Extraction and Identification of T Cell Stimulatory Self-lipid Antigens

Abstract

Autoreactive T cells restricted to CD1 molecules and specific for endogenous lipids are abundant in human blood (de Jong et al., 2010; de Lalla et al., 2011). A few self-lipid molecules recognized by diverse individual T cell clones and accumulated within APCs following stress signals or cell transformation have been identified so far (de Jong et al., 2010; Chang et al., 2008; Lepore et al., 2014). These findings suggested that auto-reactive CD1-restricted T cells display broad lipid specificities and may play critical roles in different types of immune responses including cancer immune surveillance, autoimmunity and antimicrobial immunity. Therefore, the identification of the repertoire of self-lipid molecules recognized by T cells is important to study the physiologic functions of this T cell population and to assess their therapeutic potential (Lepore et al., 2014). Here we describe the protocol we established to isolate and identify endogenous lipids derived from leukemia cells, which stimulate specific autoreactive CD1c-restricted T lymphocytes (Lepore et al., 2014). This protocol can be applied to isolate lipid antigens from any type of target cells and to investigate the self-lipid antigen specificity of autoreactive T cells restricted to all CD1 isoforms (Facciotti et al., 2012).