224 resultados para Prostatic Specific Antigen
em Université de Lausanne, Switzerland
Resumo:
Efficient vaccination against infectious agents and tumors depends on specific antigen targeting to dendritic cells (DCs). We report here that biosafe coronavirus-based vaccine vectors facilitate delivery of multiple antigens and immunostimulatory cytokines to professional antigen-presenting cells in vitro and in vivo. Vaccine vectors based on heavily attenuated murine coronavirus genomes were generated to express epitopes from the lymphocytic choriomeningitis virus glycoprotein, or human Melan-A, in combination with the immunostimulatory cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF). These vectors selectively targeted DCs in vitro and in vivo resulting in vector-mediated antigen expression and efficient maturation of DCs. Single application of only low vector doses elicited strong and long-lasting cytotoxic T-cell responses, providing protective antiviral and antitumor immunity. Furthermore, human DCs transduced with Melan-A-recombinant human coronavirus 229E efficiently activated tumor-specific CD8(+) T cells. Taken together, this novel vaccine platform is well suited to deliver antigens and immunostimulatory cytokines to DCs and to initiate and maintain protective immunity.
Resumo:
Objective. To study the impact of the neutral endopeptidase (NEP)/neuropeptides (NPs) axis and nuclear factor kappa B (NFκB) as predictors of prostate-specific antigen (PSA) recurrence after radical prostatectomy (RP). Patients and Methods. 70 patients with early-stage PC were treated with RP and their tumor samples were evaluated for expression of NEP, endothelin-1 (ET-1) and NFκB (p65). Time to PSA recurrence was correlated with the examined parameters and combined with preoperative PSA level, Gleason score, pathological TNM (pT) stage, and surgical margin (SM) assessment. Results and Limitations. Membranous expression of NEP (P < 0.001), cytoplasmic ET-1 (P = 0.002), and cytoplasmic NFκB (P < 0.001) were correlated with time to PSA relapse. NEP was associated with ET-1 (P < 0.001) and NFκB (P < 0.001). ET-1 was also correlated with NFκB (P < 0.001). NEP expression (P = 0.017), pT stage (P = 0.013), and SMs (P = 0.036) were independent predictors of time to PSA recurrence. Conclusions. There seems to be a clinical model of NEP/NPs and NFκB pathways interconnection, with their constituents following inverse patterns of expression in accordance with their biological roles and molecular interrelations.
Resumo:
Abstract: Purpose: NY-ESO-1 (ESO), a tumor-specific antigen of the cancer/testis group, is presently viewed as an important model antigen for the development of generic anticancer vaccines. The ESO119-143 region is immunodominant following immunization with a recombinant ESO vaccine. In this study, we generated DRB1*0101/ESO119-143 tetramers and used them to assess CD4 T-cell responses in vaccinated patients expressing DRB1*0101 (DR1). Experimental Design: We generated tetramers of DRB1*0101 incorporating peptide ESO119-143 using a previously described strategy. We assessed ESO119-143-specific CD4 T cells in peptide-stimulated post-vaccine cultures using the tetramers. We isolated DR1/ESO119-143 tetramer(+) cells by cell sorting and characterized them functionally. We assessed vaccine-induced CD4(+) DR1/ESO119-143 tetramer(+) T cells ex vivo and characterized them phenotypically. Results: Staining of cultures from vaccinated patients with DR1/ESO119-143 tetramers identified vaccine-induced CD4 T cells. Tetramer(+) cells isolated by cell sorting were of T(H)1 type and efficiently recognized full-length ESO. We identified ESO123-137 