Anna Fialová

High Treg and PMN-MDSC densities are a hallmark of tertiary lymphoid structures in fatal cases of cervical cancer

Background High densities of tertiary lymphoid structures (TLSs) are associated with improved clinical outcomes in various malignancies, including human papillomavirus (HPV)-associated head and neck squamous cell carcinoma (HNSCC). However, the role of TLSs in shaping antitumor immunity in HPV-induced cervical cancer (CESC) remains unclear. Therefore, we analyzed the density, composition, and prognostic impact of TLSs in patients with CESC as well as patients with HNSCC. Methods Multiplex immunofluorescence, immunohistochemistry, and spatial transcriptomics were used to analyze TLS density and composition in HNSCC and CESC tissue sections with respect to patient prognosis. The spatial approach was supplemented by flow cytometry-based analysis of the polymorphonuclear myeloid-derived suppressor cell (PMN-MDSC) phenotype in freshly resected primary tumor tissues. Results Although both indications were associated with HPV infection, we confirmed a positive correlation between TLS density and improved overall survival only in patients with HNSCC. The TLS composition differed markedly between HNSCC and CESC samples, with a shift toward high regulatory T cell (Treg) and PMN-MDSC abundance in CESC samples. The highest Treg and PMN-MDSC levels were observed in patients with CESC who died of the disease. CESC-infiltrating PMN-MDSCs showed high arginase 1 expression, which correlated with diminished T-cell receptor (TCR)ζ chain expression in CESC-infiltrating T cells. Additionally, the high number of PMN-MDSCs in TLSs was associated with the absence of HPV-specific T cells in CESC. Conclusions Unlike in HNSCC, the composition of TLSs, rather than their quantity, was associated with the overall survival of patients with CESC. High numbers of Tregs and PMN-MDSCs infiltrating immature TLSs prevail in patients with CESC who succumbed to the disease and seem to affect tumor-specific immune responses.

Tertiary lymphoid structures and B cells determine clinically relevant T cell phenotypes in ovarian cancer

AbstractIntratumoral tertiary lymphoid structures (TLSs) have been associated with improved outcome in various cohorts of patients with cancer, reflecting their contribution to the development of tumor-targeting immunity. Here, we demonstrate that high-grade serous ovarian carcinoma (HGSOC) contains distinct immune aggregates with varying degrees of organization and maturation. Specifically, mature TLSs (mTLS) as forming only in 16% of HGSOCs with relatively elevated tumor mutational burden (TMB) are associated with an increased intratumoral density of CD8+ effector T (TEFF) cells and TIM3+PD1+, hence poorly immune checkpoint inhibitor (ICI)-sensitive, CD8+ T cells. Conversely, CD8+ T cells from immunologically hot tumors like non-small cell lung carcinoma (NSCLC) are enriched in ICI-responsive TCF1+ PD1+ T cells. Spatial B-cell profiling identifies patterns of in situ maturation and differentiation associated with mTLSs. Moreover, B-cell depletion promotes signs of a dysfunctional CD8+ T cell compartment among tumor-infiltrating lymphocytes from freshly isolated HGSOC and NSCLC biopsies. Taken together, our data demonstrate that – at odds with NSCLC – HGSOC is associated with a low density of follicular helper T cells and thus develops a limited number of mTLS that might be insufficient to preserve a ICI-sensitive TCF1+PD1+ CD8+ T cell phenotype. These findings point to key quantitative and qualitative differences between mTLSs in ICI-responsive vs ICI-irresponsive neoplasms that may guide the development of alternative immunotherapies for patients with HGSOC.