CD200AR-L: mechanism of action and preclinical and clinical insights for treating high-grade brain tumors

Figures & data

Figure 1. CD200AR-L extends survival. Following surgical resection of the tumors, serial vaccinations of autologous tumor lysate and canine-specific CD200AR-L were administered to each dog. Disease status was followed using magnetic resonance imaging (MRI). Peripheral Blood Mononuclear Cells were isolated at time of treatments and analyzed for (a) Tregs, Bregs, and MDSCs and (b) CD4⁺PD-1 and CD8⁺PD-1 T-cells.

Figure 2. CD200AR-L enhances survival in murine and canine CNS glioma studies. (a) Twelve days post GL261 inoculation, mice were treated with 5 × 10⁸ plaque-forming units (pfu) of adenoviral (Ad)-Flt3L and 1.0 × 10⁸ pfu of Ad-TK followed by the administration of ganciclovir. Mice were treated with CD200AR-L (2.5 mg/kg) (s.c.) twice weekly for 4 weeks. PD-L1-neutralizing or CTLA-4-blocking antibodies were administered twice, 6d and 11d post gene therapy; animals were monitored for survival. Experiments were performed separately with appropriate controls. **p < 0.01, ***p < 0.005, by log-rank (Mantel-Cox) test, MS, median survival. Breast carcinoma mice were vaccinated weekly with CD200AR-L + autologous tumor lysates. Mice were imaged weekly and monitored for (b-e) tumor growth and (f) Survival. (g) Mice were rechallenged in the contralateral fat pad with and monitored for 14 days for tumor growth.

Figure 2. (Continued).