Genetic tracing via DNGR-1 expression history defines dendritic cells as a hematopoietic lineage

Area of Science:

• Immunology
• Cell Biology
• Hematology

Background:

• Mononuclear phagocytes, including macrophages and dendritic cells (DCs), are challenging to distinguish due to overlapping characteristics.
• Current classification relies on morphology, phenotype, and function, which are not definitive for cell-type identification.

Purpose of the Study:

• To develop a mouse model for defining dendritic cells (DCs) based on their developmental lineage.
• To establish a method for distinguishing DCs from other leukocyte populations in vivo.
• To investigate the ontogeny of mononuclear phagocytes and their potential for lineage plasticity.

Main Methods:

• Development of a mouse model utilizing DNGR-1 expression as a specific marker for dendritic cell precursors.
• Employing genetic tracing to track the developmental history of DNGR-1 expressing cells.
• Analysis of cell populations in various tissues, including under inflammatory conditions.

Main Results:

• DNGR-1 expression specifically marks precursors of conventional dendritic cells (DCs) in mice, excluding other leukocytes.
• Genetic tracing confirms that DNGR-1 marks cells belonging to the DC lineage, even after inflammation.
• Identification of cells in certain tissues, previously misclassified as monocytes/macrophages, as actual descendants of DC precursors.

Conclusions:

• The DNGR-1 mouse model provides a reliable in vivo system for fate mapping dendritic cells (DCs).
• This model enables accurate differentiation of DCs from other leukocyte lineages.
• The findings contribute to a better understanding of the mononuclear phagocyte system's complexity and cell lineage relationships.