Induction of cell-cell adhesion by monovalent antibodies in a germ cell culture.
Four monoclonal antibodies, XT-I, MT-23, MT-24 and MT-29, that bind the XT-1-differentiation-antigen of male germ cells have been used to investigate the biological role of the XT-1-molecule of germ cells in short-term primary culture. Cultures from 10 days postpartum mice demonstrate increasing numbers of antigen-positive germ cells and increased antigen expression per cell with succeeding days of culture. Treatment of the antigen-positive cultures with three of the monoclonal antibodies, XT-I, MT-23 and MT-24, increases germ cell-germ cell adhesion in a dose-dependent fashion. Treatment with the fourth monoclonal antibody, MT-29, does not induce cell adhesion. The monovalent, Fab fragment of XT-I-antibody also elicits tight cell adhesion, thus ruling out antibody cross linking of molecules or cells. Saturating or near saturating amounts of the positive antibodies are required to produce adhesion, a result consistent with perturbation of a function that is performed by the sum of action of many of the XT-1-molecules on the cell. The ability of germ cells to undergo antibody-elicited tight adhesion is dependent on germ cell age and/or XT-1-antigen concentration. We hypothesize that the XT-1-molecule is involved in regulation of cell adhesion, an event which must occur in normal development.
D000818:Animals; D000911:Antibodies, Monoclonal; D000941:Antigens / Q000032:analysis; D001666:Binding Sites, Antibody; D002448:Cell Adhesion; D002454:Cell Differentiation; D002478:Cells, Cultured; D005854:Germ Cells / Q000166:cytology* / Q000648:ultrastructure; D007124:Immunoenzyme Techniques; D007140:Immunoglobulin Fab Fragments; D051379:Mice; D008854:Microscopy, Electron
D000911:Antibodies, Monoclonal; D000941:Antigens; D007140:Immunoglobulin Fab Fragments