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Biomedical subjects

C Semino

Publications and source records attributed to C Semino.

At least 19 recordsLinked to original sources
PubMed2006

Fabrication of a three-dimensional nanostructured biomaterial for tissue engineering of bone.

A plasma process for the surface modification of HA powders has been developed. Acrylic acid and acrylic acid/octadiene plasma deposited films onto HA particles have demonstrated to interact with SBF allowing the calcium dissolution-precipitation mechanism. Therefore, a nanostructured composite between HA and a self-assembling peptide scaffold (RAD16-I) has been developed. The differentiation of mESC in this scaffold has been studied, in order to test the osteogenic capacity of the new composite material. We have observed that the mESC can be induced to produce Ca salts (mineralization) in a 3D-microenvironment and moreover, this activity can be enhanced by the presence of HA particles into the nanofiber scaffold.

Animals↗
PubMed2004

Somatostatin receptor distribution and function in immune system.

Somatostatin and cortistatin, a recently discovered endogenous neuropeptide relative of somatostatin, have multiple modulatory effects on the immune system. The specific somatostatin receptor distribution might in part explain the heterogeneity of effects of somatostatin or its analogs on immunocytes. In fact, somatostatin receptor subtypes are differentially expressed on specific cell subsets within the organs of the immune system and the expression is dynamically regulated and seems to depend on the traffic of these cells through and within lymphoid structure and homing in tissues. Somatostatin effects on immune cells are mainly based on autocrine and paracrine modes of action. In fact, activated cells producing somatostatin (or cortistatin) may interact with other cells expressing the receptors. Here, we review the postulated modes of action of somatostatin and somatostatin-like peptides, including the currently available synthetic somatostatin analogs, in cells of the immune system. We also discuss the wide distribution of somatostatin and its specific five receptor subtypes in immune cell lines, as well as throughout animal and human lymphoid organs, in both normal and pathological conditions.

Animals↗
PubMed2002

Self-assembling peptide hydrogel fosters chondrocyte extracellular matrix production and cell division: implications for cartilage tissue repair.

Emerging medical technologies for effective and lasting repair of articular cartilage include delivery of cells or cell-seeded scaffolds to a defect site to initiate de novo tissue regeneration. Biocompatible scaffolds assist in providing a template for cell distribution and extracellular matrix (ECM) accumulation in a three-dimensional geometry. A major challenge in choosing an appropriate scaffold for cartilage repair is the identification of a material that can simultaneously stimulate high rates of cell division and high rates of cell synthesis of phenotypically specific ECM macromolecules until repair evolves into steady-state tissue maintenance. We have devised a self-assembling peptide hydrogel scaffold for cartilage repair and developed a method to encapsulate chondrocytes within the peptide hydrogel. During 4 weeks of culture in vitro, chondrocytes seeded within the peptide hydrogel retained their morphology and developed a cartilage-like ECM rich in proteoglycans and type II collagen, indicative of a stable chondrocyte phenotype. Time-dependent accumulation of this ECM was paralleled by increases in material stiffness, indicative of deposition of mechanically functional neo-tissue. Taken together, these results demonstrate the potential of a self-assembling peptide hydrogel as a scaffold for the synthesis and accumulation of a true cartilage-like ECM within a three-dimensional cell culture for cartilage tissue repair.

Amino Acid Sequence↗
PubMed2002

A defective expression of ICAM-1 (CD54) on secretory endometrial cells is associated with endometriosis.

A defect in the cytolytic activity against autologous endometrial cells refluxed in the peritoneal cavity has been hypothesized as being involved in the etiology of endometriosis, although its causes have not been definitively identified. Cell adhesion molecules are necessary not only for cell-to-cell contact but also for the binding of immune effectors to their targets. In this study, the expression of CD54, CD58 and CD106, three adhesion molecules with a crucial role in cytotoxic mechanisms, was quantitatively studied on fresh endometrial cells by immunofluorescence and flow cytometry. Samples were collected from endometriosis patients (n=10) and controls (n=12), either during the follicular or luteal phase of the cycle. While no significant differences were observed for CD58 and CD106, a significantly reduced expression of CD54 in the secretory endometrial cells of women with endometriosis was observed (-75% with respect to apparently healthy controls). These findings could account for an apparently cyclic defect in the expression of CD54 that could result in poor binding of immune effectors to secretory endometrial cells in vivo. The defective recognition and removal of refluxed endometrial cells could, at least in part, be involved in the pathogenesis of endometriosis.