as the minimal optimal epitope recognized by DR1-restricted ESO-specific CD4 T cells. By assessing DR1/ESO119-143 tetramer(+) cells using T cell receptor (TCR) beta chain variable region (V beta)-specific antibodies, we identified several frequently used V beta. Finally, direct ex vivo staining of patients' CD4 T cells with tetramers allowed the direct quantification and phenotyping of vaccine-induced ESO-specific CD4 T cells. Conclusions: The development of DR1/ESO119-143 tetramers, allowing the direct visualization, isolation, and characterization of ESO-specific CD4 T cells, will be instrumental for the evaluation of spontaneous and vaccine-induced immune responses to this important tumor antigen in DR1-expressing patients
Resumo:
In a recent vaccination trial assessing the immunogenicity of an NY-ESO-1 (ESO) recombinant protein administered with Montanide and CpG, we have obtained evidence that this vaccine induces specific cytolytic T lymphocytes (CTL) in half of the patients. Most vaccine-induced CTLs were directed against epitopes located in the central part of the protein, between amino acids 81 and 110. This immunodominant region, however, is distinct from another ESO CTL region, 157-165, that is a frequent target of spontaneous CTL responses in A2+ patients bearing ESO tumors. In this study, we have investigated the CTL responses to ESO 157-165 in A2+ patients vaccinated with the recombinant protein. Our data indicate that after vaccination with the protein, CTL responses to ESO 157-165 are induced in some, but not all, A2+ patients. ESO 157-165-specific CTLs induced by vaccination with the ESO protein were functionally heterogeneous in terms of tumor recognition and often displayed decreased tumor reactivity as compared with ESO 157-165-specific CTLs isolated from patients with spontaneous immune responses to ESO. Remarkably, protein-induced CTLs used T-cell receptors similar to those previously isolated from patients vaccinated with synthetic ESO peptides (Vbeta4.1) and distinct from those used by highly tumor-reactive CTLs isolated from patients with spontaneous immune responses (Vbeta1.1, Vbeta8.1, and Vbeta13.1). Together, these results demonstrate that vaccination with the ESO protein elicits a repertoire of ESO 157-165-specific CTLs bearing T-cell receptors that are structurally distinct from those of CTLs found in spontaneous immune responses to the antigen and that are heterogeneous in terms of tumor reactivity, being often poorly tumor reactive.
Resumo:
T-cell hybridomas were obtained after fusion of BW 5147 thymoma and long-term cultured T cells specific for cytochrome c peptide 66-80 derivatized with a 2,4-dinitroaminophenyl (DNAP) group. The resulting hybridomas were selected for their capacity to specifically bind to soluble radiolabeled peptide antigen. One T-cell hybrid was positive for antigen binding. This hybrid T cell exhibits surface phenotypic markers of the parent antigen-specific T cells. The binding could be inhibited either by an excess of unlabeled homologous antigen or by cytochrome c peptide 11-25 derivatized with a 2-nitrophenylsulfenyl group. Several other peptide antigens tested failed to inhibit binding of the radioactive peptide. This suggests that a specific amino acid sequence, modified by a DNAP group, is the antigenic structure recognized by the putative T-cell receptor. In addition, direct interaction of DNAP-66-80 peptide with the hybridoma cell line induced production of the T-cell growth factor interleukin 2. Furthermore, supernatants derived from syngeneic macrophages pulsed with the relevant peptide also induced the antigen-specific hybridoma to produce interleukin 2.
