Immunological and Clinical Effects of Vaccines Targeting p53-Overexpressing Malignancies

Approximately 50% of human malignancies carry p53 mutations, which makes it a potential antigenic target for cancer immunotherapy. Adoptive transfer with p53-specific cytotoxic T-lymphocytes (CTL) and CD4+ T-helper cells eradicates p53-overexpressing tumors in mice. Furthermore, p53 antibodies and p53-specific CTLs can be detected in cancer patients, indicating that p53 is immunogenic. Based on these results, clinical trials were initiated. In this paper, we review immunological and clinical responses observed in cancer patients vaccinated with p53 targeting vaccines. In most trials, p53-specific vaccine-induced immunological responses were observed. Unfortunately, no clinical responses with significant reduction of tumor-burden have occurred. We will elaborate on possible explanations for this lack of clinical effectiveness. In the second part of this paper, we summarize several immunopotentiating combination strategies suitable for clinical use. In our opinion, future p53-vaccine studies should focus on addition of these immunopotentiating regimens to achieve clinically effective therapeutic vaccination strategies for cancer patients

Rapid and efficient generation of antigen-specific isogenic T cells from cryopreserved blood samples

Clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated gene editing has been leveraged for the modification of human and mouse T cells. However, limited experience is available on the application of CRISPR/Cas9 electroporation in cryopreserved T cells collected during clinical trials. To address this, we aimed to optimize a CRISPR/Cas9-mediated gene editing protocol compatible with peripheral blood mononuclear cells (PBMCs) samples routinely produced during clinical trials. PBMCs from healthy donors were used to generate knockout T-cell models for interferon-gamma, Cbl proto-oncogene B (CBLB), Fas cell surface death receptor (Fas) and T-cell receptor (TCR alpha beta) genes. The effect of CRISPR/Cas9-mediated gene editing on T cells was evaluated using apoptosis assays, cytokine bead arrays and ex vivo and in vitro stimulation assays. Our results demonstrate that CRISPR/Cas9-mediated gene editing of ex vivo T cells is efficient and does not overtly affect T-cell viability. Cytokine release and T-cell proliferation were not affected in gene-edited T cells. Interestingly, memory T cells were more susceptible to CRISPR/Cas9 gene editing than naive T cells. Ex vivo and in vitro stimulation with antigens resulted in equivalent antigen-specific T-cell responses in gene-edited and untouched control cells, making CRISPR/Cas9-mediated gene editing compatible with clinical antigen-specific T-cell activation and expansion assays. Here, we report an optimized protocol for rapid, viable and highly efficient genetic modification in ex vivo human antigen-specific T cells, for subsequent functional evaluation and/or expansion. Our platform extends CRISPR/Cas9-mediated gene editing for use in gold-standard clinically used immune-monitoring pipelines and serves as a starting point for development of analogous approaches, such as those including transcriptional activators and/or epigenetic modifiers

Dwarfism with joint laxity in Friesian horses is associated with a splice site mutation in B4GALT7

Background: Inbreeding and population bottlenecks in the ancestry of Friesian horses has led to health issues such as dwarfism. The limbs of dwarfs are short and the ribs are protruding inwards at the costochondral junction, while the head and back appear normal. A striking feature of the condition is the flexor tendon laxity that leads to hyperextension of the fetlock joints. The growth plates of dwarfs display disorganized and thickened chondrocyte columns. The aim of this study was to identify the gene defect that causes the recessively inherited trait in Friesian horses to understand the disease process at the molecular level. Results: We have localized the genetic cause of the dwarfism phenotype by a genome wide approach to a 3 Mb region on the p-arm of equine chromosome 14. The DNA of two dwarfs and one control Friesian horse was sequenced completely and we identified the missense mutation ECA14:g.4535550C> T that cosegregated with the phenotype in all Friesians analyzed. The mutation leads to the amino acid substitution p.(Arg17Lys) of xylosylprotein beta 1,4-galactosyltransferase 7 encoded by B4GALT7. The protein is one of the enzymes that synthesize the tetrasaccharide linker between protein and glycosaminoglycan moieties of proteoglycans of the extracellular matrix. The mutation not only affects a conserved arginine codon but also the last nucleotide of the first exon of the gene and we show that it impedes splicing of the primary transcript in cultured fibroblasts from a heterozygous horse. As a result, the level of B4GALT7 mRNA in fibroblasts from a dwarf is only 2 % compared to normal levels. Mutations in B4GALT7 in humans are associated with Ehlers-Danlos syndrome progeroid type 1 and Larsen of Reunion Island syndrome. Growth retardation and ligamentous laxity are common manifestations of these syndromes. Conclusions: We suggest that the identified mutation of equine B4GALT7 leads to the typical dwarfism phenotype in Friesian horses due to deficient splicing of transcripts of the gene. The mutated gene implicates the extracellular matrix in the regular organization of chrondrocyte columns of the growth plate. Conservation of individual amino acids may not be necessary at the protein level but instead may reflect underlying conservation of nucleotide sequence that are required for efficient splicing

