Figure 3.

Germinal centers are present in submucosal lymphoid aggregates in the lung. H-L-g7xK mice were euthanized at the time of development of severe arthritis, and were evaluated for the presence of lung pathology. Top left: Representative hematoxylin and eosin–stained section of lung lymphoid aggregate is similar to BALT at ×10 magnification. Top right: CD3 staining (brown) of same lesion at ×20 magnification. Bottom left: B220 staining (brown) of lesion. Bottom right: Peanut agglutinin (PNA) staining (brown) in B-cell follicles, as indicated by arrows, suggests germinal centers.