Analysis of candidate genes related to the role of PD-L1 in tuberculosis infection using Pdl1 knockout macrophage transcription profile

  Objective To analyze the changes in the transcription profile of macrophages (MΦ) specifically knocked out by programmed death ligand 1 (Pdl1) infected by tuberculosis (Mtb), and to screen candidate genes related to PD-L1 in MΦ. Methods Knockout mice (Pdl1Flox /-) were constructed, and homozygous and heterozygous mice (Pdl1Flox / Flox-Cre, Pdl1Flox /--Cre) with specific knockout of Pdl1 on MΦ were bred by Cre-loxp technology, and PCR And flow cytometry verification. The peritoneal MΦ of the above-mentioned mice was isolated, and the expression profile of Mtb infected MΦ 24 h was detected by transcriptome sequencing technology. The littermate negative mice (Pdl1Flox / Flox) were used as controls for bioinformatics analysis.

   Results PCR and flow cytometry confirmed that the mouse knockout was successful. Compared with homozygous, heterozygous and litter-negative mice before and after infection, the most significant enrichment of differentially expressed genes is GO (P<0.01; P <0.01), which is involved in immune response and immune process, and 17 is screened out. Candidate genes related to PD-L1. Through KEGG enrichment analysis, the most significant enrichment pathways are Toll-like receptors, NF-κB signaling pathways, etc. (P <0.01; P <0.01), and 6 candidate genes were screened out. Conclusion Through transcription profile analysis, 17 genes related to immune response and immune process, including Ccl2, Qa5, and Il12a, were identified, and 6 genes including Ptgs2, Cd40, and Card11 in immune and inflammation-related metabolic pathways were PD-L1 in MΦ infected by Mtb. Related candidate genes, except Il6, are all newly selected candidate genes in this study.