Abstract:Objective To analyze the transcription profile of Mycobacterium tuberculosis ( Mtb )-infected macrophages in which the pdl1 gene has been knocked out and screen PD-L1 related candidate genes in Mtb -infected macrophages (MΦ). Methods pdl1Flox / - mice were constructed, and homozygous (pdl1Flox / Floxwith Cre) and heterozygous (pdl1Flox / - with Cre) mice with targeted inactivation of the pdl1 gene in MΦs were bred by the Cre / loxP technique and verified by PCR and FACS. Peritoneal MΦs were isolated from different substrains of mice, and those isolated from littermate negative mice (pdl1Flox / Flox) were used as controls. Twenty-four hours after infection, the transcript profiles in the infected and uninfected groups were sequenced by RNA-Seq, and bioinformatics analysis was performed. Results pdl1- specific knockout mice were successfully generated and identified by PCR and FACS. The pdl1Flox / Floxwith Cre, pdl1Flox / - with Cre, and pdl1Flox / Flox infected groups were compared with their corresponding non-infected groups. Gene Ontology (GO) functional enrichment analysis showed that the most significant enrichments were immune response (P< 0. 01) and immune system processes (P< 0. 01). The seventeen candidate genes identified were regarded as specific genes related to PD-L1 in Mtb infection. Through the Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis, the most significantly enriched pathways included Toll-like receptor (P< 0. 01) and nuclear factor kappa-B (NF-κB) (P< 0. 01) signaling pathways, and six candidate genes related to PD-L1 were screened. Conclusions Through transcription analysis, seventeen genes related to the immune response, including Ccl2, Qa5, and Il12a, and six genes in immune - and inflammation-related metabolic pathways, including Ptgs2, Cd40, and Card11, were identified as specific candidate genes related to PD-L1 in macrophages infected with Mtb. Except for Il6, all candidate genes were selected for this research.