CD56 in the Immune System: More Than a Marker for Cytotoxicity?

Area of Science:

• Immunology
• Cell Biology

Background:

• The distinct boundaries between immune cell subsets are becoming less clear.
• CD56 (neural cell adhesion molecule) is a key marker, traditionally associated with natural killer cells.

Purpose of the Study:

• To review the expression and function of CD56 in the hematopoietic system.
• To discuss the role of CD56+ cells in health and disease.

Main Methods:

• Literature review of studies on CD56 expression and function.
• Analysis of phenotypic and functional data from various immune cells.

Main Results:

• CD56 is expressed on natural killer cells, T cells, dendritic cells, and monocytes.
• CD56+ cells possess potent immunostimulatory functions, including T helper 1 cytokine production and cytotoxicity.
• Deficiencies and alterations in CD56+ cells are observed in infectious, autoimmune, and malignant diseases.

Conclusions:

• CD56 expression is broader than previously thought, found on diverse immune cells with shared effector functions.
• Dysregulation of CD56+ immune cells is implicated in various pathologies, underscoring their clinical relevance.