Fig 6. 10.1.1 Ab induces proliferation of lymph node LECs and non-LECs.

A-B). Popliteal LN sections of control Hamster IgG-injected or 10.1.1 Ab-injected mice were stained with anti-LYVE-1 antibodies (red), and anti-CD11b (green). White boxes on low magnification images (A) identify the region of medullary sinuses shown at high magnification in (B). No double-positive LYVE-1+ CD11b+ cells were identified in either treatment condition, indicating that CD11b+ cells do not directly contribute to lymphatic sinus growth. The representation or distribution of CD11b+ macrophages on each sinus (arrowheads) also did not change, indicating that sinus macrophages proportionally coat the growing lymphatic sinuses. C-D). Popliteal LN sections of control Hamster IgG-injected or 10.1.1 Ab-injected mice were stained with anti-LYVE-1 (green) and anti-Ki67 Abs (red) to identify proliferating LECs. White boxes on 10x images (C) identify the 40x regions of the medullary sinuses shown in D and E. A number of LYVE-1+ Ki67+ LECs (e.g. arrowheads) were identified near the growing edge of the medullary lymphatics in LNs from 10.1.1 Ab-injected mice but not control Hamster IgG-injected mice. Proliferating LYVE-1- Ki67+ non-LECs were clustered adjacent to the medullary lymphatic sinuses in LNs from 10.1.1 Ab-injected mice (C, arrows). E). The Ki67+ cells are DAPI-positive (e.g. compare arrowheads in D and E) confirming nuclear localization of the Ki67 immunostaining. F). Adjacent sections were stained with anti-Prox-1 (green) and anti-Ki67 (red). A number of nuclear Prox-1+ Ki67+ proliferating LECs (e.g. arrowheads) were identified in the same regions of the growing lymphatic sinuses in LNs from 10.1.1 Ab-injected but not hamster IgG-injected mice. Scale bars are indicated.