Intratumoral delivery of CpG-conjugated anti-MUC1 antibody enhances NK cell anti-tumor activity

Monoclonal antibodies (mAbs) against tumor-associated antigens are useful anticancer agents. Antibody-dependent cellular cytotoxicity (ADCC) is one of the major mechanisms responsible for initiating natural killer cell (NK)-mediated killing of tumors. However, the regulation of ADCC via NK cells is poorly understood. We have investigated the cytolytic activity of NK cells against pancreatic cancer cells that were coated with an antibody directed against the human tumor antigen, Mucin-1 designated HMFG-2, either alone or conjugated to CpG oligodeoxynucleotide (CpG ODN). Conjugated antibodies were tested for their ability to elicit ADCC in vitro and in vivo against pancreatic cancer cells. NK cells cultured in the presence of immobilized CpG ODN, HMFG-2 Ab, or CpG ODN-conjugated HMFG-2 Ab were able to up-regulate perforin similarly. Interestingly, a significant higher ADCC was observed when CpG ODN-conjugated HMFG-2-coated tumor cells were co-cultured with NK cells compared to unconjugated HMFG-2 Ab or CpG ODN alone. Moreover, MyD88-deficient NK cells can perform ADCC in vitro. Furthermore, intratumoral injections of CpG ODN-conjugated HMFG-2 induced a significant reduction in tumor burden in vivo in an established model of pancreatic tumor in nude mice compared to CpG ODN or the HMFG-2 alone. Depletion of macrophages or NK cells before treatment confirmed that both cells were required for the anti-tumor response in vivo. Results also suggest that CpG ODN and HMFG-2 Ab could be sensed by NK cells on the mAb-coated tumor cells triggering enhanced ADCC in vitro and in vivo.     

Modulation of phenotype in cultures of human milk epithelial cells and its relation to the expression of a membrane antigen

Primary cultures of human milk epithelial cells, labelled with HMFG-1, a monoclonal antibody that recognises a differentiation antigen on the membranes of breast epithelia, were separated from unlabelled cells in a fluorescence-activated cell sorter (FACS). Cells not expressing the HMFG-1 antigen have a greater in vitro growth potential than the positive ones, and give rise to cultures containing both HMFG-1 antigen positive and negative cells. The cultures derived from negative cells usually contain colonies with 'open' cuboidal cells and these do not express the HMFG-1 antigen. However, when they differentiate into other phenotypes such as the 'closed' cuboidal cell type, expression of the differentiation antigen becomes evident and the cultures then show a reduced growth potential. When milk cells are subcultured several times, a new cell type emerges which does not express the HMFG-1 antigen or the intermediate filaments typical of epithelial cells but instead express high levels of fibronectin which is found in an extracellular matrix. Whether these cells emerge by selection of an existing phenotype or by phenotypic modulation is discussed.     

Specific tumor markers in diagnostic cytology. Immunoperoxidase studies of carcinoembryonic antigen, lysozyme and other tissue antigens in effusions, washes and aspirates

The immunoperoxidase technique was used to identify specific tumor markers in exfoliated cells in fine needle aspirates and body fluids. Carcinoembryonic antigen (CEA) and lysozyme staining was evaluated in cytocentrifuge preparations from 42 malignant effusions and aspirates and 16 benign effusions. Reactive mesothelial cells were negative for CEA and lysozyme or showed faint peripheral cytoplasmic staining. Malignant cells from 50% of the adenocarcinomas studied were positive for CEA. All tumors studied were negative for lysozyme. These staining patterns are helpful in the differential diagnosis of reactive mesothelial and adenocarcinoma cells, a frequent diagnostic dilemma. Moreover, demonstration of specific tumor antigens (e.g., prostatic acid phosphatase, calcitonin and immunoglobulin) helped define the origin of metastatic malignancy in selected cases. Estrogen receptor activity was also identified in tumor cells using this technique. Immunoperoxidase was helpful in the evaluation of malignant cytologic specimens from patients with more than one tumor. Interpretation of staining patterns is discussed, with reference to the limitations of the technique. Immunoperoxidase methods maintain cytologic detail, are readily adaptable to diagnostic cytology and increase the specificity of cytologic diagnosis.     

