Role of sphingosine kinase 1 (SK1) and sphingosine-1-phosphate (S1P) receptor (S1PR) in Triiodothyronine (T3) action in dendritic cells (DCs) and in the driven adaptive immunity

NEGRETTI-BORGA, DANA MARÍA; PIRES TEIXEIRA, MARIANA; BLANCO, ANTONELLA; PUENTES, ÉLIDA; DONADIO, ANA CAROLINA; MONTESINOS, MARÍA DEL MAR; CLARKE, CHRISTOPHER; HANNUN, YUSUF; PELLIZAS, CLAUDIA GABRIELA

Mar del Plata

Congreso; LXVIII Reunión Anual de la sociedad Argentina de Investigación Clínica; 2023

SAIC

We demonstrated that T3 induces Th1 and Th17 proinflammatory and cytotoxic responses through DC activation (T3-DC), restraining tolerogenic signals. T3 effects are mainly triggered by a mechanism that involves Akt and NF-kB activation. S1P is a bioactive sphingolipid implicated in many proinflammatory conditions. Preliminary results from our group suggested that SK1 (enzyme that produces S1P from sphingosine) participates in the actions of T3 in DCs. Herein, we aimed to investigate the role of SK1 and S1PR in these effects, and in the driven adaptive immune response. Bone marrow-derived DCs were obtained from C57BL/6 WT mice and stimulated (or not) with T3 (10nM). PF-543 (SK1 inhibitor, 100nM) or FTY720 (S1PR antagonist, 1uM) were added, and 30 min later, the T3 stimuli. p-Akt/total Akt and p-STAT3/total STAT3 were analyzed by Western Blot in DCs. Allogenic splenocytes isolated from BALB/c mice were co-cultured for 3 days with T3-DC (inhibited or not with PF543 or FTY720 and exposed to T3 for 18h). Cell viability, proliferation, lineage, maturation, and activation markers were measured by FACS. Cytokines were measured in supernatants by ELISA. Statistical analysis: Two-way ANOVA/Tukey test, and paired t test. p