CD8+ and FoxP3+ T‐Cell Cellular Density and Spatial Distribution After Programmed Death‐Ligand 1 Check Point Inhibition

• Published in: The Laryngoscope 2023-08, Vol.133 (8), p.1875-1884
• Main Authors: Curry, Joseph, Alnemri, Angela, Philips, Ramez, Fiorella, Michele, Sussman, Sarah, Stapp, Robert, Solomides, Charalambos, Harshyne, Larry, South, Andrew, Luginbuhl, Adam, Tuluc, Madalina, Martinez‐Outschoorn, Ubaldo, Argiris, Athanassios, Linnenbach, Alban, Johnson, Jennifer
• Format: Article
• Language: English
• Subjects: CD8; CD8-Positive T-Lymphocytes; digital spatial transcriptomics; FoxP3; Head & neck cancer; head and neck cancer; Head and Neck Neoplasms; Human papillomavirus; Humans; immunotherapy; Laryngoscopy; Lymphocytes, Tumor-Infiltrating; Metformin; Papillomavirus Infections; Squamous Cell Carcinoma of Head and Neck; T-Lymphocytes; Tumor Microenvironment
• ISSN: 0023-852X; 1531-4995
• DOI: 10.1002/lary.30389

Objectives To analyze CD8+ and FoxP3+ T‐cell cellular density (CD) and intercellular distances (ID) in head and neck squamous cell carcinoma (HNSCC) samples from a neoadjuvant trial of durvalumab +/− metformin. Methods Paired pre‐ and post‐treatment primary HNSCC tumor samples were stained for CD8+ and FoxP3+. Digital image analysis was used to determine estimated mean CD8+ and FoxP3+ CDs and CD8+‐FoxP3+ IDs in the leading tumor edge (LTE) and tumor adjacent stroma (TAS) stratified by treatment arm, human papillomavirus (HPV) status, and pathologic treatment response. A subset of samples was characterized for T‐cell related signatures using digital spatial genomic profiling. Results Post‐treatment analysis revealed a significant decrease in FoxP3+ CD and an increase in CD8+ CDs in the TAS between patients receiving durvalumab and metformin versus durvlaumab alone. Both treatment arms demonstrated significant post‐treatment increases in ID. Although HPV+ and HPV− had similar immune cell CDs in the tumor microenvironment, HPV+ pre‐treatment samples had 1.60 times greater ID compared with HPV− samples, trending toward significance (p = 0.05). At baseline, pathologic responders demonstrated a 1.16‐fold greater CD8+ CDs in the LTE (p = 0.045) and 2.28‐fold greater ID (p = 0.001) than non‐responders. Digital spatial profiling revealed upregulation of FoxP3+ and cytotoxic T‐lymphocyte–associated antigen 4 (CTLA‐4) in the TAS (p = 0.006, p = 0.026) in samples from pathologic responders. Conclusions Analysis of CD8+ and FoxP3+ detected population differences according to HPV status, pathologic response, and treatment. Greater CD8+‐FoxP3+ ID was associated with pathologic response. CD8+ and FoxP3+ T‐cell distributions may be predictive of response to immune checkpoint inhibition. ClinicalTrials.gov (Identifier NCT03618654). Level of Evidence 3 Laryngoscope, 133:1875–1884, 2023 We sought to analyze CD8+ and FoxP3+ T‐cell cellular density (CD) and intercellular distances (ID) in head and neck squamous cell carcinoma samples from a window of opportunity trial of durvalumab +/− metformin. Pre‐treatment CD8+ and FoxP3+ T‐cell CDs were similar while IDs differed significantly between the human papillomavirus (HPV)+ and HPV− samples. A higher pretreatment CD8+ CD in the leading tumor edge and greater FoxP3+ CD8+ ID were associated with pathologic response to therapy.