Biomaterial Database

Complement-dependent cellular cytotoxicity due to alternative pathway C3 activation by the target cell membrane. 1984

E Yefenof, and I Yron, and E Klein

The cytotoxic activity of human blood lymphocytes toward Raji cells was strongly elevated when human serum (HS) was included in the cytotoxicity assay. This phenomenon also occurred when the effector cells were activated by interferon (IFN). Hypogammaglobulinemic serum (HyS) and heat-inactivated serum could also augment cytotoxicity, but C3-depleted serum was inefficient. IFN treatment of Raji cells decreased their sensitivity to lysis and this effect was counteracted by addition of HS to the system. It is likely that C3 activation by, and deposition on, Raji cells when used as targets for cytotoxicity facilitate their recognition and lysis by lymphocytes. These events may represent one mechanism operating in the natural killing phenomenon.

UI	MeSH Term	Description	Entries
D007111	Immunity, Cellular	Manifestations of the immune response which are mediated by antigen-sensitized T-lymphocytes via lymphokines or direct cytotoxicity. This takes place in the absence of circulating antibody or where antibody plays a subordinate role.	Cell-Mediated Immunity,Cellular Immune Response,Cell Mediated Immunity,Cell-Mediated Immunities,Cellular Immune Responses,Cellular Immunities,Cellular Immunity,Immune Response, Cellular,Immune Responses, Cellular,Immunities, Cell-Mediated,Immunities, Cellular,Immunity, Cell-Mediated,Response, Cellular Immune
D007113	Immunity, Innate	The capacity of a normal organism to remain unaffected by microorganisms and their toxins. It results from the presence of naturally occurring ANTI-INFECTIVE AGENTS, constitutional factors such as BODY TEMPERATURE and immediate acting immune cells such as NATURAL KILLER CELLS.	Immunity, Native,Immunity, Natural,Immunity, Non-Specific,Resistance, Natural,Innate Immune Response,Innate Immunity,Immune Response, Innate,Immune Responses, Innate,Immunity, Non Specific,Innate Immune Responses,Native Immunity,Natural Immunity,Natural Resistance,Non-Specific Immunity
D007694	Killer Cells, Natural	Bone marrow-derived lymphocytes that possess cytotoxic properties, classically directed against transformed and virus-infected cells. Unlike T CELLS; and B CELLS; NK CELLS are not antigen specific. The cytotoxicity of natural killer cells is determined by the collective signaling of an array of inhibitory and stimulatory CELL SURFACE RECEPTORS. A subset of T-LYMPHOCYTES referred to as NATURAL KILLER T CELLS shares some of the properties of this cell type.	NK Cells,Natural Killer Cells,Cell, NK,Cell, Natural Killer,Cells, NK,Cells, Natural Killer,Killer Cell, Natural,NK Cell,Natural Killer Cell
D003167	Complement Activation	The sequential activation of serum COMPLEMENT PROTEINS to create the COMPLEMENT MEMBRANE ATTACK COMPLEX. Factors initiating complement activation include ANTIGEN-ANTIBODY COMPLEXES, microbial ANTIGENS, or cell surface POLYSACCHARIDES.	Activation, Complement,Activations, Complement,Complement Activations
D003170	Complement Pathway, Alternative	Complement activation initiated by the interaction of microbial ANTIGENS with COMPLEMENT C3B. When COMPLEMENT FACTOR B binds to the membrane-bound C3b, COMPLEMENT FACTOR D cleaves it to form alternative C3 CONVERTASE (C3BBB) which, stabilized by COMPLEMENT FACTOR P, is able to cleave multiple COMPLEMENT C3 to form alternative C5 CONVERTASE (C3BBB3B) leading to cleavage of COMPLEMENT C5 and the assembly of COMPLEMENT MEMBRANE ATTACK COMPLEX.	Alternative Complement Pathway,Properdin Pathway,Alternative Complement Activation Pathway,Complement Activation Pathway, Alternative
D003176	Complement C3	A glycoprotein that is central in both the classical and the alternative pathway of COMPLEMENT ACTIVATION. C3 can be cleaved into COMPLEMENT C3A and COMPLEMENT C3B, spontaneously at low level or by C3 CONVERTASE at high level. The smaller fragment C3a is an ANAPHYLATOXIN and mediator of local inflammatory process. The larger fragment C3b binds with C3 convertase to form C5 convertase.	C3 Complement,C3 Precursor,Complement 3,Complement C3 Precursor,Complement Component 3,Precursor-Complement 3,Pro-C3,Pro-Complement 3,C3 Precursor, Complement,C3, Complement,Complement, C3,Component 3, Complement,Precursor Complement 3,Precursor, C3,Precursor, Complement C3,Pro C3,Pro Complement 3
D003602	Cytotoxicity, Immunologic	The phenomenon of target cell destruction by immunologically active effector cells. It may be brought about directly by sensitized T-lymphocytes or by lymphoid or myeloid "killer" cells, or it may be mediated by cytotoxic antibody, cytotoxic factor released by lymphoid cells, or complement.	Tumoricidal Activity, Immunologic,Immunologic Cytotoxicity,Immunologic Tumoricidal Activities,Immunologic Tumoricidal Activity,Tumoricidal Activities, Immunologic
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man