Metabolic Deficiencies Underlie Plasmacytoid Dendritic Cell Exhaustion After Viral Infection

Area of Science:

• Immunology
• Virology
• Metabolic pathways

Background:

• Type I interferons (IFN-I) are crucial for antiviral defense, with Plasmacytoid Dendritic Cells (pDCs) being major producers.
• pDCs exhibit 'exhaustion' after initial IFN-I bursts, reducing their capacity and increasing susceptibility to secondary infections, a conserved but poorly understood phenomenon.

Approach:

• Investigated the metabolic underpinnings of pDC exhaustion.
• Identified lactate dehydrogenase B (LDHB) as a key regulator of pDC function.
• Utilized mouse and human cell models, along with in vitro and in vivo experiments.

Key Points:

• pDC exhaustion correlates with impaired oxidative and glycolytic metabolism.
• LDHB is a novel positive regulator of pDC IFN-I production in both mice and humans.
• LDHB deficiency impairs viral control and pDC metabolic function.
• Preserving LDHB expression partially restores exhausted pDC function.

Conclusions:

• LDHB plays a critical role in maintaining pDC function and antiviral immunity.
• The findings reveal a conserved mechanism balancing host immunity and pathology during viral infections.
• This work sheds light on the evolutionary significance of pDC exhaustion.