ObjectiveTo analyze the gene expression profiling characteristics of peripheral blood mononuclear cells (PBMCs) from patients with secondary syphilis, and gain an insight into the host molecular immune mechanisms involved in Treponema pallidum infection.

METHODSUsing genome-based high-throughput Illumina sequencing technology, we comprehensively determined the transcriptional difference in PBMCs from 4 secondary syphilis patients and 4 healthy controls, followed by real time PCR to validate the results of Illumina sequencing.

RESULTSTotally, 78 differentially expressed genes were found in the PBMCs of the secondary syphilis patients, among which 16 were associated with the immune system. Significant upregulation was observed in the expressions of pro-inflammatory cytokines and related receptors, such as TNF receptor super-family member 17 (TNFRSF17), IL-17C, IL-21, IL-31 receptor A (IL-31RA), chemokine C-X-C motif ligand 10 (CXCL10), and chemokine (C-C motif) ligand 1 (CCL1), as well as the transcripts for the CD4+ T lymphocytes activation markers CD38, Fc-mediated phagocytosis receptors (FcγR1A, FcγR3B), and complement (C2, SERPING1).

CONCLUSIONSSystemic innate and adaptive immune effecter molecules are involved in the host clearance mechanism of secondary syphilis.