Comparative immune phenotypic analysis of cutaneous Squamous Cell Carcinoma and Intraepidermal Carcinoma in immune-competent individuals: proportional representation of CD8+ T-cells but not FoxP3+ Regulatory T-cells is associated with disease stage

• Published in: PloS one Vol. 9; no. 10; p. e110928
• Main Authors: Freeman, Andrew, Bridge, Jennifer A, Maruthayanar, Pirashanthini, Overgaard, Nana H, Jung, Ji-Won, Simpson, Fiona, Prow, Tarl W, Soyer, H Peter, Frazer, Ian H, Freeman, Michael, Wells, James W
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 23.10.2014; Public Library of Science (PLoS)
• Subjects: Abundance; Aged; Aged, 80 and over; Biology and Life Sciences; Carcinoma, Squamous Cell - immunology; CD11c antigen; CD11c Antigen - metabolism; CD3 antigen; CD3 Complex - metabolism; CD4 antigen; CD56 antigen; CD56 Antigen - metabolism; CD8 antigen; CD8-Positive T-Lymphocytes - cytology; Cell Movement; Cytometry; Damage; Dendritic cells; Dermatology; Developmental stages; Diagnostic systems; Disease Progression; Female; Flow cytometry; Forkhead Transcription Factors - metabolism; Foxp3 protein; Histocompatibility antigen HLA; HLA-DR Antigens - metabolism; Hospitals; Humans; Immunology; Immunophenotyping; Killer Cells, Natural - cytology; Lesions; Lymphocytes T; Male; Medicine; Medicine and Health Sciences; Melanoma; Middle Aged; Mutation; Natural killer cells; Patients; Phenotype; Regression analysis; Skin - radiation effects; Skin cancer; Skin diseases; Skin Neoplasms - immunology; Squamous cell carcinoma; Sunlight - adverse effects; T cell receptors; T-Lymphocytes, Regulatory - cytology; Australia
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0110928

Squamous Cell Carcinoma (SCC) is a type of non-melanoma skin cancer prevalent in immune-suppressed transplant recipients and older individuals with a history of chronic sun-exposure. SCC itself is believed to be a late-stage manifestation that can develop from premalignant lesions including Intraepidermal Carcinoma (IEC). Notably, while SCC regression is rare, IEC typically regresses in response to immune modifying topical treatments, however the underlying immunological reasons for these differential responses remain unclear. This study aimed to define whether IEC and SCC are associated with distinct immune profiles. We investigated the immune cell infiltrate of photo-damaged skin, IEC, and SCC tissue using 10-colour flow cytometry following fresh lesion digest. We found that IEC lesions contain higher percentages of CD3+ T-cells than photo-damaged skin, however, the abundance of CD3-CD56+ Natural Killer (NK) cells, CD11c+HLA-DR+ conventional Dendritic Cells (cDC), BDCA-2+HLA-DR+ plasmacytoid DC (pDC), FoxP3+ Regulatory T-cells (T-reg), Vα24+Vβ11+ invariant NKT-cells, and γδ Tcells did not alter with disease stage. Within the total T-cell population, high percentages of CD4+ T-cells were associated with SCC, yet CD8+ T-cells were less abundant in SCC compared with IEC. Our study demonstrates that while IEC lesions contain a higher proportion of T-cells than SCC lesions in general, SCC lesions specifically display a lower abundance of CD8+ T-cells than IEC. We propose that differences in CD8+ T-cell abundance contribute critically to the different capacity of SCC and IEC to regress in response to immune modifying topical treatments. Our study also suggests that a high ratio of CD4+ T-cells to CD8+ T-cells may be a immunological diagnostic indicator of late-stage SCC development in immune-competent patients.