As a conclusion, the pp65-HLA-A2 tetramer+ fraction does not alter the TcL typology of these two patients. Altogether, these data suggest that, even if CMV is positively correlated with TCR repertoire shape, the TCR classification of these patients is not driven by the specific anti-pp65 CMV-specific T-cell response. TCR Vβ repertoire alteration could be associated with a bias of regulatory/cytopathic

immune gene balance. To test this hypothesis, we measured the gene expression of FOXP3 (prototypic regulatory-associated gene), GZMB (prototypic cytotoxicity-associated gene) and T-bet (prototypic inflammation-associated gene) in the PBMC of patients within the STA GenHomme cohort. Patients belonging to the TcL classes 3 and 4 exhibit a decrease in FOXP3 (p=0.0001) click here expression, and an increase in GZMB (p=0.001) and T-bet (p<0.0001) expression as compared with patients belonging to TcL class 1 (Fig. 4A). Correlations between PCA C1 and gene expression of FOXP3,

GZMB and T-bet at the individual level (Fig. 4B) show that FOXP3 gene expression decreased when the PCA C1 value increased (slope=−3.01±0.61; p<0.001). On the other hand, GZMB and T-bet gene expression is increased when the PCA C1 value increased (slope=2.14±0.71, p=0.003 and slope=3.34±0.52, p<0.001 respectively). Finally, we investigated whether the TcL pattern allowed the discrimination of patients with distinct clinical status (operational tolerance versus chronic rejection). PCA C1 values from TOL or CHR patients differ significantly (Mann–Whitney Test, p<0.01; TOL PCA C1 median=−0.04 versus CHR PCA C1 median=0.02;

Fig. 1) and sign the immunological differences buy Y-27632 between the two conditions (Supporting Information Fig. 3). The repertoire of CHR patients displays a higher level of clonal CDR3-LD associated with a higher quantity of Vβ transcripts as compared with the repertoire of TOL patients. Using the four TcL patterns previously defined, we confirmed this observation. More than 90% of TOL patients have the TcL pattern classes 1 and 2 (>60% with a TcL class 1; Fig. 5A). CHR patients exhibit predominately the TcL pattern classes 3 and 4. Interestingly, we noticed that CHR PCA C1 values are directly correlated to the Banff score of patients. Patients TCL with high Banff score show a significantly more altered repertoire than patients with low Banff score (PCA C1 median=0.077, IQR=0.099 versus PCA C1 median=−0.002, IQR=0.127 for patients with grade 3 versus patients with Banff grade 1 Mann–Whitney Test, p=0.0317; Fig. 5B). We have used a new statistical approach to compare the TCR repertoire typology of a large cohort of 286 patients including TOL, CHR, STA and STN patients. Special emphasis has been put on unsupervised analysis to identify TCR Vβ transcriptional patterns without statistical a priori16. This approach led us to use the Kurtosis of the CDR3-LD, an unbiased metric, which is pertinent for revealing the alteration of CDR3-LD and to estimate its “clonality” 17.