Cutting Edge: CD83 Regulates the Development of Cellular Immunity

Journal of Immunology (Baltimore, Md. : 1950). Mar, 2002  |  Pubmed ID: 11884422

We recently found that human CD83, a marker of mature dendritic cells, is an adhesion receptor that binds to resting monocytes and a subset of activated CD8(+) T cells. We injected CD83-Ig into mice transplanted with the immunogenic P815 mastocytoma and showed that it significantly enhanced the rate of tumor growth and inhibited the development of cytotoxic T cells. In contrast, mice immunized with CD83-transfected K1735 cells, a poorly immunogenic melanoma, could prevent the outgrowth of wild-type K1735 cells. Studies performed in vitro with human PBL showed that coimmobilized CD83-Ig and anti-CD3 enhanced T cell proliferation and increased the proportion of CD8(+) T cells. CD83-transfected B-lymphoblastoid T51 cells stimulated T cell proliferation more effectively than untransfected T51 cells in MLR cultures and increased the generation of cytolytic T cells. We conclude that CD83 is a functionally important receptor that can regulate the development of cellular immunity by interacting with its ligand(s).

Plasmid-based Vaccines Encoding Rat Neu and Immune Stimulatory Molecules Can Elicit Rat Neu-specific Immunity

Molecular Cancer Therapeutics. Oct, 2003  |  Pubmed ID: 14578464

DNA vaccines are ideally suited for immunizing against tumor antigens because constructs can be formulated that not only encode the tumor antigen but also encode molecules chosen to improve the ability to elicit an antitumor response. Ligands expressed on antigen-presenting cells associated with stimulating a robust T-cell response are excellent candidates for inclusion in a DNA vaccine. Mice transgenic for the HER-2/neu homologue, rat neu, were immunized with full-length rat neu cDNA given alone or in combination with plasmids encoding costimulatory molecules CD80 or CD86 and the ligand for CD137 (CD137L). Intradermal injection of the plasmid constructs resulted in both plasmid transcript and antigen protein expression being detected in lymph nodes draining the injection site. Immunization with plasmids encoding the neu antigen along with plasmids encoding CD137L and either CD80 or CD86 resulted in the generation of neu-specific antibodies that induced phopshorylation of the neu tyrosine kinase and inhibited the growth of cultured tumor cells overexpressing neu. Survival of animals was significantly prolonged after immunization with vaccines encoding neu together with the costimulatory molecules. Although tumors eventually occurred in the vaccinated animals, they were markedly infiltrated with CD4+ T cells. DNA vaccines encoding neu, when given in combination with both CD137L and either CD80 or CD86, can induce cellular and humoral immunity and result in an antitumor effect.

Bead-based ELISA for Validation of Ovarian Cancer Early Detection Markers

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. Apr, 2006  |  Pubmed ID: 16609024

Efforts to validate ovarian cancer early detection biomarkers with immunoassays are challenged by the limited specimen volumes available. We sought to develop a specimen-efficient assay to measure CA125 in serum, assess its reproducibility, validity, and performance, and test its potential for multiplexing and combining with human epididymis protein 4 (HE4), a promising novel ovarian cancer marker.

Method for Generation of in Vivo Biotinylated Recombinant Antibodies by Yeast Mating

Journal of Immunological Methods. Dec, 2006  |  Pubmed ID: 17113097

We describe here a novel method for generation of yeast-secreted, in vivo biotinylated recombinant antibodies, or biobodies. Biobodies are secreted by diploid yeast resulting from the fusion of two haploid yeast of opposite mating type. One yeast carries a cDNA encoding an antibody recognition sequence fused to an IgA1 hinge and a biotin acceptor site (BCCP) at the C-terminus; the other carries a cDNA encoding an E. coli biotin ligase (BirA) fused to KEX2 golgi-localization sequences, so that BirA can catalyze the biotin transfer to the recognition sequence-fused BCCP within the yeast secretory compartment. We illustrate this technology with biobodies against HE4, a biomarker for ovarian carcinoma. Anti-HE4 biobodies were derived from clones or pools of anti-HE4-specific yeast-display scFv, constituting respectively monoclonal (mBb) or polyclonal (pBb) biobodies. Anti-HE4 biobodies were secreted directly biotinylated thus bound to labeled-streptavidin and streptavidin-coated surfaces without Ni-purification. Anti-HE4 biobodies demonstrated specificity and sensitivity by ELISA assays, flow cytometry analysis and Western blots prior to any maturation; dissociation equilibrium constants as measured by surface plasmon resonance sensor were of K(d)=4.8 x 10(-9) M and K(d)=5.1 x 10(-9) M before and after Ni-purification respectively. Thus, yeast mating permits cost-effective generation of biotinylated recombinant antibodies of high affinity.

