Human T cell activation induces the expression of a novel CD45 isoform that is analogous to murine B220 and is associated with altered O-glycan synthesis and onset of apoptosis.
Activated T cells undergo changes during their transition to T cell blasts and, subsequently, via a phase of anergy, to apoptosis. For example, activated murine T cell blasts express the B-cell-specific CD45R isoform, B220, a marker also present on T cells in mice and humans with defective Fas-mediated apoptosis in vivo, suggesting a role for B220 up-regulation in the transition of activation to apoptosis. Human T cells, activated in vitro with superantigens and mitogens, also express B220 as they undergo blastogenesis and cell cycle progression. B220 expression peaks on T cells undergoing apoptosis. CD43-hexasaccharide glycoform expression and lectin binding profiles indicate that B220 expression is reflective of altered O-linked glycan biosynthesis found in specific T cell subsets transitioning through the phases of proliferation, anergy, and apoptosis. Potential implications of these alterations include changes in lymphocyte adhesion and trafficking and homeostasis through altered sensitivity to Fas-dependent and independent pathways of apoptosis.
Bleesing
J J
JJ
Department of Laboratory Medicine, National Institutes of Health, Bethesda, Maryland 20892, USA. BleesingJacobH@uams.edu
Morrow
M R
MR
Uzel
G
G
Fleisher
T A
TA
D000328:Adult; D000818:Animals; D017304:Annexin A5; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D017209:Apoptosis; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D004768:Enterotoxins / Q000494:pharmacology; D006801:Humans; D017493:Leukocyte Common Antigens / Q000096:biosynthesis*; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008213:Lymphocyte Activation; D051379:Mice; D008934:Mitogens / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology; D011134:Polysaccharides / Q000096:biosynthesis*; D020033:Protein Isoforms / Q000096:biosynthesis; D013194:Staining and Labeling / Q000379:methods; D013601:T-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015854:Up-Regulation / Q000187:drug effects
D017304:Annexin A5; D000911:Antibodies, Monoclonal; D004768:Enterotoxins; D008934:Mitogens; D010835:Phytohemagglutinins; D011134:Polysaccharides; D020033:Protein Isoforms; C031818:enterotoxin B, staphylococcal; D017493:Leukocyte Common Antigens