The CD56-CD16+ NK cell subset in chronic infections

Area of Science:

• Immunology
• Virology

Background:

• Long-term viral infections can induce significant changes in the human immune system.
• Natural killer (NK) cells, crucial for innate immunity, differentiate into distinct subsets in response to chronic infections.
• The CD56-CD16+ NK cell subset is found in high frequencies during Human Immunodeficiency Virus type 1 (HIV-1) infection.

Approach:

• This review examines the evidence linking CD56-CD16+ NK cells to chronic viral infections.
• It explores potential immunological pathways altered by long-term infections that drive NK cell subset differentiation.
• The role of human leukocyte antigen (HLA) class-I molecules in regulating NK cell function and frequencies is highlighted.

Key Points:

• Increasing evidence supports the classification of CD56-CD16+ cells as a distinct NK cell subset.
• Variations in HLA expression, influenced by both viral factors and host genetics, correlate with CD56-CD16+ NK cell frequencies.
• The CD56-CD16+ NK cell subset may exhibit functional similarities to CD56+CD16+ NK cells in antibody-dependent cell cytotoxicity.

Conclusions:

• The CD56-CD16+ NK cell subset represents a significant adaptation to chronic viral infections like HIV-1.
• Understanding the differentiation and function of this subset is crucial for comprehending immune responses to persistent viral challenges.
• Further research into CD56-CD16+ NK cell subpopulations may reveal nuanced degranulation capacities and therapeutic targets.