Development and in Vitro Validation of Anti-mesothelin Biobodies That Prevent CA125/Mesothelin-dependent Cell Attachment

Cancer Letters. Oct, 2007  |  Pubmed ID: 17560019

Preventing peritoneal implantation of carcinoma cells could prolong ovarian cancer patient remission and survival. Peritoneal cells constitutively express mesothelin, a ligand for CA125 that is expressed by tumor cells. Thus blocking CA125/mesothelin-dependent cell attachment may prevent or delay peritoneal metastatic recurrence. We developed a high-throughput screening system for reagents able to block CA125/mesothelin-dependent cell attachment with a sensitive quantitative readout. Using a novel yeast-expression system to produce secreted, in vivo biotinylated proteins and biobodies (Bbs), we generated anti-mesothelin Bbs. Anti-mesothelin Bbs derived from high affinity yeast-display scFv detected both membrane-bound and soluble mesothelins and inhibited CA125/mesothelin-dependent cell attachment.

Development of a CA125-mesothelin Cell Adhesion Assay As a Screening Tool for Biologics Discovery

Cancer Letters. Mar, 2007  |  Pubmed ID: 16677756

Preventing peritoneal implantation of ovarian carcinoma cells could prolong patient remission and survival. CA125 is expressed on most ovarian cancer cells and was reported to be a ligand of mesothelin, a peritoneal protein. We developed a cell adhesion assay with CA125-expresser ovarian cancer cells and human mesothelin-transfected cells and we confirmed that CA125 and mesothelin mediate cell attachment. We also showed that this assay supplies a high-throughput screening system for reagents able to block CA125/mesothelin-dependent cell attachment with a sensitive quantitative readout. We finally demonstrated that a mesothelin chimeric protein and anti-CA125 antibodies block CA125/mesothelin-dependent cell attachment.

Use of High Density Antibody Arrays to Validate and Discover Cancer Serum Biomarkers

Molecular Oncology. Dec, 2007  |  Pubmed ID: 19383305

Perhaps the greatest barrier to translation of serum biomarker discoveries is the inability to evaluate putative biomarkers in high throughput validation studies. Here we report on the development, production, and implementation of a high-density antibody microarray used to evaluate large numbers of candidate ovarian cancer serum biomarkers. The platform was shown to be useful for evaluation of individual antibodies for comparative analysis, such as with disease classification, and biomarker validation and discovery. We demonstrate its performance by showing that known tumor markers behave as expected. We also identify several promising biomarkers from a candidate list and generate hypotheses to support new discovery studies.

CA125 in Ovarian Cancer

Biomarkers in Medicine. Dec, 2007  |  Pubmed ID: 20477371

A quarter of a century since its discovery, circulating CA125 antigen is recommended for clinical use in the USA for ovarian cancer screening of high-risk women with ovaries, despite its limited sensitivity and specificity. Recent findings suggest that CA125 might also serve as a predictive marker for pre-invasive ovarian carcinoma. Methods to quantify circulating CA125 evolved toward sensitive and reliable double-determinant ELISA assays. The CA125 gene, MUC16, was cloned 20 years after the protein discovery and revealed a very complex and unusual glycoprotein structure, suggesting an immunological role. Recent evidence points toward CA125 function in the induction of materno-fetal tolerance through the alteration of natural killer phenotype. Two receptors for CA125 have been described: mesothelin and galectin-1. The specific location and functional proprieties of CA125 make it a therapeutic target of choice; clinical trials have demonstrated that anti-CA125 injections are well tolerated and suggest a potential survival benefit.

