ADP-heptose: A new innate immune modulator

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Lipopolysaccharide (LPS), a gram-negative bacterial component, is a known pathogen-associated molecular pattern (PAMP).
• Previous research indicated that d-glycero-β-d-manno-heptose 1,7-bisphosphate (HBP), an LPS intermediate, activates innate immunity via the NF-κB pathway.
• The precise PAMP status and pattern recognition receptor (PRR) for HBP remained unclear.

Purpose of the Study:

• To review the role of ADP-heptose and related metabolites in innate immunity.
• To highlight recent findings on ADP-heptose as a novel PAMP.
• To explore the potential of bacterial metabolites as immune modulators.

Main Methods:

• Literature review focusing on ADP-heptose and innate immune signaling.
• Analysis of recent studies on bacterial metabolite recognition by mammalian cells.
• Synthesis of information on the ALPK1 pathway activation by ADP-heptose.

Main Results:

• ADP-heptose, an LPS biosynthesis intermediate, is transported into mammalian cells.
• ADP-heptose binds to alpha-kinase 1 (ALPK1), initiating potent immune responses.
• These findings establish bacterial metabolites as a new class of PAMPs.

Conclusions:

• ADP-heptose and related metabolites represent a novel category of PAMPs.
• Recognition of these metabolites by PRRs like ALPK1 is crucial for innate immunity.
• Bacterial metabolites hold promise for the development of novel immune-modulating therapeutics.