W139 - Induction of Regulatory Inkt Cells by Liposomes Containing Glycolipids Using Partially Humanized Mice for Inkt Cells

Cristian Gutiérrez-Vera – PhD student, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Pablo A. Palacios – PhD student, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Daniela Schneider – Research Assistant, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Carolina Schafer – PhD student, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Álvaro Santibañez – PhD student, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Romina Falcón – Research Assistant, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile; Noemi Alejandra Saavedra-Avila – Department of Microbiology – Albert Einstein College of Medicine; Jose Gascon – Professor, Department of Chemistry, The University of Connecticut; Steven A. Porcelli – Professor, Department of Medicine, Albert Einstein College of Medicine; Amy R. Howell – Professor, Department of Chemistry, The University of Connecticut; Leandro J. Carreño – Professor, Programa de Inmunología, ICBM, Millennium Institute on Immunology and Immunotherapy, Universidad de Chile

Abstract Text: Invariant NKT (iNKT) cells, a subpopulation of NKT cells, have attracted substantial attention because of their ability to be activated specifically by glycolipid antigens. The activation of iNKT cells (mainly NKT10 cells, a novel iNKT cell subset with IL-10-dependent regulatory function) with α-galactosylceramide (α-GalCer) can protect against inflammatory diseases. Nevertheless, the strong activation of iNKT cells elicited by α-GalCer exhibits limited therapeutic efficacy, mainly due to the induction of a mixed pro- and anti-inflammatory cytokine response and anergy. Since iNKT cells can be differentially activated by α-GalCer analogs, it is crucial to determine which α-GalCer analogues will expand NKT10 cells. In this study, we identified NKT10 cells in hCD1d-KI mice (a partially humanized murine model for NKT cell responses). Hence, we evaluated different experimental conditions, such as immunization schemes, glycolipid activators of iNKT cells, and the use of glycolipid delivery systems. We observed an expansion of NKT10 cells in hCD1d-KI mice treated with α-GalCer at seven days, similar to the expansion of NKT10 cells reported during the immunization scheme of 30 days. Finally, we incorporated glycolipids ligands of iNKT cells into liposomes; it was observed that the incorporation of glycolipids into stearylated octaarginine-modified liposomes effectively induced in vitro activation of iNKT cells hybridoma and remarkably increased the in vivo expansion of NKT10 cells, which was superior in the group of mice treated with the α-GalCer analog AH10-7 incorporated in liposomes. Therefore, AH10-7 contained in liposomes could be an excellent candidate for therapies that target NKT10 cells.