Use of Yeast-secreted in Vivo Biotinylated Recombinant Antibodies (Biobodies) in Bead-based ELISA

Clinical Cancer Research : an Official Journal of the American Association for Cancer Research. May, 2008  |  Pubmed ID: 18451228

To measure circulating antigens, sandwich ELISA assays require two complementary affinity reagents. Mouse monoclonal antibodies (mAb) and polyclonal antibodies (pAb) are commonly used, but because their production is lengthy and costly, recombinant antibodies are emerging as an attractive alternative.

A Mouse to Human Search for Plasma Proteome Changes Associated with Pancreatic Tumor Development

PLoS Medicine. Jun, 2008  |  Pubmed ID: 18547137

The complexity and heterogeneity of the human plasma proteome have presented significant challenges in the identification of protein changes associated with tumor development. Refined genetically engineered mouse (GEM) models of human cancer have been shown to faithfully recapitulate the molecular, biological, and clinical features of human disease. Here, we sought to exploit the merits of a well-characterized GEM model of pancreatic cancer to determine whether proteomics technologies allow identification of protein changes associated with tumor development and whether such changes are relevant to human pancreatic cancer.

Systematic Evaluation of Candidate Blood Markers for Detecting Ovarian Cancer

PloS One. 2008  |  Pubmed ID: 18612378

Epithelial ovarian cancer is a significant cause of mortality both in the United States and worldwide, due largely to the high proportion of cases that present at a late stage, when survival is extremely poor. Early detection of epithelial ovarian cancer, and of the serous subtype in particular, is a promising strategy for saving lives. The low prevalence of ovarian cancer makes the development of an adequately sensitive and specific test based on blood markers very challenging. We evaluated the performance of a set of candidate blood markers and combinations of these markers in detecting serous ovarian cancer.

Combining a Symptoms Index with CA 125 to Improve Detection of Ovarian Cancer

Cancer. Aug, 2008  |  Pubmed ID: 18615684

The current study sought to examine whether an index based on the specific pattern of symptoms commonly reported by women with ovarian cancer could be used in combination with CA 125 to improve the sensitivity or specificity of experimental methods of screening for ovarian cancer.

Use of Cancer-specific Yeast-secreted in Vivo Biotinylated Recombinant Antibodies for Serum Biomarker Discovery

Journal of Translational Medicine. 2008  |  Pubmed ID: 18652693

Strategies to discover circulating protein markers of ovarian cancer are urgently needed. We developed a novel technology that permits us to isolate recombinant antibodies directed against the potential serum biomarkers, to facilitate the further development of affinity reagents necessary to construct diagnostic tests.

Effects of Personal Characteristics on Serum CA125, Mesothelin, and HE4 Levels in Healthy Postmenopausal Women at High-risk for Ovarian Cancer

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. Sep, 2008  |  Pubmed ID: 18768519

To evaluate if serum levels of candidate ovarian cancer biomarkers vary with individual characteristics of healthy women who are likely candidates for an ovarian cancer screening program.

Maternal Mortality from Systemic Illness: Unraveling the Contribution of the Immune Response

American Journal of Obstetrics and Gynecology. Apr, 2009  |  Pubmed ID: 19318152

Maternal morbidity and/or mortality (MM) is increased in pyelonephritis and influenza. Alterations in the immune response could account for the increase MM. We sought to determine whether the immune response is functionally different during pregnant and nonpregnant (NP) states.

Oncology Biomarkers--second Annual GTCbio Conference. Biomarkers for Disease Detection and Therapeutics Monitoring. 19-20 January 2009, Miami, FL, USA

IDrugs : the Investigational Drugs Journal. Apr, 2009  |  Pubmed ID: 19350459

Influence of Ovarian Cancer Risk Status on the Diagnostic Performance of the Serum Biomarkers Mesothelin, HE4, and CA125

Cancer Epidemiology, Biomarkers & Prevention : a Publication of the American Association for Cancer Research, Cosponsored by the American Society of Preventive Oncology. May, 2009  |  Pubmed ID: 19423517

To evaluate the effect of ovarian cancer risk on the performance of the serum biomarkers mesothelin, human epididymis protein 4 (HE4), and CA125.

Beyond CA125: the Coming of Age of Ovarian Cancer Biomarkers. Are We There Yet?

