Search bioRxiv⌕ Search

Biology subjects

Matas-Rico, E.

Publications and source records attributed to Matas-Rico, E..

3 recordsLinked to original sources

Secreted autotaxin through LPA suppresses chemotaxis and tumor infiltration of CD8+ T Cells

Autotaxin (ATX) is secreted by diverse cell types to produce lysophosphatidic acid (LPA) that regulates multiple biological functions via G protein-coupled receptors LPAR1-6. ATX/LPA promotes tumor cell migration and metastasis mainly via LPAR1; however, its actions in the tumor immune microenvironment remain unclear. Here, we show that ATX secreted by melanoma cells is chemorepulsive for tumor-infiltrating lymphocytes and circulating CD8+ T cells ex vivo, with ATX functioning as an LPA-producing chaperone. Mechanistically, T-cell repulsion predominantly involves G12/13-coupled LPAR6. Upon anti-cancer vaccination of tumor-bearing mice, ATX does not affect the induction of systemic T-cell responses but suppresses tumor infiltration of cytotoxic CD8+ T cells and thereby impairs tumor regression. Moreover, single-cell data from patient samples are consistent with intra-tumor ATX acting as a T-cell repellent. These studies highlight an unexpected role for the pro-metastatic ATX-LPAR axis in suppressing CD8+ T-cell infiltration to impede anti-tumor immunity, suggesting new therapeutic opportunities.

cancer biology↗

Sequence-dependent trafficking of GDE2, a GPI-specific phospholipase promoting neuronal differentiation

GDE2 is a six-transmembrane glycerophosphodiesterase with phospholipase D-like activity that cleaves select glycosylphosphatidylinositol (GPI)-anchored proteins and thereby influences biological signaling cascades. GDE2 promotes neuronal differentiation cell-autonomously through glypican cleavage and is a prognostic marker in neuroblastoma, while GDE2 deficiency causes progressive neurodegeneration in mice and developmental defects in zebrafish. However, the regulation of GDE2 remains unclear. Here we show that in undifferentiated neuronal cells, GDE2 undergoes constitutive internalization and traffics back along both fast and slow recycling routes, while a small percentage is sorted to late endosomes. GDE2 trafficking is dictated by distinctive C-terminal tail sequences that determine secretion, endocytosis and recycling preference, respectively, and thereby regulate GDE2 function both positively and negatively. Our study reveals the sequence determinants of GDE2 trafficking and surface localization, and provides insight into the control of GPI-anchored protein activities with potential implications for nervous system disorders associated with impaired trafficking and beyond.

neuroscience↗

Negative regulation of uPAR activity by a GPI-specific phospholipase C

The urokinase receptor (uPAR) is a glycosylphosphatidylinositol (GPI)-anchored protein that promotes tissue remodeling, tumor cell adhesion, migration and invasion. uPAR mediates degradation of the extracellular matrix through protease recruitment and enhances cell adhesion, migration and signaling through vitronectin binding and interactions with integrins and other receptors. Full-length uPAR is released from the cell surface, but the mechanism and functional significance of uPAR release remain obscure. Here we show that transmembrane glycerophosphodiesterase GDE3 is a GPI-specific phospholipase C that cleaves and releases uPAR with consequent loss of the proteolytic and non-proteolytic activities of uPAR. In breast cancer cells, high GDE3 expression depletes endogenous uPAR resulting in a less transformed phenotype, correlating with higher survival probability in patients. Our results establish GDE3 as a negative regulator of the uPAR signaling network and, more generally, highlight GPI-anchor hydrolysis as a cell-intrinsic mechanism to alter cell behavior.

cell biology↗