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Biomedical subjects

A Faggioni

Publications and source records attributed to A Faggioni.

At least 19 recordsLinked to original sources
PubMed2001

Direct correlation between human herpesvirus-8 seroprevalence and classic Kaposi's sarcoma incidence in Northern Sardinia.

The human herpesvirus-8 (HHV-8) has been associated with the development of Kaposi's sarcoma. A high incidence of classic Kaposi's sarcoma has been described in Sardinia, an island West of Italy's mainland. Different seroepidemiological analyses have reported that prevalence of HHV-8 infection varies worldwide: a high HHV-8 seroprevalence has been shown in Italy. The present survey was carried out to evaluate the correlation between HHV-8 infection and classic Kaposi's sarcoma incidence in northern Sardinia. Blood samples were collected from 226 healthy donors born and resident in five different areas of North Sardinia. Seroprevalence to HHV-8 was determined searching antibodies to viral lytic proteins by immunofluorescence in sera diluted at 1:10. Classic Kaposi's sarcoma incidence data spanning a period of 23 years were examined in the areas studied. The present screening revealed that seroprevalence was 35%, within a range of 15.3-46.3% in the five areas, although it should be considered that the seroprevalence to HHV-8 can be established more accurately by the combined use of different assays. Age emerged as an important risk factor. Indeed, subjects aged > 50 years showed a higher seroprevalence to HHV-8 as compared with younger individuals. A strong direct correlation between HHV-8 prevalence and classic Kaposi's sarcoma incidence has been also observed. The wide diffusion of HHV-8 in Sardinia appears to represent an important factor in the high incidence of classic Kaposi's sarcoma reported in the island. However, additional co-factors, such as age, sex, genetic traits, or viral strain pathogenicity, are likely to play a role in the development of the disease.

Adult↗
PubMed2001

Differential regulation of Epstein-Barr virus (EBV) latent gene expression in Burkitt lymphoma cells infected with a recombinant EBV strain.

Epstein-Barr virus (EBV)-negative Burkitt lymphomas (BLs) can be infected in vitro with prototype EBV strains to study how the virus may affect the phenotype of tumor cells. Studies thus far have concentrated on the use of transforming B95-8 and nontransforming P3HR1 strains. Immunological and phenotypic differences between the sublines infected with these two strains were reported. The majority of these differences, if not all, can be attributed to the lack of EBNA-2 coding sequences in the P3HR1 strain. The recent development of a selectable Akata strain has opened up new possibilities for infecting epithelial and T cells as well. We infected five EBV-negative BL lines with the recombinant Akata virus. Our results indicate that the infected cell lines BL28, Ramos, and DG75 express EBNA-1, EBNA-2, and LMP1, the viral proteins associated with type III latency, and use both YUK and QUK splices. In contrast, two EBV-negative variants of Akata and Mutu when reinfected displayed restricted type I latency and expressed only EBNA-1. All clones of infected Mutu cells used the QUK splice exclusively. The usage of Qp was observed in a majority of Akata clones. Some Akata clones, however, were found to have double promoter usage (Qp and C/Wp) but at 4 months after infection did not express EBNA-2. The results demonstrate differential regulation of EBV latency in BLs with the same recombinant viral strain and suggest that the choice of latency type may be cell dependent. The restricted latency observed for infected Akata and Mutu cells indicates that a BL may opt for type I latency in the absence of immune pressure as well.

Burkitt Lymphoma↗
PubMed2001

Human herpesvirus 6 infection in neoplastic and normal brain tissue.

The presence and variant distribution of human herpesvirus 6 (HHV-6) was investigated by a nested polymerase chain reaction (PCR) in 118 biopsies from patients affected by nervous tissue tumor (115 primary tumors and 3 metastasis) and in 31 autopsy samples from the brain of healthy individuals. HHV-6 DNA sequences were detected in normal and neoplastic nervous tissue at a frequency of 32% and 37%, respectively. In both tissues, variant A was three times more frequent than the variant B. Peripheral blood lymphocytes (PBLs) derived from seven tumor affected patients contained the same variant as their respective brain sample, as judged by PCR. The expression of HHV-6 encoded immediate early protein p41 was detected by immunohistochemistry in neoplastic but not in normal brain. This may reflect viral reactivation from latency in immunocompromised patients. The seroepidemiological data indicated a frequency distribution of anti-HHV-6 antibodies in patients with brain tumors similar to that found in healthy donors.