Resumo:
PURPOSE: Prostate cancer is the most commonly diagnosed cancer in the United States. The diagnosis or followup of prostate cancer in men older than 50 years is based on digital rectal examination, measurement of the free-to-total prostatic specific antigen ratio and transrectal ultrasound assisted needle biopsy of the prostate. We developed and evaluated a noninvasive method for diagnosing prostate cancer based on the measurement of telomerase activity after prostatic massage in fresh voided urine or after urethral washing. MATERIALS AND METHODS: We obtained 36 specimens of cells after prostatic massage in the fresh voided urine of 16 patients who subsequently underwent radical prostatectomy and after urethral washing in 20 who underwent prostate needle biopsies. Ethylenediaminetetraacetic acid was immediately added to the collected urine or washing to a final concentration of 20 mM. After protein extraction by CHAPS buffer each specimen was tested for telomerase activity in a 2-step modified telomeric repeat amplification protocol assay. The 2 prostate cancer cell lines PC-3 and LNCaP with high telomerase activity were used as a positive control. RESULTS: Telomerase activity was detected in 14 of 24 samples with known prostate cancer (sensitivity 58%). In contrast, no telomerase activity was found in the 12 cases without histological evidence of prostate tumor (specificity 100%). Eight of 9 poorly differentiated cancers expressed telomerase activity (89%), while only 6 of 15 well and moderately differentiated cancers showed telomerase activity (40%). CONCLUSIONS: Our data illustrate that telomerase activity may be detected in voided urine or washing after prostatic massage in patients with prostate cancer. Sensitivity was higher for poorly differentiated tumors. This approach is not currently available for detecting prostate cancer in clinical practice. However, these results are promising and further studies are ongoing.
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The SSX-2 gene encodes a tumor-specific antigen expressed in neoplasms of various histological types. By analyzing a tumor-infiltrated lymph node of a melanoma patient bearing an SSX-2-expressing tumor, we have recently identified the first SSX-2-derived CD8(+) T-cell epitope, that corresponds to peptide SSX-2(41-49), and is recognized by specific CTL in an HLA-A2 restricted fashion. Here, we have used fluorescent HLA-A2/SSX-2(41-49) peptide multimeric complexes to analyze the response to SSX-2(41-49) in melanoma patients and healthy donors. Multimer(+) CD8(+) T cells were readily detected in the majority of patients bearing SSX-2-expressing tumors and, at lower proportions, in patients with nonexpressing tumors and healthy donors. Importantly, isolated A2/SSX-2(41-49) multimer(+) CD8(+) T cells exhibited a large functional heterogeneity in terms of antigen recognition and tumor reactivity. SSX-2-specific CTLs isolated from tumor-infiltrated lymph node of antigen-expressing patients as well as from the corresponding peripheral blood mononuclear cells exhibited high functional avidity of antigen recognition and efficiently recognized antigen-expressing tumors. In contrast, SSX-2-specific CTLs isolated from patients with undetectable responses in the tumor-infiltrated lymph node, as well as from healthy donors, recognized the antigen with decreased functional avidity and were not tumor reactive. Together, these data indicate that CD8(+) T-cell responses to SSX-2(41-49) frequently occur in SSX-2-expressing melanoma patients and suggest that SSX-2(41-49)-specific CTLs of high avidity and tumor reactivity are selectively expanded during immune responses to SSX-2-expressing tumors in vivo.
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PURPOSE: To understand the reasons for differences in the delineation of target volumes between physicians. MATERIAL AND METHODS: 18 Swiss radiooncology centers were invited to delineate volumes for one prostate and one head-and-neck case. In addition, a questionnaire was sent to evaluate the differences in the volume definition (GTV [gross tumor volume], CTV [clinical target volume], PTV [planning target volume]), the various estimated margins, and the nodes at risk. Coherence between drawn and stated margins by centers was calculated. The questionnaire also included a nonspecific series of questions regarding planning methods in each institution. RESULTS: Fairly large differences in the drawn volumes were seen between the centers in both cases and also in the definition of volumes. Correlation between drawn and stated margins was fair in the prostate case and poor in the head-and-neck case. The questionnaire revealed important differences in the planning methods between centers. CONCLUSION: These large differences could be explained by (1) a variable knowledge/interpretation of ICRU definitions, (2) variable interpretations of the potential microscopic extent, (3) difficulties in GTV identification, (4) differences in the concept, and (5) incoherence between theory (i.e., stated margins) and practice (i.e., drawn margins).
