Topological analysis reveals a PD-L1-associated microenvironmental niche for Reed-Sternberg cells in Hodgkin lymphoma

• Published in: Blood Vol. 130; no. 22; pp. 2420 - 2430
• Main Authors: Carey, Christopher D., Gusenleitner, Daniel, Lipschitz, Mikel, Roemer, Margaretha G.M., Stack, Edward C., Gjini, Evisa, Hu, Xihao, Redd, Robert, Freeman, Gordon J., Neuberg, Donna, Hodi, F. Stephen, Liu, Xiaole Shirley, Shipp, Margaret A., Rodig, Scott J.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 30.11.2017; American Society of Hematology
• Subjects: B7-H1 Antigen - analysis; Fluorescent Antibody Technique; Hodgkin Disease - pathology; Humans; Lymphoid Neoplasia; Macrophages - pathology; Programmed Cell Death 1 Receptor - analysis; Reed-Sternberg Cells - pathology; T-Lymphocytes - pathology; Tumor Microenvironment
• ISSN: 0006-4971; 1528-0020; 1528-0020
• DOI: 10.1182/blood-2017-03-770719

Signaling between programmed cell death protein 1 (PD-1) and the PD-1 ligands (PD-L1, PD-L2) is essential for malignant Hodgkin Reed-Sternberg (HRS) cells to evade antitumor immunity in classical Hodgkin lymphoma (cHL). Copy number alterations of 9p24.1/CD274(PD-L1)/PDCD1LG2(PD-L2) contribute to robust PD-L1 and PD-L2 expression by HRS cells. PD-L1 is also expressed by nonmalignant tumor-associated macrophages (TAMs), but the relationships among PD-L1+ HRS cells, PD-L1+ TAMs, and PD-1+ T cells remain undefined. We used multiplex immunofluorescence and digital image analysis to examine the topography of PD-L1+ and PD-1+ cells in the tumor microenvironment (TME) of cHL. We find that the majority of PD-L1 in the TME is expressed by the abundant PD-L1+ TAMs, which physically colocalize with PD-L1+ HRS cells in a microenvironmental niche. PD-L1+ TAMs are enriched for contacts with T cells, and PD-L1+ HRS cells are enriched for contacts with CD4+ T cells, a subset of which are PD-1+. Our data define a unique topology of cHL in which PD-L1+ TAMs surround HRS cells and implicate CD4+ T cells as a target of PD-1 blockade. •Regionally localized PD-L1+ macrophages form a specialized microenvironmental niche for Hodgkin Reed-Sternberg cells in cHL. [Display omitted]