Adult↗
PubMed2001

HLA class I molecule expression is up-regulated during maturation of dendritic cells, protecting them from natural killer cell-mediated lysis.

It has been widely demonstrated that natural killer (NK) cells are able to discriminate between normal and abnormal cells on the basis of the interaction of their NKRs with the MHC molecules expressed on the target cells. Recent studies showed that also normal dendritic cells are susceptible to NK cell-mediated lysis. In this work, the potential relationships between the expression of different surface molecules on both immature and mature DC and susceptibility to lysis have been investigated. The reduced density of HLA class I on the surface of immature DC resulted in the only permissive signal to NK cell mediated killing. On the contrary, the remarkable increase in HLA class I molecules detected during DC maturation was strictly related to the resistance to NK cell. Contemporary, no clear evidences of a role for other surface molecules modulated during DC maturation (CD80, CD83, CD86 and CD40), were obtained.

Antibodies, Monoclonal↗
PubMed2001

Analysis of HLA-class-I specific natural killer cell receptors expressed on T lymphocytes infiltrating non-small-cell lung cancer.

HLA-class I-specific natural killer cell receptors (HNKR) have been described to significantly interfere with both specific and non-specific functional activities of T lymphocytes. Despite the clear evidences obtained in T cells derived from peripheral blood, little is known about the activity of HNKR expressed in tumor infiltrating lymphocytes. For this reason, we have studied T lymphocytes derived from advanced non small cell lung cancers (NSCLC). The population of T cells expressing the HNKR(+) phenotype was rare both in NSCLC-associated lymphocytes and in the peripheral blood. The two populations were clearly oligoclonal, as shown by the analysis of T cell receptor repertoire. Interestingly, while HNKR(+) T cells derived from the peripheral blood belonged to the CD45R0 phenotype, the large majority of HNKR(+) T cells in TIL were CD45RA. Functionally, all HNKR(+) T cells displayed a cytolytic activity against allogeneic NSCLC. Autologous NSCLC, tested in a single patient, was lysed efficiently by HNKR(+) T cells, thus suggesting that at least in this model, the presence of HNKR did not significantly interfere with the functional capacity of effector cells.

Aged↗
PubMed2001

Intensified chemotherapy supported by DMSO-free peripheral blood progenitor cells in breast cancer patients.

BACKGROUND: The majority of high-dose chemotherapy (HDC)-related complications results from bone marrow aplasia, but the graft infusion per se may cause adverse reactions due to the injection of both dimethyl sulfoxide (DMSO) and cell lysis products. We evaluated the feasibility of a two-step chemotherapy regimen with peripheral blood progenitor cell (PBPC) support in association with a novel procedure to remove DMSO and products of cell lysis from the cryopreserved cells. PATIENTS AND METHODS: Stage III and IV breast cancer patients received induction chemotherapy with three cycles of CEF (cyclophosphamide 600 mg/m2, epirubicin 100 mg/m2, 5-fluorouracil 600 mg/m2) followed by three cycles of HDC consisting of escalating doses of cyclophosphamide (dose range 1200 3000 mg/m2) and carboplatin (dose range 600-1000 mg/m2), supported by DMSO-free PBPC reinfusion. DMSO was removed by a washing/enzymatic digestion procedure. RESULTS: Twenty patients received induction chemotherapy and eighteen completed the entire chemotherapy program; a total of fifty-four cycles of HDC were administered. Dose limiting toxicity of HDC was long-lasting grade 4 neutropenia associated with documented infection. The maximum tolerated dose (MTD) was cyclophosphamide 3000 mg/m2 and carboplatin 600 mg/m2. No side effects related to PBPC reinfusion were observed. CONCLUSIONS: The proposed two-step chemotherapy regimen, associated with a novel washing/enzymatic digestion procedure, is feasible in advanced breast cancer patients in the absence of complications related to the specific toxicity of PBPC reinfusion.

