Figure 1.
Cellular composition and architecture of C57BL/6 Aire−/− prostates and comparison with human prostates. (A) H&E sections of human prostate immune cells showing stromal lymphoid cells in loose aggregates (left) to dense lymphoid structures (right). (B) IHC of stromal lymphocytes in organizing lymphoid structures, highlighting CD79a+ B cells (top left), CD8+ T cells (top right), CD4+ T cells (bottom left), and intraepithelial CD8+ T cells (arrowheads). (C) H&E section (left) of human prostate showing intraluminal macrophages (asterisk). Toluidine blue‐stained section (right) highlighting stromal mast cells (arrowheads) adjacent to gland (asterisk). (D) Overview of mouse experimental design. Aire KO mice in a C57BL/6 background were injected with prostate homogenate protein and Freund's Incomplete Adjuvant. After 10 days, mice again received a booster of prostate homogenate protein and Freund's Incomplete Adjuvant. All four lobes of the prostates were harvested at either 21 days or at 35 days after receiving the booster and were subjected to scRNA‐seq, histological analysis, or cell flow cytometry. Created in BioRender. Lanman, N. (2026) https://BioRender.com/xk0z12a. (E) H&E sections of dorsal prostate from immunized C57BL/6 Aire−/− mouse prostates with prominent lymphoid aggregates (left) and organizing lymphoid structures (right) with germinal center‐like areas (asterisks). (F) Dorsal prostate of immunized C57BL/6 Aire−/− mouse showing infiltration of lymphoid cells (arrowheads) adjacent to glandular epithelium (arrows). Infiltrating cells consist of lymphoid cells including numerous plasma cells (bold arrows). (G) IF (left) and IHC (right) highlighting arrangement of CD4 (orange) and CD8 (green) T cells and CD20 (DAB) B cells in stromal lymphoid aggregates. (H) Immune cell flow cytometry of Day 31 post‐immunization C57BL/6 Aire−/−, C57BL/6 Aire+/−, and C57BL/6 Aire+/+ mouse prostates. Scale bars, 100 μm. Flow cytometry data are presented as mean ± SEM.