Chemotherapy Drives Tertiary Lymphoid Structures That Correlate with ICI-Responsive TCF1+CD8+ T Cells in Metastatic Ovarian Cancer.

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.

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

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 (T) cells and TIM3PD1, hence poorly immune checkpoint inhibitor (ICI)-sensitive, CD8 T cells.

Type I interferon signaling in malignant blasts contributes to treatment efficacy in AML patients.

While type I interferon (IFN) is best known for its key role against viral infection, accumulating preclinical and clinical data indicate that robust type I IFN production in the tumor microenvironment promotes cancer immunosurveillance and contributes to the efficacy of various antineoplastic agents, notably immunogenic cell death inducers. Here, we report that malignant blasts from patients with acute myeloid leukemia (AML) release type I IFN via a Toll-like receptor 3 (TLR3)-dependent mechanism that is not driven by treatment. While in these patients the ability of type I IFN to stimulate anticancer immune responses was abolished by immunosuppressive mechanisms elicited by malignant blasts, type I IFN turned out to exert direct cytostatic, cytotoxic and chemosensitizing activity in primary AML blasts, leukemic stem cells from AML patients and AML xenograft models.

Polymer-ritonavir derivate nanomedicine with pH-sensitive activation possesses potent anti-tumor activity in vivo via inhibition of proteasome and STAT3 signaling.

Drug repurposing is a promising strategy for identifying new applications for approved drugs. Here, we describe a polymer biomaterial composed of the antiretroviral drug ritonavir derivative (5-methyl-4-oxohexanoic acid ritonavir ester; RD), covalently bound to HPMA copolymer carrier via a pH-sensitive hydrazone bond (P-RD). Apart from being more potent inhibitor of P-glycoprotein in comparison to ritonavir, we found RD to have considerable cytostatic activity in six mice (IC ~ 2.

M2-like macrophages dictate clinically relevant immunosuppression in metastatic ovarian cancer.

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 to assess DC-dependent priming of T cell responses by dying cells.

Dendritic cells have been widely investigated in cancer immunotherapy clinical trials for the last two decades mainly due to their robust ability to elicit an adaptive anticancer immune response of the cellular and humoral types. Immature DCs can be easily loaded with desired antigens. However, to become efficient antigen-presenting cells, DCs must first undergo a process of maturation.

Assessment of NK cell-mediated cytotoxicity by flow cytometry after rapid, high-yield isolation from peripheral blood.

Natural killer (NK) cells constitute the predominant innate lymphocyte subset that mediates the anti-viral and anti-tumor immune responses. NK cells use an array of innate receptors to sense their environment and to respond to infections, cellular stress and transformation. The resulting NK cell activation, including cytotoxicity and cytokine production, is a fundamental component of the early immune response.

Calreticulin exposure correlates with robust adaptive antitumor immunity and favorable prognosis in ovarian carcinoma patients.

Background: Adjuvanticity, which is the ability of neoplastic cells to deliver danger signals, is critical for the host immune system to mount spontaneous and therapy-driven anticancer immune responses. One of such signals, i.e.

Dendritic cells pulsed with tumor cells killed by high hydrostatic pressure inhibit prostate tumor growth in TRAMP mice.

Dendritic cell (DC)-based vaccines pulsed with high hydrostatic pressure (HHP)-inactivated tumor cells have recently been shown to be a promising tool for prostate cancer chemoimmunotherapy. In this study, DC-based vaccines, both pulsed and unpulsed, were as effective as docetaxel (DTX) in reducing prostate tumors in the orthotopic transgenic adenocarcinoma of the mouse prostate (TRAMP) model. However, we did not observe any additive or synergic effects of chemoimmunotherapy on the tumor growth, while only the combination of DTX and pulsed dendritic cells resulted in significantly lower proliferation detected by Ki67 staining in histological samples.

High hydrostatic pressure affects antigenic pool in tumor cells: Implication for dendritic cell-based cancer immunotherapy.

High hydrostatic pressure (HHP) can be used to generate dendritic cell (DC)-based active immunotherapy for prostate, lung and ovarian cancer. We showed here that HHP treatment of selected human cancer cell lines leads to a degradation of tumor antigens which depends on the magnitude of HHP applied and on the cancer cell line origin. Whereas prostate or ovarian cell lines displayed little protein antigen degradation with HHP treatment up to 300MPa after 2h, tumor antigens are hardly detected in lung cancer cell line after treatment with HHP 250MPa at the same time.

Caspase-2 and oxidative stress underlie the immunogenic potential of high hydrostatic pressure-induced cancer cell death.

High hydrostatic pressure (HHP) promotes key characteristics of immunogenic cell death (ICD), in thus far resembling immunogenic chemotherapy and ionizing irradiation. Here, we demonstrate that cancer cells succumbing to HHP induce CD4 and CD8 T cell-dependent protective immunity . Moreover, we show that cell death induction by HHP relies on the overproduction of reactive oxygen species (ROS), causing rapid establishment of the integrated stress response, eIF2α phosphorylation by PERK, and sequential caspase-2, -8 and -3 activation.

Calreticulin exposure by malignant blasts correlates with robust anticancer immunity and improved clinical outcome in AML patients.

Cancer cell death can be perceived as immunogenic by the host only when malignant cells emit immunostimulatory signals (so-called "damage-associated molecular patterns," DAMPs), as they die in the context of failing adaptive responses to stress. Accumulating preclinical and clinical evidence indicates that the capacity of immunogenic cell death to (re-)activate an anticancer immune response is key to the success of various chemo- and radiotherapeutic regimens. Malignant blasts from patients with acute myeloid leukemia (AML) exposed multiple DAMPs, including calreticulin (CRT), heat-shock protein 70 (HSP70), and HSP90 on their plasma membrane irrespective of treatment.

Direct culture-independent Strain typing of Burkholderia cepacia complex in sputum samples from patients with cystic fibrosis.

We examined if multilocus sequence typing (MLST), a method for genotyping and species identification of Burkholderia cepacia complex bacteria, could be applied directly to cystic fibrosis sputum. The redesigned nested-PCR MLST format was successfully used to accurately identify strains in 23 sputum samples, of which 8 were culture negative.

Oxidative stress of Burkholderia cenocepacia induces insertion sequence-mediated genomic rearrangements that interfere with macrorestriction-based genotyping.

Burkholderia cenocepacia can cause serious infections and epidemics in patients with cystic fibrosis (CF). A CF population in the Czech Republic experienced an epidemic outbreak caused by a B. cenocepacia ST-32 strain.

High genotypic diversity of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis in the Czech Republic.

Over the last decade, epidemic and frequently multidrug-resistant Pseudomonas aeruginosa has increasingly been found among European cystic fibrosis (CF) patients. In the Czech Republic, more than half of the registered CF patients attend the Prague CF centre. At this centre, a Burkholderia cenocepacia strain was recently found to have spread among the patients.

Widespread clone of Burkholderia cenocepacia in cystic fibrosis patients in the Czech Republic.

The morbidity and mortality rates in patients with cystic fibrosis (CF) are significantly affected by infections with Burkholderia cepacia complex. In a Czech CF Centre, the prevalence of the infection reached up to 30 %, with the majority of patients found to be infected with Burkholderia cenocepacia (formerly genomovar III of the Burkholderia cepacia complex). Since B.