Immunological effect of E.coli L-asparaginase.

The effect of asparaginase on cellular immunity was investigated on human peripheral blood lymphocytes incubated in the culture system. Results showed that asparaginase inhibits lymphocyte blastogenesis, both when stimulated with PHA or PKW, and in the mixed lymphocyte cultures. This happened when the enzyme was added directly to the culture medium, as well as when the enzyme was administered i.v. in humans, and then the blood lymphocytes were removed and put into the PHA-culture medium added to the lymphocyte donor's plasma. Crossed experiments showed that: a) lymphocytes from asparaginase injected subjects which were set up in a PHA-culture-medium to which plasma (20%) from non-injected subjects had been added, undergo a normal amount of blastogenesis; and b) lymphocytes from non-injected subjects, set up in a PHA-culture-medium with plasma (20%) from asparaginase injected subjects show an inhibition in their blastic transformation.