Biomarkers in Medicine. Jun, 2009  |  Pubmed ID: 19684876

Ovarian cancer (OC) is the fourth leading cause of cancer deaths among women in the United States, despite its relatively low incidence of 50 per 100,000. Even though advances in therapy have been made, the OC fatality-to-case ratio remains exceedingly high, due to the lack of accurate tools to diagnose early-stage disease when cure is still possible. The most studied marker for OC, CA125, is only expressed by 50-60% of patients with early stage disease. Large efforts have been deployed to identify novel serum markers, yet no single marker has emerged as a serious competitor for CA125. Various groups are investing in combination approaches to increase the diagnostic value of existing markers, but many markers may still lie in under-explored areas of ovarian cancer biology, such as tumor vasculature environment and post-translational modifications (glycomics).

Antifouling Surface Layers for Improved Signal-to-noise of Particle-based Immunoassays

Langmuir : the ACS Journal of Surfaces and Colloids. Dec, 2009  |  Pubmed ID: 19928944

A 10-fold improvement in the signal-to-noise (S/N) ratio of an optically encoded silica particle-based immunoassay was achieved through incorporating a protein resistant poly(ethylene glycol) (PEG) surface layer and optimizing antibody immobilization conditions. PEG was activated using 2,2,2-trifluoroethanesulfonyl chloride (tresyl) and required a minimum reaction time of 1.5 h. The activated PEG had a reactive half-life of approximately 5 h when stored in acidified dimethyl sulfoxide (DMSO). By increasing the protein incubation time and concentration, a maximum antibody loading on the particle surface of 1.6 x 10(-2) molecules per nm(2) was achieved. The assay S/N ratio was assessed using a multiplexed multicomponent optically encoded species-specific immunoassay. Encoded particles were covalently grafted or nonspecifically coated with either bovine or mouse IgG for the simultaneous detection of complementary anti-IgG "target" or uncomplementary anti-IgG "noise". The versatility and potential as a serum-based assay platform was demonstrated by immobilizing either a polyclonal antibody or an engineered single-chain variable fragment (scFv) capture probe on particles for the detection of the ovarian cancer biomarker, mesothelin (MSLN). The MLSN antigen was spiked into PBS buffer or 50% human serum. Both capture probe orientations, and media conditions showed similar low level detection limits of 5 ng/mL; however, a 40% decrease in maximum signal intensity was observed for assays run in 50% serum.

Use of a Symptom Index, CA125, and HE4 to Predict Ovarian Cancer

Gynecologic Oncology. Mar, 2010  |  Pubmed ID: 19945742

Prior studies suggest that combining the Symptom Index (SI) with a serum HE4 test or a CA125 test may improve prediction of ovarian cancer. However, these three tests have not been evaluated in combination.

Assessing Lead Time of Selected Ovarian Cancer Biomarkers: a Nested Case-control Study

Journal of the National Cancer Institute. Jan, 2010  |  Pubmed ID: 20042715

CA125, human epididymis protein 4 (HE4), mesothelin, B7-H4, decoy receptor 3 (DcR3), and spondin-2 have been identified as potential ovarian cancer biomarkers. Except for CA125, their behavior in the prediagnostic period has not been evaluated.

Rapid Isolation of High-affinity Human Antibodies Against the Tumor Vascular Marker Endosialin/TEM1, Using a Paired Yeast-display/secretory ScFv Library Platform

Journal of Immunological Methods. Jan, 2011  |  Pubmed ID: 20837020

Endosialin/TEM1 is predominantly expressed on neovasculature, thus ideally suited for diagnostic, targeted imaging and therapy of cancer. To isolate TEM1-specific affinity reagents, we thought to screen a recombinant antibody (scFv) library derived from the repertoire of a patient with thrombotic thrombocytopenic purpura (TTP), as autoimmune disorders may produce self-reactive specificities. The yeast-display scFv library was constructed by homologous recombination of the TTP patient repertoire originally expressed on M13 bacteriophage in the novel vector pAGA2 for yeast-display expression. The TTP yeast-display library (10⁹ members) was screened by magnetic and flow sorting with human TEM1 recombinant protein. A pool of yeast-display scFv able to detect 2nM of TEM1 was obtained and transformed into yeast-secreted scFv by homologous recombination using the novel p416 BCCP vector for yeast secretion of biotinylated scFv. Anti-TEM1 yeast-secreted scFv were independently validated in vitro by flow cytometry analysis and ELISA assays, then in vivo biotinylated in N-termini to produce biobodies. Biobody-78 bound specifically to Endosialin/TEM1-expressing ovarian tumor in vivo, with functional stability over 48 h. Our results suggest that our novel paired display-secretory yeast libraries can serve as an ideal platform for the rapid isolation of high-affinity reagents, and that anti-TEM1 biobody-78 can be used for in vitro assays including flow cytometry analysis, as well as in vivo for targeted imaging and therapy of cancer.

