Lectin binding sites on CD34+ human haematopoietic stem cells and lymphocytes from peripheral blood: an ultrastructural post-embedding study.
This study was performed to obtain a better insight into the glycosylation pattern of human CD34+ haematopoietic stem cells and lymphocytes from peripheral blood using an ultrastructural post-embedding technique. Lectins applied were derived from Canavalia ensiformis (Con A), Triticum vulgare (WGA), Lycopersicon esculentum (LEA), Limulus polyphemus (LPA), Ulex europaeus-I (UEA-I), Bauhinia purpurea (BPA), Glycine max (SBA), Helix pomatia (HPA), Arachis hypogaea (PNA) and Erythrina cristagalli (ECA). Our results showed almost identical staining patterns with both CD34+ cells and mature lymphocytes from peripheral blood. Con A displayed a prominent reactivity with the nuclear envelope and a weak staining of the plasma membrane. As demonstrated by an elaborate lectin double-labelling technique, WGA revealed an opposite staining pattern. Following neuraminidase treatment of sections, BPA, PNA and SBA exhibited a prominent staining of the plasma membrane in CD34+ cells and lymphocytes as well. Membrane reactivity with HPA was restricted to the majority of lymphocytes, presumably T-lymphocytes. Infrequently occurring dense cytoplasmic (lysosomal) bodies were reactive with a variety of lectins, and a weak diffuse nuclear labelling was observable with LPA, UEA-I, WGA and Con A. It is tempting to speculate that carbohydrate moieties on plasma membranes may be involved in the complex mechanisms characterizing cell-to-cell interactions (adhesion) and particularly in the so-called phenomenon of homing.
Kuemmel
T A
TA
Institute of Pathology, University of Cologne, Germany.
Thiele
J
J
Blaeser
A H
AH
Wickenhauser
C
C
Baldus
S E
SE
Fischer
R
R
D000818:Animals; D018952:Antigens, CD34 / Q000276:immunology / Q000378:metabolism*; D001665:Binding Sites; D002448:Cell Adhesion; D002462:Cell Membrane / Q000378:metabolism; D004076:Digoxigenin / Q000032:analysis; D006412:Hematopoietic Stem Cells / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000648:ultrastructure
D018952:Antigens, CD34; D037102:Lectins; D004076:Digoxigenin