Antibodies, Viral↗
PubMed2000

Early interactions of human herpesvirus 6 with lymphoid cells: role of membrane protein components and glycosaminoglycans in virus binding.

A microassay was developed to detect human herpesvirus 6 (HHV-6) binding to its cellular receptor using flow cytometry. Comparable results were obtained either by using HHV-6 preparations conjugated with fluorescein isothiocyanate or by indirect immunofluorescent labeling of membrane-bound virus using as primary antibody a monoclonal antibody specific for the HHV-6 gp60/110 envelope glycoprotein. Virus attachment to the plasma membrane was specific and saturable. As expected, among cell lines of various origin, maximum binding was detected on human T-lymphoid cells (HSB-2). Papain digestion of HSB-2 cells prevented HHV-6 attachment and reduced significantly virus infection, indicating the involvement of a protein-based receptor in the attachment step. After removal of the protease, virus receptors were resynthesized and their regeneration was prevented partially by cycloheximide, an inhibitor of protein synthesis. Unexpectedly, only high concentrations (mg/ml) of soluble heparan sulfate and heparin inhibited HHV-6 binding and infection. Under the same conditions, few micrograms (per ml) of heparin suppressed completely herpes simplex type 1 (HSV-1) attachment to the same cell line. Treatment of HSB-2 cells with heparitinase and heparinase, at doses that reduced significantly HSV-1 attachment, had little effect on HHV-6 binding to the cell membrane, indicating a different requirement of heparan sulfate-containing glycosaminoglycans for the two herpesviruses. These data suggest that protein components of the cellular membrane play an essential role in HHV-6 binding and infection while heparan sulfate-glycos-aminoglycans appear to be involved only partially in virus-receptor interaction.

Animals↗
PubMed2000

The BFRF1 gene of Epstein-Barr virus encodes a novel protein.

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are approximately 100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The BamHI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the BamHI F region (BFRF1). Histidine and glutathione S-transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 MAb recognizes a doublet migrating at 37 to 38 kDa in cells extracts from EBV-infected cell lines following lytic cycle activation and in an EBV-negative cell line (DG75) transfected with a plasmid expressing the BFRF1 gene. Northern blot analysis allowed the detection of a major transcript of 3.7 kb highly expressed in EBV-positive lytic cycle-induced cell lines. Treatment with inhibitors of viral DNA polymerase, such as phosphonoacetic acid and acyclovir, reduced but did not abolish the transcription of BFRF1, thus indicating that BFRF1 can be classified as an early gene. Cell fractionation experiments, as well as immunolocalization by immunofluorescence microscopy, immunohistochemistry, and immunoelectron microscopy, showed that BFRF1 is localized on the plasma membrane and nuclear compartments of the cells and is a structural component of the viral particle. Identification of BFRF1 provides a new marker with which to monitor EBV infection and might help us better understand the biology of the virus.

Amino Acid Sequence↗
PubMed2000

Wilms' tumor gene expression by normal and malignant human B lymphocytes.

Very little is known about Wilms' tumor gene (WT1) expression in B cells and its importance for growth regulation and differentiation. We have investigated WT1 expression in fresh B lymphocytes and in a panel of B-cell lines of normal and malignant origin, including both Epstein-Barr virus (EBV) genome negative and EBV carrying cell lines. WT1 is constitutively activated in all lymphoblastoid cell lines (LCL) derived from EBV immortalization of lymphocytes from normal donors in vitro. These cell lines are distinguished for the presence of activated B-cell markers and an unrestricted expression of viral latent genes. In contrast, WT1 expression is abrogated in normal B lymphocytes and in all Burkitt tumor derived cell lines, irrespective of the EBV genome carrying status and their phenotype pattern. A single step RT-PCR for simultaneous detection of the four spliced transcript isoforms has been applied to confirm their expression. Analysis of variant relative proportions suggested the maintenance of a balanced expression of the isoforms in LCL, as reported in non tumorous tissues. These data, together with the evidence that the replication in vitro of lymphoblastoid cells is not affected by WT1 activation following viral immortalization, support the hypothesis that gene inactivation, in addition to disrupted alternate splicing, may play a role in growth control derangements.

