Hydroxychloroquine-Mediated Autophagy Inhibition Shifts Monocyte-Derived Dendritic Cells Toward Immunogenic Phenotype In Vitro

Dendritic cells (DCs) are recognized as the most potent antigen-presenting cells (APCs) and act as intermediaries between the innate and adaptive immune systems. The maturation and function of DCs are significantly influenced by autophagy. Hence, the current research evaluated the effect of hydroxychloroquine (HCQ), an autophagy inhibitor, on the maturation and activation of monocyte-derived DCs. Monocytes were cultured and induced to differentiate into monocyte-derived DCs by the addition of granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) cytokines. After five days, the immature DCs were exposed to HCQ and Lipopolysaccharides (LPS), followed by a 24-hour incubation period. On the sixth day, the flow cytometry technique was employed to assess the impact of HCQ on the phenotypic characteristics of the DCs. Finally, the expression of both pro- and anti-inflammatory genes in the HCQ-treated and untreated DCs groups was examined using the real-time PCR method. DCs that were subjected to treatment with HCQ exhibited a notable augmentation in the expression of CD11c, CD86, and HLA-DR, which are markers associated with maturation and antigen presentation. Furthermore, the DCs treated with HCQ demonstrated a significant reduction in the expression of IL-10, TGF-β, and IDO genes, while displaying an increase in the expression of TNF-α and IL-12 when compared to the control group. These findings indicate that targeting autophagy can induce a shift in DCs towards an immunogenic state. However, further investigations are necessary to assess the impact of HCQ-treated DCs on T cell responses both in vitro and in vivo in tumor-bearing animal models.