Cancer Immune Therapy Edited by G. Stuhler and P. Walden ...

40 Cancer Immune Therapie: Current and Future Strategies
Edited by G. Stuhler and P. Walden
Copyright # 2002 Wiley-VCH Verlag GmbH & Co. KGaA
ISBNs: 3-527-30441-X (Hardback); 3-527-60079-5
(Electronic)
4
T Cells In Tumor Immunity
Pedro Romero, Mikael J. Pittet, Alfred Zippelius, Danielle Li nard, Ferdy J.
Lejeune, Danila Valmori, Daniel E. Speiser and Jean-Charles Cerottini
4.1
Introduction
Experimental work during the last decades of last century firmly established the concept
that T cell immunity may limit tumor progression and even mediate tumor rejection.
However, this conclusion was achieved through a twisted road. For instance,
the role of T cells in tumor immunity was seriously challenged in the 1970s. Rigorous
experimentation in the last 30 years has clearly demonstrated the important role
of immunity in protecting against cancer. Moreover, recent results in well-defined
animal models have rekindled the immunosurveillance hypothesis. Both interferon
(IFN)-g and T lymphocytes were found to contribute to reducing the incidence of
chemically induced tumors as well as to shaping the antigenic make-up of emerging
tumors [1]. The measurement of incidence of malignancies in pharmacologically immunosuppressed
patients has also provided clues for the role of immunesurveillance
in tumor control. Indeed, a long-term study of kidney transplant patients
clearly indicates an increased risk of neoplasia [2].
As suggested by Burnett, thymus-dependent lymphocytes, i.e. T cells, are the most
important effectors of immunosurveillance [3]. Decisive evidence of the involvement
of T cells in antitumor immunity has finally emerged during the past 10 years with
the cloning of genes encoding tumor antigens and the subsequent molecular identification
of tumor-associated T cell epitopes. In turn, the detailed knowledge of T celldefined
tumor antigens has opened the possibility to dissect the interplay between
tumors and lymphocytes, to monitor the natural immune response against tumors,
to design therapeutic-specific cancer vaccines, and to assess their impact in immunized
patients. In this chapter, we will focus on the work concerning T cell-mediated
immunity in human cancer.