L1CAM expression in uterine carcinosarcoma is limited to the epithelial component and may be involved in epithelial-mesenchymal transition

Uterine carcinosarcoma (UCS) has been proposed as a model for epithelial-mesenchymal transition (EMT), a process characterized by a functional change facilitating migration and metastasis in many types of cancer. L1CAM is an adhesion molecule that has been involved in EMT as a marker for mesenchymal phenotype. We examined expression of L1CAM in UCS in a cohort of 90 cases from four different centers. Slides were immunohistochemically stained for L1CAM and scored in four categories (0%, 50%). A score of more than 10% was considered positive for L1CAM. The median age at presentation was 68.6years, and half of the patients (53.3%) presented with FIGO stage 1 disease. Membranous L1CAM expression was positive in the epithelial component in 65.4% of cases. Remarkably, expression was negative in the mesenchymal component. In cases where both components were intermingled, expression limited to the epithelial component was confirmed by a double stain for L1CAM and keratin. Expression of L1CAM did not relate to overall or disease-free survival. Our findings suggest L1CAM is either not a marker for the mesenchymal phenotype in EMT, or UCS is not a good model for EMT

Transcriptional Activity and Stability of CD39+CD103+CD8+T Cells in Human High-Grade Endometrial Cancer

Tumor-infiltrating CD8+ T cells (TIL) are of the utmost importance in anti-tumor immunity. CD103 defines tumor-resident memory T cells (T-RM cells) associated with improved survival and response to immune checkpoint blockade (ICB) across human tumors. Co-expression of CD39 and CD103 marks tumor-specific T-RM with enhanced cytolytic potential, suggesting that CD39+CD103+ T-RM could be a suitable biomarker for immunotherapy. However, little is known about the transcriptional activity of T-RM cells in situ. We analyzed CD39+CD103+ T-RM cells sorted from human high-grade endometrial cancers (n = 3) using mRNA sequencing. Cells remained untreated or were incubated with PMA/ionomycin (activation), actinomycin D (a platinum-like chemotherapeutic that inhibits transcription), or a combination of the two. Resting CD39+CD103+ T-RM cells were transcriptionally active and expressed a characteristic T-RM signature. Activated CD39+CD103+ T-RM cells differentially expressed PLEK, TWNK, and FOS, and cytokine genes IFNG, TNF, IL2, CSF2 (GM-CSF), and IL21. Findings were confirmed using qPCR and cytokine production was validated by flow cytometry of cytotoxic TIL. We studied transcript stability and found that PMA-responsive genes and mitochondrial genes were particularly stable. In conclusion, CD39+CD103+ T-RM cells are transcriptionally active T-RM cells with a polyfunctional, reactivation-responsive repertoire. Secondly, we hypothesize that differential regulation of transcript stability potentiates rapid responses upon T-RM reactivation in tumors

Predicting inpatient violence using an extended version of the Brøset-Violence-Checklist: instrument development and clinical application

BACKGROUND: Patient aggression is a common problem in acute psychiatric wards and calls for preventive measures. The timely use of preventive measures presupposes a preceded risk assessment. The Norwegian Brøset-Violence-Checklist (BVC) is one of the few instruments suited for short-time prediction of violence of psychiatric inpatients in routine care. Aims of our study were to improve the accuracy of the short-term prediction of violence in acute inpatient settings by combining the Brøset-Violence-Checklist (BVC) with an overall subjective clinical risk-assessment and to test the application of the combined measure in daily practice. METHOD: We conducted a prospective cohort study with two samples of newly admitted psychiatric patients for instrument development (219 patients) and clinical application (300 patients). Risk of physical attacks was assessed by combining the 6-item BVC and a 6-point score derived from a Visual Analog Scale. Incidents were registered with the Staff Observation of Aggression Scale-Revised SOAS-R. Test accuracy was described as the area under the receiver operating characteristic curve (AUC(ROC)). RESULTS: The AUC(ROC )of the new VAS-complemented BVC-version (BVC-VAS) was 0.95 in and 0.89 in the derivation and validation study respectively. CONCLUSION: The BVC-VAS is an easy to use and accurate instrument for systematic short-term prediction of violent attacks in acute psychiatric wards. The inclusion of the VAS-derived data did not change the accuracy of the original BVC

Therapy-Induced Changes in CXCR4 Expression in Tumor Xenografts Can Be Monitored Noninvasively with N-[C-11]Methyl-AMD3465 PET

