Overexpression of Human Aspartyl (Asparaginyl) ß-hydroxylase in NSCLC: Its Diagnostic Value by Means of Exosomes of Bronchoalveolar Lavage.

The human aspartyl ß-hydroxylase (ASPH) is overexpressed in tumor tissues. Bronchoalveolar lavage (BAL) is a diagnostic procedure for infections and malignancies. The aim of this study was to investigate whether tumor exosomes carrying ASPH gene marker were present in bronchoalveolar fluid of patients with non-small cell lung cancer (NSCLC). A tissue microarray analysis was applied to explore the expression of ASPH in different histologic NSCLC. The human NSCLC cell lines and normal bronchial cell lines were used to study exosomal ASPH exprerssion. A total of 27 NSCLC, 21 benign tumor, and 15 healthy controls underwent BAL. Immunohistochemistry was performed to study the ASPH expression in malignant and normal lung tissues. The expression characteristics of ASPH in different NSCLC and normal bronchial cells and pneumocytes were confirmed by cell blocks. A reverse transcription-quantitative polymerase chain reaction was carried out to study the levels of exosomal ASPH expression. Immunohistochemical staining of tissue microarray demonstrated that overexpression of ASPH was found in NSCLC tissues including adenocarcinoma, large cell carcinoma, and squamous cell carcinoma, but absent in adjacent normal tissues. All NSCLC specimens exhibited high levels of ASPH immunoreactivity, while nonmalignant and normal lung tissues exhibited a very low level of expression. Overexpression of ASPH was found in exosomes from NSCLC cell lines but absent from the normal bronchial cell line NL-20. ASPH level from BAL exosomes was significantly increased in NSCLC patients compared with that from nonmalignant or health group. Our method of isolation of BAL exosomes was easily performed in the clinical laboratory. BAL exosomal ASPH can be a potential biomarker for NSCLC diagnosis.

Galectin-3 and ß-catenin are associated with a poor prognosis in serous epithelial ovarian cancer.

PURPOSE: This study was designed to explore the expression levels of Galectin-3 (Gal-3) and ß-catenin in serous epithelial ovarian cancer (SEOC), the linkage between their expressions, and the clinicopathological features of SEOC patients. PATIENTS AND METHODS: Seventy-four SEOC patients' specimens were detected for Gal-3 and ß-Catenin expressions using immunohistochemistry, and the association between ß-catenin or Gal-3 protein expressions and clinicopathological features, treatment effects, and prognosis were analyzed using SPSS 19.0. Western blot was used to analyze protein expressions of Wnt/ß-catenin pathway in ovarian cancer cell lines. RESULTS: There was a statistically significant positive correlation between Gal-3 and ß-catenin expressions in SEOC (r=0.304 and P=0.001). Gal-3 expression was related to the grade (P=0.037), clinical stage (P=0.034), platinum resistance (P=0.030), and recurrence (P=0.001) in SEOC. There was a significant correlation between ß-catenin with recurrence in SEOC (P=0.035). Platinum resistance (P=0.003) and Gal-3 expression (P<0.001) were independent risk factors for poorer overall survival (OS). OS of the strongly positive Gal-3 group was significantly lower than that of the negative and weakly positive groups (log-rank test, P=0.001). OS of the positive ß-catenin group was lower than that of the negative ß-catenin group (log-rank test, P=0.034). Downregulating Gal-3 expression attenuated the protein expressions of Wnt/ß-catenin pathway in ovarian cancer cell lines. CONCLUSION: Gal-3 might activate Wnt/ß-catenin signaling pathway in SEOC. Hence, Gal-3 may serve as a prognostic factor for SEOC. Targeting Gal-3 may be a promising new treatment approach for SEOC.

Evaluation of HE4 and TTR for diagnosis of ovarian cancer: Comparison with CA-125.

