INSTITUTO DE INVESTIGACIONES BIOTECNOLOGICAS
Unidad Ejecutora - UE
congresos y reuniones científicas
Galectin-8 enhances antigen uptake, processing and presentation to CD4+ T cells
JULIETA CARABELLI; OSCAR CAMPETELLA ; CECILIA ARAHÍ PRATO; MARÍA VIRGINIA TRIBULATTI
Simposio; 3rd Argentinian Symposium on Glycobiology; 2019
Galectin-8 (Gal-8) is a mammalian lectin endowed with proinflammatoryproperties. Our recent findings showed that Gal-8has the ability to activate dendritic cells (DC) by inducing theexpression of costimulatory molecules, the secretion of proinflammatorycytokines, and an augmented capacity of antigenspecificT cell stimulation. We also found that Gal-8 improves thespecific and neutralizing humoral response in the Foot-and-Mouth Disease virus experimental model, resulting in animalprotection upon viral challenge. Here, we aim to study themolecular mechanism underlying the stimulating effect of Gal-8in the elicitation of the immune response. First, we observed thatGal-8 not only binds to DC surface on a lectin dependent manner,but it also induces the pre-attachment of soluble and particulatedantigens, resulting in a more efficient internalization. By confocalmicroscopy, we observed that Gal-8 is endocytosed together withOVA antigen, finding a significant co-localization with EEA1 andtransferrin, but not with Lamp1 positive-compartments. Inaddition, using DQ-OVA (a fluorogenic substrate for lysosomalproteases), we found that antigen processing is also enhanced inthe presence of Gal-8. Finally, we observed a significantincrement of specific CD4+T cell proliferation when cultured withDC previously pulsed with OVA and Gal-8, supporting the notionthat Gal-8, by promoting antigen uptake and processing,enhances its presentation to T cells.