Fig. 1.

The thymus-associated B cell repertoire is distinct from the paired circulating repertoire. AIRR-seq was performed to generate B cell repertoires for eight MGTX trial-derived thymus specimens and paired PBMCs collected at baseline. Key features of antigen-experience B cells in each of the respective repertoires were then compared. (A) Overall constant region (isotype) usage frequencies are quantified for thymus compared to the circulating compartment per patient. Horizontal bars show the average frequency of constant region usage across patients. Frequencies belonging to the same patient are paired with a black line. (B) Individual SHM frequencies for thymus compared to circulating B cells are presented. Horizontal bars show the average SHM frequency for a given sample status (i.e., thymus or circulation). Frequencies belonging to the same patient are paired with a black line. (C) BASELINe probability distribution functions (PDF) are shown for thymus and circulating repertoires, with density shown for a range of selection strengths (∑) on the x axis. PDFs were determined via convolution of subject-specific PDFs for each status to generate a single aggregate status. (D) Individual frequencies for the occurrence of glycosylation (N[X][S/T]) sites are quantified for thymus compared to circulating B cells and (E) for the inferred germline of these sequences. Horizontal bars show the average glycosylation frequency for a given cluster. Frequencies belonging to the same patient are paired with a black line. Statistical differences are shown only when significant (****P < 0.0001; ***P < 0.001; **P < 0.01; *P < 0.05).