Role of LFA-1, CD2, VLA-5/CD29, and CD43 surface receptors in CD4+ T cell adhesion to B cells.
We investigated the adhesion to B cells of CD4+ T cells both in the resting state and following activation by CD3 cross-linking or stimulation by PMA/ionomycine/IL2 for 6 days. Both resting and activated CD4+ T cell adhesion were inhibited by anti-LFA-1, -CD2, -VLA-5/CD29, and -CD43 antibodies, suggesting coordinated upregulation of T cell adhesion. The CD2 and LFA-1 adhesion pathways were found to act independently, as CD2 was functional in T cells not expressing LFA-1, and vice versa, and as specific antibodies had additive effects. In contrast, LFA-1- and VLA-5/CD29-specific antibodies did not have an additive blocking effect on CD4+ T cell adhesion, suggesting that efficient adhesion requires a competitive association of integrins with cytoskeleton elements. Although the involvement of fibronectin (coated to B cells via VLA-4) in VLA-5-mediated T cell adhesion to B cells is feasible, an anti-fibronectin and a VLA-4-specific antibody had no blocking effect. The involvement of an unidentified B cell ligand can also be envisaged.
Lecomte
O
O
INSERM U 132, Hôpital Necker-Enfants Malades, Paris, France.
Hauss
P
P
Barbat
C
C
Mazerolles
F
F
Fischer
A
A
D000595:Amino Acid Sequence; D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000502:physiology*; D001402:B-Lymphocytes / Q000502:physiology*; D018801:CD2 Antigens / Q000502:physiology; D015496:CD4-Positive T-Lymphocytes / Q000502:physiology*; D002448:Cell Adhesion / Q000502:physiology*; D005434:Flow Cytometry; D006801:Humans; D019012:Integrin beta1; D016023:Integrins / Q000502:physiology; D051917:Leukosialin; D008213:Lymphocyte Activation / Q000276:immunology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000502:physiology; D008969:Molecular Sequence Data; D016029:Receptors, Very Late Antigen / Q000502:physiology*; D012795:Sialoglycoproteins / Q000502:physiology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018801:CD2 Antigens; D019012:Integrin beta1; D016023:Integrins; D051917:Leukosialin; D016169:Lymphocyte Function-Associated Antigen-1; D016029:Receptors, Very Late Antigen; C465014:SPN protein, human; D012795:Sialoglycoproteins