Adult↗
PubMed2000

Cetirizine-induced downregulation of airway fibroblast proliferation and function: a rationale for a different approach to allergy treatment?

Recently, airway fibroblasts captured the attention of both allergists and basic scientists since they are no longer considered as mere bystanders, as far as allergic airway diseases are concerned. The aim of the present study was to assess the effects of different Cetirizine (Cet) concentrations (0.01, 0.05, 0.1 mg/ml) on human airway fibroblast proliferation and on CD54 expression. By means of flow cytometry analysis, we evaluated CD54 expression by airway fibroblasts in basal conditions or after gammaIFN stimulation in the presence of Cetirizine; we also evaluated the effect of the drug on cell proliferation by a [3H]thymidine incorporation assay. All of the tested doses of Cetirizine were able to significantly reduce CD54 upregulation induced by gammaIFN; concerning the fibroblast proliferation, we observed a dose-dependent inhibition of [3H]thymidine incorporation. These results show that Cetirizine exerts a biologic effect directly on human airway fibroblasts, suggesting a new rationale in the use of this compound.

Anti-Allergic Agents↗
PubMed2000

Engagement of CD33 surface molecules prevents the generation of dendritic cells from both monocytes and CD34+ myeloid precursors.

Although CD33 represents an important marker of myeloid cell differentiation, its function remains poorly defined. In view of its homology with p75/AIRM1, a recently identified surface molecule which exerts a potent inhibition on NK cell function, we re-evaluated the effect of CD33 engagement in defined myeloid cell functions. Addition of anti-CD33 mAb to cultures of CD14+ monocytes supplemented with granulocyte-macrophage colony-stimulating factor (GM-CSF), IL-4 and TNF-alpha, prevented the generation of dendritic cells. In these cultured cells, engagement of CD33 resulted in an increased surface binding of annexin-V, followed by cell death. Mature dendritic cells were resistant to the CD33-mediated effect. Also in CD34+ precursors, cultured in the presence of flt3-ligand, c-Kit-ligand, GM-CSF, IL-4 and TNF-alpha, addition of anti-CD33 mAb prevented the recovery of mature dendritic cells. These data suggest a regulatory role of CD33 in the myeloid cell maturation and may offer a tool to interfere with the monocyte/macrophage cell function as well as with the development of dendritic cells.

Antibodies, Monoclonal↗
PubMed2000

Detection of anti-erythropoietin antibodies in haemodialysis patients treated with recombinant human-erythropoietin.

An enzyme-immunoassay was developed to evaluate the presence of anti-erythropoietin antibodies in plasma samples obtained from renal failure patients treated with recombinant human erythropoietin (rh-EPO). The assay was specific and reproducible. Normal donors had no antibodies to EPO, while 67% of treated patients were positive to the assay. While the specificity of anti-EPO IgG antibodies was high, their affinity for the antigen was low. This finding can be explained by the very small differences in the structure of rh-EPO compared to that of natural EPO. The assay described could be useful in evaluating the long-term effects of rh-EPO treatment on the control of anaemia in renal failure patients.

Anemia↗
PubMed2000

Quantitative flow cytometric analysis of the effects of cetirizine on the expression of ICAM-1/CD54 on primary cultured nasal cells.

An in vitro flow cytometric model has been developed to evaluate the effects of antiallergic drugs such as cetirizine (CTZ) on the expression of surface molecules on primary cultured normal cells. Quantitative analysis demonstrated that HLA class I and ICAM-1/CD54 molecules are present on both epithelial and stromal cells, and that their expression is strongly enhanced by treatment with interferon-gamma (IFN-gamma). Nevertheless, the IFN-gamma-mediated upregulation of ICAM-1/CD54 was inhibited by treatment with CTZ, demonstrating a direct effect on both cell types. This finding is particularly interesting because ICAM-1/CD54 is the main rhinovirus receptor, and rhinoviruses are the principal cause of asthma exacerbation in children. Thus, according to data derived from this in vitro model, CTZ should have an important role in the reduction of infectious exacerbation of asthma in atopic patients.