OBJECTIVE: Serum human epididymis protein 4 (HE4) and transthyretin (TTR) are new markers for ovarian cancer. We compared HE4 and TTR with the gold marker CA-125 for the diagnosis of ovarian cancer patients. METHODS: One hundred and thirty serum samples from benign ovarian tumor and 400 serum samples from healthy women were used to set up the cut-off. One hundred and twenty-six serum samples from ovarian cancer patients before operation were collected to test the diagnostic value of these ELISA assays. The sensitivity, positive predictive value (PPV) and ROC curves were used to evaluate the diagnostic value. RESULTS: For CA-125, the sensitivity and PPV were respectively 64.29% and 53.57% for stage I-II cancer patients, and respectively 91.43% and 88.57% for stage III-IV cancer patients. For HE4, the sensitivity and PPV were respectively 46.4% and 43.3% for stage I-II cancer patients, and respectively 88.6% and 49.2% for stage III-IV cancer patients. For TTR, the sensitivity and PPV were respectively 78.6% and 68.8% for stage I-II cancer patients, and respectively 82.9% and 74.3% for stage III-IV cancer patients. For CA125, the ROC was respectively 0.7941 and 0.9520 for stage I-II patients and stage III-IV patients. For HE4, the diagnostic value of ROC was 0.7071 for stage I-II cancer patients and 0.9250 for stage III-IV cancer patients. For TTR, the diagnostic value of ROC was 0.9112 for stage I-II cancer patients and 0.9322 for stage III-IV cancer patients. CONCLUSION: Our results support that TTR is an efficient serum marker for the diagnosis of early stage ovarian cancer patients.

Genistein attenuates monocrotaline-induced pulmonary arterial hypertension in rats by activating PI3K/Akt/eNOS signaling.

INTRODUCTION: Phytoestrogen genistein may be useful to treat pulmonary arterial hypertension (PAH). However, its mechanism is still not clear. The aim of the present study was to confirm the therapeutic effects of phytoestrogen genistein on PAH in monocrotaline-induced rat model and to explore its mechanism. MATERIALS AND METHODS: Sprague-Dawley male rats were randomly divided into 4 groups: control group (n=8), PAH group (n=8), genistein treament group with three different doses (n=8 in each dose group) and group of PI3K inhibitor LY294002. The rat model of PAH was induced by monocrotaline (MCT). The situation of survival of rats was observed. Pathological studies of lung and heart tissues were performed. Western-blot detection of P-Akt and P-eNOS expression levels in lung tissue was carried out. Nitrate reductase analysis was used to measure nitric oxide (NO) in lung tissue. RESULTS: Genistein treatment resulted in significant improvement in the speed of tricuspid regurgitation, diameter of pulmonary artery, mean pulmonary artery pressure and right ventricular hypertrophy index. Genistein treatment also resulted in significant improvement in the stenosis of pulmonary artery, proliferation of smooth muscle, right ventricular hypertrophy and myocardial hypertrophy. These therapeutic effects were more obvious with increasing dose of genistein. After genistein treatment, amelioration in survival rates of PAH rats was observed. PI3K inhibitor LY294002 could block these therapeutic effects. In rat lung tissue, P-Akt, P-eNOS and NO expressions were increased significantly in genistein treatment group when compared with PAH group (p<0.05, respectively). The increase in expression level of P-Akt, P-eNOS and NO was correlated with genistein dose. P-Akt, P-eNOS and NO expressions in lung tissue increased slightly in the PI3K inhibitor LY294002 group when compared with PAH group, but the difference was not statistically significant (p>0.05). CONCLUSIONS: We confirmed that genistein could relax pulmonary vascular resistance, reduce pulmonary artery pressure, improve right heart function and ameliorate survival rate in the rat model of PAH. Our study suggested that its mechanism was related with PI3K/Akt/eNOS signal pathway. Phytoestrogen genistein may become a new and effective drug for patients with PAH.

Galectin-3 regulates metastatic capabilities and chemotherapy sensitivity in epithelial ovarian carcinoma via NF-κB pathway.

