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Allogenic whole cell vaccine against renal cell carcinoma. A novel murine C-57 protection model
ALLOGENIC WHOLE CELL VACCINE AGAINST RENAL CELL CARCINOMA. A NOVEL MURINE C-57 PROTECTION MODEL Erik G. Havranek, Mike Whelana, Peter Thravesa, Chris Anderson, Hardev Pandhab. Department of Urology, St. George’s Hospital, Blackshaw Road, London a Onyvax, St. George’s Hospital Medical School, Cranmer Terrace, London b Department of Clinical Oncology, St. George’s Hospital Medical School, London Introduction: Allogeneic whole cell vaccination is currently being employed as a novel cancer immunotherapy in several cancers. Its mode of action is believed to be the generation of tumour-reactive effector cells specific for shared antigens between vaccine and host tumour. In order to optimise this technology an animal model would be useful, although few models exist for renal cell cancer, with the notable exception of RenCa. Murine models are particularly appropriate since they allow high throughput and are amenable to immunological investigation.
Materials and Methods: A novel cell line (RVIK) was cloned from a murine C57 (H-2b) freshly isolated kidney and immortalised with an HPV-16 E6E7 construct. The line was thoroughly characterised both phenotypically and by measuring doubling times. Furthermore, cells were tested for tumourigenicity in both syngeneic and SCID mice, and as a vaccine in an allogeneic protection model. Specifically, Balb/c (H-2d) were vaccinated three times at weekly intervals with irradiated RVIK cells and then challenged with a syngeneic RenCa clone. Survival was compared between control, a syngeneic RenCa, and an early or late passage RVIK.
Results: The immortal RVIK line had a doubling time of 28 hours which did not vary between passage 15 and 79. RVIK stained positive for pancytokeratin (AlA3) and murine proximal tubules (URO-4). It was negative for actin, desmin, antifibroblast (ASOI) and CD34. 29% of RVIK cells expressed MHC I, which increased to 66% after interferon? stimulation. MHC I expression may be cell cycle dependent, unlike RenCa which showed 95% expression. In the protection experiment, the control group developed tumour within 45 days, whilst syngeneic vaccine showed 100% protection. The early passage RVIK clone showed no significant protection, however, the late RVIK clone conferred between 40 and 50% protection at 60 days.
Conclusion: RVIK is a novel non-tumourigenic murine renal epithelial cell line. However, it demonstrates clear efficacy when used as an allogeneic vaccine. Consequently, it may form the basis of a useful model of allogeneic vaccination allowing the optimisation of vaccination schedules and adjuvants. These data would be crucial for the successful development of future human clinical trials.
Materials and Methods: A novel cell line (RVIK) was cloned from a murine C57 (H-2b) freshly isolated kidney and immortalised with an HPV-16 E6E7 construct. The line was thoroughly characterised both phenotypically and by measuring doubling times. Furthermore, cells were tested for tumourigenicity in both syngeneic and SCID mice, and as a vaccine in an allogeneic protection model. Specifically, Balb/c (H-2d) were vaccinated three times at weekly intervals with irradiated RVIK cells and then challenged with a syngeneic RenCa clone. Survival was compared between control, a syngeneic RenCa, and an early or late passage RVIK.
Results: The immortal RVIK line had a doubling time of 28 hours which did not vary between passage 15 and 79. RVIK stained positive for pancytokeratin (AlA3) and murine proximal tubules (URO-4). It was negative for actin, desmin, antifibroblast (ASOI) and CD34. 29% of RVIK cells expressed MHC I, which increased to 66% after interferon? stimulation. MHC I expression may be cell cycle dependent, unlike RenCa which showed 95% expression. In the protection experiment, the control group developed tumour within 45 days, whilst syngeneic vaccine showed 100% protection. The early passage RVIK clone showed no significant protection, however, the late RVIK clone conferred between 40 and 50% protection at 60 days.
Conclusion: RVIK is a novel non-tumourigenic murine renal epithelial cell line. However, it demonstrates clear efficacy when used as an allogeneic vaccine. Consequently, it may form the basis of a useful model of allogeneic vaccination allowing the optimisation of vaccination schedules and adjuvants. These data would be crucial for the successful development of future human clinical trials.