Adult↗
PubMed2000

alpha-Interferon treatment induces quantitative modifications of HLA class I-associated peptides eluted from cultured cancer cell lines.

Interferons upregulate the expression of HLA class I antigens on cancer cells. Nevertheless, little is known about the panel of HLA class I antigen-associated peptides presented by recombinant alpha-interferon (r(alpha)-IFN)-treated cells. For this reason, peptides were eluted from five cancer cell lines (four melanoma and one non-small cell lung cancer) following treatment with r(alpha)-IFN. High-performance liquid chromatography (HPLC) profiles of the peptide fractions were compared with those obtained from untreated cells. No significant differences in peptide characteristics (detectable on the basis of retention times) were observed, but significant differences in terms of peptide quantities were observed. Mass spectrometry performed on HPLC peaks allowed not only the detection of three different peptides (two derived from the MAGE family of genes and one from the mart-1) both in untreated and in treated cells, but also gave an indication of the number of peptides within one HPLC peak. This data demonstrates that r(alpha)-IFN-treated cells express a similar peptide pattern as untreated cells, with significant quantitative differences. Interestingly, this finding also explains the higher susceptibility to lysis (mediated by specific cytolytic lymphocytes, which recognize cancer cells in an HLA-restricted fashion) of r(alpha)-IFN-treated cells.

Antigens, Neoplasm↗
PubMed2000

Dendritic cells efficiently cross-prime HLA class I-restricted cytolytic T lymphocytes when pulsed with both apoptotic and necrotic cells but not with soluble cell-derived lysates.

Dendritic cells (DC) have been shown to efficiently present antigen to CD8(+) cytolytic T cells (CTL) when pulsed with apoptotic cells as a source of cell-derived antigen. Such cross-priming could not be detected by the use of necrotic cells, while conflicting results have been reported for cell-derived soluble lysates. In this study, we reinvestigated this issue by using autologous Epstein-Barr virus-transformed lymphoblastoid cell lines (LCL) as a source of antigen to pulse monocyte-derived DC. Both autologous and HLA-mismatched allogeneic LCL have been used either in the form of apoptotic or of necrotic cells or of soluble cell lysates. At day 7, DC were co-cultured with the autologous CD8(+) lymphocyte fraction for an additional 9 days, in the presence of exogenous IL-2 (added after 48 h). At the end of the culture period, CD8(+) CTL efficiently lysed autologous LCL only when they had been co-cultured with DC pulsed with necrotic or apoptotic cells. That an efficient cross-priming of autologous CD8(+) cells could be induced by DC pulsed with apoptotic or necrotic LCL but not with cell lysates was further demonstrated in assays of IFN-gamma production in response to short-term re-stimulation of CD8(+) cells with LCL. In addition, LCL-specific CD8(+) cells could specifically lyse autologous DC that had been pulsed with LCL-derived antigens, further suggesting that DC presented exogenous antigens on HLA class I molecules.

Antigen Presentation↗
PubMed2000

Phase II study of combined immunotherapy, chemotherapy, and radiotherapy in the postoperative treatment of advanced non-small-cell lung cancer.