Galectin-3 (Gal-3) has been found to be involved in the tumor progression and chemoresistance of epithelial ovarian cancer (EOC). Some studies have shown that Gal-3 may interact with nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). However, it is unclear whether the effects of Gal-3 on the metastasis and chemosensitivity of EOC are related to NF-κB. In this study, we aimed to explore whether Gal-3 promoted progression and carboplatin resistance in EOC via NF-κB pathway. Plasmid transfection and RNA interference were used to upregulate or downregulate the expression of Gal-3 in ovarian cancer cell lines. Then, the expression of Gal-3 and the protein expressions of phosphorylation NF-κB pathway molecules were further detected by Western blot. Transwell migration assay was employed to detect the effects of Gal-3 on the migration and invasion of ovarian cancer cell lines. After treatment with carboplatin, flow cytometry (FCM) was employed to detect the effects of Gal-3 on carboplatin-induced apoptosis. Immunofluorescence technique was used to examine the translocation of phosphorylated P65 into the nucleus in ovarian cancer cells after the upregulation of Gal-3. After the knockdown of Gal-3 by small interfering RNA (siRNA), the migration and the invasion of cancer cells were significantly inhibited while the apoptosis and the sensitivities to carboplatin increased. Western blot showed reduction in the phosphorylation components of the NF-κB pathway: inhibitor of kappa B (IκB), IκB kinase (IKK), and P65. However, after the Gal-3 upregulation by plasmid transfection, the capabilities of migration and invasion of cancer cells were significantly promoted while the apoptosis and the sensitivities to carboplatin decreased. Immunofluorescence showed increased nuclear translocation of P65. Inhibitors of the NF-κB pathway did not affect the Gal-3 expression level in ovarian cancer cells. Gal-3 may affect the migratory and invasive capabilities of cancer cells as well as the chemosensitiviy to carboplatin in EOC by acting through the NF-κB pathway.

Galectin-3 inhibition suppresses drug resistance, motility, invasion and angiogenic potential in ovarian cancer.

OBJECTIVE: Ovarian cancer is the most deadly gynecologic malignancy worldwide. Since the pathogenesis of ovarian cancer is incompletely understood, and there are no available screening techniques for early detection, most patients are diagnosed with advanced, incurable disease. In an effort to develop innovative and effective therapies for ovarian cancer, we tested the effectiveness of Galecti-3C in vitro. This is a truncated, dominant negative form of Galectin-3, which is thought to act by blocking endogenous Galectin-3. METHODS: We produced a truncated, dominant-negative form of Galectin-3, namely Galetic-3C. Ovarian cancer cell lines and primary cells from ovarian cancer patients were treated with Galectin-3C, and growth, drug sensitivity, and angiogenesis were tested. RESULT: We show, for the first time, that Galectin-3C significantly reduces the growth, motility, invasion, and angiogenic potential of cultured OC cell lines and primary cells established from OC patients. CONCLUSIONS: Our findings indicate that Galectin-3C is a promising new compound for the treatment of ovarian cancer.

Overexpression of netrin-1 increases the expression of tight junction-associated proteins, claudin-5, occludin, and ZO-1, following traumatic brain injury in rats.

The function of the blood-brain barrier (BBB) depends on the integrity of tight junction (TJ)-associated proteins. Netrin-1 is known to promote angiogenesis and may also regulate the BBB. To understand the association between netrin-1 and the TJ-associated proteins, the expression levels of proteins involved in maintaining the integrity of the BBB, including netrin-1, claudin-5, occludin and zonula occluden (ZO)-1, were investigated in the present study using quantitative polymerase chain reaction, western blot analysis and immunofluorescence. The aim of the present study was to determine the changes in BBB permeability and whether pZsGreen1-N1 mediated overexpression of netrin-1 increased the expression of the TJ-associated proteins following traumatic brain injury (TBI). The results demonstrated that the levels of mRNA transcription and protein expression of the TJ-associated proteins, claudin-5, occludin and ZO-1, were significantly reduced following TBI. Furthermore, the changes in the expression of these three TJ proteins were consistent with the changes in the BBB permeability, indicating that weakening intercellular junctions leads to BBB opening. The present study also demonstrated that netrin-1 significantly increased the downregulation of claudin-5, occludin and ZO-1 expression levels induced by TBI, which provided a basis for further investigation on the role of netrin-1 in the integrity of TJs and proper functioning of the BBB.

Selective expression and immunogenicity of the cancer/testis antigens SP17, AKAP4 and PTTG1 in non-small cell lung cancer: new candidates for active immunotherapy.

