Background: It has been reported that the laminin derivative synthetic peptide YIGSR can bind to a metastasis-associated laminin receptor and inhibit experimental metastasis. Several antiidiotypic antibody (anti-Id) vaccines have been used in clinical trials with promising results. We used an anti-Id vaccine based on peptide YIGSR for the inhibition of spontaneous metastasis in Lewis Lung carcinoma-bearing mice.
Materials and methods: High titer anti-YIGSR serum from immunized rabbits was used to immunize sixteen Lewis Lung Carcinoma (LLC)-bearing mice. Another group of sixteen mice (controls) inoculated with LLC was immunized with control rabbit serum. After 24 days of tumor growth, the volume of the tumor was estimated, a blood sample was collected and the lungs were examined macroscopically and microscopically for metastasis. The presence of anti-Id antibodies was detected by Western blotting, ELISA and inhibition of cell attachment assays.
Results: Tumor growth was limited and metastasis was inhibited in the mice that received the anti-Id YIGSR vaccine as compared to controls. Both groups of mice developed anti-rabbit antibodies as indicated by Western blotting. However only the serum of mice immunized with high titer anti-YIGSR rabbit serum (anti-Id YIGSR vaccine) could inhibit the binding of the anti-YIGSR rabbit serum to the peptide YIGSR in ELISA assays. In addition the serum of mice that received the anti-Id YIGSR vaccine but not the controls inhibited cell attachment to the peptide on solid face assays.
Conclusion: An anti-Id antimetastatic vaccine may be developed based on YIGSR.