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Jackaman C, Gardner JK, Tomay F, Spowart J, Crabb H, Dye DE, Fox S, Proksch S, Metharom P, Dhaliwal SS, Nelson DJ. CD8 + cytotoxic T cell responses to dominant tumor-associated antigens are profoundly weakened by aging yet subdominant responses retain functionality and expand in response to chemotherapy. Oncoimmunology 2019; 8:e1564452. [PMID: 30906657 PMCID: PMC6422383 DOI: 10.1080/2162402x.2018.1564452] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 11/30/2018] [Accepted: 12/11/2018] [Indexed: 12/21/2022] Open
Abstract
Increasing life expectancy is associated with increased cancer incidence, yet the effect of cancer and anti-cancer treatment on elderly patients and their immune systems is not well understood. Declining T cell function with aging in response to infection and vaccination is well documented, however little is known about aged T cell responses to tumor antigens during cancer progression or how these responses are modulated by standard chemotherapy. We examined T cell responses to cancer in aged mice using AE17sOVA mesothelioma in which ovalbumin (OVA) becomes a 'spy' tumor antigen containing one dominant (SIINFEKL) and two subdominant (KVVRFDKL and NAIVFKGL) epitopes. Faster progressing tumors in elderly (22-24 months, cf. 60-70 human years) relative to young (2-3 months, human 15-18 years) mice were associated with increased pro-inflammatory cytokines and worsened cancer cachexia. Pentamer staining and an in-vivo cytotoxic T lymphocyte (CTL) assay showed that whilst elderly mice generated a greater number of CD8+ T cells recognizing all epitopes, they exhibited a profound loss of function in their ability to lyse targets expressing the dominant, but not subdominant, epitopes compared to young mice. Chemotherapy was less effective and more toxic in elderly mice however, similar to young mice, chemotherapy expanded CTLs recognizing at least one subdominant epitope in tumors and draining lymph nodes, yet treatment efficacy still required CD8+ T cells. Given the significant dysfunction associated with elderly CTLs recognizing dominant epitopes, our data suggest that responses to subdominant tumor epitopes may become important when elderly hosts with cancer are treated with chemotherapy.
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Affiliation(s)
- Connie Jackaman
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Joanne K Gardner
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Federica Tomay
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Joshua Spowart
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Hannah Crabb
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Danielle E Dye
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Simon Fox
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Stephen Proksch
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Pat Metharom
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
| | - Satvinder S Dhaliwal
- Curtin Health Innovation Research Institute, Curtin University, Perth, Australia.,School of Public Health, Curtin University, Perth, Australia
| | - Delia J Nelson
- School of Pharmacy and Biomedical Sciences, Curtin University, Perth, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, Australia
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