Cytotoxic CD8+ T cells target citrullinated antigens in rheumatoid arthritis.
2023; 14 (1): 319
The immune mechanisms that mediate synovitis and joint destruction in rheumatoid arthritis (RA) remain poorly defined. Although increased levels of CD8+ T cells have been described in RA, their function in pathogenesis remains unclear. Here we perform single cell transcriptome and T cell receptor (TCR) sequencing of CD8+ T cells derived from anti-citrullinated protein antibodies (ACPA)+ RA blood. We identify GZMB+CD8+ subpopulations containing large clonal lineage expansions that express cytotoxic and tissue homing transcriptional programs, while a GZMK+CD8+ memory subpopulation comprises smaller clonal expansions that express effector T cell transcriptional programs. We demonstrate RA citrullinated autoantigens presented by MHC class I activate RA blood-derived GZMB+CD8+ T cells to expand, express cytotoxic mediators, and mediate killing of target cells. We also demonstrate that these clonally expanded GZMB+CD8+ cells are present in RA synovium. These findings suggest that cytotoxic CD8+ T cells targeting citrullinated antigens contribute to synovitis and joint tissue destruction in ACPA+ RA.
View details for DOI 10.1038/s41467-022-35264-8
View details for PubMedID 36658110
View details for PubMedCentralID PMC9852471
Rheumatoid Arthritis Patient-derived Anti-citrullinated Protein Antibodies (ACPAs) Ameliorate Joint Inflammation in Early Collagen-antibody Induced Arthritis (CAIA)
WILEY. 2022: 69-70
View details for Web of Science ID 000877386500045
Clonally Expanded B Cells in Multiple Sclerosis Bind EBV EBNA1 and GlialCAM.
Multiple sclerosis (MS) is a heterogenous autoimmune disease in which autoreactive lymphocytes attack the myelin sheath of the central nervous system (CNS). B lymphocytes in the cerebrospinal fluid (CSF) of MS patients contribute to inflammation and secrete oligoclonal immunoglobulins1,2. Epstein-Barr virus (EBV) infection has been linked to MS epidemiologically, but its pathological role remains unclear3. Here we demonstrate high-affinity molecular mimicry between the EBV transcription factor EBNA1 and the CNS protein GlialCAM, and provide structural and in-vivo functional evidence for its relevance. A cross-reactive CSF-derived antibody was initially identified by single-cell sequencing of the paired-chain B cell repertoire of MS blood and CSF, followed by protein microarray-based testing of recombinantly expressed CSF-derived antibodies against MS-associated viruses. Sequence analysis, affinity measurements, and the crystal structure of the EBNA1-peptide epitope in complex with the autoreactive Fab fragment allowed for tracking the development of the naïve EBNA1-restricted antibody to a mature EBNA1/GlialCAM cross-reactive antibody. Molecular mimicry is facilitated by a post-translational modification of GlialCAM. EBNA1 immunization exacerbates the mouse model of MS and anti-EBNA1/GlialCAM antibodies are prevalent in MS patients. Our results provide a mechanistic link for the association between MS and EBV, and could guide the development of novel MS therapies.
View details for DOI 10.1038/s41586-022-04432-7
View details for PubMedID 35073561