[Ca++-dependent immunosuppressive effect of ethylenediaminetetraacetic acid (EDTA)]

Subcutaneous injection of a sum total dose of 6.44.10(-5) M of ethylenediaminetetraacetic acid (EDTA), which binds divalent cations, inhibits the process of accumulation of antibody-forming cells in the spleen of mice (CBA X C57BL) F1 hybrids, immunizated with sheep red blood cells. In a dose of 5.2.10(-5) M CaCl2 eliminated the immunodepressive effect of EDTA almost completely. It was assumed that EDTA action was produced through the Ca++-controlled regulation mechanism of one of the following processes: the interaction between T- and B-lymphocytes; proliferation and differentiation of T- and B-cells in the course of the immune response to sheep red blood cells. A more complex mechanism of EDTA action on the above-mentioned processes is not excluded, however.