Induction of aggregation in porcine lymphoid cells by antibodies to CD46.
CD46 is a major transmembrane glycoprotein that belongs to the regulator of complement activation (RCA) family. Recently, mAbs to human CD46 were shown to suppress IL-12 production. Here, we describe that mAbs against different porcine CD46 epitopes induced a marked adhesion of normal lymphocytes. Addition of low amounts of antibody to freshly isolated lymphocytes or thymocytes resulted in the clustering of the cells. Cross-linking of CD46 molecules seems essential since Fab fragments failed to induce aggregation. This aggregation was dependent on active cell metabolism and on the presence of divalent cations and required a functional cytoskeleton. It was not inhibited by antibodies to CD18, CD29, CD2, CD11a and CD11b. Staurosporine, an inhibitor of protein kinases, partially blocked the aggregation. This finding is indicative of a role of protein kinases in the transduction of the signal generated by CD46 engagement.
Bullido
R
R
Centro de Investigación en Sanidad Animal INIA, Madrid, Spain.
Pérez de la Lastra
J
J
Almazán
F
F
Ezquerra
A
A
Llanes
D
D
Alonso
F
F
Domínguez
J
J
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology*; D015703:Antigens, CD / Q000502:physiology*; D002449:Cell Aggregation; D008214:Lymphocytes / Q000502:physiology*; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D013552:Swine / Q000276:immunology*
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; C497859:Mcp protein, mouse; D051916:Membrane Cofactor Protein; D008562:Membrane Glycoproteins