IMMUNOLOGICAL EFFECTS OF NATIVE AND POLYETHYLENE GLYCOL-MODIFIED ASPARAGINASES FROM VIBRIO-SUCCINOGENES AND ESCHERICHIA-COLI IN NORMAL AND TUMOR-BEARING MICE

  • 1 January 1982
    • journal article
    • research article
    • Vol. 48  (1) , 273-278
Abstract
The immunosuppressive effects of polyethylene glycol[PEG]-modified asparaginases from V. succinogenes (PEG-asparaginase VS) and E. coli (PEG-asparaginase EC) are investigated in mice. Measurements of the mitogen-induced blastogenic responses of splenocytes, harvested 5 days after in vivo administration of the PEG-enzymes, show that PEG-asparaginase VS is not immunosuppressive, whereas PEG-asparaginase EC does cause immunosuppression. Both enzymes cause the spleen to be smaller than the control mice. In mice carrying the L5178Y tumor (mouse leukemia cell) and its associated lactate dehydrogenase-elevating virus, which causes the circulation life of asparaginase VS to be comparable to that of PEG-asparaginase VS, tumor regression and its attendant immunological changes are identical in animals treated with either the native or the modified enzyme. Thus, PEG-asparaginase VS may be the enzyme of choice for clinical use.