Expression and Analyses of CXCL9/10/11 and CXCR3 in Ulcerative Cutaneous Tuberculosis

We explored the biological functions, signaling pathways, potential inflammation, and immune biomarkers involved in ulcerative cutaneous tuberculosis (UCT). Mycobacterium tuberculosis-infected tissues from UCT patients and patients with noncutaneous tuberculous ulcers (NCTUs) were studied using transcriptomic analysis. Functional enrichment determined using the Gene Ontology database and enrichment of signaling pathways was ascertained using the Kyoto Encyclopedia of Genes and Genomes database. Protein-protein interaction (PPI) networks were analyzed to determine the hub genes. A total of 4,396 differentially expressed genes (DEGs) were identified. DEGs were enriched in CXCR3 chemokine receptor binding, chemokine activity, and cytokine-cytokine receptor interaction and other aspects. Analyses of PPI networks identified 15 hub genes. Expression of chemokine (C-X-C motif) ligand 9 (CXCL9)/10/11 messenger RNA (mRNA) and C-X-C motif chemokine receptor 3 (CXCR3) mRNA in the lesions of patients with UCT increased compared with that in NCTU cases. Expression of CXCL9 mRNA and CXCL10 mRNA in plasma also increased, which was consistent with other test results. We discovered a novel plasma CXC chemokine signature that could be used to differentiate UCT from NCTU. Our study (1) provides a reference for UCT diagnosis and selection of diagnostic markers and (2) lays the foundation for further elucidation of UCT pathogenesis.