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Melanoma antigen recognized by T cells 1 (MART-1) is a melanoma-specific antigen, which has been thoroughly studied in the context of immunotherapy against malignant melanoma and which is found only in the pigment cell lineage. However, its exact function and involvement in pigmentation is not clearly understood. Melanoma antigen recognized by T cells 1 has been shown to interact with the melanosomal proteins Pmel17 and OA1. To understand the function of MART-1 in pigmentation, we developed a new knockout mouse model. Mice deficient in MART-1 are viable, but loss of MART-1 leads to a coat color phenotype, with a reduction in total melanin content of the skin and hair. Lack of MART-1 did not affect localization of melanocyte-specific proteins nor maturation of Pmel17. Melanosomes of hair follicle melanocytes in MART-1 knockout mice displayed morphological abnormalities, which were exclusive to stage III and IV melanosomes. In conclusion, our results suggest that MART-1 is a pigmentation gene that is required for melanosome biogenesis and/or maintenance.
Resumo:
Prostate cancer (PCa) is a potentially curable disease when diagnosed in early stages and subsequently treated with radical prostatectomy (RP). However, a significant proportion of patients tend to relapse early, with the emergence of biochemical failure (BF) as an established precursor of progression to metastatic disease. Several candidate molecular markers have been studied in an effort to enhance the accuracy of existing predictive tools regarding the risk of BF after RP. We studied the immunohistochemical expression of p53, cyclooxygenase-2 (COX-2) and cyclin D1 in a cohort of 70 patients that underwent RP for early stage, hormone naïve PCa, with the aim of prospectively identifying any possible interrelations as well as correlations with known prognostic parameters such as Gleason score, pathological stage and time to prostate-specific antigen (PSA) relapse. We observed a significant (p = 0.003) prognostic role of p53, with high protein expression correlating with shorter time to BF (TTBF) in univariate analysis. Both p53 and COX-2 expression were directly associated with cyclin D1 expression (p = 0.055 and p = 0.050 respectively). High p53 expression was also found to be an independent prognostic factor (p = 0.023). Based on previous data and results provided by this study, p53 expression exerts an independent negative prognostic role in localized prostate cancer and could therefore be evaluated as a useful new molecular marker to be added in the set of known prognostic indicators of the disease. With respect to COX-2 and cyclin D1, further studies are required to elucidate their role in early prediction of PCa relapse after RP.
Resumo:
INTRODUCTION: The cell surface endopeptidase CD10 (neutral endopeptidase) and nuclear factor-κB (NF-κB) have been independently associated with prostate cancer (PC) progression. We investigated the correlations between these two factors and their prognostic relevance in terms of biochemical (prostate-specific antigen, PSA) relapse after radical prostatectomy (RP) for localized PC. PATIENTS AND METHODS: The immunohistochemical expression of CD10 and NF-κB in samples from 70 patients who underwent RP for localized PC was correlated with the preoperative PSA level, Gleason score, pathological stage and time to PSA failure. RESULTS: CD10 expression was inversely associated with NF-κB expression (p < 0.001), stage (p = 0.03) and grade (p = 0.003), whereas NF-κB was directly related with stage (p = 0.006) and grade (p = 0.002). The median time to PSA failure was 56 months. CD10 and NF-κB were directly (p < 0.001) and inversely (p < 0.001) correlated with biochemical recurrence-free survival, respectively. CD10 expression (p = 0.022) and stage (p = 0.018) were independently associated with time to biochemical recurrence. CONCLUSION: Low CD10 expression is an adverse prognostic factor for biochemical relapse after RP in localized PC, which is also associated with high NF-κB expression. Decreased CD10 expression which would lead to increased neuropeptide signaling and NF-κB activity may be present in a subset of early PCs.
