Isoforms of the E2 molecule: D44 monoclonal antibody defines an epitope on E2 and reacts differentially with T cell subsets.
Human T cell rosetting with erythrocytes is clearly dependent on the CD2-CD58 interaction. We have previously demonstrated that other T cell molecules are involved in the rosette phenomenon, including the E2 molecule, a 32-kDa transmembrane glycoprotein. In this report we show that the D44 monoclonal antibody (mAb), previously shown to subdivide T cells into subpopulations with distinct functional repertoires and to identify 70% of lymphocytes from bronchoalveolar lavage from HIV+ patients, defined a new epitope on the E2 molecule. This was illustrated by the reactivity of the D44 mAb in Western blot experiments performed with the immunoaffinity purified E2 molecule. Moreover, double-labeling experiments showed that the E2 molecule exhibited varying epitopes when expressed in different cell types. The D44 and 12E7 epitopes were restricted to distinct subpopulations of T cells and, more importantly, the D44 expression was limited to the CD29+ population including the memory subset. The O662 and L129 epitopes are present on all T cells. Thus, the E2 molecule has both common and variable epitopes in its extracellular domain, and only the common epitopes seem to be involved in T cell adhesion processes.
Gelin
C
C
Laboratoire d'Immunology des Tumeurs de l'Enfant, Institut Gustave-Roussy, Villejuif.
Zoccola
D
D
Valentin
H
H
Raynal
B
B
Bernard
A
A
D000071443:12E7 Antigen; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000032:analysis; D000943:Antigens, Differentiation / Q000032:analysis; D000945:Antigens, Differentiation, T-Lymphocyte / Q000032:analysis; D000954:Antigens, Surface / Q000276:immunology*; D016827:CD8 Antigens; D015815:Cell Adhesion Molecules / Q000276:immunology*; D000939:Epitopes; D005434:Flow Cytometry; D006649:Histocompatibility Antigens / Q000032:analysis; D006801:Humans; D019012:Integrin beta1; D017493:Leukocyte Common Antigens; D008562:Membrane Glycoproteins / Q000276:immunology*; D012397:Rosette Formation; D016176:T-Lymphocyte Subsets / Q000276:immunology*
D000071443:12E7 Antigen; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D000943:Antigens, Differentiation; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D016827:CD8 Antigens; C061828:CD99 protein, human; D015815:Cell Adhesion Molecules; D000939:Epitopes; D006649:Histocompatibility Antigens; D019012:Integrin beta1; D008562:Membrane Glycoproteins; D017493:Leukocyte Common Antigens