Single-cell profiling reveals the importance of CXCL13/CXCR5 axis biology in lymphocyte-rich classic Hodgkin lymphoma

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 118; no. 41; pp. 1 - 11
• Main Authors: Aoki, Tomohiro, Chong, Lauren C., Takata, Katsuyoshi, Milne, Katy, Marshall, Ashley, Chavez, Elizabeth A., Miyata-Takata, Tomoko, Ben-Neriah, Susana, Unrau, Doria, Telenius, Adele, Boyle, Merrill, Weng, Andrew P., Savage, Kerry J., Scott, David W., Farinha, Pedro, Shah, Sohrab P., Nelson, Brad H., Steidl, Christian
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 12.10.2021
• Subjects: B-Lymphocytes - metabolism; B7-H1 Antigen - metabolism; Biological Sciences; CD4 antigen; Chemokine CXCL13 - metabolism; Chemokines; Crosstalk; CXCL13 protein; CXCR5 protein; Fluorescent Antibody Technique; Gene sequencing; Hodgkin Disease - pathology; Hodgkin's lymphoma; Humans; Immune system; Immunofluorescence; Lymph nodes; Lymph Nodes - cytology; Lymphocytes; Lymphocytes B; Lymphocytes T; Lymphoma; PD-1 protein; Programmed Cell Death 1 Receptor - metabolism; Receptors, CXCR5 - metabolism; Reed-Sternberg Cells - pathology; RNA-Seq; Sclerosis; Single-Cell Analysis; Spatial analysis; T-Lymphocytes, Helper-Inducer - metabolism; Tumor microenvironment; Tumor Microenvironment - immunology; PD-L1; single-cell analyses; CXCL13; PD-1; Hodgkin lymphoma
• DOI: 10.1073/pnas.2105822118
• ISSN: 0027-8424

Lymphocyte-rich classic Hodgkin lymphoma (LR-CHL) is a rare subtype of Hodgkin lymphoma. Recent technical advances have allowed for the characterization of specific cross-talk mechanisms between malignant Hodgkin Reed-Sternberg (HRS) cells and different normal immune cells in the tumor microenvironment (TME) of CHL. However, the TME of LR-CHL has not yet been characterized at single-cell resolution. Here, using single-cell RNA sequencing (scRNA-seq), we examined the immune cell profile of 8 cell suspension samples of LR-CHL in comparison to 20 samples of the mixed cellularity (MC, 9 cases) and nodular sclerosis (NS, 11 cases) subtypes of CHL, as well as 5 reactive lymph node controls. We also performed multicolor immunofluorescence (MC-IF) on tissue microarrays from the same patients and an independent validation cohort of 31 pretreatment LR-CHL samples. ScRNA-seq analysis identified a unique CD4⁺ helper T cell subset in LR-CHL characterized by high expression of Chemokine C-X-C motif ligand 13 (CXCL13) and PD-1. PD-1⁺CXCL13⁺ T cells were significantly enriched in LR-CHL compared to other CHL subtypes, and spatial analyses revealed that in 46%of the LR-CHL cases these cells formed rosettes surrounding HRS cells. MC-IF analysis revealed CXCR5⁺ normal B cells in close proximity to CXCL13⁺ T cells at significantly higher levels in LR-CHL. Moreover, the abundance of PD-1⁺CXCL13⁺ T cells in the TME was significantly associated with shorter progression-free survival in LR-CHL (P = 0.032). Taken together, our findings strongly suggest the pathogenic importance of the CXCL13/CXCR5 axis and PD-1⁺CXCL13⁺ T cells as a treatment target in LR-CHL.