Differential, LFA-1-sensitive effects of antibodies to nectadrin, the heat-stable antigen, on B lymphoblast aggregation and signal transduction.
Nectadrin, the heat-stable antigen (HSA), is a highly glycosylated GPI-linked glycoprotein that can undergo homophilic and heterophilic binding. In the present work we have examined short-term effects of nectadrin antibodies on splenic B lymphoblast aggregation and signal transduction. Monoclonal antibody 79 inhibited cell aggregation and induced an intracellular Ca++ signal in the absence of cross-linking. Both these effects were perturbed in the presence of LFA-1 antibodies. Nectadrin antibody M1/69 and polyclonal nectadrin antibodies stimulated cell aggregation, did not induce a Ca++ signal, and their effects were functionally independent of LFA-1. These results suggest that nectadrin may concomitantly mediate primary and activate secondary adhesion mechanisms whereby each of these processes may be related to a different signal transduction pathway.
Kadmon
G
G
Department of Cellular Immunology 710, German Cancer Research Center, Heidelberg.
von Bohlen und Halbach
F
F
Schachner
M
M
Altevogt
P
P
D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D015703:Antigens, CD / Q000276:immunology / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D051927:CD24 Antigen; D002118:Calcium / Q000378:metabolism*; D002449:Cell Aggregation / Q000187:drug effects; D002478:Cells, Cultured; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D016169:Lymphocyte Function-Associated Antigen-1 / Q000276:immunology / Q000494:pharmacology*; D008562:Membrane Glycoproteins; D051379:Mice; D008811:Mice, Inbred DBA; D012477:Salmonella enteritidis; D015398:Signal Transduction / Q000187:drug effects*; D013154:Spleen / Q000276:immunology
D000906:Antibodies; D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D051927:CD24 Antigen; C497890:Cd24a protein, mouse; D017261:Glycosylphosphatidylinositols; D008070:Lipopolysaccharides; D016169:Lymphocyte Function-Associated Antigen-1; D008562:Membrane Glycoproteins; D002118:Calcium