Angiogenic lymphokines of activated T-cell origin

Inflammation often is accompanied by neovascularization. This is especially evident in the normally avascular cornea, where an angiogenic response occurs with keratitis or during graft rejection. In the current experiments, supernatants from cultured lymph node cell populations were incorporated in Elvax 40 slow-release polymers and implanted in the corneal stroma. Separation of whole lymph node cells into highly T-enriched and macrophage populations permitted investigation of soluble cell products responsible for angiogenesis. It was found that sepharose-linked concanavalin A was an adequate stimulus for the generation of angiogenic activity, as assessed in the rabbit corneal micropocket assay. Cytoadherence, nylon wool column cell separation, and mitomycin C treatment of individual populations were used to demonstrate that stimulated T cells are a source of angiogenic material. The time-course and magnitude of the angiogenic response were equivalent in normal and x-irradiated leukopenic animals. These observations demonstrate that a potent angiogenic lymphokine secreted by stimulated T cells is active in the corneal micropocket assay system.