Self Reactive Delayed Type Hypersensitivity (DTH) Induced in Mice by Syngeneic Lymphoblasts

Normal and x-irradiated A mice injected with syngeneic concanavalin A (Con A)-induced lymphoblasts revealed after challenge with syngeneic lipopolysaccharide (LPS)-induced lymphoblasts delayed type hypersensitivity (DTH) measured both by footpad swelling and by ¹²⁵IudR accumulation. Mice injected with allogeneic Con A-induced lymphoblasts and challenged with syngeneic LPS-induced lymphoblasts or vice versa, also generated an appreciable DTH response. In contrast, Con A-induced blast cells of human origin (xenogeneic cells) generated a considerably less effective DTH. The DTH response was more profound and consistent in x-irradiated mice, suggesting that irradiation sensitive cells control this response. The syngeneic DTH response was efficiently transferred to naive recipients with Thy-1⁺, nylon wool passed cells. The establishment of the DTH activity was associated with the lymphoblasts own (differentiation?) antigens and not with contaminants attached to the cells, such as Con A or fetal calf serum. The results were compared with similar results reported by other groups and the biological significance of all findings was evaluated.