Fc receptor-mediated immune complex endocytosis

Definition

Target type: biologicalprocess

An endocytosis process mediated by the Fc receptor for the purpose of delivery of antigen-bound immunoglobulin to an intracellular compartment where the antigen can be processed and loaded onto MHC molecules. This process selectively targets antigens for presentation by MHC class II or cross-presentation by MHC class I. [PMID:28389502, PMID:9143687, PMID:9463401]

Fc receptor-mediated immune complex endocytosis is a critical process in the adaptive immune response, facilitating the clearance of pathogens and immune complexes. This process involves the recognition of immune complexes, which are formed when antibodies bind to antigens, by specialized cell surface receptors known as Fc receptors (FcRs). FcRs are expressed on various immune cells, including B cells, macrophages, neutrophils, and dendritic cells, and are named for their binding specificity to the Fc portion of antibodies.

The process begins when an immune complex binds to the Fc portion of an FcR on the surface of an immune cell. This binding event triggers a cascade of intracellular signaling events, leading to the internalization of the immune complex within a clathrin-coated vesicle. This vesicle is then transported to an endosome, where the immune complex is further processed.

The endosome subsequently fuses with lysosomes, acidic organelles containing hydrolytic enzymes. The lysosomal enzymes degrade the antigens within the immune complex, effectively dismantling the pathogen or immune complex. The degraded antigens can then be presented to other immune cells, such as T cells, triggering an adaptive immune response.

Fc receptor-mediated immune complex endocytosis is a highly regulated process, involving several key signaling pathways. These pathways ensure that the process is specific for immune complexes and that the internalized complexes are efficiently degraded. Dysregulation of this process can lead to autoimmune diseases, such as rheumatoid arthritis, or impaired immune responses.

In summary, Fc receptor-mediated immune complex endocytosis is a crucial process in the immune system that serves to clear pathogens and immune complexes. This process is initiated by the binding of immune complexes to Fc receptors on immune cells, leading to the internalization and subsequent degradation of the complex within lysosomes. This process plays a vital role in the adaptive immune response by presenting antigens to other immune cells and promoting immune homeostasis.'
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Proteins (1)

Compounds (3)