Search

Purpose: The successful implementation of immune checkpoint inhibitors (ICI) in the clinical management of various solid tumors has raised considerable expectations for patients with epithelial ovarian carcinoma (EOC). However, EOC is poorly responsive to ICIs due to immunologic features including limited tumor mutational burden (TMB) and poor lymphocytic infiltration. An autologous dendritic cell (DC)-based vaccine (DCVAC) has recently been shown to be safe and to significantly improve progression-free survival (PFS) in a randomized phase II clinical trial enrolling patients with EOC (SOV01, NCT02107937). Patients and Methods: We harnessed sequencing, flow cytometry, multispectral immunofluorescence microscopy, and IHC to analyze (pretreatment) tumor and (pretreatment and posttreatment) peripheral blood samples from 82 patients enrolled in SOV01, with the aim of identifying immunologic biomarkers that would improve the clinical management of patients with EOC treated with DCVAC. Results: Although higher-than-median TMB and abundant CD8+ T-cell infiltration were associated with superior clinical benefits in patients with EOC receiving standard-of-care chemotherapy, the same did not hold true in women receiving DCVAC. Conversely, superior clinical responses to DCVAC were observed in patients with lower-than-median TMB and scarce CD8+ T-cell infiltration. Such responses were accompanied by signs of improved effector functions and tumor-specific cytotoxicity in the peripheral blood. Conclusions: Our findings suggest that while patients with highly infiltrated, “hot” EOCs benefit from chemotherapy, women with “cold” EOCs may instead require DC-based vaccination to jumpstart clinically relevant anticancer immune responses.

Purpose:The successful implementation of immune checkpoint inhibitors (ICI) in the clinical management of various solid tumors has raised considerable expectations for patients with epithelial ovarian carcinoma (EOC). However, EOC is poorly responsive to ICIs due to immunologic features including limited tumor mutational burden (TMB) and poor lymphocytic infiltration. An autologous dendritic cell (DC)-based vaccine (DCVAC) has recently been shown to be safe and to significantly improve progression-free survival (PFS) in a randomized phase II clinical trial enrolling patients with EOC (SOV01, NCT02107937).Patients and Methods:We harnessed sequencing, flow cytometry, multispectral immunofluorescence microscopy, and IHC to analyze (pretreatment) tumor and (pretreatment and posttreatment) peripheral blood samples from 82 patients enrolled in SOV01, with the aim of identifying immunologic biomarkers that would improve the clinical management of patients with EOC treated with DCVAC.Results:Although higher-than-median TMB and abundant CD8+ T-cell infiltration were associated with superior clinical benefits in patients with EOC receiving standard-of-care chemotherapy, the same did not hold true in women receiving DCVAC. Conversely, superior clinical responses to DCVAC were observed in patients with lower-than-median TMB and scarce CD8+ T-cell infiltration. Such responses were accompanied by signs of improved effector functions and tumor-specific cytotoxicity in the peripheral blood.Conclusions:Our findings suggest that while patients with highly infiltrated, “hot” EOCs benefit from chemotherapy, women with “cold” EOCs may instead require DC-based vaccination to jumpstart clinically relevant anticancer immune responses.

Supplementary Figure from An Autologous Dendritic Cell Vaccine Promotes Anticancer Immunity in Patients with Ovarian Cancer with Low Mutational Burden and Cold Tumors

Supplementary Data from An Autologous Dendritic Cell Vaccine Promotes Anticancer Immunity in Patients with Ovarian Cancer with Low Mutational Burden and Cold Tumors

The adaptive immune response to severe acute respiratory coronavirus 2 (SARS-CoV-2) is important for vaccine development and in the recovery from coronavirus disease 2019 (COVID-19). Men and cancer patients have been reported to be at higher risks of contracting the virus and developing the more severe forms of COVID-19. Prostate cancer (PCa) may be associated with both of these risks. We show that CD4+ T cells of SARS-CoV-2-unexposed patients with hormone-refractory (HR) metastatic PCa had decreased CD4+ T cell immune responses to antigens from SARS-CoV-2 spike glycoprotein but not from the spiked glycoprotein of the ‘common cold’-associated human coronavirus 229E (HCoV-229E) as compared with healthy male volunteers who responded comparably to both HCoV-229E- and SARS-CoV-2-derived antigens. Moreover, the HCoV-229E spike glycoprotein antigen-elicited CD4+ T cell immune responses cross-reacted with the SARS-CoV-2 spiked glycoprotein antigens. PCa patients may have impaired responses to the vaccination, and the cross-reactivity can mediate antibody-dependent enhancement (ADE) of COVID-19. These findings highlight the potential for increased vulnerability of PCa patients to COVID-19.

