Targeting resistance to radiation-immunotherapy in cold HNSCCs by modulating the Treg-dendritic cell axis.

Abstract

BACKGROUND:

Numerous trials combining radiation therapy (RT) and immunotherapy in head and neck squamous cell carcinoma (HNSCC) are failing. Using preclinical immune cold models of HNSCC resistant to RT-immune checkpoint inhibitors, we investigate therapeutic approaches of overcoming such resistance by examining the differential microenvironmental response to RT.

METHODS:

We subjected two HPV-negative orthotopic mouse models of HNSCC to combination RT, regulatory T cells (Treg) depletion, and/or CD137 agonism. Tumor growth was measured and intratumorous and lymph node immune populations were compared among treatment groups. Human gene sets, genetically engineered mouse models DEREG and BATF3-/-, flow and time-of-flight cytometry, RNA-Seq, Treg adoptive transfer studies, and in vitro experiments were used to further evaluate the role of dendritic cells (DCs) and Tregs in these treatments.

RESULTS:

In MOC2 orthotopic tumors, we find no therapeutic benefit to targeting classically defined immunosuppressive myeloids, which increase with RT. In these radioresistant tumors, supplementing combination RT and Treg depletion with anti-CD137 agonism stimulates CD103+ DC activation in tumor-draining lymph nodes as characterized by increases in CD80+ and CCR7+ DCs, resulting in a CD8 T cell-dependent response. Simultaneously, Tregs are reprogrammed to an effector phenotype demonstrated by increases in interferonγ+, tumor necrosis factorα+, PI3K+, pAKT+ and Eomes+ populations as well as decreases in CTLA4+ and NRP-1+ populations. Tumor eradication is observed when RT is increased to an 8 Gy x 5 hypofractionated regimen and combined with anti-CD25+ anti-CD137 treatment. In a human gene set from oral squamous cell carcinoma tumors, high Treg number is associated with earlier recurrence.

CONCLUSIONS:

Regulating Treg functionality and DC activation status within the lymph node is critical for generating a T cell effector response in these highly radioresistant tumors. These findings underscore the plasticity of Tregs and represent a new therapeutic opportunity for reprogramming the tumor microenvironment in HNSCCs resistant to conventional radioimmunotherapy approaches.

• Authors: Michael W Knitz, Thomas E Bickett, Laurel B Darragh, Ayman J Oweida, Shilpa Bhatia, Benjamin Van Court, Shiv Bhuvane, Miles Piper, Jacob Gadwa, Adam C Mueller, Diemmy Nguyen, Varuna Nangia, Douglas G Osborne, Xiyuan Bai, Sarah E Ferrara, Mary-Keara Boss, Andrew Goodspeed, Matthew A Burchill, Beth A Jirón Tamburini, Edward D Chan, Curtis R Pickering, Eric T Clambey, Sana D Karam
• Journal: Journal for immunotherapy of cancer (J Immunother Cancer) Vol. 9 Issue 4 (04 2021) ISSN: 2051-1426 [Electronic] England
• PMID: 33883256 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: © Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Chemical References

• Antineoplastic Agents, Immunological
• Basic-Leucine Zipper Transcription Factors
• Il2ra protein, mouse
• Immune Checkpoint Inhibitors
• Interleukin-2 Receptor alpha Subunit
• Repressor Proteins
• SNFT protein, mouse
• Tnfrsf9 protein, mouse
• Tumor Necrosis Factor Receptor Superfamily, Member 9

Topics

• Animals
• Antineoplastic Agents, Immunological (pharmacology)
• Basic-Leucine Zipper Transcription Factors (genetics, metabolism)
• Cell Line, Tumor
• Combined Modality Therapy
• Dendritic Cells (drug effects, immunology, metabolism)
• Drug Resistance, Neoplasm
• Head and Neck Neoplasms (immunology, metabolism, pathology, therapy)
• Immune Checkpoint Inhibitors (pharmacology)
• Immunotherapy
• Interleukin-2 Receptor alpha Subunit (antagonists & inhibitors, metabolism)
• Lymphocyte Depletion
• Mice, Inbred BALB C
• Mice, Inbred C57BL
• Mice, Knockout
• Phenotype
• Radiation Dose Hypofractionation
• Radiation Tolerance
• Repressor Proteins (genetics, metabolism)
• Squamous Cell Carcinoma of Head and Neck (immunology, metabolism, pathology, therapy)
• T-Lymphocytes, Regulatory (drug effects, immunology, metabolism)
• Tumor Burden
• Tumor Microenvironment
• Tumor Necrosis Factor Receptor Superfamily, Member 9 (antagonists & inhibitors, metabolism)
• Mice