Original ArticlesCD80-mediated induction of immunostimulation in two ocular melanoma cell lines is augmented by interferon-γMulcahy, K. A.; Alexander, S.; Platts, K. E.; Wardle, C.; Sisley, K.*; Rennie, I. G.; Murray, A. K.Author Information Section of Oncology and Pathology (Cancer Studies), University of Sheffield Medical School, Beech Hill Road, Sheffield, S10 2RX, UK (K. A. Mulcahy, S. Alexander, K. E. Platts, C. Wardle and A. K. Murray). Academic Unit of Ophthalmology and Orthoptics, University of Sheffield, Royal Hallamshire Hospital, Glossop Road, Sheffield S10 2JF, UK (K. Sisley and I. G. Rennie) Tel: (+44) (0)114 271 3199; Fax: (+44) (0)114 276 6381; Email: [email protected] (K. Sisley) *To whom correspondence should be addressed (Received 13 March 2001;accepted in revised form 29 June 2001) Melanoma Research: April 2002 - Volume 12 - Issue 2 - p 129-138 Buy Abstract Although the transfection of the T-cell costimulatory molecule CD80 cDNA into human tumours can augment their immunogenicity in vitro, its expression alone is ineffective in many tumour systems. We evaluated the influence of CD80 expression on the immunostimulatory activity of ocular melanoma cell lines and determined whether IFN-γ could enhance the effect. Two ocular melanoma cell lines were transfected with CD80 cDNA. The immunostimulatory capacity of the CD80+ transfectants was determined by their ability to stimulate the proliferation of allogeneic peripheral blood mononuclear cells (PBMC). The influence of additional accessory molecules on PBMC proliferation was assessed by pre-treating the CD80 transfectants with IFN-γ. The CD80+ transfectants induced proliferation of allogeneic PBMC. IFN-γ treatment of the tumour cells induced upregulated expression of MHC class I, de novo expression of MHC class II and CD54, and enhanced the ability of the CD80+ transfectants to stimulate PBMC proliferation. CD4+ T cells were not required for the proliferative response against untreated CD80+ tumour cells but were necessary for the augmentation of proliferation observed following IFN-γ treatment. CD80+ ocular melanoma cells possess immunostimulatory potential which is augmented by IFN-γ induced upregulation of cell surface molecules. Further studies on the role of costimulatory molecules in inducing anti-tumour immunity in ocular melanoma may help to define new strategies for application of immunotherapeutic approaches to treat this aggressive disease. © 2002 Lippincott Williams & Wilkins, Inc.