Ovarian Cancer Biomarker Performance in Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial Specimens

Cancer Prevention Research (Philadelphia, Pa.). Mar, 2011  |  Pubmed ID: 21372036

Establishing a cancer screening biomarker's intended performance requires "phase III" specimens obtained in asymptomatic individuals before clinical diagnosis rather than "phase II" specimens obtained from symptomatic individuals at diagnosis. We used specimens from the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial to evaluate ovarian cancer biomarkers previously assessed in phase II sets. Phase II specimens from 180 ovarian cancer cases and 660 benign disease or general population controls were assembled from four Early Detection Research Network or Ovarian Cancer Specialized Program of Research Excellence sites and used to rank 49 biomarkers. Thirty-five markers, including 6 additional markers from a fifth site, were then evaluated in PLCO proximate specimens from 118 women with ovarian cancer and 474 matched controls. Top markers in phase II specimens included CA125, HE4, transthyretin, CA15.3, and CA72.4 with sensitivity at 95% specificity ranging from 0.73 to 0.40. Except for transthyretin, these markers had similar or better sensitivity when moving to phase III specimens that had been drawn within 6 months of the clinical diagnosis. Performance of all markers declined in phase III specimens more remote than 6 months from diagnosis. Despite many promising new markers for ovarian cancer, CA125 remains the single-best biomarker in the phase II and phase III specimens tested in this study.

A Framework for Evaluating Biomarkers for Early Detection: Validation of Biomarker Panels for Ovarian Cancer

Cancer Prevention Research (Philadelphia, Pa.). Mar, 2011  |  Pubmed ID: 21372037

A panel of biomarkers may improve predictive performance over individual markers. Although many biomarker panels have been described for ovarian cancer, few studies used prediagnostic samples to assess the potential of the panels for early detection. We conducted a multisite systematic evaluation of biomarker panels using prediagnostic serum samples from the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial. Using a nested case-control design, levels of 28 biomarkers were measured laboratory-blinded in 118 serum samples obtained before cancer diagnosis and 951 serum samples from matched controls. Five predictive models, each containing 6 to 8 biomarkers, were evaluated according to a predetermined analysis plan. Three sequential analyses were conducted: blinded validation of previously established models (step 1); simultaneous split-sample discovery and validation of models (step 2); and exploratory discovery of new models (step 3). Sensitivity, specificity, sensitivity at 98% specificity, and AUC were computed for the models and CA125 alone among 67 cases diagnosed within one year of blood draw and 476 matched controls. In step 1, one model showed comparable performance to CA125, with sensitivity, specificity, and AUC at 69.2%, 96.6%, and 0.892, respectively. Remaining models had poorer performance than CA125 alone. In step 2, we observed a similar pattern. In step 3, a model derived from all 28 markers failed to show improvement over CA125. Thus, biomarker panels discovered in diagnostic samples may not validate in prediagnostic samples; utilizing prediagnostic samples for discovery may be helpful in developing validated early detection panels.

Novel Surface Targets and Serum Biomarkers from the Ovarian Cancer Vasculature

Cancer Biology & Therapy. Aug, 2011  |  Pubmed ID: 21617380

The molecular phenotype of tumor vasculature is different from normal vasculature, offering new opportunities for diagnosis and therapy of cancer, but the identification of tumor-restricted targets remains a challenge. We investigated 13 tumor vascular markers (TVMs) from 50 candidates identified through expression profiling of ovarian cancer vascular cells and selected to be either transmembrane or secreted, and to be either absent or expressed at low levels in normal tissues while overexpressed in tumors, based on analysis of 1,110 normal and tumor tissues from publicly available Affymetrix microarray data. Tumor-specific expression of each TVM was confirmed at the protein level in tumor tissue and/or in serum. Among the 13 TVMs, 11 were expressed on tumor vascular endothelium; the remaining 2 TVMs were expressed by tumor leukocytes. Our results demonstrate that certain transmembrane TVMs such as ADAM12 and CDCP1 are selectively expressed in tumor vasculature and represent promising targets for vascular imaging or anti-vascular therapy of epithelial ovarian cancer, while secreted or shed molecules such as TNFRSF21/DR6 can function as serum biomarkers. We have identified novel tumor-specific vasculature markers which appear promising for cancer serum diagnostics, molecular imaging and/or therapeutic targeting applications and warrant further clinical development.

Potential Role of HE4 in Multimodal Screening for Epithelial Ovarian Cancer

Journal of the National Cancer Institute. Nov, 2011  |  Pubmed ID: 21917606

In screening for epithelial ovarian cancer, unnecessary surgery can be reduced by limiting use of transvaginal ultrasound (TVU) to women with increasing CA125 serum levels. Replacing or augmenting TVU with measurement of a serum marker specific for malignancy might further improve screening performance. Serum samples from 112 invasive ovarian cancer patients and 706 matched control subjects from the Prostate, Lung, Colorectal, and Ovarian trial were used to evaluate human epididymis protein 4 (HE4), mesothelin, matrix metalloproteinase 7 (MMP7), SLPI, Spondin2, and insulin-like growth factor binding protein 2 (IGFBP2) for their potential use in screening. TVU results were available for a subset of 84 patients and 516 control subjects used to compare the best marker with TVU. HE4 was found to perform better than TVU as a second-line screen, confirming 27 of 39 cancers with increasing CA125 serum levels compared with 17 cancers confirmed by TVU (P = .03). Serum HE4 levels were found to increase with age and smoking status, suggesting that a longitudinal algorithm might improve its performance.

Redirected Antitumor Activity of Primary Human Lymphocytes Transduced With a Fully Human Anti-mesothelin Chimeric Receptor

Molecular Therapy : the Journal of the American Society of Gene Therapy. Nov, 2011  |  Pubmed ID: 22127019

Cancer regression by gene-modified T cells bearing a chimeric antigen receptor (CAR) exodomain of mouse origin can be limited by the induction of transgene immunogenicity resulting in poor persistence and function in vivo. The development of functionally-active CAR of human origin can address this issue. Here, we constructed and evaluated fully human anti-mesothelin CARs comprised of a human mesothelin-specific single-chain antibody variable fragment (P4 scFv) coupled to T cell signaling domains. Primary human T cells expressing P4 CAR specifically produced proinflammatory cytokines, degranulated and exerted potent cytolytic functions when cultured with mesothelin-expressing tumors in vitro. P4 CAR T cells also mediated bystander killing of mesothelin-negative cancer cells during coculture. CAR reactivity was not abrogated by soluble tumor-secreted or recombinant mesothelin protein even at supraphysiological levels. Importantly, adoptive transfer of P4 CAR-expressing T cells mediated the regression of large, established tumor in the presence of soluble mesothelin in a xenogenic model of human ovarian cancer. Thus, primary human T cells expressing fully human anti-mesothelin CAR efficiently kill mesothelin-expressing tumors in vitro and in vivo and have the potential to overcome the issue of transgene immunogenicity that may limit CAR T cell trials that utilize scFvs of mouse origin.

Mannose Receptor (MR) Engagement by Mesothelin GPI Anchor Polarizes Tumor-associated Macrophages and is Blocked by Anti-MR Human Recombinant Antibody

