title: Antibody-independent activation of C1, the first component of complement.
mesh_terms: D000936:Antigen-Antibody Complex; D001666:Binding Sites, Antibody; D003166:Complement Activating Enzymes / Q000378:metabolism; D003167:Complement Activation; D003172:Complement C1 / Q000276:immunology*; D015922:Complement C1q; D015923:Complement C1r; D004136:Dinitrobenzenes / Q000276:immunology; D006801:Humans; D007136:Immunoglobulins / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology; D046911:Macromolecular Substances; D011951:Receptors, Complement; D012709:Serum Albumin / Q000276:immunology; D014301:Trinitrobenzenes / Q000276:immunology
chemical_list: D000936:Antigen-Antibody Complex; D003172:Complement C1; D004136:Dinitrobenzenes; D007136:Immunoglobulins; D008070:Lipopolysaccharides; D046911:Macromolecular Substances; D011951:Receptors, Complement; D012709:Serum Albumin; D014301:Trinitrobenzenes; D015922:Complement C1q; D003166:Complement Activating Enzymes; D015923:Complement C1r