Clonally expanded HSP-specific T cells contribute to glaucomatous neurodegeneration via the mTORC1 pathway

Emerging evidence implicates autoimmune mechanisms, particularly T cell–mediated responses, in the pathogenesis of glaucoma, however, the underlying autoantigen and cellular drivers in glaucomatous optic neuropathy remain incompletely defined. In this study, we applied single-cell RNA sequencing (scRNA-seq) and single-cell TCR sequencing (scTCR-seq) to human glaucomatous and healthy retinas, uncovering pathological T cell infiltration and clonally expansion process in glaucomatous retinas, with shared TCR repertoires between retina and peripheral blood. Elevated expression of HLA-A and heat shock proteins (HSPs) in glaucomatous neurons suggested that stressed retinal ganglion cells (RGCs) may act as sources of autoantigens that drive T cell–mediated injury. Structure-based affinity prediction via AlphaFold2 identified 5 TCR sequences exhibiting high binding affinity to HSP27. In a mouse model of transient high intraocular pressure (HIOP), the overlapping of TCR in different immune compartments has also been detected. In vitro stimulation of lymphocytes from HSP27-immunized mice identified 12 unique TCR clones, three of which matched those observed in glaucomatous retinas. HSP27 pre-immunization exacerbated RGC loss, coinciding with further enhanced mTORC1 activation and elevated IFN-γ production in T cells. Adoptive transfer of T cells from HIOP or HSP27-immunized mice exacerbated RGC loss in host HIOP mice, while T cells from rapamycin-treated donors attenuated retinal damage. Collectively, our findings indicate that RGC-derived HSP27 acts as an autoantigen in glaucoma, driving mTORC1-mediated expansion of pathogenic T cells and contributing to sustained autoimmune neurodegeneration.