PloS One. 2011  |  Pubmed ID: 22163010

Tumor-infiltrating macrophages respond to microenvironmental signals by developing a tumor-associated phenotype characterized by high expression of mannose receptor (MR, CD206). Antibody cross-linking of CD206 triggers anergy in dendritic cells and CD206 engagement by tumoral mucins activates an immune suppressive phenotype in tumor-associated macrophages (TAMs). Many tumor antigens are heavily glycosylated, such as tumoral mucins, and/or attached to tumor cells by mannose residue-containing glycolipids (GPI anchors), as for example mesothelin and the family of carcinoembryonic antigen (CEA). However, the binding to mannose receptor of soluble tumor antigen GPI anchors via mannose residues has not been systematically studied. To address this question, we analyzed the binding of tumor-released mesothelin to ascites-infiltrating macrophages from ovarian cancer patients. We also modeled functional interactions between macrophages and soluble mesothelin using an in vitro system of co-culture in transwells of healthy donor macrophages with human ovarian cancer cell lines. We found that soluble mesothelin bound to human macrophages and that the binding depended on the presence of GPI anchor and of mannose receptor. We next challenged the system with antibodies directed against the mannose receptor domain 4 (CDR4-MR). We isolated three novel anti-CDR4-MR human recombinant antibodies (scFv) using a yeast-display library of human scFv. Anti-CDR4-MR scFv #G11 could block mesothelin binding to macrophages and prevent tumor-induced phenotype polarization of CD206(low) macrophages towards TAMs. Our findings indicate that tumor-released mesothelin is linked to GPI anchor, engages macrophage mannose receptor, and contributes to macrophage polarization towards TAMs. We propose that compounds able to block tumor antigen GPI anchor/CD206 interactions, such as our novel anti-CRD4-MR scFv, could prevent tumor-induced TAM polarization and have therapeutic potential against ovarian cancer, through polarization control of tumor-infiltrating innate immune cells.

Oncology Biomarkers for Gynecologic Malignancies

Frontiers in Bioscience (Elite Edition). 2012  |  Pubmed ID: 22201939

Current therapies efficiently treat most patients with gynecologic malignancies detected at an early stage. Thus, the identification of oncology biomarkers for screening and monitoring of occult tumors has been highly prioritized. Hyperglycosylated human chorionic gonadotropin (hCG) epitomizes oncologic biomarker, as the serum level of this hormone is elevated in virtually all cases of gestational trophoblastic diseases. On the other hand, despite the availability of various markers such as CA125, CA19.9, CA15.3, CA72-4, Inhibin, beta-hCG, AFP, CEA and many more biomarkers under investigation, fewer than 25percent of all ovarian cancers are currently detected in stage I. Large efforts have been undertaken to further identify composite markers for gynecologic malignancies that may exhibit greater specificity when studied over time, as well as to develop risk models and screening algorithms aimed at improving the specificity and sensitivity of diagnostic tests. In this review, we provide a comprehensive analysis of the biomarkers currently used in clinics for gynecologic malignancies, as well as an outlook of the most promising oncologic biomarkers currently under study.

A Universal Strategy for Adoptive Immunotherapy of Cancer Through Use of a Novel T Cell Antigen Receptor

Cancer Research. Feb, 2012  |  Pubmed ID: 22315351

Adoptive immunotherapies composed of T cells engineered to express a chimeric antigen receptor (CAR) offer an attractive strategy for treatment of human cancer. However, CARs have a fixed antigen specificity such that only one tumor-associated antigen (TAA) can be targeted, limiting the efficacy that can be achieved due to heterogeneous TAA expression. For this reason, a more generalized and effective application of CAR therapy would benefit from the capability to produce large panels of CARs against many known TAAs. In this study, we demonstrate a novel strategy to extend the recognition specificity potential of a bioengineered lymphocyte population, allowing flexible approaches to redirect T cells against various TAAs. Our strategy employs a biotin-binding immune receptor (BBIR) composed of an extracellular-modified avidin linked to an intracellular T cell signaling domain. BBIR T cells recognized and bound exclusively to cancer cells pre-targeted with specific biotinylated molecules. The versatility afforded by BBIRs permitted sequential or simultaneous targeting of a combination of distinct antigens. Together, our findings demonstrate that a platform of universal T cell specificity can significantly extend conventional CAR approaches, permitting the tailored generation of T cells of unlimited antigen specificity for improving the effectiveness of adoptive T cell immunotherapies for cancer.

Correlation of Serum HE4 with Tumor Size and Myometrial Invasion in Endometrial Cancer

Gynecologic Oncology. Feb, 2012  |  Pubmed ID: 22037318

To evaluate the utility of serum (HE4) as a marker for high risk disease in patients with endometrial cancer (EC).