title: The B lymphocyte adhesion molecule CD22 interacts with leukocyte common antigen CD45RO on T cells and alpha 2-6 sialyltransferase, CD75, on B cells.
abstract: Functional maturation of B lymphocytes correlates with expression of the B lineage-specific cell surface glycoprotein CD22. Two CD22 polypeptides have been characterized and suggested to play a role in B cell-B cell interaction as well as in B cell adhesion to monocytes. In this work we provide evidence that CD22 is directly involved in the cognate interaction between B and T cells. One of the two CD22 polypeptides, CD22 beta, interacts with a specific ligand on a subpopulation of CD4+ T cells. Our results suggest that the T cell ligand of CD22 is CD45RO, an isoform of the leukocyte common antigen class of phosphotyrosine phosphatases associated with the helper T cell phenotype. We further demonstrate that CD22 recognizes a second ligand, CD75, expressed predominantly on activated B cells and shown to be a cell surface alpha 2-6 sialyltransferase.
authors.affiliation: Department of Pathology, Massachusetts General Hospital, Charlestown.
authors.forename: I
authors.initials: I
authors.lastname: Stamenkovic
authors.forename: D
authors.initials: D
authors.lastname: Sgroi
authors.forename: A
authors.initials: A
authors.lastname: Aruffo
authors.forename: M S
authors.initials: MS
authors.lastname: Sy
authors.forename: T
authors.initials: T
authors.lastname: Anderson
mesh_terms: D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000235:genetics / Q000502:physiology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000235:genetics / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology; D001402:B-Lymphocytes / Q000502:physiology*; D001483:Base Sequence; D017252:CD3 Complex; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D000939:Epitopes; D006649:Histocompatibility Antigens / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D037102:Lectins; D017493:Leukocyte Common Antigens; D008024:Ligands; D008213:Lymphocyte Activation; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D014066:Palatine Tonsil / Q000166:cytology; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D011993:Recombinant Fusion Proteins; D051918:Sialic Acid Binding Ig-like Lectin 2; D012799:Sialyltransferases / Q000502:physiology*; D013329:Structure-Activity Relationship; D013601:T-Lymphocytes / Q000502:physiology*; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase
chemical_list: D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; D000945:Antigens, Differentiation, T-Lymphocyte; C497867:CD22 protein, human; D017252:CD3 Complex; D015815:Cell Adhesion Molecules; D000939:Epitopes; D006649:Histocompatibility Antigens; D037102:Lectins; D008024:Ligands; D009841:Oligonucleotides; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; D051918:Sialic Acid Binding Ig-like Lectin 2; D004247:DNA; D012799:Sialyltransferases; D017493:Leukocyte Common Antigens; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase