Lymphocyte emperipolesis in human glial cells

Area of Science:

• Neuroscience
• Cell Biology
• Immunology

Background:

• Astrocytes, a type of glial cell, are known to internalize lymphocytes within their cytoplasm, a process termed emperipolesis.
• This phenomenon has been observed in pathological conditions like multiple sclerosis plaques and brain tumors.

Purpose of the Study:

• To characterize the adhesive, emperipoleic, and phagocytic properties of human astrocytes and microglia in culture.
• To differentiate emperipolesis from phagocytosis and identify factors influencing emperipolesis.

Main Methods:

• Primary human fetal and adult astrocyte and microglia cultures were established.
• Lymphocyte-glial cell interactions were analyzed, focusing on adhesion, emperipolesis, and phagocytosis.
• The effects of temperature, cations, CD8, and MHC Class I antigens on emperipolesis were investigated.

Main Results:

• Astrocytes exhibited both adhesion and emperipolesis of lymphocytes.
• Emperipolesis, unlike adhesion, was dependent on temperature and cations.
• CD8 and MHC Class I antigens were implicated in the emperipolesis process.
• Lymphocytes generally remained viable within astrocytes, though occasional lysis or astrocyte damage occurred.
• Microglia demonstrated significant phagocytosis but not emperipolesis, while astrocytes were efficient emperipolites with limited phagocytic activity.

Conclusions:

• Emperipolesis is a distinct cellular process mediated by astrocytes, separate from microglial phagocytosis.
• The study elucidates key characteristics and molecular players involved in astrocyte-lymphocyte emperipolesis.