Published in:
01-01-2011 | Original Article
MAGE-A3 and MAGE-A4 specific CD4+ T cells in head and neck cancer patients: detection of naturally acquired responses and identification of new epitopes
Authors:
Valérie Cesson, Jean-Paul Rivals, Anette Escher, Elsa Piotet, Kris Thielemans, Vilmos Posevitz, Danijel Dojcinovic, Philippe Monnier, Daniel Speiser, Luc Bron, Pedro Romero
Published in:
Cancer Immunology, Immunotherapy
|
Issue 1/2011
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Abstract
Frequent expression of cancer testis antigens (CTA) has been consistently observed in head and neck squamous cell carcinomas (HNSCC). For instance, in 52 HNSCC patients, MAGE-A3 and -A4 CTA were expressed in over 75% of tumors, regardless of the sites of primary tumors such as oral cavity or hypopharynx. Yet, T-cell responses against these CTA in tumor-bearing patients have not been investigated in detail. In this study, we assessed the naturally acquired T-cell response against MAGE-A3 and -A4 in nonvaccinated HNSCC patients. Autologous antigen-presenting cells pulsed with overlapping peptide pools were used to detect and isolate MAGE-A3 and MAGE-A4 specific CD4+ T cells from healthy donors and seven head and neck cancer patients. CD4+ T-cell clones were characterized by cytokine secretion. We could detect and isolate MAGE-A3 and MAGE-A4 specific CD4+ T cells from 7/7 cancer patients analyzed. Moreover, we identified six previously described and three new epitopes for MAGE-A3. Among them, the MAGE-A3111–125 and MAGE-A3161–175 epitopes were shown to be naturally processed and presented by DC in association with HLA-DP and DR, respectively. All of the detected MAGE-A4 responses were specific for new helper epitopes. These data suggest that naturally acquired CD4+ T-cell responses against CT antigens often occur in vivo in HNSCC cancer patients and provide a rationale for the development of active immunotherapeutic approaches in this type of tumor.