Resumo:
In 2009, the American Cancer Society (ACS) Prostate Cancer Advisory Committee began the process of a complete update of recommendations for early prostate cancer detection. A series of systematic evidence reviews was conducted focusing on evidence related to the early detection of prostate cancer, test performance, harms of therapy for localized prostate cancer, and shared and informed decision making in prostate cancer screening. The results of the systematic reviews were evaluated by the ACS Prostate Cancer Advisory Committee, and deliberations about the evidence occurred at committee meetings and during conference calls. On the basis of the evidence and a consensus process, the Prostate Cancer Advisory Committee developed the guideline, and a writing committee drafted a guideline document that was circulated to the entire committee for review and revision. The document was then circulated to peer reviewers for feedback, and finally to the ACS Mission Outcomes Committee and the ACS Board of Directors for approval. The ACS recommends that asymptomatic men who have at least a 10-year life expectancy have an opportunity to make an informed decision with their health care provider about screening for prostate cancer after they receive information about the uncertainties, risks, and potential benefits associated with prostate cancer screening. Prostate cancer screening should not occur without an informed decision-making process. Men at average risk should receive this information beginning at age 50 years. Men in higher risk groups should receive this information before age 50 years. Men should either receive this information directly from their health care providers or be referred to reliable and culturally appropriate sources. Patient decision aids are helpful in preparing men to make a decision whether to be tested.
Resumo:
In 2011, new tools to evaluate life expectancy are available. Controversy about PSA-based screening for prostate cancer is still going on, with new data from the US Preventive services task force. A brief behavioral treatment for insomnia can be efficient and durable. Gliptines are be useful to avoid treatment-induced hypoglycemia in diabetic patients. New Alzheimer diagnostic criteria, including biomarkers, have been published.
Resumo:
Spontaneous CD4(+) T-cell responses to the tumor-specific antigen NY-ESO-1 (ESO) are frequently found in patients with epithelial ovarian cancer (EOC). If these responses are of effector or/and Treg type, however, has remained unclear. Here, we have used functional approaches together with recently developed MHC class II/ESO tetramers to assess the frequency, phenotype and function of ESO-specific cells in circulating lymphocytes from EOC patients. We found that circulating ESO-specific CD4(+) T cells in EOC patients with spontaneous immune responses to the antigen are prevalently T(H)1 type cells secreting IFN-γ but no IL-17 or IL-10 and are not suppressive. We detected tetramer(+) cells ex vivo, at an average frequency of 1:25,000 memory cells, that is, significantly lower than in patients immunized with an ESO vaccine. ESO tetramer(+) cells were mostly effector memory cells at advanced stages of differentiation and were not detected in circulating CD25(+)FOXP3(+)Treg. Thus, spontaneous CD4(+) T-cell responses to ESO in cancer patients are prevalently of T(H)1 type and not Treg. Their relatively low frequency and advanced differentiation stage, however, may limit their efficacy, that may be boosted by immunogenic ESO vaccines.
Resumo:
PURPOSE OF REVIEW: Amplification and overexpression of the epidermal growth factor receptor (EGFR) gene are a hallmark of primary glioblastoma (45%), making it a prime target for therapy. In addition, these amplifications are frequently associated with oncogenic mutations in the extracellular domain. However, efforts at targeting the EGFR tyrosine kinase using small molecule inhibitors or antibodies have shown disappointing efficacy in clinical trials for newly diagnosed or recurrent glioblastoma. Here, we review recent insights into molecular mechanisms relevant for effective targeting of the EGFR pathway. RECENT FINDINGS: Molecular workup of glioblastoma tissue of patients under treatment with small molecule inhibitors has established drug concentrations in the tumor tissue, and has shed light on the effectiveness of target inhibition and respective effects on pathway signaling. Further, functional analyses of interaction of small molecule inhibitors with distinct properties to bind to the active or inactive form of EGFR have provided new insights that will impact the choice of drugs. Finally, vaccination approaches targeting the EGFRvIII mutant featuring a tumor-specific antigen have shown promising results that warrant larger controlled clinical trials. SUMMARY: A combination of preclinical and clinical studies at the molecular level has provided new insights that will allow refining strategies for targeting the EGFR pathway in glioblastoma.