Energy restriction impairs dendritic cell development in C57BL/6J mice

Area of Science:

• Immunology
• Cell Biology
• Dietary Interventions

Background:

• Dendritic cells (DCs) are crucial antigen-presenting cells that initiate T lymphocyte responses.
• Energy restriction (ER) is a dietary intervention linked to longevity but with complex effects on immunity.
• Understanding DC development under ER is vital for assessing immune function.

Purpose of the Study:

• To investigate the impact of a 40% energy restriction (ER) diet on dendritic cell development in adult C57Bl6J mice.
• To analyze changes in myeloid progenitors, DC subsets, and related immune cells in the bone marrow of ER-fed mice.

Main Methods:

• Adult C57Bl6J mice were fed a 40% ER diet or an ad libitum (AL) diet.
• Flow cytometry was used to analyze bone marrow cell populations, including myeloid progenitors and DC subsets.
• Proliferation rates were assessed using BrdU incorporation and Ki-67 staining.

Main Results:

• ER mice exhibited increased myeloid progenitors but decreased common DC progenitors, precursor conventional DCs, and plasmacytoid DCs.
• A rise in macrophages and CD169+ cells was observed in the bone marrow of ER mice.
• In vitro culture with GM-CSF or Flt3L did not reveal significant differences in DC subsets, suggesting proliferation rates are key.

Conclusions:

• Energy restriction alters myelopoiesis, leading to reduced dendritic cell development and enhanced monocyte/macrophage development in steady-state mice.
• These findings may explain previously observed impaired innate immune responses to primary infections, like influenza, in ER-fed mice.