B-Lymphocytes↗
PubMed2000

Augmentation of leukocyte infiltration in murine tumors expressing B-cell derived but not nasopharyngeal carcinoma derived EBV membrane protein LMP1.

The Epstein-Barr virus (EBV) encoded latent membrane protein of B cell origin, B-LMP1 (B95-8 prototype) and nasopharyngeal carcinoma (NPC) derived C-LMP1 (CAO prototype) were transfected individually in S6C adenocarcinoma cells of ACA (H-2f) origin. We have shown previously that inoculation of B-LMP1 expressing S6C cells led to tumor rejection in pre-immunized, immunocompetent syngeneic ACA mice, whereas the C-LMP1 transfectants were not immunogenic. Furthermore, B-LMP1 but not C-LMP1 expressing S6C cells grew with necrosis and extensive skin damage in non-immunized mice. A study was carried out to determine whether the in vivo growth pattern of S6C cells expressing two different LMP1 isolates could be correlated to any immunomodulatory mechanism. An increased infiltration of CD45+ leukocytes was found in B-LMP1 expressing S6C tumors originating in non-immunized, syngeneic ACA mice. The C-LMP1 expressors, vector transfectants and untransfected parental tumors had significantly lower number of infiltrating leukocytes. The immunoaccessory molecules ICAM-1, B7-1 and MHC Class I and II expression was unaltered in both B- and C-LMP1 transfectants. The data suggest that B-LMP1 but not C-LMP1 induce anti-tumor immune response.

Animals↗
PubMed1999

The benign cystic lymphoepithelial lesion of the parotid gland is a viral reservoir in HIV type 1-infected patients.

The presence of HIV-1 in cystic fluid aspirates from six cases of benign cystic lymphoepithelial lesion (BLL) of the parotid gland, a rare disorder affecting HIV-1-infected patients, has been investigated. HIV-1 p24 protein was present at a concentration ranging from 3 to 15 ng/ml, while it was undetectable in the peripheral blood of the same patients. The number of RNA copies of HIV-1 in the cystic fluids was high, ranging from 0.5 x 10(7) to 7.2 x 10(7) RNA copies/ml. BLL cystic fluid aspirates, despite the high level of HIV-1 RNA, were found to contain only a few infectious virions. The low infectivity correlated with the infrequent detection by electron microscopy of complete HIV-1 particles. The pathogenic mechanism leading to virus accumulation in the cystic fluid was studied by immunohistochemistry of tissue sections. p24 protein was associated with DRC-1+/S-100+ follicular dendritic reticulum cells, which were also present within the cystic cavities. Our findings are consistent with the possibility that the large amounts of virus present in the fluid derive from continuous shedding of HIV-1-infected cells from the surrounding lymphoid tissue.

Adult↗
PubMed1999

Intracellular transport and maturation pathway of human herpesvirus 6.

A peculiar characteristic of cells infected with human herpesvirus 6 (HHV6) is the absence of viral glycoproteins on the plasma membrane, which may reflect an atypical intracellular transport of the virions and/or the viral glycoproteins, different from that of the other members of the herpesvirus family. To investigate the maturation pathway of HHV-6 in the human T lymphoid cell line HSB-2, we used lectin cytochemistry and immunogold labeling combined with several electron microscopical techniques, such as ultrathin frozen sections, postembedding, and fracture-label. Immunolabeling with anti-gp116 and anti-gp82-gp105 monoclonal antibodies revealed that the viral glycoproteins are undetectable on nuclear membranes and that at the inner nuclear membrane nucleocapsids acquire a primary envelope lacking viral glycoproteins. After de-envelopment, cytoplasmic nucleocapsids acquire a thick tegument and a secondary envelope with viral glycoproteins at the level of neo-formed annulate lamellae or at the cis-side of the Golgi complex. Cytochemical labeling using helix pomatia lectin revealed that the newly acquired secondary viral envelopes contain intermediate forms of glycocomponents, suggesting a sequential glycosylation of the virions during their transit through the Golgi area before their final release into the extracellular space. Immunogold labeling also showed that the viral glycoproteins, which are not involved in the budding process, reach and accumulate in the endosomal/lysosomal compartment. Pulse-chase analysis indicated degradation of the gp116, consistent with its endosomal localization and with the absence of viral glycoproteins on the cell surface of the infected cells.

Biological Transport↗
PubMed1999

E.A.E.S. multicenter prospective randomized trial comparing two-stage vs single-stage management of patients with gallstone disease and ductal calculi.

