A chimeric cell adhesion molecule mediates homing of lymphocytes to vascularized tumors

To facilitate tumor colonization by adoptively transferred cells of the imm une system, we created a chimeric cell adhesion molecule that mediates tumo r-specific homing by binding to the integrin alpha v beta 3 on angiogenic e ndothelial cells, A high-affinity cell adhesion molecule for integrin alpha v beta 3 was generated by fusing the disintegrin kistrin to the transmembr ane adhesion molecule CD31/PECAM-1, This chimeric cell adhesion molecule, t ermed KISS31, mediates adhesion of lymphoid cells to soluble recombinant in tegrin alpha v beta 3 and to endotheliomal monolayers in vitro, KISS31-expr essing lymphoid cells accumulate in angiogenic tumors in two in vivo models , in B16/129 melanoma xenografts on the chick chorioallantois and in s.c. g rowing Lewis lung carcinoma in mice. Our data indicate that expression of KISS31 on lymphoid cells confers tumor -specific homing. This is, to our knowledge, the first example of an experi mental mechanism that targets living cells to tumors by redirecting their h oming pattern.