Galactoside-Binding Lectin in Human Tissues

Abstract

Lactose-inhibitable lectin activity has been analyzed by hemagglutination assay in a variety of human tissues and cells obtained at surgery and autopsy. The lectin activity was detected in surgically removed melanoma, sarcoma, colon carcinoma, breast carcinoma, adjacent non-malignant tissues, non-malignant tissues obtained at autopsy and in cells isolated from malignant effusions. Although, on average, malignant tissue had a higher hemag-glutinating titer than non-malignant tissue, similar tissues from different individuals varied widely in their apparent lectin content. The lectin was isolated from lung by affinity chro-matography and was found to have a native molecular mass of 31,000 daltons and a subunit molecular mass of 14,000 daltons. Utilizing rabbit anti-lung lectin serum in an immunohis-tochemical assay, the lectin was found to be distributed throughout the cytoplasm of lung epithelial cells. Ouchterlony immunodiffusion analysis confirmed the presence of this lectin in a variety of tissues and in some body fluids. In vitro metabolic radiolabelling experiments showed that the presence of lectin in tissues was most likely due to endogenous synthesis rather than absorption from body fluids. Lectin isolated from several tissues was found to bind to human buffy coat cell receptors.

CD4+CD7− leukemic T cells from patients with Sézary syndrome are protected from galectin-1-triggered T cell death

“…9,11 This observation, however, is controversely discussed as Kamarashev et al 13 More recently, CD7 was shown to be a ligand of galectin-1 that initiates a signaling cascade resulting in apoptosis of CD7 + T cells. [18][19][20][21] Considering the rather abundant presence of galectin-1 in human tissues, 22,23 we assume that CD7-negative Sézary cells may be resistant to galectin-1-mediated cell death thereby favoring their accumulation within the tissues during progression of the disease. Using a panel of stimulation experiments we demonstrate here that CD7 − Sézary cells are resistant to galectin-1-induced cell death compared to neoplastic CD7 + T cells from patients with Sézary syndrome (SS) or non-SS leukemia.…”

Localization of Endogenous β-Galactoside-Binding Lectin in Human Cells and Tissues

“…One of the S-type lectins is frequently iso lated as a native ~ 30-kilodalton (kDa) di mer composed of identical ~ 14.5-kDa sub units [7,8]. For convenience, this lectin is defined here as galaptin, a term used pre viously to describe a larger group of lectins [9], Galaptin is present in a wide variety of human tissues as revealed by hemagglutina tion and immunodiffusion assays [8], and appears to be the product of a single gene [10,11].…”

Galaptin and Galaptin-Binding Glycoconjugates in Serum and Effusions of Carcinoma Patients

“…We had previously reported the qualitative presence of galaptin in several body fluids, including serum and effusions, as detected by immunodiffusion [6].…”

“…The pres ence of galaptin in normal serum [9] and other body fluids [6] has been previously demon strated. However, the levels of galaptin were not quantified; nor was any information available on the presence of galaptin inhibi tors in body fluids.…”

“…Galaptin is present in a wide variety of hu man cells and tissues [6], Its expression may be depressed in some carcinomas [7]; how ever, it appears to be an abundant protein in human ovarian carcinoma cells obtained from patient effusions [8,9], This lectin is also present in the extracellular matrix [8,9], and it may have a role in cell adhesion via interac tion with cell surface receptors [8,10,11].…”