Tertiary lymphoid structures in desmoplastic melanoma have increased lymphocyte density, lymphocyte proliferation, and immune cross talk with tumor when compared to non-desmoplastic melanomas

ABSTRACT

Tertiary lymphoid structures (TLS) are ectopic lymphoid structures that can arise in human cancers and are associated with improved overall survival (OS) and response to immune checkpoint blockade (ICB) in several cancers, including non-desmoplastic metastatic melanoma (NDMM). Desmoplastic melanoma (DM) has one of the highest response rates to ICB, and we previously identified that primary DM (PDM) contains TLS. Despite the association of TLS with survival and ICB response, it is unknown whether TLS or associated markers of immune activity can differ between PDM and NDMM. We hypothesized that PDM would contain higher frequencies of TLS than NDMM, that T and B-cell densities and proliferation would be greater in TLS of PDM than TLS of NDMM, and that proliferation rates of T and B-cells in PDM TLS would be concordant with those of intratumoral lymphocytes. We found that four features of TLS in PDM distinguish them from TLS in NDMM. TLS were peritumoral in NDMM but intratumoral in PDM. CD8⁺ T-cell and CD20⁺ B-cell densities and proliferative fractions were higher in PDM TLS than NDMM TLS. Additionally, the proliferative fractions of T- and B-cells were concordant between the TLS and tumor site in PDM and discordant in NDMM. Collectively, these data suggest that TLS and associated immune markers can differ across melanoma subsets and suggest that PDM TLS may be more immunologically active and have enhanced immune cell trafficking between tumor and TLS compared to NDMM.

KEYWORDS:

• Immunology
• tumor infiltrating lymphocytes
• multiplex immunofluorescence histology
• tertiary lymphoid structures
• melanoma
• desmoplastic melanoma

Acknowledgments

We thank the Molecular and Immunologic Translational Studies Core and the Biorepository and Tissue Research Facility for help with these studies. Additionally, we thank Samuel Young and Adela Mahmutovic for their assistance with staining samples and Marieke Jones for assistance with statistical analyses.

Disclosure statement

Dr. Slingluff has the following disclosures, none of which conflict with the present manuscript: Research support to the University of Virginia from Celldex (funding, drug), Glaxo-Smith Kline (funding), Merck (funding, drug), 3M (drug), Theraclion (device staff support); Funding to the University of Virginia from Polynoma for PI role on the MAVIS Clinical Trial; Funding to the University of Virginia for roles on Scientific Advisory Boards for CureVac. Also Dr. Slingluff receives licensing fee payments through the UVA Licensing and Ventures Group for patents for peptides used in cancer vaccines. The other authors do not have any financial conflicts to disclose relevant to this manuscript.

Abbreviations

Primary desmoplastic melanoma (PDM), non-desmoplastic metastatic melanoma (NDMM), desmoplastic melanoma (DM), tertiary lymphoid structures (TLS), multiplex immunofluorescence histology (mIFH), immune checkpoint blockade (ICB), tumor infiltrating lymphocytes (TIL), high endothelial venules (HEV), dendritic cells (DC), lymph nodes (LN), regions of interest (ROI), tumor microenvironment (TME)

Data availability statement

All data are available from the authors on reasonable request.

Contributorship

Conception and design: IM, CLS. Development and execution of methodology: IM, PK. Acquisition of data: IM, NLE, SEG. Analysis and interpretation of data (e.g., statistical analysis, computational analysis): NLE, IM and CLS. Writing, review and/or revision of the manuscript: NLE, IM, CLS, VE, KL, AMS, AAG. Administrative, technical, or material support (assisting in experiments): ISM, PK.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/2162402X.2022.2164476

Additional information

Funding

Support provided by the US Public Health Services Training Grant T32HL007849 (KL), an internal grant from the UVA Department of Surgery (ISM), the Rebecca Clary Harris Memorial Fellowship from the University of Virginia (KL, NLE), the Harrison grant from the University of Virginia (PK), and a Melanoma Research Alliance Established Investigator Award (VHE). Additional support was received from the University of Virginia Cancer Center Support Grant (NIH P30 CA044579), and NIH/NCI K25CA181638.