Microphagy

Microphagy refers to the process of engulfing and ingesting microorganisms, such as bacteria, viruses, or other small particles, by cells. This process is commonly seen in various eukaryotic cells, including phagocytes like neutrophils and macrophages in the immune system. Microphagy plays a crucial role in maintaining cellular homeostasis and protecting against infections.

The process of microphagy involves the extension of a portion of the cell membrane around the target microorganism, forming a membrane-bound vesicle called a phagosome. The phagosome then merges with a lysosome, a cell organelle that contains digestive enzymes, resulting in the breakdown and degradation of the ingested microorganism. This process prevents the spread of infection and helps to eliminate pathogens from the cell.

Microphagy is distinct from two other processes related to ingestive behavior in eukaryotic cells. Endocytosis involves the uptake of molecules or particles into the cell through invagination of the plasma membrane, whereas pinocytosis involves the ingestion of liquids and small particles. Unlike these processes, which involve the formation of vesicles with the same membrane composition as the cell surface, microphagy involves the ingestion of extracellular particles and the formation of phagosomes, which are destined for lysosome fusion and degradation.

Microphagy is essential for regulating the numbers of microorganisms in the environment surrounding eukaryotic cells and it is an important component of the immune response.