Expression of epithelial membrane antigen on malignant mesothelioma cells. An immunocytochemical and immunoelectron microscopic study

The presence of epithelial membrane antigen (EMA) on malignant mesothelial cells found in pleural and ascitic fluids was demonstrated immunocytochemically using a monoclonal anti-EMA antibody. Serous fluids of 25 patients with malignant mesotheliomas were investigated. In 23 cases, varying numbers of EMA-positive tumor cells were present; in 2 cases, no such cells were found. Immunoelectron microscopy was performed both on Lowicryl-embedded sediments of serous fluids and by application of preembedding techniques using the immunogold method. Expression of EMA by the immunogold method was found selectively on the villi of the malignant mesothelioma cells whereas the nonvillous, flat surfaces were largely EMA-negative. The results indicate that immunoelectron microscopy may offer a useful adjunct in the diagnosis of malignant mesothelioma in serous fluids.     

Improved identification of malignant cells in serous effusions using a small, robust panel of antibodies on paraffin-embedded cell suspensions

OBJECTIVE: To evaluate the expression of these markers individually and to find out which markers would be the most effective in a diagnostic panel to reliably discriminate these lesions. STUDY DESIGN: Sections from cell blocks of these fluids were stained with antibodies against calretinin, EMA, HMFG-2, BerEp4, B72.3 and CEA. A preliminary diagnosis was formulated based on cytomorphologic criteria. Subsequently, results of all 6 immunocytochemical stainings were evaluated, the most effective diagnostic pane of antibodies was proposed and staining results using this panel were compared to results obtained by solely cytomorphologic evaluation and to the ultimate diagnosis. RESULTS: Additional immunocytochemical staining with the proposed panel of calretinin, EMA, HMFG-2 and CEA improved sensitivity for malignancy in general from 78% to 96% and specificity from 73% to 91%. Sensitivity for malignant mesothelioma increased from 45% to 91%, with an increase in specificity from 87% to 96%. Sensitivity for adenocarcinoma decreased slightly from 100% to 92%, but specificity increased from 86% to 100%. Overall, diagnostic accuracy increased from 76% to 94%. CONCLUSION: Immunocytochemical staining of standardized cell block reparations of serous fluid cells with a small panel of 4 antibodies significantly improves diagnostic results compared to cytomorphologic evaluation alone.     

A comparison of immunomagnetic and surface adhesion immunofluorescent techniques for the rapid detection of Listeria monocytogenes and Listeria innocua in meat

an immunomagnetic immunofluorescent method was investigated for the rapid detection of Listeria monocytogenes and Listeria innouca . This technique involved enrichment of the suspect sample at 30°C overnight. Listeria monocytogenes cells were isolated from the enriched sample using immunomagnetic separation and Listeria were subsequently visualized using an immunofluorescent microscopy technique. This technique was used in the detection of Listeria cells from pure culture, inoculated beef mince samples and naturally contaminated retail beef mince samples. A detection level of approximately 1×10³ cfu ml⁻¹ was achieved. When compared with traditional detection methods no false negatives or positives were recorded for L. monocytogenes or L. innocua . The immunomagnetic immunofluorescent technique had a detection level similar to a previously described surface adhesion immunofluorescent technique. Isolation of the Listeria cells by surface adhesion involved dipping a membrane attached to a microscope slide into the enriched sample for 10 min. This was quicker and simpler to perform than the immunomagnetic separation technique which took 2 h to carry out.     

Effect of long-term culture of a human laryngeal carcinoma cell line on epitectin production and tumorigenicity in athymic mice

Epitectin is a high molecular weight mucin-type glycoprotein over-expressed on the surface of human carcinoma cells. In cancer cells, it is proposed to play a protective function and to modulate cell surface properties such as antigenicity and cell adhesion. We have examined the effect of long-term culture on the cell curface expression of epitectin by a human laryngeal carcinoma cell line and the correlation between epitectin expression and tumor production in athymic mice. Indirect immunofluorescence labelling using an epitectin specific monoclonal antibody showed that the level of epitectin on the cell surface was significantly reduced after 78 or more generations in culture. Gel electrophoresis of cell extracts, followed by wheat germ agglutinin and peanut agglutinin overlay analyses, demonstrated similar losses in total cellular epitectin as a result of prolonged passage in culture. The levels of other glycoproteins reacting with wheat germ agglutinin were not significantly altered in high passage cells. Similar results were obtained when HMFG-2 monoclonal antibody was used to probe the levels of cell surface epitectin. In contrast to the above probes, the binding of HMFG-2 to epitectin is independent of glycosylation, therefore it can be concluded that the observed changes are not due to aberration in epitectin glycosylation with increasing passage number but rather due to lack of synthesis of epitectin. The ability of the low epitectin producing H.Ep.2 cells to grow as tumors in athymic mice was reduced compared to the high epitectin producing cells.This work comprises part of a doctoral thesis by N.A.D. submitted to the Pennsylvania State University.     

Naturally soluble tumor antigens from guinea pig hepatomas: isolation and partial characterization.

