Figure 5. Isolated lymphoid follicles contribute to region-specific adaptive immune responses.
(A) Proportion of LP PC expressing IgA and (B) proportion of LP IgA+ cells that were PC in indicated tissue. Each circle represents an individual donor with paired samples. (C–G) The IgA repertoire in ileum and proximal colon GALT and LP was determined in 3 individual donors. (C and D) The Morisita-Horn similarity index (MHI) between (C) six individual cLP and siLP samples and (D) six individual PP and colon SM-ILF follicles, collected from each of the three patients analyzed. (E) Percentage of the most dominant GALT IgA clones in indicated LP samples. The 100 most abundant clones within each PP follicle (n=6) and SM-ILF (n=6) were pooled (PP: 471–583; SM-ILF: 521–570 clones) and the percentage of these clones that were present with ≥10 reads in each of the ileum and colon LP samples assessed. (F) Percentage of top 100 clones present in each individual GALT sample (X axis) from patient 3 that were present with ≥10 reads in each LP sample. (G) Proportion of the IgA repertoire in each LP sample that was covered by the dominating 100 clones in the 6 pooled SM-ILF (521–570 clones) or 6 pooled PP follicles (471–583 clones). Data from each of the three patients (X axis) is shown. (E-G) Bars represent boxplots with 1st, median and 3rd quartile. (H) Representative flow cytometry plots and (I) pooled analysis of intestinal homing receptor expression by IgA+ PC in indicated tissue. Each circle represents an individual donor with paired samples. PP, Peyer’s patch; SM-ILF, submucosal follicle; M-ILF, mucosal follicle; LP, lamina propria; GALT, gut-associated lymphoid tissue. See also Figure S5.