Context-specific regulatory genetic variation in MTOR dampens neutrophil-T cell crosstalk in pneumonia-associated sepsis.

Summary

This study identifies a regulatory variant (rs4845987) that differentially modulates MTOR expression in activated T cells versus neutrophils and is associated with improved survival in pneumonia-associated sepsis in an endotype-specific manner. Ex vivo experiments show activated T cells drive immunosuppressive neutrophils via cytokines, attenuated by hypoxia and rapamycin, with allelic modulation by vitamin C.

Key Findings

• The rs4845987 G-allele reduces MTOR expression in activated T cells (opposite direction in neutrophils) and is associated with improved survival in pneumonia-associated sepsis in an endotype-specific fashion.
• Activated T cells induce immunosuppressive neutrophils via cytokines ex vivo; this process is dampened by hypoxia and the mTOR inhibitor rapamycin.
• A variant-containing regulatory element fine-tunes MTOR transcription with an allelic effect observed upon vitamin C treatment.

Clinical Implications

Supports stratified immunomodulation in pneumonia-associated sepsis: patients with favorable MTOR regulatory alleles/endotypes may benefit from tailored mTOR pathway modulation (e.g., rapamycin) or metabolic co-therapies, while highlighting potential interactions with hypoxia and vitamin C.

Limitations

• Observational survival associations may be confounded and require replication in larger, multi-ethnic cohorts.
• Endotype specificity may limit generalizability; no interventional clinical trial evidence yet.

Future Directions

Design genotype- and endotype-stratified trials testing mTOR-pathway modulation and evaluate vitamin C as a potential modifier; map temporal dynamics of T cell–neutrophil crosstalk in sepsis.