Human peripheral blood T lymphocyte subpopulations isolated on the basis of their affinity for sheep red blood cells differ in angiogenesis-inducing capability.

Human peripheral blood lymphocytes injected intradermally into X-ray immunosuppressed mice were tested for angiogenesis-inducing capacity. Both T and B lymphocytes evoked angiogenesis of the same intensity. The total T cell population was fractionated into three subpopulations on the basis of their different affinities for sheep red blood cells (SRBC). Cells belonging to the subpopulation of T lymphocytes displaying moderate affinity for SRBC induced angiogenesis of the higher intensity, higher than that induced by cells of the total T lymphocyte population. However, lymphocytes both with the highest and with moderate affinity for SRBC, mixed together, evoked angiogenesis no different from that evoked by cells of the total T lymphocyte population, suggesting that inhibitory interactions occur among T cells.