PURPOSE: Patients with high-grade serous ovarian carcinoma (HGSOC) are virtually insensitive to immune checkpoint inhibitors (ICI) employed as standalone therapeutics, at least in part reflecting microenvironmental immunosuppression. Thus, conventional chemotherapeutics and targeted anticancer agents that not only mediate cytotoxic effects but also promote the recruitment of immune effector cells to the HGSOC microenvironment stand out as promising combinatorial partners for ICIs in this oncological indication. EXPERIMENTAL DESIGN: We harnessed a variety of transcriptomic, spatial, and functional assays to characterize the differential impact of neoadjuvant paclitaxel-carboplatin on the immunological configuration of paired primary and metastatic HGSOC biopsies as compared to neoadjuvant chemotherapy (NACT)-naïve HGSOC samples from five independent patient cohorts. RESULTS: We found NACT-driven endoplasmic reticulum stress and calreticulin exposure in metastatic HGSOC lesions culminates with the establishment of a dense immune infiltrate including follicular T cells (TFH cells), a prerequisite for mature tertiary lymphoid structure (TLS) formation. In this context, TLS maturation was associated with an increased intratumoral density of ICI-sensitive TCF1+PD1+ CD8+ T cells over their ICI-insensitive TIM-3+PD1+ counterparts. Consistent with this notion, chemotherapy coupled with a PD1-targeting ICI provided a significant survival benefit over either therapeutic approach in syngeneic models of HGSOC bearing high (but not low) tumor mutational burden. CONCLUSIONS: Altogether, our findings suggest that NACT promotes TLS formation and maturation in HGSOC lesions, de facto preserving an intratumoral ICI-sensitive T-cell phenotype. These observations emphasize the role of rational design, especially relative to the administration schedule, for clinical trials testing chemotherapy plus ICIs in patients with HGSOC. See related commentary by Bravo Melgar and Laoui, p. 10.

• MeSH
• CD8-Positive T-Lymphocytes * immunology   drug effects   MeSH
• Tertiary Lymphoid Structures * immunology   pathology   MeSH
• Hepatocyte Nuclear Factor 1-alpha * genetics   metabolism   MeSH
• Immune Checkpoint Inhibitors * therapeutic use   pharmacology   MeSH
• Carboplatin administration & dosage   pharmacology   therapeutic use   MeSH
• Humans MeSH
• Tumor Microenvironment * immunology   drug effects   MeSH
• Ovarian Neoplasms * drug therapy   immunology   pathology   MeSH
• Neoadjuvant Therapy methods   MeSH
• Paclitaxel administration & dosage   therapeutic use   pharmacology   MeSH
• Antineoplastic Combined Chemotherapy Protocols therapeutic use   pharmacology   MeSH
• Cystadenocarcinoma, Serous drug therapy   pathology   immunology   MeSH
• Endoplasmic Reticulum Stress drug effects   immunology   MeSH
• Lymphocytes, Tumor-Infiltrating immunology   drug effects   metabolism   MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Hepatocyte Nuclear Factor 1-alpha * MeSH
• Immune Checkpoint Inhibitors * MeSH
• Carboplatin MeSH
• Paclitaxel MeSH

Intratumoral 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.

• MeSH
• CD8-Positive T-Lymphocytes MeSH
• Tertiary Lymphoid Structures * MeSH
• Phenotype MeSH
• Humans MeSH
• Tumor Microenvironment MeSH
• Lung Neoplasms * MeSH
• Ovarian Neoplasms * pathology   MeSH
• Carcinoma, Non-Small-Cell Lung * MeSH
• Lymphocytes, Tumor-Infiltrating MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Epithelial ovarian carcinoma (EOC) is a relatively rare malignancy but is the fifth-leading cause of cancer-related death in women, largely reflecting early, prediagnosis dissemination of malignant disease to the peritoneum. At odds with other neoplasms, EOC is virtually insensitive to immune checkpoint inhibitors, correlating with a tumor microenvironment that exhibits poor infiltration by immune cells and active immunosuppression. Here, we comparatively summarize the humoral and cellular features of primary and metastatic EOC, comparatively analyze their impact on disease outcome, and propose measures to alter them in support of treatment sensitivity and superior patient survival.

• Keywords
• female, genital neoplasms, immunologic surveillance, immunotherapy, tumor biomarkers, tumor microenvironment,
• MeSH
• Carcinoma, Ovarian Epithelial immunology   MeSH
• Immunosuppression Therapy methods   MeSH
• Immunotherapy methods   MeSH
• Humans MeSH
• Tumor Microenvironment MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Review MeSH

Accumulating evidence indicates that immune checkpoint inhibitors (ICIs) can restore CD8+ cytotoxic T lymphocyte (CTL) functions in preclinical models of acute myeloid leukemia (AML). However, ICIs targeting programmed cell death 1 (PDCD1, best known as PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA4) have limited clinical efficacy in patients with AML. Natural killer (NK) cells are central players in AML-targeting immune responses. However, little is known on the relationship between co-inhibitory receptors expressed by NK cells and the ability of the latter to control AML. Here, we show that hepatitis A virus cellular receptor 2 (HAVCR2, best known as TIM-3) is highly expressed by NK cells from AML patients, correlating with improved functional licensing and superior effector functions. Altogether, our data indicate that NK cell frequency as well as TIM-3 expression levels constitute prognostically relevant biomarkers of active immunity against AML.

