Emperipolesis

Emperipolesis is a cellular phenomenon that occurs within the human body, specifically in certain types of cells. It is characterized by the presence of one cell engulfing another intact cell, resulting in the formation of a unique cellular structure. This process is often observed in various physiological and pathological conditions, and its significance in cellular biology has been a subject of extensive research.

Overview

Emperipolesis, derived from the Greek words "emperi" meaning "within" and "polesis" meaning "to dwell," was first described by Ernst Neumann in 1876. It is a rare phenomenon that can be observed in different cell types, including lymphocytes, macrophages, and epithelial cells. The engulfed cell, known as the "victim cell," remains viable within the host cell, forming a distinct intracellular compartment.

Mechanism

The exact mechanism of emperipolesis is not fully understood, but several hypotheses have been proposed. One theory suggests that it may be a result of active cellular processes, such as phagocytosis or endocytosis, where the host cell engulfs the victim cell. Another hypothesis suggests that emperipolesis could be a passive process, occurring due to physical forces or cellular overcrowding.

Physiological Significance

Emperipolesis has been observed in various physiological contexts, such as during embryonic development, immune responses, and tissue repair. In embryogenesis, emperipolesis plays a crucial role in cell migration and tissue remodeling. It has also been implicated in the immune system, where lymphocytes can be found within the cytoplasm of other immune cells, potentially facilitating cell-to-cell communication and antigen presentation.

Pathological Significance

Emperipolesis has been associated with several pathological conditions, including certain types of cancers, autoimmune diseases, and viral infections. In cancer, emperipolesis has been observed in tumor cells, suggesting a potential role in tumor progression and metastasis. In autoimmune diseases, the presence of emperipolesis has been linked to aberrant immune responses and tissue damage. Additionally, viral infections, such as HIV and herpes viruses, have been shown to induce emperipolesis in infected cells, potentially aiding in viral dissemination.

Research and Future Directions

The study of emperipolesis is an active area of research, with scientists aiming to unravel its underlying mechanisms and functional implications. Advanced imaging techniques, such as confocal microscopy and electron microscopy, have provided valuable insights into the structural aspects of emperipolesis. Furthermore, genetic and molecular studies are being conducted to identify the key molecules and signaling pathways involved in this phenomenon.

See Also

• Phagocytosis
• Endocytosis
• Cellular Biology
• Immune System
• Tumor Progression
• Autoimmune Diseases
• Viral Infections

• 

  Emperipolesis at very high magnification

• 

  A band neutrophil inside a megakaryocyte

• 

  Rosai-Dorfman disease

• 

  Emperipolesis