Naturally soluble tumor antigens were detected in the ascites fluid of guinea pigs bearing an ascites tumor and from exhausted tissue culture media of cultured tumor cells. Two antigenically distinct cell lines of diethylnitrosamine-induced strain-2 guinea pig hepatomas (line-10 and line-1) served as the source of tumor antigens. Tumor antigen activity was detected by four different techniques: immunodiffusion, inhibition of complement-mediated cytotoxicity, inhibition of membrane immunofluorescence, and delayed cutaneous hypersensitivity. With syngeneic tumor-specific antiserum, line-10 guinea pig tumor antigens were detected by immunofluorescence in the concentrated ascites and tissue culture fluids. With a xenogenic antiserum, demonstrated to be tumor specific, line-10 tumor antigens were detected not only in the concentrated ascites and tissue culture fluids but also in two of the partially purified fractions of these fluids. When the line-10 concentrated ascites and its fraction I were subjected to ultracentrifugation at 300,000 x G for 1 hr, the antigen activity was retained in the supernatant and thus by this criterion the tumor antigens detected in these samples are soluble. Immunodiffusion data indicate that more than one antigen is present in the line-10 system since three lines of precipitation were detected when line-10 concentrated ascites was reacted with the line-10 tumor-specific antiserum. In contrast to this, the line-10-concentrated tissue culture fluid displayed only one line of precipitation. Although tumor antigens could not be demonstrated in the other antigenically distinct tumor cell line, line-1, by immunodiffusion or inhibition of membrane immunofluorescence, inhibition of complement-mediated cytotoxicity was able to detect tumor antigens in the line-1 concentrated ascites and tissue culture fluids.     

A gold nanoparticles based immuno-bioprobe for detection of Vi capsular polysaccharide of Salmonella enterica serovar Typhi

A rapid and sensitive gold-nanobioprobe based immunoassay format has been presented for the detection of capsular Vi polysaccharide of Salmonella enterica serovar Typhi (surface antigen) using anti-Vi antibodies. The Vi antigen was extracted from serovar Typhi cells, under the optimised growth conditions for its over-expression. Anti-Vi antibodies were produced and conjugated with gold nanoparticles (GNPs) of definite size (~30 nm), which served as the nano-bioprobe in the detection system. A sandwich immunoassay was developed using nitrocellulose dot blot comb (8/12 wells) membranes immobilized with anti-Salmonella antibodies at the optimal concentration (43 ng spot(-1)). The Vi antigen in the clinical isolates, spiked samples and also in the standard strain (serovar Typhi Ty2) was detected by measuring the colour intensity of GNPs and correlating it with the concentration of serovar Typhi in samples. Using this developed immunoassay technique Vi positive serovar Typhi strains could be detected with a sensitivity of up to 10(2) cells mL(-1) in the clinical isolates as well as in the spiked samples. The developed immunoassay technique could be useful for the detection of typhoid fever and may be important from an epidemiological point of view.     

Double immunocytochemical staining in the study of antibody-producing cells in vivo. Detection of specific antibody-producing cells in the spleen and simultaneous determination whether or not they produce immunoglobulin G antibodies

Rabbits were primed intravenously with human serum albumin (HSA) and boosted with the same antigen 2 months later. Cells producing specific antibodies against HSA could be detected in vivo and it could be determined whether or not they belonged to the immunoglobulin (Ig) G class using a combined peroxidase (HRP) and alkaline phosphatase (AP) immunocytochemical technique. HRP-HSA conjugate was used for detection of anti-HSA-producing cells and AP-sheep anti-rabbit IgG (SRIgG) was used to determine the IgG class of the antibodies produced by these cells in the same spleen section. After performing both HRP and AP cytochemistry, cells with a red-stained cytoplasm represent anti-HSA-producing cells not stained for their antibody class and cells with a blue-stained cytoplasm represent cells producing IgG antibodies not directed against HSA. Cells with a double-stained cytoplasm represent cells producing anti-HSA antibodies belonging to the IgG class. We also attempted to determine whether or not part of the anti-HSA-producing cells belonged to the IgM class using AP-sheep anti-rabbit IgM (SRIgM). In this case no double-stained cells were detected, indicating that the affinity of intracellular IgM-anti-HSA antibodies is too low to allow detection using the present technique.     

