Impaired T Follicular Regulatory Cell Function and Enhanced T Follicular Helper Cell Activity in Experimental Autoimmune Encephalomyelitis: Mechanistic Insights into CNS Autoimmunity
International Journal of Molecular Sciences, cilt.27, sa.6, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Cilt numarası: 27 Sayı: 6
- Basım Tarihi: 2026
- Doi Numarası: 10.3390/ijms27062901
- Dergi Adı: International Journal of Molecular Sciences
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, EMBASE, MEDLINE, Academic Search Ultimate (EBSCO), Biomedical Reference Collection: Corporate Edition (EBSCO), Health Research Premium Collection (ProQuest)
- Anahtar Kelimeler: EAE, CXCR5, PD-1, ICOS, FOXP3, IL-21
- Sağlık Bilimleri Üniversitesi Adresli: Evet
Özet
Multiple sclerosis is a chronic immune-mediated central nervous system disorder marked by neuroinflammation, demyelination, and neurodegeneration, and effectively modeled by experimental autoimmune encephalomyelitis. The objective of this study was to elucidate the roles of T follicular helper and T follicular regulatory cells in the progression of experimental autoimmune encephalomyelitis and to assess their association with IL-21 expression and central nervous system tissue pathology. In this study, experimental autoimmune encephalomyelitis was induced in 25 adult female C57BL/6 mice. Fluorescent double immunostaining for CXCR5 in combination with PD-1, ICOS, CD4, and FOXP3 was performed, along with the analysis of IL-21 mRNA expression. Histopathological assessment was conducted on the cerebrum, cerebellum, and medulla spinalis to evaluate neuroinflammation and myelin loss. A significant increase in CXCR5+PD-1+ and CXCR5+ICOS+ T follicular helper-like cells was observed in brain tissue, indicating immune activation and T follicular helper cell involvement. Simultaneously, a marked decrease in FOXP3+ T follicular regulatory-like cells suggested impaired immune tolerance and enhanced autoimmune activity. The infiltration of T follicular helper-like cells was identified as a key driver of inflammation and demyelination in the central nervous system. Additionally, the elevated IL-21 mRNA expression highlighted B cell activation and the initiation of antibody-mediated responses. These findings suggest that dysregulation of the T follicular helper/T follicular regulatory axis and elevated IL-21 expression contribute to the immunopathogenesis of experimental autoimmune encephalomyelitis, providing further insight into the mechanisms underlying multiple sclerosis development.