ABSTRACT BACKGROUND. Lung cancer is the leading cause of cancer deaths in both genders worldwide, with an incidence only second to prostate cancer in men and breast cancer in women. The lethality of the disease highlights the urgent need for innovative therapeutic options. Immunotherapy can afford efficient and specific targeting of tumor cells, improving efficacy and reducing the side effects of current therapies. We have previously reported the aberrant expression of cancer/testis antigens (CTAs) in tumors of unrelated histological origin. In this study we investigated the expression and immunogenicity of the cancer/testis antigens (CTAs) Sperm Protein 17 (SP17), A-kinase anchor protein 4 (AKAP4) and Pituitary Tumor Transforming Gene 1 (PTTG1) in human non-small cell lung cancer (NSCLC) cell lines and primary tumors. METHODS. We used RT-PCR, immunofluorescence, flow cytometry, ELISA and cytotoxicity assays to determine the expression levels and immunogenicity of SP17, AKAP4 and PTTG1 in human NSCLC cell lines and primary tumors. RESULTS. We found that SP17, AKAP4 and PTTG1 are aberrantly expressed in NSCLC cancer cell lines and primary tumor tissues from patients, compared to normal lung cell lines and tissues. We established the immunogenicity of these CTAs by measuring CTA-specific autoantibodies in patients' sera and generating CTA-specific autologous cytotoxic lymphocytes (CTLs) from patients' peripheral blood mononuclear cells (PBMCs). CONCLUSIONS. Our results provide proof of principle that the CTAs SP17/AKAP4/PTTG1 are expressed in both human NSCLC cell lines and primary tumors and can elicit an immunogenic response in NSCLC patients. Based on our findings, further studies are warranted to explore the feasibility of developing CTA-specific immunotherapeutic strategies for NSCLC patients.

Identification of AKAP-4 as a new cancer/testis antigen for detection and immunotherapy of prostate cancer.

BACKGROUND: Prostate cancer (PC) is the second most common cancer in older men, after skin cancer. PC is difficult to diagnose because the prostate-specific antigen screening method is associated with many false positives. In addition there is a need to develop new and more effective treatments. Among presently available new treatments, immunotherapy is a promising approach. We investigated the expression of the cancer/testis antigen, AKAP-4, in PC patients to evaluate the possibility of exploiting AKAP-4 as a target for immunotherapy. METHODS: We analyzed normal prostate tissues, 15 patients with PC and the LnCAP PC cell line by immunohistochemistry. We tested AKAP-4 immunogenicity through indirect ELISA on sera from patients and healthy subjects, and we generated in vitro AKAP-4-specific cytotoxic lymphocytes from peripheral blood mononuclear cells. RESULTS: AKAP-4 was shown both at the cytoplasmic and surface levels of the LnCAP PC cell line. AKAP-4 was also highly expressed in PC cells from patients. We detected specific anti-AKAP-4 circulating immunoglobulins in AKAP-4 positive subjects. Using recombinant AKAP-4 loaded autologous dendritic cells, we generated AKAP-4-specific and HLA-I-restricted cytotoxic T lymphocytes able to kill PC cells in vitro. Further characterization indicated a Th-1 skewing in the cytokine secretion profile of these cells. CONCLUSIONS: We demonstrate the aberrant expression of AKAP-4 in PC, which will potentially be developed as a biomarker in PC. We provide evidence that AKAP-4 is a potential target for PC adoptive immunotherapy or anti-tumor vaccination.

Tracking human multiple myeloma xenografts in NOD-Rag-1/IL-2 receptor gamma chain-null mice with the novel biomarker AKAP-4.

BACKGROUND: Multiple myeloma (MM) is a fatal malignancy ranking second in prevalence among hematological tumors. Continuous efforts are being made to develop innovative and more effective treatments. The preclinical evaluation of new therapies relies on the use of murine models of the disease. METHODS: Here we describe a new MM animal model in NOD-Rag1null IL2rgnull (NRG) mice that supports the engraftment of cell lines and primary MM cells that can be tracked with the tumor antigen, AKAP-4. RESULTS: Human MM cell lines, U266 and H929, and primary MM cells were successfully engrafted in NRG mice after intravenous administration, and were found in the bone marrow, blood and spleen of tumor-challenged animals. The AKAP-4 expression pattern was similar to that of known MM markers, such as paraproteins, CD38 and CD45. CONCLUSIONS: We developed for the first time a murine model allowing for the growth of both MM cell lines and primary cells in multifocal sites, thus mimicking the disease seen in patients. Additionally, we validated the use of AKAP-4 antigen to track tumor growth in vivo and to specifically identify MM cells in mouse tissues. We expect that our model will significantly improve the pre-clinical evaluation of new anti-myeloma therapies.

