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The Role of the Immune Response in Merkel Cell Carcinoma
Taussig Cancer Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
Departments of Dermatology and Anatomic Pathology, Cleveland Clinic Foundation, 9500 Euclid Avenue, Cleveland, OH 44195, USA
* Author to whom correspondence should be addressed.
Received: 7 December 2012; in revised form: 30 January 2013 / Accepted: 6 February 2013 / Published: 28 February 2013
(This article belongs to the Special Issue Skin Cancer
Abstract: Merkel cell carcinoma (MCC) is an aggressive neuroendocrine skin cancer. The Merkel cell polyomavirus (MCPyV) is implicated in its pathogenesis. Immune mechanisms are also implicated. Patients who are immunosuppressed have an increased risk. There is evidence that high intratumoral T-cell counts and immune transcripts are associated with favorable survival. Spontaneous regressions implicate immune effector mechanisms. Immunogenicity is also supported by observation of autoimmune paraneoplastic syndromes. Case reports suggest that immune modulation, including reduction of immune suppression, can result in tumor regression. The relationships between MCPyV infection, the immune response, and clinical outcome, however, remain poorly understood. Circulating antibodies against MCPyV antigens are present in most individuals. MCPyV-reactive T cells have been detected in both MCC patients and control subjects. High intratumoral T-cell counts are also associated with favorable survival in MCPyV-negative MCC. That the immune system plays a central role in preventing and controlling MCC is supported by several observations. MCCs often develop, however, despite the presence of humoral and cellular immune responses. A better understanding on how MCPyV and MCC evade the immune response will be necessary to develop effective immunotherapies.
Keywords: merkel cell polyomavirus; immune suppression; tumor infiltrating lymphocytes; regulatory T cells; immunotherapy
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MDPI and ACS Style
Triozzi, P.L.; Fernandez, A.P. The Role of the Immune Response in Merkel Cell Carcinoma. Cancers 2013, 5, 234-254.
Triozzi PL, Fernandez AP. The Role of the Immune Response in Merkel Cell Carcinoma. Cancers. 2013; 5(1):234-254.
Triozzi, Pierre L.; Fernandez, Anthony P. 2013. "The Role of the Immune Response in Merkel Cell Carcinoma." Cancers 5, no. 1: 234-254.