Anti mhc 2 bv510

The cells were blocked with 1 µg anti-CD16/32 per 10⁶ cells for 15 min at 4 °C. Cells were incubated with antibodies in the dark for 1 h on ice. After washing with 1% BSA in PBS, cells were filtered and resuspended in the cell staining buffer for characterization of murine immune cell subsets according to a previously reported protocol [31 ]. The following antibodies were used: anti-CD3-BV650, anti-CD11b-Pacific Blue, anti-CD11c-PE/Cy7, anti-CD19-BV605, anti-CD45-Per-CP-Cy5.5, anti-MHC-II-BV510, anti-F4/80-PE, and anti-Ly6G-FITC (BioLegend, CA, USA). Data acquisition was performed on a CytoFLEX Flow Cytometer (Beckman Coulter, CA, USA) and analyzed with Kaluza software (version 4.2, Beckman Coulter).

BMDMs were cultured in 12-well plates. Two to three days later, equal volume of LL-2-CM, CMT-64-CM, or new DMEM medium was added into RPMI-1640 medium that used for culturing BMDMs for further 12 h, 24 h, or 48 h. For LPS stimulation, 20 ng/ml LPS (L2880, Sigma-Aldrich) was added into RPMI-1640 medium with or without 10 $\mu \mathrm{M}$ BAPTA-AM (HY-100545, MedChemExpress) to culture BMDMs for further 24 h. Cells were collected and stained by antibodies in 4 ${}^{\circ }\mathrm{C}$ for 30 min. Anti-CD45 BV421 (103,133, Biolegend), anti-CD206 APC (141,707, Biolegend), anti-CD206 PE (141,706, Biolegend), anti-MHC-II BV510 (107,635, Biolegend), and anti-MHC-II BV711 (107,643, Biolegend) were used. At the same time, LIVE/DEAD™ Fixable Near-IR Dead Cell Stain Kit (L34975, Thermo Fisher) was added to exclude non-specific staining. After staining, the cells were washed once by PBS and analyzed by ACEA NovoCyte (ACEA Biosciences). The gating strategies for our experiments have been shown in supplementary Fig. 1.