BackgroundThe 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.MethodsRNA 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.Results1468 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.ConclusionsImmunosuppressive M2-like TAM infiltrating metastatic sites limit clinically relevant immune responses against HGSCs.

Recent studies have identified molecular events characteristic of immunogenic cell death (ICD), including surface exposure of calreticulin (CRT), the heat shock proteins HSP70 and HSP90, the release of high-mobility group box protein 1 (HMGB1) and the release of ATP from dying cells. We investigated the potential of high hydrostatic pressure (HHP) to induce ICD in human tumor cells. HHP induced the rapid expression of HSP70, HSP90 and CRT on the cell surface. HHP also induced the release of HMGB1 and ATP. The interaction of dendritic cells (DCs) with HHP-treated tumor cells led to a more rapid rate of DC phagocytosis, upregulation of CD83, CD86 and HLA-DR and the release of interleukin IL-6, IL-12p70 and TNF-α. DCs pulsed with tumor cells killed by HHP induced high numbers of tumor-specific T cells. DCs pulsed with HHP-treated tumor cells also induced the lowest number of regulatory T cells. In addition, we found that the key features of the endoplasmic reticulum stress-mediated apoptotic pathway, such as reactive oxygen species production, phosphorylation of the translation initiation factor eIF2α and activation of caspase-8, were activated by HHP treatment. Therefore, HHP acts as a reliable and potent inducer of ICD in human tumor cells.

The ybxF gene is a member of the streptomycin operon in a wide range of gram-positive bacteria. In Bacillus subtilis , it codes for a small basic protein (82 amino acids, pI 9.51) of unknown function. We demonstrate that, in B. subtilis , YbxF localizes to the ribosome, primarily to the 50S subunit, with dependence on growth phase. Based on three-dimensional structures of YbxF generated by homology modeling, we identified helix 2 as important for the interaction with the ribosome. Subsequent mutational analysis of helix 2 revealed Lys24 as crucial for the interaction. Neither the B. subtilis ybxF gene nor its paralogue, the ymxC gene, is essential, as shown by probing Δ ybxF , Δ ymxC , or Δ ybxF Δ ymxC double deletion strains in several functional assays.

e22129 Background: Ovarian cancer is diagnosed in more than 190,000 new patients every year and is known to have the highest mortality rate among gynaecologic cancers. The type of immune cells that are present within the tumor microenvironment can play a crucial role in the survival of patients. However, little is known about the dynamics of the tumor-infiltrating immune cells during disease progression. Methods: We studied the immune cells infiltrating the tumor tissue of ovarian cancer patients at different stages of disease. We analysed the patterns of T lymphocytes in fresh tumor tissue as well as blood samples of 44 newly diagnosed ovarian cancer patients by flow cytometry. To evaluate whether regulatory T cells (Tregs) develop in situ or migrate to tumor tissue, we measured a concentration of chemokine CCL22 in tumor cell culture supernatants. We also determined the expression of CCR4 on circulating as well as tumor-infiltrating Tregs by flow cytometry. Results: The early stages of development of ovarian carcinomas were characterized by a strong Th17 immune response, whereas in stage II patients, recruitment of high numbers of Th1 cells was observed. In disseminated tumors (stage III-IV), we detected a dominant population of Helios+ activated regulatory T cells along with high numbers of macrophages and immature myeloid dendritic cells. Tumor-infiltrating Tregs had markedly lower expression of CCR4 than circulating Tregs, and the numbers of tumor-infiltrating Tregs significantly correlated with the levels of CCL22 in ovarian tumor cell culture supernatants, suggesting their recruitment via a CCR4/CCL22 interaction. CCL22 was mainly produced by tumor cells, macrophages and mDCs in the primary ovarian tumors, and its expression markedly increased in response to IFNgamma. Conclusions: Taken together, the specific recruitment of Tregs, probably triggered by inflammatory stimuli, leads to a significant immune suppression in the advanced stages of ovarian cancer.