Lymphocyte–Induced Angiogenesis: Effect of Different Antigenic Stimuli

It is known that tumor cells activate spleen cells to induce an angiogenic response. In this report we studied whether different antigenic stimuli, other than tumor cells, were able to activate spleen lymphocytes to induce angiogenesis in syngeneic combination (SLIA). For this purpose, mice were inoculated with sheep red blood cells (SRBC), allogeneic kidney and syngeneic fetal tissues. The effect of pregnancy (syngeneic or allogeneic) on the ability of spleen cells to induce a neovascular response was also assessed. None of the different stimuli were able to induce spleen lymphocytes to evoke angiogenesis. Although allogeneic lymphocytes from virgin females induced a strong neovascular response, the same population, but from allogeneic pregnant mice, did not evoke this response. We conclude that tumor cells seem to be the only antigenic stimuli able to activate spleen lymphocytes to induce SLIA.