Conventional and Regulatory CD4+ T Cells That Share Identical TCRs Are Derived from Common Clones.
Results from studies comparing the diversity and specificity of the TCR repertoires expressed by conventional (Tconv) and regulatory (Treg) CD4+ T cell have varied depending on the experimental system employed. We developed a new model in which T cells express a single fixed TCRα chain, randomly rearranged endogenous TCRβ chains, and a Foxp3-GFP reporter. We purified CD4+Foxp3- and CD4+Foxp3+ cells, then performed biased controlled multiplex PCR and high throughput sequencing of endogenous TCRβ chains. We identified >7,000 different TCRβ sequences in the periphery of 5 individual mice. On average, ~12% of TCR sequences were expressed by both conventional and regulatory populations within individual mice. The CD4+ T cells that expressed shared TCR sequences were present at higher frequencies compared to T cells expressing non-shared TCRs. Furthermore, nearly all (>90%) of the TCR sequences that were shared within mice were identical at the DNA sequence level, indicating that conventional and regulatory T cells that express shared TCRs are derived from common clones. Analysis of TCR repertoire overlap in the thymus reveals that a large proportion of Tconv and Treg sharing observed in the periphery is due to clonal expansion in the thymus. Together these data show that there are a limited number of TCR sequences shared between Tconv and Tregs. Also, Tconv and Tregs sharing identical TCRs are found at relatively high frequencies and are derived from common progenitors, of which a large portion are generated in the thymus.
Department of Molecular Microbiology and Immunology, Saint Louis University, School of Medicine, Saint Louis, Missouri, United States of America.
Kyle J
http://orcid.org/0000-0003-4874-2911
KJ
Wolf
Adaptive Biotechnologies Corporation, Seattle, Washington, United States of America.
Ryan O
RO
Emerson
Department of Molecular Microbiology and Immunology, Saint Louis University, School of Medicine, Saint Louis, Missouri, United States of America.
Jeanette
J
Pingel
Department of Molecular Microbiology and Immunology, Saint Louis University, School of Medicine, Saint Louis, Missouri, United States of America.
R Mark
RM
Buller
Department of Molecular Microbiology and Immunology, Saint Louis University, School of Medicine, Saint Louis, Missouri, United States of America.
Richard J
RJ
DiPaolo
D000595:Amino Acid Sequence; D000818:Animals; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002454:Cell Differentiation; D019070:Cell Lineage; D002999:Clone Cells; D005260:Female; D005434:Flow Cytometry; D051858:Forkhead Transcription Factors / Q000502:physiology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000502:physiology*; D017386:Sequence Homology, Amino Acid; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013950:Thymus Gland / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
D051858:Forkhead Transcription Factors; C498833:Foxp3 protein, mouse; D011948:Receptors, Antigen, T-Cell