CD7 delivers a pro-apoptotic signal during galectin-1-induced T cell death.

Cutting Edge: CD7 Delivers a Pro- Apoptotic Signal During Galectin-1- Induced T Cell Death

Restricted receptor segregation into membrane microdomains occurs on human T cells during apoptosis induced by galectin-1.

Galectin-1 induces apoptosis of human thymocytes and activated T cells by an unknown mechanism. Apoptosis is a novel function for a mammalian lectin; moreover, given the ubiquitous distribution of the oligosaccharide ligand recognized by galectin-1, it is not clear how susceptibility to and signaling by galectin-1 is regulated. We have determined that galectin-1 binds to a restricted set of T c...

Haploinsufficiency of C2GnT-I glycosyltransferase renders T lymphoma cells resistant to cell death.

Neoplastic T cells in mycosis fungoides (MF) are resistant to apoptotic agents, including galectin-1 that is abundant in skin. Although MF cells are typically CD7-, and thus galectin-1 resistant, CD7+ HH cells, derived from a patient with MF, were also resistant to galectin-1. HH cells demonstrate altered cell surface glycosylation, with loss of core 2 O-glycan ligands for galectin-1 created by...

Galectin-3 and galectin-1 bind distinct cell surface glycoprotein receptors to induce T cell death.

Galectins are a family of mammalian beta-galactoside-binding proteins that positively and negatively regulate T cell death. Extracellular galectin-1 directly induces death of T cells and thymocytes, while intracellular galectin-3 blocks T cell death. In contrast to the antiapoptotic function of intracellular galectin-3, we demonstrate that extracellular galectin-3 directly induces death of huma...

CD45 modulates galectin-1-induced T cell death: regulation by expression of core 2 O-glycans.

Galectin-1 induces death of immature thymocytes and activated T cells. Galectin-1 binds to T cell-surface glycoproteins CD45, CD43, and CD7, although the precise roles of each receptor in cell death are unknown. We have determined that CD45 can positively and negatively regulate galectin-1-induced T cell death, depending on the glycosylation status of the cells. CD45(+) BW5147 T cells lacking t...