Effect of Rifampin on expression of inflammatory and non-inflammatory factors of monocyte-derived dendritic cells pulsed with lysate of oral squamous cell carcinoma

Abstract

Oral squamous cell carcinoma (OSCC) is one of the most common head and neck cancers. The immune system plays an important role in fighting this type of cancer. Dendritic cells (DC) are the most powerful antigen presenting cells and are an important intermediary between the innate and specific immune systems. Two-way interactions between DCs and antigen-specific T cells can cause antigen-specific T cell responses in the way of their stimulation or tolerance induction. Rifampin is a broad-spectrum antibiotic that is prepared semi-synthetically. Research shows that rifampin has anti-inflammatory properties. Our aim in this study was to investigate the effects of rifampin and OSCC tumor lysate on the differentiation and maturation of monocyte-derived DCs and the effect of this treatment on the expression of different inflammatory and anti-inflammatory genes in DCs treated with rifampin.

Materials and methods: After isolation of peripheral blood mononuclear cells (PBMCs) using the Ficoll technique, monocytes were isolated from PBMCs by MACS method. After cultivating monocytes in 6-well plates and adding cytokines granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4), the plate was placed in the 0C37 incubator and checked daily for contamination. On day 3, half of the medium on the wells was slowly removed and replaced with fresh medium containing cytokines. After examining the differentiation of mo-DCs by flow cytometry, mo-DCs were treated with rifampin. To investigate the effect of rifampin treatment on the phenotypic characteristics of mo-DCs, flow cytometry technique was used. Real-time PCR method was used to investigate the expression of different inflammatory and anti-inflammatory genes in treated and untreated mo-DC groups.

Results: Treatment of mDCs with rifampin and OSCC tumor lysate increased the expression of CD86, CD11c and HLA-DR, which are markers related to antigen presentation function and differentiation in DCs. Also, this treatment caused a significant increase in the expression of IL-18 and TNF-α inflammatory genes. Also, this treatment decreased the expression of anti-inflammatory genes STAT3, TGF-β and IL-10 in the treatment group.

Conclusion: Treatment of monocyte-derived DCs with rifampin and OSCC tumor lysate increases the stimulatory activity of DCs. Also, the gene expression related to inflammatory cytokines increased in the treatment group compared to the control group, and the expression of anti-inflammatory genes decreased in the treatment group. These findings show that these treated cells probably acquired the immunogen phenotype and can probably be used in the treatment of Oral Squamous Cell Carcinoma.