Epstein-Barr virus (EBV) is one of the most common viruses in humans， capable of causing life-threatening infections and cancers in immunocompromised individuals. Although CD8 T cells provide key protection against EBV， the persistence and dynamics of specific T-cell receptor (TCR) clones during immunosuppression in transplant patients is largely unknown. For the first time， we used a novel single-cell TCRαβ multiplex-nested reverse transcriptase PCR to dissect TCRαβ clonal diversity within GLCTLVAML (GLC)-specific CD8 T cells in healthy individuals and immunocompromised lung transplant recipients. The GLC peptide presented by HLA-A*02:01 is one of the most immunogenic T-cell targets from the EBV prot... More
Epstein-Barr virus (EBV) is one of the most common viruses in humans， capable of causing life-threatening infections and cancers in immunocompromised individuals. Although CD8 T cells provide key protection against EBV， the persistence and dynamics of specific T-cell receptor (TCR) clones during immunosuppression in transplant patients is largely unknown. For the first time， we used a novel single-cell TCRαβ multiplex-nested reverse transcriptase PCR to dissect TCRαβ clonal diversity within GLCTLVAML (GLC)-specific CD8 T cells in healthy individuals and immunocompromised lung transplant recipients. The GLC peptide presented by HLA-A*02:01 is one of the most immunogenic T-cell targets from the EBV proteome. We found that the GLC-specific TCRαβ repertoire was heavily biased toward TRAV5 and encompassed five classes of public TCRαβs， suggesting that these clonotypes are preferentially utilized following infection. We identified that a common TRAV5 was diversely paired with different TRAJ and TRBV/TRBJ genes， in both immunocompetent and immunocompromised individuals， with an average of 12 different TCRαβ clonotypes/donor. Moreover， pre-transplant GLC-specific TCRαβ repertoires were relatively stable over 1 year post transplant under immunosuppression in the absence or presence of EBV reactivation. In addition， we provide the first evidence of early GLC-specific CD8 T cells at 87 days post transplant， which preceded clinical EBV detection at 242 days in an EBV-seronegative patient receiving a lung allograft from an EBV-seropositive donor. This was associated with a relatively stable TCRαβ repertoire after CD8 T-cell expansion. Our findings provide insights into the composition and temporal dynamics of the EBV-specific TCRαβ repertoire in immunocompromised transplant patients and suggest that the early detection of EBV-specific T cells might be a predictor of ensuing EBV blood viremia.
