Cell-based experiments found that Aggregatibacter actinomycetemcomitans, a bacterium associated with periodontitis, can degrade neutrophil extracellular traps after capture and identified membrane-associated NadN as an important mediator. Expressing NadN in Lactococcus lactis conferred NET-degrading activity, but patient or animal evidence of disease impact is not yet available.
Key findings
- Both wild type and ΔCdtB were trapped but degraded NETs after three hours. Survival was CdtB-independent and degradation was cell-associated. LC-MS/MS identified NadN; recombinant NadN degraded NETs, and NadN expression in L. lactis was sufficient to confer the phenotype in vitro.
Why this matters globally
NadN is a mechanistic target for further study of periodontal virulence and immune evasion, but it is too early to propose it as a biomarker, drug target, or vaccine antigen.
Thai researcher contribution
The collaboration across Mahidol, Navamindradhiraj, Chulalongkorn, Chulabhorn Research Institute, and KMUTT integrated microbiology, oral immunology, proteomics, and biological engineering.
Limitations to consider
This is an in-vitro study using a principal strain and controlled NET system. Heterologous expression demonstrates sufficiency but not necessity in the native organism because the abstract does not report NadN knockout and rescue in A. actinomycetemcomitans. Lesion concentrations, microbiome effects, and patient associations remain unknown.