The association of adoptive immunotherapy (AI) and radiotherapy has been shown to be effective in the control of residual intrathoracic disease, while having no systemic advantages, in patients operated on for locally advanced non-small-cell lung cancer (NSCLC). The potential synergy of coupling immunotherapy and chemotherapy has been emphasized in several tumors including NSCLC. The aim of this work was to determine the feasibility and activity of a combined therapeutic program, including AI, chemotherapy, and radiotherapy in patients who had undergone incomplete resections for NSCLC. In a phase II trial, 13 patients received the combined treatment. AI was given from week 4 after surgery until week 8. Concurrent chemo-(cisplatin and etoposide)-radiotherapy (60 Gy) was given from week 9 to week 14. Twenty eligible patients received chemoradiotherapy only and were used as a non-randomized concomitant group for merely descriptive purposes. At 9-month follow-up, 10 of the 13 patients had progression of disease and the study was stopped. Progression-free survival and survival were similar to those of the chemoradiotherapy group. The present study showed that the sequence of immunotherapy followed by chemotherapy is not effective as adjuvant treatment in patients operated on for stage III NSCLC, at least when used according to the adopted schedule.

Adult↗
PubMed2000

Natural killer cells lyse autologous herpes simplex virus infected targets using cytolytic mechanisms distributed clonotypically.

Natural killer (NK) cells have the capability of lysing targets that have down-regulated the expression of HLA class I molecules. Herpes simplex virus (HSV) infection results in a profound reduction of HLA class I molecules on the surface of infected cells. For this reason, NK cell populations kill efficiently HSV-infected cells. The recent availability of a panel of monoclonal antibodies directed to NK receptors for HLA class I (CD158a, CD158b, anti-p70, anti-p140, and CD94) allowed an accurate dissection of the NK cell subpopulations. Using this approach, the relationship between the expression of NK cell receptors and the capability of lysing HSV-infected cell targets was analyzed at the clonal level. NK cell clones were derived from healthy donors, and cytolytic properties were assayed against HSV-infected autologous fibroblasts. NK cell clones, classified according to the expression of natural killer-cell receptors on their surface, displayed a great heterogeneity of cytolytic properties against HSV-infected cells. Nevertheless, a more accurate functional analysis demonstrated not only that HSV infection downregulated the expression of HLA-A and HLA-B and did not modify the expression of HLA-C, but also that NK cell clones expressing the "activating" form of the anti HLA-C NK cell receptor were more cytolytic than other clones. This finding suggests that two different and clonally distributed mechanisms of NK cell activation may be employed by NK cells to kill HSV-infected autologous target cells.

Cells, Cultured↗
PubMed1999

Cytotoxic properties of CD4(+) T-cell clones which lyse HLA class II negative autologous non-small-cell lung cancer cells.

In this report, a subset of CD4(+) cells which kills autologous HLA class I positive and HLA class II negative non-small-cell lung cancer (NSCLC) cells is described. Killing was performed both by direct cytolytic mechanisms and by apoptosis. The peculiar characteristic of these effectors was their capability of lysing only interferon (IFN)-gamma-treated NSCLC target cells, expressing high numbers of HLA class I molecules. Analysis at the clonal level confirmed that cytolytic capability was distributed clonotypically. The addition of anti-HLA class I monoclonal IgM abrogated the susceptibility to lysis. Notably, the CD4-mediated cytolytic effect on IFN-gamma-treated targets was incomplete. Thus cytofluorimetric DNA and HLA class I expression analyses of target cells were performed: "resistant" targets consisted of large, aneuploid cells expressing a low number of HLA class I molecules. These findings suggested a direct role of HLA class I expression in the recognition of autologous cancer cells mediated by cytolytic CD4(+) cells.

Aged↗
PubMed1998

Normal epithelial cells modulating HLA class I surface molecules are susceptible to lysis mediated by CD3(+) and CD3(-) "nonspecific" killer cells.

Natural killer (NK) cells and NK-like T cells have been described as efficiently lysing neoplastic cells derived from hematopoietic tumors. By modulating the expression of HLA class I surface molecules on normal epithelial cells, we also observed that nonneoplastic cells can efficiently be lysed by "nonspecific" effectors. Clonal analysis clearly demonstrates that the presence of HLA-specific inhibitory NK receptors, such as CD94, CD158a, and CD158b, described on NK cells, is responsible for the inhibitory signal. Thus, NK cells, as well as NK-like T cells, in the absence of HLA surface molecules on normal target cells, efficiently lyse epithelial cells.

Antibodies, Monoclonal↗