Fig. 10

Elevated frequency of TIGIT⁺ TCRVβ13.1⁺ FoxP3⁺ Tregs in the peripheral blood of an Mreg-treated kidney transplant recipient at ~7 years after surgery. The 1-year outcome of an Mreg-treated kidney transplant recipient, who is known as patient CA, has been previously reported. At ~7 years post transplant, patient CA had stable graft function and was receiving tacrolimus monotherapy as his only maintenance immunosuppression. a At intervals during the first months of follow-up, peripheral blood samples were taken from patient CA for PCR-based TCR spectratyping. These analyses revealed an oligoclonal expansion of TCRVβ13.1⁺ T cells that occurred after Mreg administration and persisted throughout the first 6 months. b–q At ~7 years post transplant, peripheral blood samples from patient CA were analysed by flow cytometry for the presence of TCRVβ13.1⁺ T cells. Compared to 15 healthy donors without transplants, patient CA was not exceptional with respect to b CD4⁺ T-cell frequency, c CD4⁺/CD8⁺ T-cell ratio or d overall frequency of FoxP3⁺ Treg. e Patient CA exhibited only a marginally higher frequency of peripheral blood TIGIT⁺ CD4⁺ T cells compared to the reference population. f Patient CA exhibited a higher frequency of TCRVβ13.1⁺ T cells in peripheral blood than controls. g Patient CA had a higher proportion of Tregs within TCRVβ13.1⁺ CD4⁺ T cells compared to his overall CD4⁺ T-cell pool. h By contrast, Tregs were not enriched amongst TCRVβ13.1⁻ CD4⁺ T cells. i Patient CA showed a higher ratio of TCRVβ13.1⁺ Treg to TCRVβ13.1⁻ Treg than healthy controls. j As a proportion of all CD4⁺ T cells, TCRVβ13.1⁺ Treg frequency was higher in patient CA than healthy controls. k Notably, patient CA also exhibited a higher proportion of TCRVβ13.1⁺ TIGIT⁺ Treg within the CD4⁺ T-cell compartment compared to the reference group. l Consistent with TCR spectratyping results from the first 6 months, patient CA exhibited no enrichment of TCRVβ12⁺ T cells. m–q Differences between patient CA and healthy controls observed in TCRVβ13.1⁺ CD4⁺ T cells were not reflected in TCRVβ12⁺ T cells