Gpnmb

The following antibodies (Abs) were used for flow cytometry analysis: CD11b and CD4 from BD Biosciences (USA); Gr‐1 from Biolegend Inc (USA); GPNMB, CD8a, and CD107a from ThermoFisher Scientific (USA). The cells were surface‐labeled with anti‐mouse Abs for 30 min at 4°C in the dark, and subsequently washed, fixed, and permeabilized by the Cytofix/Cytoperm Solution Kit (BD Biosciences, USA). The permeabilized cells were labeled by anti‐mouse CD107a for 30 min at 4°C in the dark. The cells were read using a FACS Celesta flow cytometer, and data were analyzed by FlowJo software (Version 10.0).

iMGLs on day 40 were treated for 24 h and collected using RLT buffer. RNA extraction was done using an RNease Plus mini kit (Qiagen) according to the manufacturer’s protocol. For quantitative rtPCR, a TaqMan RNA-to-Ct 1-step kit (Thermo Fisher Scientific) was used according to the manufacturer’s protocol using the following TaqMan probes (Thermo Fisher Scientific): GAPDH (HS02786624_G1) and GPNMB (HS01095669_M1). Quantification was done using the 2 ^−ΔΔCT method^{52 (link)}. Each biological sample was measured in triplicate, and the average for each biological sample is shown in the corresponding graph. Statistics were analyzed using Prism9 software, and graphs show individual cells with mean and s.d. Two-tailed t-tests were used to determine significance.

Samples were isolated for RNA according to the manufacturer's protocol using Direct-zol™ RNA MicroPrep kit (Genesee Scientific). RNA concentration was obtained by nanodrop, and cDNA was made using qscript cDNA supermix following the manufacturer’s instructions (Quantabio). cDNA was synthesized at 1000 ng using BioRAD iQ5 thermocycler. Cycles were: Priming for 5 min at 25 °C, RT: 30 min at 42 °C and RT inactivation for 5 min at 85 °C. cDNA was used to analyze gene expression by real time polymerase chain reaction (RT q-PCR) using PerfeCTa qPCR FastMixII (QUantbio). TaqMan assays used were Il6, Tnfα, Il1b, Gpnmb, Col1a1, Timp1, Mmp12, Rsad2, Ilrn1, Il1bp and 18S eukaryotic endogenous control (Thermo Fisher Scientific). Samples were normalized to 18S.