BACKGROUND: The current management of patients with gallstone disease and ductal calculi consists of endoscopic stone extraction (ESE) followed by laparoscopic cholecystectomy (LC). Following the advent of techniques of laparoscopic ductal stone clearance, an alternative single-stage laparoscopic treatment was introduced for these patients. The European Association of Endoscopic Surgery (E.A. E.S.) set up a ductal stone trial to compare the relative efficacy and outcome of these two management options. METHODS: A prospective randomized controlled clinical trial compared two management options. Group A (n = 150) received preoperative endoscopic retrograde cholangiography (ERC) with ESE followed by LC during the same hospital admission, and group B (n = 150) received single-stage laparoscopic management. RESULTS: There were no significant differences between the two groups in the clinical demographic details and the pretreatment biochemical findings. In group A, 14 of 150 patients received single-stage treatment; in group B, 17 of 150 were managed by the two-stage approach (protocol violation = 31/300, 10%). In group A patients managed in accordance with randomization, ERC was successful in 129/136 (95%) and preoperative ESE succeeded in 82/98 (84%) with ductal calculi detected by the ERC. Two patients had malignancies and one refused surgery. Thus, 133 patients underwent surgery. Of this group, 116 had LC only and 17 had LC and attempted laparoscopic duct exploration. There were eight conversions to open surgery (6%), 17 complications for both stages (12.8%), and two postoperative deaths (1.5%). In group B patients managed in accordance with randomization, intraoperative cholangiography was successful in 132/133 (99%). Twenty-one (16%) had normal findings, ductal calculi were found in 109, and other pathology was noted in two (periampullary cancer, severe pancreatitis). These two patients and one other (who had gross adhesion in the triangle of Calot) were converted at the start of the procedure. Transcystic ductal stone clearance was successful in 45 of 56 patients (80%), and laparoscopic direct common duct (CBD) exploration was successful in 47 of 55 patients (85%). This group includes 53 patients who underwent primary direct exploration and two failed attempts at transcystic extraction. The conversion rate was 13%. Postoperative complications were encountered in 21 patients (15.8%), and one patient died of a major myocardial infarction (0. 75%). The one postoperative death and the 10/11 biliary complications occurred in the laparoscopic supraduodenal CBD exploration subgroup. The conversion rate was higher in group B (17 vs eight; p = 0.08). Laparotomy in the postoperative period was required in three patients in group A and four patients in group B. The group B patients were in hospital for 3 days less than patients who had two-stage management (median, 6.0, IQR = 4.25-12 vs median, 9.0, IQR = 5.5-14; p < 0.05). CONCLUSIONS: The results demonstrate equivalent success rates and patient morbidity for the two management options but a significantly shorter hospital stay with the single-stage laparoscopic treatment. The findings indicate that in fit patients (ASA I and II), single-stage laparoscopic treatment is the better option, and preoperative ESE should be confined to poor-risk patients-i.e., those with cholangitis or severe pancreatitis.

Adolescent↗
PubMed1999

Human herpes virus-6 seroprevalence and leukaemias: a case-control study. GIMEMA (Gruppo Italiano Malattie Ematologiche dell' Adulto).

The relationships between acute myeloid leukaemia (AML), acute lymphocytic leukaemia (ALL), chronic myeloid leukaemia (CML) and refractory anaemia with excess of blasts (RAEB) and human herpes virus (HHV)-6 antibody level were investigated in a multicentre case-control study. An association between increased HHV-6 seropositivity and geometric mean titre ratio with AML was shown: P for trend = 0.022, adjusted odds ratio 1.20, 95% confidence interval 1.07-1.33 respectively. No association was found between HHV-6 and ALL, CML or RAEB.

Adolescent↗
PubMed1998

gamma-Interferon production in peripheral blood mononuclear cells and tumor infiltrating lymphocytes from Kaposi's sarcoma patients: correlation with the presence of human herpesvirus-8 in peripheral blood mononuclear cells and lesional macrophages.

