(A) Bone marrow-derived macrophages (BMDMs) were treated for 24 hours with cytokines or media containing 50% GL261 cell supernatant. Supernatant was collected after another 48 hours for CCL2 analysis by ELISA. S/N control denotes the CCL2 content in GL261 supernatant. (n = 3–6) (B) Microglia from neonatal mixed-cortical cell cultures (MCCC) were treated with the indicated cytokines or with media containing GL261 supernatant. (n = 3). (C–D) Mouse cytokine array from MCCC or GL261 supernatant. (E–F) CCL2 secretion from BMDMs treated with candidate cytokines/chemokines identified from the antibody arrays (n = 3–6). (G) CCL2 secretion from microglia treated with candidate cytokines/chemokines (n = 3). Data in A, B, E–G are representative of 3–4 independent experiments. Data are represented as mean ± SEM; *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 by ordinary one-way ANOVA with Tukey’s multiple comparisons test.