• Keywords
• Co-inhibitory receptor, innate lymphoid cells, lag-3, tigit, vista,
• MeSH
• Leukemia, Myeloid, Acute * drug therapy   MeSH
• Hepatitis A Virus Cellular Receptor 2 * MeSH
• Killer Cells, Natural * MeSH
• CD8-Positive T-Lymphocytes MeSH
• T-Lymphocytes, Cytotoxic MeSH
• Humans MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Hepatitis A Virus Cellular Receptor 2 * MeSH
• HAVCR2 protein, human MeSH Browser

Antibodies targeting the co-inhibitory receptor programmed cell death 1 (PDCD1, best known as PD-1) or its main ligand CD274 (best known as PD-L1) have shown some activity in patients with metastatic triple-negative breast cancer (TNBC), especially in a recent Phase III clinical trial combining PD-L1 blockade with taxane-based chemotherapy. Despite these encouraging findings, however, most patients with TNBC fail to derive significant benefits from PD-L1 blockade, calling for the identification of novel therapeutic approaches. Here, we used the 4T1 murine mammary cancer model of metastatic and immune-resistant TNBC to test whether focal radiation therapy (RT), a powerful inducer of immunogenic cell death, in combination with various immunotherapeutic strategies can overcome resistance to immune checkpoint blockade. Our results suggest that focal RT enhances the therapeutic effects of PD-1 blockade against primary 4T1 tumors and their metastases. Similarly, the efficacy of an antibody specific for V-set immunoregulatory receptor (VSIR, another co-inhibitory receptor best known as VISTA) was enhanced by focal RT. Administration of cyclophosphamide plus RT and dual PD-1/VISTA blockade had superior therapeutic effects, which were associated with activation of tumor-infiltrating CD8+ T cells and depletion of intratumoral granulocytic myeloid-derived suppressor cells (MDSCs). Overall, these results demonstrate that RT can sensitize immunorefractory tumors to VISTA or PD-1 blockade, that this effect is enhanced by the addition of cyclophosphamide and suggest that a multipronged immunotherapeutic approach may also be required to increase the incidence of durable responses in patients with TNBC.

• Keywords
• 4T1 cells, C10orf54, CD8+ T cells, MDSCs, PD-1, TCGA, VSIR, cyclophosphamide, focal radiotherapy, immunological checkpoints, immunosurveillance, myeloid cells,
• MeSH
• CD8-Positive T-Lymphocytes MeSH
• Immunotherapy MeSH
• Humans MeSH
• Myeloid-Derived Suppressor Cells * MeSH
• Mice MeSH
• Triple Negative Breast Neoplasms * drug therapy   MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH

BACKGROUND: The immunological microenvironment of primary high-grade serous carcinomas (HGSCs) has a major impact on disease outcome. Conversely, little is known on the microenvironment of metastatic HGSCs and its potential influence on patient survival. Here, we explore the clinical relevance of the immunological configuration of HGSC metastases. METHODS: RNA sequencing was employed on 24 paired primary tumor microenvironment (P-TME) and metastatic tumor microenvironment (M-TME) chemotherapy-naive HGSC samples. Immunohistochemistry was used to evaluate infiltration by CD8+ T cells, CD20+ B cells, DC-LAMP+ (lysosomal-associated membrane protein 3) dendritic cells (DCs), NKp46+ (natural killer) cells and CD68+CD163+ M2-like tumor-associated macrophages (TAMs), abundance of PD-1+ (programmed cell death 1), LAG-3+ (lymphocyte-activating gene 3) cells, and PD-L1 (programmed death ligand 1) expression in 80 samples. Flow cytometry was used for functional assessments on freshly resected HGSC samples. RESULTS: 1468 genes were differentially expressed in the P-TME versus M-TME of HGSCs, the latter displaying signatures of extracellular matrix remodeling and immune infiltration. M-TME infiltration by immune effector cells had little impact on patient survival. Accordingly, M-TME-infiltrating T cells were functionally impaired, but not upon checkpoint activation. Conversely, cytokine signaling in favor of M2-like TAMs activity appeared to underlie inhibited immunity in the M-TME and poor disease outcome. CONCLUSIONS: Immunosuppressive M2-like TAM infiltrating metastatic sites limit clinically relevant immune responses against HGSCs.

• Keywords
• macrophages, tumor biomarkers, tumor microenvironment,
• MeSH
• Immunosuppression Therapy methods   MeSH
• Middle Aged MeSH
• Humans MeSH
• Macrophages immunology   MeSH
• Neoplasm Metastasis MeSH
• Biomarkers, Tumor metabolism   MeSH
• Tumor Microenvironment MeSH
• Ovarian Neoplasms immunology   MeSH
• Retrospective Studies MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Aged, 80 and over MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Names of Substances
• Biomarkers, Tumor MeSH