SPHINGOSYLPHOSPHORYLCHOLINE TRIGGERS

ANA CEBALLOS, JUAN SABATTÉ, GABRIELA SALAMONE, DIEGO MARTÍNEZ, MÓNICA VERMEULEN, HORACIO SALOMÓN, JORGE GEFFNER.

Córdoba, Argentina

Congreso; ALAI VII Congreso Latinoamericano de Inmunología; 2005

ALAI

Sphingosylphosphorylcholine (SPC) is a bioactive lipid molecule involved in the development of different inflammatory responses. Here, we examined its ability to modulate the function of human dendritic cells (DC). DC were obtained from human monocytes cultured for 6 days in the presence of GM-CSF and IL-4. Since SPC is a high-affinity ligand for ovarian cancer G-protein coupled receptor 1 (OGR1), we first examined the expression of this receptor by DC. Analysis by RT-PCR from total RNA showed the presence of the mRNA for OGR1 in DC. Analysis by flow cytometry, using a policlonal rabbit antibody directed to OGR1 showed that DC express this receptor: mean fluorescence intensity (MFI) = 7 ± 3 vs 118 ± 15, isotype vs antibodies directed to OGR1 (n=7, p< 0.001). Treatment of DC with 25 mM of SPC during 24 h at 37oC triggered the maturation of DC, as judged by its ability to increase: a) the percentage of CD83+ cells (12 ± 5 vs 82 ± 15%, n=5, p< 0.05, untreated vs SPC-treated DC); b) the expression of HLA-DR (MFI: 112 ± 16 vs 478 ± 35,  n=5, p< 0.05); the expression of CD86 (MFI: 45 ± 11 vs 139 ± 17,  n=5, p< 0.05). Our results suggest a novel role for SPC in the development of the adaptative immune response.