Purpose Chemokine CXCL12 and its receptor CXCR4 are constitutively overexpressed in human cancers. The CXCL12-CXCR4 signaling axis plays an important role in tumor progression and metastasis, but also in treatment-induced recruitment of CXCR4-expressing cytotoxic immune cells. Here, we aimed to demonstrate the feasibility of N-[C-11]methyl-AMD3465 positron emission tomography (PET) to monitor changes in CXCR4 density in tumors after single-fraction local radiotherapy or in combination with immunization. Procedure TC-1 cells expressing human papillomavirus antigens E6 and E7 were inoculated into the C57BL/6 mice subcutaneously. Two weeks after tumor cell inoculation, mice were irradiated with a single-fraction 14-Gy dose of X-ray. One group of irradiated mice was immunized with an alpha-viral vector vaccine, SFVeE6,7, and another group received daily injections of the CXCR4 antagonist AMD3100 (3 mg/kg -intraperitoneal (i.p.)). Seven days after irradiation, all animals underwent N-[C-11]methyl-AMD3465 PET. Results PET imaging showed N-[C-11]methyl-AMD3465 uptake in the tumor of single-fraction irradiated mice was nearly 2.5-fold higher than in sham-irradiated tumors (1.07 +/- 0.31 %ID/g vs. 0.42 +/- 0.05 % ID/g, p <0.01). The tumor uptake was further increased by 4-fold (1.73 +/- 0.17 % ID/g vs 0.42 +/- 0.05 % ID/g, p <0.01) in mice treated with single-fraction radiotherapy in combination with SFVeE6,7 immunization. Administration of AMD3100 caused a 4.5-fold reduction in the tracer uptake in the tumor of irradiated animals (0.24 +/- 0.1 % ID/g, p <0.001), suggesting that tracer uptake is indeed due to CXCR4-mediated chemotaxis. Conclusion This study demonstrates the feasibility of N-[C-11]methyl-AMD3465 PET imaging to monitor treatment-induced changes in the density of CXCR4 receptors in tumors and justifies further evaluation of CXCR4 as a potential imaging biomarker for evaluation of anti-tumor therapies

Borderline ovarian tumor frozen section diagnoses with features suspicious of invasive cancer:a retrospective study

Abstract Background A frozen section diagnosis of a borderline ovarian tumor with suspicious features of invasive carcinoma (“at least borderline” or synonymous descriptions) presents us with the dilemma of whether or not to perform a full ovarian cancer staging procedure. Quantification of this dilemma may help us with the issue of this clinical decision. The present study assessed and compared both the prevalence of straightforward borderline and “at least borderline” frozen section diagnoses and the proportion of these women with a final histopathological diagnosis of invasive carcinoma, with a special interest in histologic subtypes. Methods A retrospective cohort study was performed in three hospitals in The Netherlands. All women that underwent ovarian surgery with perioperative frozen section evaluation in one of these hospitals between January 2007 and July 2018 were identified and included in case of a borderline or “at least borderline” frozen section diagnosis and a borderline ovarian tumor or invasive carcinoma as a final diagnosis. Results A total of 223 women were included, of which 41 women (18.4%) were diagnosed with “at least borderline” at frozen section. Thirteen of forty-one women (31.7%) following “at least borderline” frozen section diagnosis and 14 of 182 women (7.7%) following a straightforward borderline frozen section diagnosis were diagnosed with invasive carcinoma at paraffin section evaluation (p < 0.001). When compared to straightforward borderline frozen section diagnoses, the proportion of women diagnosed with invasive carcinoma increased from 3.1 to 35.7% for serous tumors (p = 0.001), 10.0 to 21.7% for mucinous tumors (p = 0.129) and 50.0 to 75.0% (p = 0.452) in case of other histologic subtypes following an “at least borderline” frozen section diagnosis. Conclusions Overall, when compared to women with a decisive borderline frozen section diagnosis, women diagnosed with “at least borderline” frozen section diagnoses were found to have a higher chance of carcinoma upon final diagnosis (7.7% vs 31.7%). Especially in the serous subtype, full staging during initial surgery might be considered after preoperative consent to prevent a second surgical procedure or chemotherapy in unstaged women. Further studies are needed to evaluate whether additional sampling in case of an “at least borderline” diagnosis may decrease the risk of surgical over-treatment

L1CAM expression in uterine carcinosarcoma is limited to the epithelial component and may be involved in epithelial–mesenchymal transition

Uterine carcinosarcoma (UCS) has been proposed as a model for epithelial–mesenchymal transition (EMT), a process characterized by a functional change facilitating migration and metastasis in many types of cancer. L1CAMis an adhesion molecule that has been involved in EMT as a marker for mesenchymal phenotype.We examined expression of L1CAM in UCS in a cohort of 90 cases from four different centers. Slides were immunohistochemically stained for L1CAMand scored in four categories (0%, 50%). A score of more than 10% was considered positive for L1CAM. The median age at presentation was 68.6 years, and half of the patients (53.3%) presented with FIGO stage 1 disease. Membranous L1CAM expression was positive in the epithelial component in 65.4% of cases. Remarkably, expression was negative in the mesenchymal component. In cases where both components were intermingled, expression limited to the epithelial component was confirmed by a double stain for L1CAMand keratin. Expression of L1CAMdid not relate to overall or disease-free survival. Our findings suggest L1CAMis either not a marker for the mesenchymal phenotype in EMT, or UCS is not a good model for EMT