Faculty, Staff and Student Publications

Publication Date

1-1-2025

Journal

Frontiers in Immunology

DOI

10.3389/fimmu.2025.1560778

PMID

40364843

PMCID

PMC12069457

PubMedCentral® Posted Date

4-29-2025

PubMedCentral® Full Text Version

Post-print

Abstract

Introduction: Immune checkpoint inhibitors (ICIs) have significantly improved survival for patients with metastatic melanoma, yet many experienceresistance due to immunosuppressive mechanisms within the tumor immune microenvironment (TIME). Understanding how the spatial architecture of immune and inflammatory components changes across disease stages may reveal novel prognostic biomarkers and therapeutic targets.

Methods: We performed high-dimensional spatial profiling of two melanoma tissue microarrays (TMAs), representing Stage III (n = 157) and Stage IV (n = 248) metastatic tumors. Using imaging mass cytometry (IMC) and multiplex immunofluorescence (mIF), we characterized the phenotypic, functional, and spatial properties of the TIME. Cellular neighborhoods were defined by inflammatory marker expression, and spatial interactions between immune and tumor cells were quantified using nearest-neighbor functions (G-cross). Associations with survival were assessed using Cox proportional hazards models with robust variance estimation.

Results: Stage IV tumors exhibited a distinct immune landscape, with increased CD74- and MIF-enriched inflammatory neighborhoods and reduced iNOS-associated regions compared to Stage III. Cytotoxic T lymphocytes (CTLs) and tumor cells were more prevalent in Stage IV TIME, while B cells and NK cells were depleted. Spatial analysis revealed that CTL-Th cell, NK-T cell, and B-NK cell interactions were linked to improved survival, whereas macrophage aggregation and excessive B-Th cell clustering in inflammatory regions correlated with worse outcomes. Organ-specific analyses showed that CTL infiltration near tumor cells predicted survival in gastrointestinal metastases, while NK-T cell interactions were prognostic in lymph node and skin metastases.

Discussion: Our results reveal stage-specific shifts in immune composition and spatial organization within the melanoma TIME. In advanced disease, immunosuppressive neighborhoods emerge alongside changes in immune cell localization, with spatial patterns of immune coordination-particularly involving CTLs, NK cells, and B cells-strongly predicting survival. These findings highlight spatial biomarkers that may refine patient stratification and guide combination immunotherapy strategies targeting the inflammatory architecture of the TIME.

Keywords

Humans, Melanoma, Tumor Microenvironment, Female, Male, Lymphocytes, Tumor-Infiltrating, Neoplasm Staging, Skin Neoplasms, Middle Aged, Neoplasm Metastasis, Prognosis, Killer Cells, Natural, Tissue Array Analysis, Biomarkers, Tumor, tumor immune microenvironment (TIME), immune exclusion, spatial immune profiling, inflammatory biomarkers, melanoma progression, prognostic immune signatures, inflammatory signaling pathways, immune cell crosstalk

Published Open-Access

yes

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.