Galectin-3C inhibits tumor growth and increases the anticancer activity of bortezomib in a murine model of human multiple myeloma.

Galectin-3 is a human lectin involved in many cellular processes including differentiation, apoptosis, angiogenesis, neoplastic transformation, and metastasis. We evaluated galectin-3C, an N-terminally truncated form of galectin-3 that is thought to act as a dominant negative inhibitor, as a potential treatment for multiple myeloma (MM). Galectin-3 was expressed at varying levels by all 9 human MM cell lines tested. In vitro galectin-3C exhibited modest anti-proliferative effects on MM cells and inhibited chemotaxis and invasion of U266 MM cells induced by stromal cell-derived factor (SDF)-1α. Galectin-3C facilitated the anticancer activity of bortezomib, a proteasome inhibitor approved by the FDA for MM treatment. Galectin-3C and bortezomib also synergistically inhibited MM-induced angiogenesis activity in vitro. Delivery of galectin-3C intravenously via an osmotic pump in a subcutaneous U266 cell NOD/SCID mouse model of MM significantly inhibited tumor growth. The average tumor volume of bortezomib-treated animals was 19.6% and of galectin-3C treated animals was 13.5% of the average volume of the untreated controls at day 35. The maximal effect was obtained with the combination of galectin-3C with bortezomib that afforded a reduction of 94% in the mean tumor volume compared to the untreated controls at day 35. In conclusion, this is the first study to show that inhibition of galectin-3 is efficacious in a murine model of human MM. Our results demonstrated that galectin-3C alone was efficacious in a xenograft mouse model of human MM, and that it enhanced the anti-tumor activity of bortezomib in vitro and in vivo. These data provide the rationale for continued testing of galectin-3C towards initiation of clinical trials for treatment of MM.

Cancer testis antigen, ropporin, is a potential target for multiple myeloma immunotherapy.

Despite recent improvements in standard pharmacologic treatments of multiple myeloma (MM), immunotherapy may prove to be more effective due to its higher specificity and lower toxicity. A novel cancer/testis antigen, ropporin, is a testis-specific protein localized in the sperm flagella. Comparing ropporin expression in healthy and MM samples, we did not detect ropporin expression in the normal tissues, but positive signals were found in 44% of the MM primary samples. The immunogenicity of ropporin was confirmed by the presence of specific antibodies detected by enzyme-linked immunosorbent assay in patients' serum. Our results show that ropporin is a novel cancer/testis antigen for MM. Except for in the testis, an immune privileged site, ropporin was not expressed in normal tissues, but was present in MM cell lines and patients' samples. Noteworthy, we show for the first time that ropporin was present at the cell surface of MM plasma cells. We suggest that ropporin is a promising target for MM immunotherapy, as we were able to generate human leukocyte antigen class I-restricted cytotoxic lymphocytes able to kill autologous MM cells.

Cancer testis antigen vaccination affords long-term protection in a murine model of ovarian cancer.

Sperm protein (Sp17) is an attractive target for ovarian cancer (OC) vaccines because of its over-expression in primary as well as in metastatic lesions, at all stages of the disease. Our studies suggest that a Sp17-based vaccine can induce an enduring defense against OC development in C57BL/6 mice with ID8 cells, following prophylactic and therapeutic treatments. This is the first time that a mouse counterpart of a cancer testis antigen (Sp17) was shown to be expressed in an OC mouse model, and that vaccination against this antigen significantly controlled tumor growth. Our study shows that the CpG-adjuvated Sp17 vaccine overcomes the issue of immunologic tolerance, the major barrier to the development of effective immunotherapy for OC. Furthermore, this study provides a better understanding of OC biology by showing that Th-17 cells activation and contemporary immunosuppressive T-reg cells inhibition is required for vaccine efficacy. Taken together, these results indicate that prophylactic and therapeutic vaccinations can induce long-standing protection against OC and delay tumor growth, suggesting that this strategy may provide additional treatments of human OC and the prevention of disease onset in women with a family history of OC.

Protective CD8+ T-cell responses to cytomegalovirus driven by rAAV/GFP/IE1 loading of dendritic cells.

