5-HT7R enhances neuroimmune resilience and alleviates meningitis by promoting CCR5 ubiquitination

J Adv Res. 2025 Feb:68:317-330. doi: 10.1016/j.jare.2024.02.017. Epub 2024 Mar 1.

Abstract

Introduction: Excessive immune activation induces tissue damage during infection. Compared to external strategies to reconstruct immune homeostasis, host balancing ways remain largely unclear.

Objectives: Here we found a neuroimmune way that prevents infection-induced tissue damage.

Methods: By FACS and histopathology analysis of brain Streptococcus pneumonia meningitis infection model and behavioral testing. Western blot, co-immunoprecipitation, and ubiquitination analyze the Fluoxetine initiate 5-HT7R-STUB1-CCR5 K48-linked ubiquitination degradation.

Results: Fluoxetine, a selective serotonin reuptake inhibitor, or the agonist of serotonin receptor 5-HT7R, protects mice from meningitis by inhibiting CCR5-mediated excessive immune response and tissue damage. Mechanistically, the Fluoxetine-5-HT7R axis induces proteasome-dependent degradation of CCR5 via mTOR signaling, and then recruits STUB1, an E3 ubiquitin ligase, to initiate K48-linked polyubiquitination of CCR5 at K138 and K322, promotes its proteasomal degradation. STUB1 deficiency blocks 5-HT7R-mediated CCR5 degradation.

Conclusion: Our results reveal a neuroimmune pathway that balances anti-infection immunity via happiness neurotransmitter receptor and suggest the 5-HT7R-CCR5 axis as a potential target to promote neuroimmune resilience.

Keywords: 5-HT(7)R; CCR5; Meningitis; Neuroimmune; STUB1; Ubiquitination.

MeSH terms

  • Animals
  • Disease Models, Animal
  • Humans
  • Male
  • Meningitis, Pneumococcal / drug therapy
  • Meningitis, Pneumococcal / immunology
  • Meningitis, Pneumococcal / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Neuroimmunomodulation
  • Receptors, CCR5* / metabolism
  • Receptors, Serotonin* / metabolism
  • Signal Transduction / drug effects
  • Streptococcus pneumoniae
  • Ubiquitin-Protein Ligases / metabolism
  • Ubiquitination*

Substances

  • Receptors, Serotonin
  • Receptors, CCR5
  • serotonin 7 receptor
  • Ubiquitin-Protein Ligases
  • CCR5 protein, mouse