Phenotype and function of activated natural killer cells from patients with prostate cancer: patient-dependent responses to priming and IL-2 activation

Background: Although immunotherapy has emerged as the "next generation" of cancer treatments, it has not yet been shown to be successful in the treatment of patients with prostate cancer, for whom therapeutic options remain limited to radiotherapy and androgen (hormone) deprivation therapy. Previous studies have shown that priming natural killer (NK) cells isolated from healthy individuals via co-incubation with CTV-1 cells derived from an acute lymphoblastic leukemia (ALL) enhances their cytotoxicity against human DU145 (metastatic) prostate cancer cells, but it remains unknown to what extent NK cells from patients with prostate cancer can be triggered to kill. Herein, we explore the phenotype of peripheral blood NK cells in patients with prostate cancer and compare the capacity of CTV-1 cell-mediated priming and IL-2 stimulation to trigger NK cell-mediated killing of the human PC3 (metastatic) prostate cancer cell line. Methods: The phenotype of resting, primed (co-incubation with CTV-1 cells for 17 h) and IL-2 activated (100 IU/ml IL-2 for 17 h) NK cells isolated from frozen-thawed peripheral blood mononuclear cell (PBMC) preparations from patients with benign disease (n = 6) and prostate cancer (n = 18) and their cytotoxicity against PC3 and K562 cells was determined by flow cytometry. Relationship(s) between NK cell phenotypic features and cytotoxic potential were interrogated using Spearman Rank correlation matrices. Results and Conclusions: NK cell priming and IL-2 activation of patient-derived NK cells resulted in similar levels of cytotoxicity, but distinct NK cell phenotypes. Importantly, the capacity of priming and IL-2 stimulation to trigger cytotoxicity was patient-dependent and mutually exclusive, in that NK cells from ~50% of patients preferentially responded to priming whereas NK cells from the remaining patients preferentially responded to cytokine stimulation. In addition to providing more insight into the biology of primed and cytokine-stimulated NK cells, this study supports the use of autologous NK cell-based immunotherapies for the treatment of prostate cancer. However, our findings also indicate that patients will need to be stratified according to their potential responsiveness to individual therapeutic approaches

Investigating the Clinical Validity of CUB and Zona-Pellucida-like Domain-Containing Protein 1 (CUZD1) in Malignant and Non-Malignant Human Diseases

CUB and zona pellucida-like domain-containing protein 1 (CUZD1) has been previously shown to be specifically expressed in normal pancreas and was proposed as a candidate biomarker for pancreatic related disorders. Due to the lack of specific reagents and techniques, its levels in tissues and biological fluids have not been extensively examined. We generated mouse monoclonal antibodies against recombinant CUZD1 and used them for the development of an enzyme-linked immunosorbent assay (ELISA). Analysis of various human extracts showed that CUZD1 is measured in high levels in pancreas and at much lower (but detectable) levels in several other tissues. Analysis of biological fluids showed that CUZD1 is detected exclusively in pancreatic juice. CUZD1 has been previously linked to diseases (such as pancreatitis, ovarian cancer and IBD) but it is currently unknown if the expression levels of this antigen are elevated in any of the aforementioned or other disorders. Analysis of a large number of serum samples from patients with various malignant and benign disorders showed that CUZD1 levels were elevated in patients with ovarian cysts but not ovarian cancer. CUZD1 is a pancreas-specific protein but it is unclear if its expression is elevated in malignant conditions of the pancreas. IHC staining of pancreatic ductal adenocarcinoma (PDAC) and acinar cell carcinoma (ACC) tissue sections revealed that CUZD1 protein was highly expressed in ACC but not in PDAC. CUZD1 is one of the targets of pancreatic autoantibodies (PABs) which have been emerged as possible biomarkers for Inflammatory Bowel Disease (IBD). Data assessing the diagnostic significance of CUZD1 autoantibodies in patients with IBD are scarce, mainly due to the lack of high throughput techniques for their detection. We developed an ELISA targeting CUZD1 autoantibodies and used it to analyze 200 serum samples from IBD patients and 129 patients assessed for various autoimmune diseases (vADs). CUZD1 autoantibodies were detected in 16% of CrD patients in 9% of UC patients and in less than 5% of patients being tested for vADs. In conclusion, this thesis encompasses the development and validation of analytical techniques targeting CUZD1 antigen and CUZD1 autoantibodies. These tools can facilitate future investigations aiming to delineate the role of CUZD1 in physiology and pathobiology.Ph.D

Cancer immunotherapy: the beginning of the end of cancer?