BACKGROUND: Recent studies demonstrate that recombinant adeno-associated virus (rAAV)-based antigen loading of dendritic cells (DCs) generates in vitro, significant and rapid cytotoxic T-lymphocyte (CTL) responses against viral antigens. METHODS: We used the rAAV system to induce specific CTLs against CVM antigens for the development of cytomegalovirus HCMV) gene therapy. As an extension of the versatility of the rAAV system, we incorporated immediate-early 1 (IE1), expressed in HCMV. Our rAAV vector induced a strong stimulation of CTLs directed against the HCMV antigen IE1. We then investigated the efficiency of the CTLs in killing IE1 targeted cells. RESULTS: A significant MHC Class I-restricted, anti-IE1-specific CTL killing was demonstrated against IE1 positive peripheral blood mononuclear cells (PBMC) after one, in vitro, stimulation. CONCLUSION: In summary, single PBMC stimulation with rAAV/IE1 pulsed DCs induces strong antigen specific-CTL generation. CTLs were capable to lyse low doses of peptides pulsed into target cells. These data suggest that AAV-based antigen loading of DCs is highly effective for generating human CTL responses against HCMV antigens.

Sperm protein 17 is a suitable target for adoptive T-cell-based immunotherapy in human ovarian cancer.

For ovarian cancer (OC) patients with advanced or metastatic disease, standard treatments (chemotherapy and radiotherapy) are not very effective and have undesirable side effects. Newer and more promising approaches in cancer treatment use components of the immune system. In this study, we applied an adoptive immunotherapy-based approach using a cancer testis antigen, sperm protein 17, as a target for the treatment of human metastatic OC in a NOD.CB17-PrkDCcid/J (nonobese, diabetic severe combined immunodeficient) mouse model. We used the human SK-OV-3A2.A3 OC cell line, endogenously expressing sperm protein 17, to induce tumor growth in mice. We provide direct evidence, for the first time, that in vitro cultured, monoclonal, cytotoxic T lymphocytes (derived either from advanced OC patients or from healthy donors), specific for sperm protein 17, can eradicate human metastatic OC cells. In addition, we observed no evidence of autoimmunity after histologic examination of the tissue sections adding to the safety profile of our approach.

The pituitary tumor transforming gene 1 (PTTG-1): an immunological target for multiple myeloma.

BACKGROUND: Multiple Myeloma is a cancer of B plasma cells, which produce non-specific antibodies and proliferate uncontrolled. Due to the potential relapse and non-specificity of current treatments, immunotherapy promises to be more specific and may induce long-term immunity in patients. The pituitary tumor transforming gene 1 (PTTG-1) has been shown to be a novel oncogene, expressed in the testis, thymus, colon, lung and placenta (undetectable in most other tissues). Furthermore, it is over expressed in many tumors such as the pituitary adenoma, breast, gastrointestinal cancers, leukemia, lymphoma, and lung cancer and it seems to be associated with tumorigenesis, angiogenesis and cancer progression. The purpose was to investigate the presence/rate of expression of PTTG-1 in multiple myeloma patients. METHODS: We analyzed the PTTG-1 expression at the transcriptional and the protein level, by PCR, immunocytochemical methods, Dot-blot and ELISA performed on patient's sera in 19 multiple myeloma patients, 6 different multiple myeloma cell lines and in normal human tissue. RESULTS: We did not find PTTG-1 presence in the normal human tissue panel, but PTTG-1 mRNA was detectable in 12 of the 19 patients, giving evidence of a 63% rate of expression (data confirmed by ELISA). Four of the 6 investigated cell lines (66.6%) were positive for PTTG-1. Investigations of protein expression gave evidence of 26.3% cytoplasmic expression and 16% surface expression in the plasma cells of multiple myeloma patients. Protein presence was also confirmed by Dot-blot in both cell lines and patients. CONCLUSION: We established PTTG-1's presence at both the transcriptional and protein levels. These data suggest that PTTG-1 is aberrantly expressed in multiple myeloma plasma cells, is highly immunogenic and is a suitable target for immunotherapy of multiple myeloma.

rAAV/Her-2/neu loading of dendritic cells for a potent cellular-mediated MHC class I restricted immune response against ovarian cancer.

