Arginine vasopressin (AVP) treatment increases the expression of inhibitory immune checkpoint molecules in monocyte-derived dendritic cells.

Arginine vasopressin (AVP) has disparate impacts on immune responses by divergent receptors on cells including DCs. This study was conducted with the aim of investigating the impact of AVP on the maturation and expression of the inhibitory immune checkpoint molecules in tolerogenic monocyte-derived DCs. CD14 marker was used to separate monocytes from peripheral blood mononuclear cells (PBMCs) by MACS method. To differentiate monocytes from DCs, we utilized GM-CSF and IL-4 cytokines. Tolerogenic DCs were generated using vitamin D3 and dexamethasone. We added LPS and AVP to the culture medium on day 6 after incubation of DCs at 37 °C. Finally, we assessed the surface molecules by flow cytometry and used real-time PCR to evaluate the expression of genes related to the inhibitory immune checkpoints. Based on the obtained data, AVP increased the expression of CD11c (P ≤ 0.0001), HLA-DR (P ≤ 0.01), and CD86 (P ≤ 0.01) in AVP-mDCs. Also, the expression of all the immune checkpoint genes including CTLA-4 (P ≤ 0.001), BTLA (P ≤ 0.001), PDL-1 (P ≤ 0.05), B7H7 (P ≤ 0.001), LAG3 (P ≤ 0.01), and VISTA (P ≤ 0.001) in AVP-mDCs was increased in comparison to the control group. Vasopressin caused the generation of mature and tolerogenic DCs. Our data may help to consider AVP-mDCs to take part in autoimmune disease therapy, transplanted tissue rejection impedance, and allergies.