Antibodies to different members of the beta 1 (CD29) integrins induce homotypic and heterotypic cellular aggregation.
Members of the beta 1 (CD29) integrin family are involved in cellular adhesion to extracellular matrix. However, there have been several reports of CD29 integrin participation in intercellular adhesion. For example, the treatment of the human T cell line Jurkat with antibodies to alpha 4 (CD49d) causes homotypic aggregation. The present report describes the induction of aggregation of Jurkat cells by antibodies to alpha 5 (CD49e) and to a lesser extent by antibodies to the common beta 1/CD29 chain of these integrins. The metabolic requirements for these aggregations are compared with that of the CD49d-induced process. The possible involvement of fibronectin in the cytoadhesion appears to be unlikely as (1) the aggregates form in the absence of plasma fibronectin; (2) antibodies to fibronectin do not inhibit the cell adhesion; and (3) exogenous fibronectin does not influence the process. One of the cognate partners involved in the CD49e-induced aggregation appears to be present on non-antibody-treated Jurkat cells as the cells are coincorporated into aggregates of anti-CD49e-stimulated cells. The adhesion does not appear to involve members of the CD2, CD3, CD4, or CD18 receptor groups. These results indicate that interaction with alpha 4, alpha 5 chain or the beta 1 chain of the CD29 integrins leads to the induction of intercellular adhesion. The possible biological significance of this process is discussed.
Shen
C X
CX
Rheumatic Diseases Unit Research Laboratory, University of Manitoba, Winnipeg, Canada.
Stewart
S
S
Wayner
E
E
Carter
W
W
Wilkins
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology*; D002448:Cell Adhesion; D002449:Cell Aggregation; D002460:Cell Line; D005260:Female; D005353:Fibronectins / Q000502:physiology; D006801:Humans; D019012:Integrin beta1; D016023:Integrins / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic / Q000502:physiology
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D005353:Fibronectins; D019012:Integrin beta1; D016023:Integrins; D017469:Receptors, Fibronectin; D011971:Receptors, Immunologic