Tissue-Resident Immune Cells in Humans.

Area of Science:

• Immunology
• Cell Biology
• Human Physiology

Background:

• Tissue-resident immune cells, spanning myeloid and lymphoid lineages, are vital for immune responses, homeostasis, and repair.
• Studying these cells in human tissues presents challenges, but recent advances offer new insights.
• Each tissue harbors a unique set of resident immune cells with shared core properties and tissue-specific adaptations.

Purpose of the Study:

• To propose a five-point checklist for defining human tissue-resident immune cell types.
• To summarize current knowledge on the features, development, and functions of these cells in various human organs.
• To consider future research directions and therapeutic applications for tissue-resident immune cells.

Main Methods:

• Review and synthesis of existing literature on tissue-resident immune cells.
• High-dimensional profiling and advanced sampling techniques in human tissues.
• Comparative analysis of immune cell populations across different human organs.

Main Results:

• A proposed five-point checklist for defining resident immune cell types in humans.
• Detailed description of known features, developmental mechanisms, and putative functions of resident immune cells.
• Identification of tissue-specific adaptations within resident immune cell populations.

Conclusions:

• Standardized criteria are needed to define human tissue-resident immune cell types.
• Understanding these cells is crucial for comprehending tissue immunity and repair.
• Further research into tissue-resident immune cells holds promise for novel therapeutic strategies.