Evidence indicates that, at least in the early stage, Kaposi's sarcoma (KS) is a cytokine-mediated disease and that it is consistently associated with a novel herpesvirus termed human herpesvirus-8 (HHV-8). To gain insights into the mechanisms by which cytokines and HHV-8 may cooperate in disease pathogenesis, we examined the phenotype, the Th1 (gamma-interferon [gamma IFN]) and Th2 (interleukin-4 [IL-4] cytokine profile and the presence of HHV-8 in peripheral blood mononuclear cells (PBMC), tumor-infiltrating lymphocytes (TIL), and spindle cell cultures derived from skin lesions of patients affected by classical KS (C-KS) and acquired immunodeficiency syndrome (AIDS)-associated KS (AIDS-KS). TIL and spindle cell cultures were examined at day 0 or after culture in conditioned media from activated T cells (TCM) that contain the same cytokines increased in KS tissues. No differences were found in the immunophenotype of PBMC from C-KS patients versus controls, except for AIDS-KS patients who showed a T-CD8+ expansion. However, a preferential infiltration of T-CD8+ cells was found in all KS lesions examined, which was maintained after culture of TIL in TCM. gamma IFN production was found in both PBMC and cultures derived from all KS examined; some IL-4 positive supernatants were found only in three AIDS-KS cases. Uninvolved skin did not show appreciable lymphocyte infiltration or cytokine production. The culture conditions of the lesional skin allowed also the appearance of adherent, spindle-like cells bearing markers of tissue macrophages. Finally, most or all of the PBMC, lesions, and macrophagic cell cultures from the skin lesions were found to be positive for HHV-8 infection by nested polymerase chain reaction (PCR). These findings indicate that patients with KS express a Th1 phenotype with a prevalent gamma IFN production, likely accounted for by the local T-CD8+ infiltration. By analogy with other viral infections (i.e., Epstein-Barr virus), this suggests that in loco recruitment of lymphoid cells and the subsequent gamma IFN production may be in response to or elicited by HHV-8 that was found in both PBMC and macrophagic cell cultures from the lesions of the same patients.

Adult↗
PubMed1998

High prevalence of antibodies to human herpesvirus 8 in relatives of patients with classic Kaposi's sarcoma from Sardinia.

A survey for antibodies to a recombinant small viral capsid antigen (sVCA) of human herpesvirus type 8 (HHV-8) was conducted in Sardinia, one of the world's highest incidence areas for classic Kaposi's sarcoma (KS). Prevalence of antibodies to HHV-8 sVCA was greatest in patients with KS (95%), followed by family members (39%) and a Sardinian control population age- and sex-matched to the relatives (11%). Within families, prevalence of antibodies was about equal among spouses, children, and siblings of KS patients, a finding that raises the possibilities of intrafamilial person-to-person or vertical transmission. Antibodies were detected 2-3 times more frequently in males than in females. The data show that prevalence of antibodies to HHV-8 sVCA correlates with the distribution of classic KS in a high- incidence area. Clustering of seroprevalence within some families suggests the presence of familial risk factors for active HHV-8 infection.

Age Factors↗
PubMed1998

Viral glycoproteins accumulate in newly formed annulate lamellae following infection of lymphoid cells by human herpesvirus 6.

Ultrastructural analysis of HSB-2 T-lymphoid cells and human cord blood mononuclear cells infected with human herpesvirus 6 revealed the presence, in the cell cytoplasm, of annulate lamellae (AL), which were absent in uninfected cells. Time course analysis of the appearance of AL following viral infection showed that no AL were visible within the first 72 h postinfection and that their formation correlated with the expression of the late viral glycoprotein gp116. The requirement of active viral replication for AL neoformation was further confirmed by experiments using inactivated virus or performed in presence of the viral DNA polymerase inhibitor phosphonoacetic acid. Both conventional electron microscopic examination and immunogold fracture labeling with anti-endoplasmic reticulum antibodies indicated a close relationship of AL with the endoplasmic reticulum and nuclear membranes. However, when the freeze-fractured cells were immunogold labeled with an anti-gp116 monoclonal antibody, AL membranes were densely labeled, whereas nuclear membranes and endoplasmic reticulum cisternae appeared virtually unlabeled, showing that viral envelope glycoproteins selectively accumulate in AL. In addition, gold labeling with Helix pomatia lectin and wheat germ agglutinin indicated that AL cisternae, similar to cis-Golgi membranes, contain intermediate, but not terminal, forms of glycoconjugates. Taken together, these results suggest that in this cell-virus system, AL function as a viral glycoprotein storage compartment and as a putative site of O-glycosylation.

Cell Line↗