Ss. Craig et al., IMMUNOELECTRON MICROSCOPIC LOCALIZATION OF GALECTIN-3, AN IGE BINDING-PROTEIN, IN HUMAN MAST-CELLS AND BASOPHILS, The Anatomical record, 242(2), 1995, pp. 211-219
Galectin-3 is an endogenous soluble lectin within the family called ga
lectins that bind beta-galactosides. Homologs of the protein isolated
hom different sources were previously designated as IgE-binding protei
n (epsilon BP), CEP35, CPB30, Mac-2, RL-29, RLL, L-29, and HL-29. All
are now renamed galectin-3. This lectin is widely distributed in cells
and tissues of mice, rats, dogs, hamsters, and humans. Light microsco
pic immunohistochemistry and ultrastructural immunogold labeling metho
ds were used to determine the distribution of galectin-3 in human mast
cells of several organs, in mast cells developed in vitro from human
fetal liver cells, and in human peripheral blood basophils. Immunolabe
ling for the protein was observed in mast cells from all sources and i
n basophils. The lectin was detected in the nucleus and/or the cytopla
sm. The nuclear labeling was over heterochromatin whereas euchromatin
was unlabeled. Cytoplasmic labeling was concentrated over secretory gr
anules. The intensity of staining generally was greater in mast cells
of skin when compared with that of mast cells in other locations and w
ith that of basophils. Studies have indicated that in mast cells galec
tin-3 may be involved in promoting their adhesion to basal laminae. In
this study the localization of galectin-3 in the secretory granules o
f human mast cells and basophils suggests that these cells may release
this lectin when activated to degranulate. (C) 1995 Wiley-Liss, Inc.