title: T cell receptor CDR3 sequence but not recognition characteristics distinguish autoreactive effector and Foxp3(+) regulatory T cells.
abstract: The source, specificity, and plasticity of the forkhead box transcription factor 3 (Foxp3)(+) regulatory T (Treg) and conventional T (Tconv) cell populations active at sites of autoimmune pathology are not well characterized. To evaluate this, we combined global repertoire analyses and functional assessments of isolated T cell receptors (TCR) from TCRalpha retrogenic mice with autoimmune encephalomyelitis. Treg and Tconv cell TCR repertoires were distinct, and autoantigen-specific Treg and Tconv cells were enriched in diseased tissue. Autoantigen sensitivity and fine specificity of these cells intersected, implying that differences in responsiveness were not responsible for lineage specification. Notably, autoreactive Treg and Tconv cells could be fully distinguished by an acidic versus aliphatic variation at a single TCR CDR3 residue. Our results imply that ontogenically distinct Treg and Tconv cell repertoires with convergent specificities for autoantigen respond during autoimmunity and argue against more than limited plasticity between Treg and Tconv cells during autoimmune inflammation.
authors.affiliation: Department of Pathology, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Liu
authors.forename: Phuong
authors.initials: P
authors.lastname: Nguyen
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.forename: Cheng
authors.initials: C
authors.lastname: Cheng
authors.forename: Meredith
authors.initials: M
authors.lastname: Steeves
authors.forename: John C
authors.initials: JC
authors.lastname: Obenauer
authors.forename: Jing
authors.initials: J
authors.lastname: Ma
authors.forename: Terrence L
authors.initials: TL
authors.lastname: Geiger
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000276:immunology / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D004681:Encephalomyelitis, Autoimmune, Experimental / Q000276:immunology*; D051858:Forkhead Transcription Factors / Q000276:immunology; D006023:Glycoproteins / Q000276:immunology / Q000494:pharmacology; D007376:Interleukin-2 / Q000096:biosynthesis / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D063308:Myelin-Oligodendrocyte Glycoprotein; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology* / Q000494:pharmacology; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics / Q000276:immunology*; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*
chemical_list: D001324:Autoantigens; D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D006023:Glycoproteins; D007376:Interleukin-2; D063308:Myelin-Oligodendrocyte Glycoprotein; D010446:Peptide Fragments; D016693:Receptors, Antigen, T-Cell, alpha-beta; C109168:T-cell receptor Vbeta 8.2; C445081:myelin oligodendrocyte glycoprotein (35-55)