Immunization against transplantable leukemia impaired in copper-deficient mice.

Inbred C58 mice, kept on a copper-deficient (-Cu) diet from birth, were tested for their ability to be immunized to, and subsequently challenged with, line Ib syngeneic transplantable malignant lymphocytes (Ib cells). -Cu mice had significantly lowered hematocrits and serum ceruloplasmin (EC 1.16.3.1) values in contrast to those of the copper-supplemented (+Cu) controls. All male +Cu mice (17/17) survived the immunization regimen (consisting of approximately 10(3) viable and 10(7) inactivated Ib cells) and the challenge dose (10(6) viable Ib cells). Male -Cu mice had a survival rate of only 15% (4/27) after the immunization process and an overall survival rate of 11% (3/27). Female +Cu mice had survival rates of 86% (19/22) after immunization and of 74% (14/19) after the challenge dose, compared to 54% (15/28) and 47% (7/15) survival rates, respectively, for the female -Cu mice. Overall, the +Cu mice had a 79% (31/39) survival of both immunization and challenge compared to an 18% (10/55) survival for the -Cu mice. These results indicate that the initiation and maintenance of cell-mediated immunity to leukemia cells are severely impaired in -Cu animals.