Insoluble fraction of tumor cell homogenate is a useful material for eliciting cytotoxic T lymphocytes: a unique method for protein solubilization.

Background/aim: Dendritic cell (DC)-based cancer immunotherapy using tumor homogenate has been evaluated. In all previously reported cases, DCs have been pulsed with a soluble fraction (lysate) of the tumor homogenate. The aim of this study was the evaluation of DCs pulsed with solubilized insoluble fraction of tumor cells.

Materials And Methods: Solubilized recombinant murine TRP-2 and solubilized-insoluble fraction of B16 melanoma was prepared by a novel method using nucleotides. Bone marrow-derived DCs were electroloaded with the solubilized proteins.

Results: Cytotoxic T lymphocytes were elicited in the splenocytes of C57BL/6 mice immunized with electroloaded DCs with solubilized rTRP-2. CD8(+) T-cells derived from immunized mice with electroloaded DCs using the solubilized insoluble fraction of B16 melanoma had specific killing activity. The effects were augmented when DCs were electroloaded with both the soluble and insoluble fractions of B16 homogenate.

Conclusion: Insoluble fraction of tumor cells is a useful material for cancer immunotherapy.