Immune cell profile of sentinel lymph nodes in patients with malignant melanoma – FOXP3+ cell density in cases with positive sentinel node status is associated with unfavorable clinical outcome

Abstract

BackgroundBesides being a preferential site of early metastasis, the sentinel lymph node (SLN) is also a privileged site of T-cell priming, and may thus be an appropriate target for investigating cell types involved in antitumor immune reactions.MethodsIn this retrospective study we determined the prevalence of OX40+ activated T lymphocytes, FOXP3+ (forkhead box P3) regulatory T cells, DC-LAMP+ (dendritic cell-lysosomal associated membrane protein) mature dendritic cells (DCs) and CD123+ plasmacytoid DCs by immunohistochemistry in 100 SLNs from 60 melanoma patients. Density values of each cell type in SLNs were compared to those in non-sentinel nodes obtained from block dissections (n = 37), and analyzed with regard to associations with clinicopathological parameters and disease outcome.ResultsSentinel nodes showed elevated amount of all cell types studied in comparison to non-sentinel nodes. Metastatic SLNs had higher density of OX40+ lymphocytes compared to tumor-negative nodes, while no significant difference was observed in the case of the other cell types studied. In patients with positive sentinel node status, high amount of FOXP3+ cells in SLNs was associated with shorter progression-free (P = 0.0011) and overall survival (P = 0.0014), while no significant correlation was found in the case of sentinel-negative patients. The density of OX40+, CD123+ or DC-LAMP+ cells did not show significant association with the outcome of the disease.ConclusionsTaken together, our results are compatible with the hypothesis of functional competence of sentinel lymph nodes based on the prevalence of the studied immune cells. The density of FOXP3+ lymphocytes showed association with progression and survival in patients with positive SLN status, while the other immune markers studied did not prove of prognostic importance. These results, together with our previous findings on the prognostic value of activated T cells and mature DCs infiltrating primary melanomas, suggest that immune activation-associated markers in the primary tumor may have a higher impact than those in SLNs on the prognosis of the patients. On the other hand, FOXP3+ cell density in SLNs, but not in the primary tumor, was found predictive of disease outcome in melanoma patients.

Transcriptional Profiling of Melanoma Sentinel Nodes Identify Patients with Poor Outcome and Reveal an Association of CD30+ T Lymphocytes with Progression

“…This is the first study to analyze whole-genome gene expression profiling in SNB samples. Broad defects affecting different immunologic components have been extensively documented in SNs with respect to nontumor-draining nodes, including a decreased frequency of CD8 þ effector T cells, a reduced presence of stimulatory CD86 þ and CD11c þ DCs, and increased Foxp3 density and Th2 cytokine levels (7,11,(32)(33)(34)(35)(36)(37). Our findings partially contradict such observations because we found that immune dysfunction is detected in tumor-positive SNBs in association with disease progression.…”

“…Increasing evidence supports the view that the triggering of immunosuppressive pathways at the microenvironment level, which inactivate tumor-specific T-cell responses, is associated with systemic immune dysfunction (4). These signs of local and systemic immunologic dysfunction, including the accumulation of myeloid-derived suppressor cells (5), tumor-specific CTLs with an anergic phenotype (6), regulatory T cells (Treg) and Th2 cells (7,8), and dendritic cells (DC) with diminished functionality (9), are definitively detected in those patients with a poor clinical outcome (10,11).…”

Association of PD-1, PD-1 Ligands, and Other Features of the Tumor Immune Microenvironment with Response to Anti–PD-1 Therapy

“…Similar to our findings with CD3+ TILs, CD20+ B-cells were significantly associated with PD-L1 expression by tumor and infiltrating immune cells, but their presence alone did not correlate with clinical outcomes following PD-1 blockade, suggesting the importance of defining cellular functional profiles. Other immune cell types, including suppressive cells (regulatory T-cells and myeloid-derived suppressor cells), remain to be explored in the context of PD-1 pathway blockade (39, 40) .…”

FoxP3 and indoleamine 2,3-dioxygenase immunoreactivity in sentinel nodes from melanoma patients

“…Staining for CD3 and CD4 was also initially performed to confirm that the FoxP3+ cells represented T cells, rather than another FoxP3+ cell type. FoxP3 positivity alone has previously been used as the most specific marker of Tregs [15,[24][25][26].…”