL3 and CCL5 produced in H1N1/98- and H9N2/G1-infected monocyte-derived macrophages (MDMs). The supernatants from H1N1/98- and H9N2/G1-infected MDMs were collected at the 6-h, 12-h, and 24-h points of infection (POIs) and assayed by ELISA, as described in Materials and Methods. At early time points (6-h and 12-h POIs) after infection with H9N2/G1, much higher concentrations of CCL3 and CCL5 were detected in adult MDMs than in neonatal MDMs. Compared with those from H1N1/98-infected MDMs, there were 5–10-fold increases in CCL5 and CCL3 concentrations in the culture supernatants from H9N2/G1-infected MDMs at the 24-h POI. The data shown are the mean±SE from 5 sets of independent experiments. *P<.05; **P<.01