December 21, 2012

Cancer Vaccines

"Some researchers believe that cancer cells routinely arise and are destroyed by the healthy immune system;[2] cancer forms when the immune system fails to destroy them.[3]" Source article here from Wikipedia (from where preceding quote was taken).

Footnote [2]: Shankaran V, Ikeda H, Bruce AT, White JM, Swanson PE, Old LJ, Schreiber RD. (2001-04-26). "IFNbig gamma and lymphocytes prevent primary tumour development and shape tumour immunogenicity." Nature 410 (6832): 1107–1111.
Abstract: After a century of controversy, the notion that the immune system regulates cancer development is experiencing a new resurgence. An overwhelming amount of data from animal models—together with compelling data from human patients—indicate that a functional cancer immunosurveillance process indeed exists that acts as an extrinsic tumor suppressor. However, it has also become clear that the immune system can facilitate tumor progression, at least in part, by sculpting the immunogenic phenotype of tumors as they develop. The recognition that immunity plays a dual role in the complex interactions between tumors and the host prompted a reļ¬nement of the cancer immunosurveillance hypothesis into one termed “cancer immunoediting.” In this review, we summarize the history of the cancer immunosurveillance controversy and discuss its resolution and evolution into the three Es of cancer immunoediting—elimination, equilibrium, and escape.
Footnote [3]: Dunn GP, Old LJ, Schreiber RD. (2004). "The three Es of cancer immunoediting." Annual Rev Immunology 22 (1): 329–360.
Abstract: Lymphocytes were originally thought to form the basis of a 'cancer immunosurveillance' process that protects immunocompetent hosts against primary tumour development, but this idea was largely abandoned when no differences in primary tumour development were found between athymic nude mice and syngeneic wild-type mice. However, subsequent observations that nude mice do not completely lack functional T cells and that two components of the immune system—IFNbig gamma and perforin—help to prevent tumour formation in mice have led to renewed interest in a tumour-suppressor role for the immune response. Here we show that lymphocytes and IFNbig gamma collaborate to protect against development of carcinogen-induced sarcomas and spontaneous epithelial carcinomas and also to select for tumour cells with reduced immunogenicity. The immune response thus functions as an effective extrinsic tumour-suppressor system. However, this process also leads to the immunoselection of tumour cells that are more capable of surviving in an immunocompetent host, which explains the apparent paradox of tumour formation in immunologically intact individuals.

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