Panel A: Flow cytometry plots show early T cell differentiation markers C D 5, C D 7, and C D 1 a in control and P S M B 10 G 209 R cells. Panel B: Flow cytometry plots show late T cell differentiation markers C D 4, C D 8, C D 3, and T C R alpha beta in control and mutant cells. Panel C: Scatter plots show T C R repertoire metrics including clonality, richness, and diversity comparing control and P S M B 10 G 209 R samples. Panel D: Bar plot shows T R B V gene usage frequencies indicating mild skewing in T C R repertoire between control and mutant samples. Panel E: Table summarizes variant allele counts in C D 3 (T cells), C D 19 (B cells), and C D 56 (N K cells) populations. Panel F: Line graph shows longitudinal immune cell counts (C D 4, C D 8, C D 4 slash C D 45 R A) with clinical events and vaccinations over 24 months.
Neonatal lymphopenia in PSMB10 G209R resolves over time and is not related to impaired thymocyte differentiation. (A and B) Flow plots showing ex vivo differentiated proportions of patient- and healthy donor–derived cells (gated within live CD45+ cells) expressing (A) early T cell progenitor differentiation markers CD5, CD7, and CD1a, and (B) late T cell differentiation markers CD4, CD8, CD3, and TCRab from PSMB10 WT and PSMB10 G209R HSCs in ATOs. (C) Bulk TCR repertoire sequencing of PSMB10 G209R compared with 10 age-matched individuals shows similar clonality, richness, and diversity. (D) VJ architecture of TCR repertoire displays mild skewing as compared to the control samples. This skewing is mainly mediated by differential usage of distinct T cell receptor beta variable region (TRBV) (enrichment of TRBV29-1, TRBV30, TRBV6-5; reduced usage of TRBV27, TRBV18, TRBV19) (see also Fig. S5 D). (E) T cell reconstitution and clinical course of the PSMB10 G209R patient in the first 24 mo of life. Total CD8, total CD4, and naïve CD4 cell counts, clinical events (AIN = autoimmune neutropenia, RSV = respiratory syncytial virus infection), and medical interventions (white flash in the top: prophylaxis given; black arrows = vaccines given 6 + 1 = inactivated vaccine again tetanus, diphtheria, pertussis, poliomyelitis, Haemophilus influenzae type B, hepatitis B, and S. pneumoniae; MMR+V = live vaccine against measles, mumps, rubella, and chickenpox) are shown.