TARGETING THE TUMOUR ASSOCIATED ANTIGENS PLAC1 AND GP100 WITH ONCOLYTIC CANCER VACCINES

Abstract

<p>In spite of the tremendous body of cancer research, cancer remains a significant health issue requiring development of better therapeutics. The elucidation of the relationship between cancer and the immune system and the identification of tumour associated antigens together suggest that novel therapeutics using the immune system to target cancer is a promising avenue of research. Since immunological tolerance is a barrier to generating immune responses to self antigen, strategies to circumvent tolerance need to be investigated to target given antigens.</p> <p>Plac1 is a novel tumour associated antigen with expression restricted to placenta, testis and many tumour cells. Initial reports concerning the expression, immunogenicity and potential tumourigenic function of Plac1 suggest that it would be an ideal tumour antigen. Initial experiments in mice indicated that generating an immune response against the murine Plac1 would be difficult and the subsequent work sought to employ strategies to facilitate anti murine Plac1 immune responses and anti tumour efficacy in Plac1 expressing tumours.</p> <p>Another more studied tumour associated antigen is gp100. Unlike Plac1, immune responses against the murine gp100 can be generated through vaccination. These responses are unable to demonstrate any anti tumour activity in gp100 expressing cells. The bulk of the gp100 studies described here sought to modify the immune:tumour interaction such that the anti tumour activity of the anti gp100 responses could be improved.</p> <p>While the specific barriers to Plac1 vaccination and efficacy and gp100 vaccination and efficacy are different, they have in common that they represent likely issues in using therapeutic cancer vaccines clinically. In both cases investigating how these barriers can be overcome is important and relevant to the understanding of these barriers to success when they appear in the clinic.</p>