In Vivo Function of Immune Murine Peritoneal Exudate Cells after Freezing and Thawing

Pentoneal exudate cells (PEC) were collected from Balb/c mice immunized against a 3-methylcholanthrene-induced (3-MCA) tumor and known to be capable of conferring tumor transplantation resistance in vivo in syngeneic recipients. These PEC were frozen in RPMI 1640 supplemented with 20% fetal calf serum, 1% nonessential amino acids, 2 mM glutamine, and 1 mM sodium pyruvate using dimethylsulfoxide as the cryopreservative agent. Adoptive transfer of tumor resistance in syngeneic recipients challenged with homologous 3-MCA sarcoma cells was attempted using these frozen exudate cells. Cells were thawed 1, 4, 7, 10, or 30 days after freezing and admixed with tumor cells in ratios of 100:1 or 1000:1 before injecting into mice. Tumorigenesis was decreased and delayed in groups receiving the 100:1 ratio. Less than 3% of the mice developed tumors in groups receiving the 1000:1 ratio. The number of cells recovered post-thawing ranged from 60 to 80%; viability of post-thawed cells ranged from 80 to 96%. © 1980, SAGE Publications. All rights reserved.