Recent studies demonstrate that recombinant adeno-associated virus (rAAV)-based antigen loading of dendritic cells (DCs) generates, in vitro, significant and rapid cytotoxic T-lymphocyte (CTL) responses against viral antigens. We used the rAAV system to induce specific CTLs against tumor antigens for the development of ovarian cancer (OC) gene therapy. As an extension of the versatility of the rAAV system, we incorporated a self-antigen, Her-2/neu, which is expressed in many cancers, including breast and ovarian. We analyzed two different vectors containing a short (157-612) and long domain (1-1197). Our rAAV vector induced strong stimulation of CTLs directed against the self tumor antigen, Her-2/neu. We then investigated the efficiency of the CTLs in killing Her-2/neu-targeted cells. A significant MHC class I-restricted, anti-Her-2/neu-specific CTL killing was demonstrated against Her-2/neu-positive OC cells after one in vitro stimulation. In summary, single peripheral blood mononuclear cell (PBMC) stimulation with rAAV/157-612- or rAAV/1-1197-pulsed DCs induces strong antigen-specific CTL generation. The CTLs were capable of lysing low doses of peptides pulsed into target cells or OC Her-2/neu(+) tumors. These data suggest that AAV-based antigen loading of DCs is highly effective for generating human CTL responses against OC antigens.

Production of monoclonal antibodies to Tropheryma whipplei and identification of recognized epitopes by two-dimensional electrophoresis and mass spectrometry.

Tropheryma whipplei, the agent of Whipple's disease, is a gram-positive rod-shaped bacterium that belongs to the group of actinobacteria. In order to produce monoclonal antibodies (MAbs) against this bacterium, we inoculated mice with two different strains, Slow2 and Endo5. We produced 13 and 10 MAbs against Slow2 and Endo5, respectively. Nine of the Slow2 MAbs and seven of the Endo5 MAbs recognized a 58-kDa epitope. In addition, three other Endo5 MAbs detected a unique 84-kDa epitope. These MAbs were species specific, as they did not react with a selection of 22 different bacterial species, but they were not strain specific, as they did react with six other strains of T. whipplei. Two-dimensional gel electrophoresis (2-DE) was combined with mass spectrometry (MS) to identify the 58-kDa and 84-kDa epitopes recognized by MAbs. After trypsin in-gel digestion of the spot, the 58-kDa protein was identified as an ATP synthase F1 complex beta chain, whereas the 84-kDa protein was identified as a polyribonucleotide nucleotidyltransferase by MS with matrix-assisted laser desorption ionization-time of flight. In an in vitro model, one of these MAbs allowed good detection of T. whipplei in stool samples, contrary to a rabbit polyclonal antibody, which led to high fluorescent background. In the prospective studies, the produced MAb will be tested for detection of T. whipplei in clinical samples, and the gene coding for identified 58-kDa and 84-kDa antigens will be tentatively cloned and then tested for its use in a diagnostic enzyme-linked immunosorbent assay for Whipple's disease.

Induction of protective immunity against scrub typhus with a 56-kilodalton recombinant antigen fused with a 47-kilodalton antigen of Orientia tsutsugamushi Karp.

A partial gene sequence encoding the 56-kD scrub typhus antigen (Sta56) was amplified from genomic DNA of the Orientia tsutsugamushi Karp strain by a polymerase chain reaction (PCR). The PCR product was ligated with the 47-kD scrub typhus antigen (Sta47) gene in the pQE30/47 expression vector, and the resulting recombinant expression vector was designated pQE30/56-47. A fusion antigen (Sta56-47) was expressed in Escherichia coli cells transformed with pQE30/56-47 after induction with isopropyl-beta-d-thiogalactopyranoside. The Sta56-47 antigen was recognized by both Sta47 and Sta56 immune sera and by immune serum to Sta56-47 in an immunoblot assay. This antigen was purified and used to immunize BALB/c mice. The animals immunized with Sta56-47 exhibited profound humoral and cellular immune responses, as well as increased resistance to O. tsutsugamushi Karp compared with mice immunized with Sta56 or Sta47. These results strongly suggest that Sta56-47 contains antigenic epitopes of the Sta56 and Sta47 antigens of O. tsutsugamushi Karp, and is a more suitable candidate for replacing whole-cell antigen of O. tsutsugamushi Karp to induce protective immunity against scrub typhus.