Abstract These are exciting times for cancer immunotherapy. After many years of disappointing results, the tide has finally changed and immunotherapy has become a clinically validated treatment for many cancers. Immunotherapeutic strategies include cancer vaccines, oncolytic viruses, adoptive transfer of ex vivo activated T and natural killer cells, and administration of antibodies or recombinant proteins that either costimulate cells or block the so-called immune checkpoint pathways. The recent success of several immunotherapeutic regimes, such as monoclonal antibody blocking of cytotoxic T lymphocyte-associated protein 4 (CTLA-4) and programmed cell death protein 1 (PD1), has boosted the development of this treatment modality, with the consequence that new therapeutic targets and schemes which combine various immunological agents are now being described at a breathtaking pace. In this review, we outline some of the main strategies in cancer immunotherapy (cancer vaccines, adoptive cellular immunotherapy, immune checkpoint blockade, and oncolytic viruses) and discuss the progress in the synergistic design of immune-targeting combination therapies

Novel immunoassays for detection of CUZD1 autoantibodies in serum of patients with inflammatory bowel diseases

Pancreatic autoantibodies (PABs) are detected in patients with inflammatory bowel disease (IBD). Their prevalence is higher in Crohn's disease (CrD) than in ulcerative colitis (UC). Glycoprotein 2 (GP2) and, more recently, CUB and zona pellucida-like domain-containing protein 1 (CUZD1) have been identified as target autoantigens of PAB. The clinical utility of CUZD1 autoantibodies has only recently been assessed by indirect immunofluorescence (IIF) assays. In this study, we developed and validated novel immunoassays for the detection of CUZD1 autoantibodies. Recombinant CUZD1 protein was utilized as a solid-phase antigen for the development of two immunoassays for the detection of IgG and IgA CUZD1 autoantibodies. Serum samples from 100 patients with CrD, 100 patients with UC, 129 patients assessed for various autoimmune diseases (vADs) and 50 control individuals were analyzed. Two immunofluorometric assays for the detection of IgG and IgA CUZD1-specific antibodies were developed. CUZD1 autoantibodies were detected in 12.5% (25/200) IBD patients, including 16% of patients with CrD and in 9% of patients with UC (CrD vs. UC, p<0.05), compared with 3.1% (4/129) patients suspected of having vADs (CrD vs. ADs, p<0.05; UC vs. ADs, p=0.08). CUZD1 autoantibody positivity was not found to be related to disease location, age of disease onset or disease phenotype. This is the first study to describe novel IgA and IgG CUZD1 autoantibody enzyme-linked immunosorbent assay. These immunoassays agree well with standard IIF techniques and can be utilized in multicenter studies to investigate the diagnostic and clinical utility of CUZD1 autoantibodies. © 2017 Walter de Gruyter GmbH, Berlin/Boston

Biochemical and functional characterization of the human tissue kallikrein 9

Human tissue kallikrein 9 (KLK9) is a member of the kallikrein-related family of proteases. Despite its known expression profile, much less is known about the functional roles of this protease and its implications in normal physiology and disease. We present here the first data on the biochemical characterization of KLK9, investigate parameters that affect its enzymatic activity (such as inhibitors) and provide preliminary insights into its putative substrates. We show that mature KLK9 is a glycosylated chymotrypsin-like enzyme with strong preference for tyrosine over phenylalanine at the P1 cleavage position. The enzyme activity is enhanced by Mg2+ and Ca2+, but is reversibly attenuated by Zn2+. KLK9 is inhibited in vitro by many naturally occurring or synthetic protease inhibitors. Using a combination of degradomic and substrate specificity assays, we identified candidate KLK9 substrates in two different epithelial cell lines [the non-tumorigenic human keratinocyte cells (HaCaT) and the tumorigenic tongue squamous carcinoma cells (SCC9)]. Two potential KLK9 substrates [KLK10 and midkine (MDK)] were subjected to further validation. Taken together, our data delineate some functional and biochemical properties of KLK9 for future elucidation of the role of this enzyme in health and disease.</p

