Stimulated macrophages express a new glycoprotein receptor reactive with Griffonia simplicifolia I-B4 isolectin.

Abstract

This paper presents data on reactions of murine macrophages with a variety of lectins, with special focus on Griffonia simplicifolia I-B4 isolectin, the only lectin we tried that distinguishes stimulated macrophages from resident populations. Specificity of Gniffonia simplicifolia I reaction with carbohydrate determinants at the cell surface is shown by (i) ability of a-galactosidase treatment of intact cells to abolish all lectin binding whereas .-galactosidase has no effect on lectin binding, (ii) ability ofmethyl a-D-galactopyranoside to completely inhibit lectin binding with methyl a-D-glucopyranoside having no effect on lectin binding, (iii) ability of brief treatment of intact cells with trypsin to liberate a glycopeptide that reacts with G. simplicifolia I to form a precipitate that is dissolved by addition ofmethyl a-D-galactopyranoside or a-galactosidase but not by addition of methyl a-D-glucopyranoside or /3-galactosidase, (iv) ability of methyl a-D-galactopyranoside (but no other monosaccharide) to completely inhibit avid binding of macrophages to G. simplicifolia I lectin immobilized on an insoluble support, and (v) ability of immobilized lectin to separate macrophages into highly pure subpopulations of lectin-reactive and lectin-unreactive cells, as shown by examination offluorescein-labeled lectin-treated cells with phase-contrast/ fluorescence microscopy. During investigations on the surface glycoproteins of the Ehrlich ascites tumor cell and their interactions with lectins, it was observed that intraperitoneal injection of Griffonia simplicifolia § lectin I (GSI) at the time of intraperitoneal inoculation with Ehrlich tumor gave virtually complete protection of the animal against growth of the tumor. This paper reports on one phase of subsequent work directed at elucidation of the mech-

Atm deletion with dual recombinase technology preferentially radiosensitizes tumor endothelium

“…Staining with Griffonia simplicifolia-IB 4 lectin (GS-IB 4 ) to label endothelial cells (28) and macrophages (29) confirmed that tumor cells had recombined the eYFP reporter, while the stromal cells were not infected by the adenovirus ( Figure 1D). …”

Breakdown of the Blood-Retinal Barrier Induced by Activated T Cells of Nonneural Specificity

“…In addition to causing a mild breakdown of the BRB, injection of OVA-activated T cells induced a limited activation of microglia, as indicated by changes in microglial morphology and up-regulation of ␣D galactose 23 and ED1 expression by resident microglia. Unlike the situation in control rats, in which microglia are stained only weakly with GS lectin and exhibit a ramified morphology 3 ( Figure 2B), resident microglia became intensely labeled with GS lectin, adopted an ameboid morphology, and exhibited prominent distensions along their processes between 12 and 24 hours after injection of OVA-activated T cells (Figure 2, D and H).…”

Hematopoietic Stem Cells Provide Repair Functions after Laser-Induced Bruch's Membrane Rupture Model of Choroidal Neovascularization

“…The GS isolectin B4 stains VECs and microglia in the rat central nervous system 43,44 and is up-regulated on activated macrophages. [45][46][47] Like von Willebrand factor, GS isolectin labels endothelial cells in culture. 48 This marker detects the smallest capillary and endothelial extensions, not always detectable by von Willebrand factor, 41,49 and does not label pericytes or astrocytes.…”