Studies with anti-bromodeoxyuridine antibodies: II. Simultaneous immunocytochemical detection of antigen expression and DNA synthesis by in vivo labeling of mouse intestinal mucosa

We developed a rapid and convenient immunocytochemical method for simultaneous detection of antigen expression and S-phase cells by means of anti-bromodeoxyuridine (BrdUrd) antibodies. Immunocytochemical detection of BrdUrd after in vivo administration in mice was compared with autoradiography using [3H]-BrdUrd. Both the sensitivity and specificity of the technique were high. For the dual peroxidase staining technique, DAB color modification by cobalt ions was used. We showed that antigen localization was not affected by the BrdUrd staining protocol. The technique we describe here can be performed on frozen or paraffin-embedded tissue and on cytocentrifuge preparations for analysis of the cytokinetics of phenotypically defined cells in heterogeneous populations.     

Multiplexed electrical detection of cancer markers with nanowire sensor arrays

We describe highly sensitive, label-free, multiplexed electrical detection of cancer markers using silicon-nanowire field-effect devices in which distinct nanowires and surface receptors are incorporated into arrays. Protein markers were routinely detected at femtomolar concentrations with high selectivity, and simultaneous incorporation of control nanowires enabled discrimination against false positives. Nanowire arrays allowed highly selective and sensitive multiplexed detection of prostate specific antigen (PSA), PSA-alpha1-antichymotrypsin, carcinoembryonic antigen and mucin-1, including detection to at least 0.9 pg/ml in undiluted serum samples. In addition, nucleic acid receptors enabled real-time assays of the binding, activity and small-molecule inhibition of telomerase using unamplified extracts from as few as ten tumor cells. The capability for multiplexed real-time monitoring of protein markers and telomerase activity with high sensitivity and selectivity in clinically relevant samples opens up substantial possibilities for diagnosis and treatment of cancer and other complex diseases.     

Malignant ascites of serous papillary ovarian adenocarcinoma. An immunocytochemical study of the tumor cells

In 17 malignant peritoneal effusions due to papillary serous adenocarcinoma of the ovary, the reaction patterns of the tumor cells to monoclonal antibodies (MAbs) against surface antigens were studied and compared with the reaction patterns of mesothelial cells in the same effusions. The following surface markers were used with the adhesive slide method: epithelial membrane antigen (EMA), human epithelium-specific cell surface antigen (HEA-125), human endothelial antigen (BMA-120), carcinoembryonic antigen (CEA 3-13), an antibody against natural killer cells and cytotoxic cells (BMA-070), granulocyte antigen (Leu M1) and leukocyte antigen of class I (HLA-1). In all cases, from 30% to 95% of the tumor cells reacted with EMA and HEA-125. Tumor cells showed a positive staining with CEA 3-13 in only five cases. In all cases, from 75% to 95% of the tumor cells reacted positively with BMA-120. The reactivity of a few mesothelial cells with EMA and of all mesothelial cells with BMA-120 did not interfere with the identification of positive tumor cells since the reaction patterns were different. Interestingly, our study demonstrated that BMA-070, an MAb identifying natural killer cells and cytotoxic cells, is also a most useful tumor marker. The same was found to be true for Leu M1, an MAb originally thought to react only with granulocytes. The tumor cells showed a partial or total loss of the expression of HLA-1 reactivity. Since all cases were immunocytochemically positive for tumor cells while conventional cytology was positive in only 13 of the cases, the immunocytochemical analysis of malignant peritoneal effusions due to papillary serous adenocarcinoma of the ovary seems able to improve the cytologic diagnosis of the fluids.     

Simultaneous flow cytometric detection of nuclear DNA and tumor-associated antigens in lung cancers

Flow cytometric (FCM) determinations of DNA index were found to be insufficient to distinguish the presence of tumor cells from normal ones in neoplastic tissues obtained from 29 patients with lung cancer. Therefore, the DNA and tumor-associated antigen (TAA) contents of cultured human lung cancer cells were simultaneously analyzed using FCM to assess whether this dual technique would help in distinguishing tumor cells from normal ones. For the study, cells from PC-10 (a squamous cell carcinoma line), PC-3 (an adenocarcinoma line) and PC-6 (a small cell carcinoma line) were mixed with normal peripheral lymphocytes. The TAAs studied were carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCCA) and neuron-specific enolase (NSE). The alcohol-fixed cells were treated with the respective primary TAA, followed by fluorescein-isothiocyanate-conjugated secondary antibody; the cellular DNA was then stained using propidium iodide. Red and green fluorescences were measured simultaneously by FCM. The results showed CEA mainly in PC-3 cells, SCC in PC-10 cells and NSE in PC-6 cells; thus, each cell type had a relatively specific TAA. DNA content and cell size analyses differentiated neoplastic cells from normal lymphocytes for PC-3 and PC-10 cells, but not for PC-6 cells. Simultaneous FCM analyses of DNA and the TAA specific for the individual cell type made it possible to distinguish all tumor cell types from normal lymphocytes.     

