Immunoreactive lactoferrin in resting, activated, and neoplastic lymphocytes.
Lactoferrin (Lf) in lymphocytes was assessed with immunofluorescence/flow cytometric technique. Surface Lf was detected primarily among B-cell-enriched preparations. Tonsillar B-cells of different densities expressed surface Lf similarly. Very small percentages of CALLA+ ALL, HCL, or EBV-transformed B-cells expressed surface Lf, whereas B-CLL lymphocytes had the highest percentages of surface Lf positivity. Few resting, cultured, or neoplastic T-lymphocytes expressed Lf. The pattern of immunofluorescence and analyses of surface and total cellular immunoreactive Lf indicated that Lf is associated primarily with the lymphocyte surface. The percentage and/or intensity of surface Lf-specific fluorescence were not significantly altered in B- or T-cells by incubation with physiologic concentrations of differric Lf, and the percentages of Lf-positive cells detected in respective subjects remained stable over time. Surface Lf positivity was unrelated to the expression of other surface antigens (except those marking B- or T-cell lineage) or cell cycle. Expression and/or binding of Lf in B-lymphocytes may become increased during certain stages of cell maturation.
Department of Medicine, University of Alabama, Birmingham 35294.
T W
TW
Butler
C E
CE
Grossi
A
A
Canessa
V
V
Pistoia
J C
JC
Barton
D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007781:Lactoferrin / Q000276:immunology / Q000378:metabolism*; D007782:Lactoglobulins / Q000378:metabolism*; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000378:metabolism; D007945:Leukemia, Lymphoid / Q000378:metabolism*; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism
D007782:Lactoglobulins; D007781:Lactoferrin