Ephrin-B2-expressing natural killer cells induce angiogenesis.

Background: Therapeutic angiogenesis aims to induce new blood vessel growth in ischemic tissues; however, previous clinical trials have had limited success. Studies of uterine angiogenesis revealed a specialized subset of natural killer (NK) cells, called uterine NK (uNK) cells, which have unique proangiogenic abilities.

Methods: We show that uNK cells in mice express ephrin-B2, a regulator of angiogenesis, to induce tubule formation in an ex vivo coculture tubule formation assay. We next induced the expression of ephrin-B2 by splenic NK (sNK) cells harvested from male mice.

Results: We showed that induced NK (iNK) cells can also instruct endothelial cells to form tubules using ephrin-B2.

Conclusions: We concluded that Ephrin-B2 is a marker of proangiogenic uNK cells and that a proangiogenic phenotype characterized by ephrin-B2 can be induced in sNK cells to induce therapeutic angiogenesis.