A new approach to phenotyping disseminated tumor cells: methodological advances and clinical implications

At the time of primary therapy (surgery, systemic chemotherapy and/or radiation), disseminated tumor cells in the bone marrow can be found in almost one-third of patients with cancer of the breast, ovary, esophagus, stomach, colon, and other solid tumors. Whereas the prognostic impact of the mere presence of these cells is still a matter of debate, it has been shown that expression of tumor-associated antigens in disseminated tumor cells is linked to more aggressive disease. Therefore, further characterization of disseminated tumor cells at the protein and gene level has become increasingly important. To date, the most common detection method for disseminated tumor cells in the bone marrow is an immunocytochemical approach using cytokeratin-directed antibodies for detection of epithelial cells and the APAAP system for their visualization. We have established a new double immunofluorescence technique enabling simultaneous detection, phenotyping, and antigen quantification of disseminated tumor cells. Mononuclear cells from bone marrow are enriched by Ficoll gradient centrifugation and cytospins are prepared. Double immunofluorescence is performed using antibodies against cytokeratins 8/18/19 (mAb A45B/B3) and the uPA receptor CD87 (pAb HU277). CD87 expression is recorded by confocal laser scanning microscopy (CLSM) using fluorescence labeled latex beads as the reference; staining intensities of all the scans are then summed and quantified (extended focus). This protocol, originally designed for disseminated tumor cells in bone marrow, can also be applied to disseminated tumor cells in blood, to leukapheresis cells or to cells present in malignant ascites or other malignant effusions. The tumor cells detected may be used for gene and mRNA analyses. Furthermore, disseminated tumor cells also represent interesting targets for clinical studies on patient prognosis or prediction of therapy response as well as for specific tumor-biological therapies.     

系统解剖学立体化双语教学资源建设的探讨

系统解剖学是医学生最为重要的专业基础课程之一。近年来,我们一直坚持双语教学,2008年我校系统解剖学获得首批国家双语教学示范课程。为建设好双语教学示范课程,我们积极开展解剖学双语教学探索和实践,着重于该门课程的立体化双语教学资源的建设,以纸质教材为主体,利用不同教学媒体的优点来呈现解剖学不同的教学内容,形成一个立体化的双语教学资源,并应用于教学实践活动中,达到提高学生专业英语理解能力,灵活运用外语思维解决医学问题能力的目标。     

MUC1 (EMA) expressing plasma cells in bone marrow infiltrated by plasma cell myeloma

MUC1 (also called: epithelial membrane antigen, EMA) represents a mucin molecule strongly expressed in various epithelia and epithelial neoplasms. Its expression correlates with clinical and pathological factors as well as prognosis in some tumor types. Additionally, MUC1 was detected in normal haematopoietic cell lines and neoplasms, especially subgroups of human lymphomas including plasma cell myeloma. Therefore, the expression of MUC1 in trephine biopsies exhibiting infiltrates of plasma cell myeloma were investigated immunohistochemically. An immunoreactivity of two monoclonal antibodies (EMA and HMFG-2) was observed in about 50% of the cases. In cases exhibiting a so-called packed marrow, EMA immunoreactivity was reduced. However, MUC1 positivity did not correlate with the cytologic grade of differentiation, the fibre content of the marrow, or survival probability of the patients. However, its strong expression in a certain percentage of cases of plasma cell myeloma may be of therapeutic impact, since new therapeutic strategies include the enrichment of MUC1-specific T cells or MUC1 vaccination.     

Detection and Assay of Avian Tumor Virus Group-Specific Antigen and Antibody by the Paired Radioiodine-Labeled Antibody Technique

The paired radioiodine-labeled antibody technique (PRILAT) was applied to the detection and quantitation of avian tumor virus group-specific (gs) antigens and antibody. The technique proved to be specific, repeatable, and appreciably more sensitive than the microcomplement-fixation test for avian leukosis (COFAL). The PRILAT facilitated direct measurement of comparative antigen content of several types of transformed, neoplastic, or virus-infected cells and the magnitude of nonspecific antibody binding by appropriate control cells. The versatility of the technique was illustrated by application to the detection and quantitation of gs antibody content of chicken, turkey, pigeon, and hamster sera. Antibodies were detected in COFAL-negative sera from hamsters bearing tumors induced by the Schmidt-Ruppin strain of Rous sarcoma virus. Sera from chickens bearing similar tumors were not positive for gs antibodies, although sera from turkeys and chickens immunized with avian leukosis virus did contain gs antibodies.