Pik3ca mutational status in circulating tumor cells can change during disease recurrence or progression in patients with breast cancer

Molecular characterization of circulating tumor cells (CTC) is crucial for the investigation of molecular-targeted therapies while PIK3CA somatic mutations play a crucial role in therapy response. We investigated the presence of PIK3CA mutations in CTC and whether this is associated with clinical outcome. We developed and validated an ultrasensitive methodology for the detection of PIK3CA mutations that is based on a combination of allele-specific, asymmetric rapid PCR and melting analysis. We analyzed PIK3CA hotspot mutations in: (i) a training group consisting of EpCAM-positive CTC fraction from 37 patients with clinically confirmed metastasis, and 26 healthy female volunteers and 15 primary breast tumor tissues and (ii) an independent group consisting of EpCAM-positive CTC fraction from 57 metastatic and 118 operable breast cancer patients and 76 corresponding primary tumors. The assay could detect 0.05% of mutated dsDNA in the presence of 99.95% wtDNA for both exons (9 and 20) and was highly specific (0/26 healthy donors). PIK3CA mutations were identified in EpCAM-positive CTC in 20 of 57(35.1%) and in 23 of 118 (19.5%) patients with metastatic and operable breast cancer, and in 45 of 76(59.2%) corresponding FFPEs. Our data indicate that PIK3CA mutational status in CTCs can change during disease progression and is associated with worse survival (P ? 0.047). PIK3CA hotspot mutations are present at a relatively high frequency in CTCs and their presence is associated with worse survival in patients with breast cancer with metastasis. Evaluation of PIK3CA mutational status in CTCs is a strategy with potential clinical application. Clin Cancer Res; 20(22); ©-2014 American Association for Cancer Research

Novel immunoassays for detection of CUZD1 autoantibodies in serum of patients with inflammatory bowel diseases

AbstractBackground:Pancreatic autoantibodies (PABs) are detected in patients with inflammatory bowel disease (IBD). Their prevalence is higher in Crohn’s disease (CrD) than in ulcerative colitis (UC). Glycoprotein 2 (GP2) and, more recently, CUB and zona pellucida-like domain-containing protein 1 (CUZD1) have been identified as target autoantigens of PAB. The clinical utility of CUZD1 autoantibodies has only recently been assessed by indirect immunofluorescence (IIF) assays. In this study, we developed and validated novel immunoassays for the detection of CUZD1 autoantibodies.Methods:Recombinant CUZD1 protein was utilized as a solid-phase antigen for the development of two immunoassays for the detection of IgG and IgA CUZD1 autoantibodies. Serum samples from 100 patients with CrD, 100 patients with UC, 129 patients assessed for various autoimmune diseases (vADs) and 50 control individuals were analyzed.Results:Two immunofluorometric assays for the detection of IgG and IgA CUZD1-specific antibodies were developed. CUZD1 autoantibodies were detected in 12.5% (25/200) IBD patients, including 16% of patients with CrD and in 9% of patients with UC (CrD vs. UC, p&lt;0.05), compared with 3.1% (4/129) patients suspected of having vADs (CrD vs. ADs, p&lt;0.05; UC vs. ADs, p=0.08). CUZD1 autoantibody positivity was not found to be related to disease location, age of disease onset or disease phenotype.Conclusions:This is the first study to describe novel IgA and IgG CUZD1 autoantibody enzyme-linked immunosorbent assay. These immunoassays agree well with standard IIF techniques and can be utilized in multicenter studies to investigate the diagnostic and clinical utility of CUZD1 autoantibodies.</jats:sec