Lymphatic vessels associated with tertiary lymphoid organs in the pancreas induced by ectopic expression of LTα. (A) H&E, DAPI, and Prox1 staining of 1-year-old RIPLTα pancreas (40× objective; Zeiss Axioscope). (B) Merge of peri-islet bright field staining for hematoxylin and dark field for LYVE-1 positive lymphatic vessels (red) in the pancreas. More lymphatic vessels are associated with TLOs around the islets of RIPLTα and RIPLTαLTβ^−/− mice than WT mice (n = 3 per group; 20× objective; Zeiss Axioscope). (C) Morphometric quantification reveals a significant increase in peri-islet LYVE-1 positive vessel area in the pancreata of RIPLTα and RIPLTαLTβ^−/− mice compared with WT mice (*P < .05). No significant difference in LYVE-1 positive vessel area was found between RIPLTα and RIPLTαLTβ^−/− pancreata.