Galectin-1, an alternative signal for T cell death, is increased in activated macrophages

Abstract

Galectin-1 belongs to an evolutionarily conserved family of animal ß-galactoside-binding proteins, which exert their functions by crosslinking the oligosaccharides of specific glycoconjugate ligands. During the past decade, attempts to identify the functional role of galectin-1 suggested participation in the regulation of the immune response. Only in the last few years has the molecular mechanism involved in these properties been clearly elucidated, revealing a critical role for galectin-1 as an alternative signal in the generation of T cell death. In the present study we will discuss the latest advances in galectin research in the context of the regulation of the immune response, not only at the central level but also at the periphery. Moreover, we will review the purification, biochemical properties and functional significance of a novel galectin-1-like protein from activated rat macrophages, whose expression is differentially regulated according to the activation state of the cells. The novel role of a carbohydrate-binding protein in the regulation of apoptosis is providing a breakthrough in galectin research and extending the interface between immunology, glycobiology and clinical medicine. Correspondence

Transplantation of Schwann cells and/or olfactory ensheathing glia into the contused spinal cord: Survival, migration, axon association, and functional recovery

“…Following SCI, SCs migrating into the CNS have been shown to be in close association with both newly formed blood vessels (Gilmore et al, 1993;Raine et al, 1978) and sprouting sensory axons (Bunge et al, 1994;Raine et al, 1978) implying that either angiogenic or axonal signals stimulate the proliferation and ingress of SCs from the dorsal roots. The observation that cell grafting into the injured spinal cord enhances endogenous SC ingress, both in the current study and others, implies that possibly chemotaxic factors, such as galectin-1 (Fukaya et al, 2003;Rabinovich et al, 1999), released by an enhanced immune response that targets the death and/or clearance of the implanted cells, could stimulate SC migration. Indeed, in PNS injury there is close coordination between the immune system, largely macrophages, and SCs in facilitating repair (Chumasov and Svetikova, 1992).…”

Morphine and Galectin-1 Modulate HIV-1 Infection of Human Monocyte-Derived Macrophages

“…Studies have found an increase expression of galectin-1 in activated macrophages (50). Galectin-1 modulates constitutive and inducible FcγRI expression on monocytes/macrophages and FcγRI-dependent phagocytosis through an ERK1/2-dependent pathway (51).…”

Regulated Expression and Effect of Galectin-1 onTrypanosoma cruzi-Infected Macrophages: Modulation of Microbicidal Activity and Survival

“…It was previously reported that by using exogenous stimuli, such as phorbol esters (PMA) and chemotactic agonists (fMLP), Gal-1 expression is differentially regulated in activated M according to the activation state of the cells (33,35,37). To investigate whether T. cruzi could specifically modulate Gal-1 expression in vitro, we used the J774 M cell line.…”

“…In this regard, the purification, biochemical properties, and functional significance of Gal-1 in activated M was recently reported (35). The protein's total and surface expression was found to be increased when M were activated in vitro with phorbol esters (PMA) or chemotactic agonists (fMLP) (33,37). M are one of the most widely investigated types of cells which function as scavengers or cytotoxic or regulatory cells in the immune system.…”