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Biomedical subjects

M R Capobianchi

Publications and source records attributed to M R Capobianchi.

At least 91 records · Page 5Linked to original sources
PubMed1980

Interferon effects on Friend leukaemia cells. I. EXpression of virus and erythroid markers in untreated and dimethyl sulphoxide-treated cells.

The effects of low doses (40 to 1000 units/ml) of mouse interferon (IF) on the expression of Friend leukaemia virus (FLV) and globin genes in Friend leukaemia cells (FLC) have been examined. IF blocks production of extracellular virus, but virus antigens accumulate in the cytoplasm. In cells treated with IF at the time of seeding, there is a reduction in the amount of RNA specified by the lymphatic leukaemia virus (LLV) component of FLV; with the same IF dose there is a small but definite stimulation of haemoglobin and globin mRNA synthesis. The effects of IF on LLV gene expression are even more pronounced in dimethyl sulphoxide (DMSO)-stimulated LFC. No correlation was found between LLV gene expression and the appearance of erythroid markers.

Antigens, Viral↗
PubMed1976

Mosaicism for sulfoiduronate sulfatase deficiency in carriers of Hunter's syndrome.

Using an assay for sulfoiduronate sulfatase based on the degradation of 35S mucopolysaccharides in a cell-free system, two clonal populations have been demonstrated in fibroblasts of heterozygotes for Hunter's syndrome. The locus responsible for sulfoiduronate sulfatase deficiency in this X-linked mucopolysaccharidosis is therefore subjected to dosage compensation in females.

Clone Cells↗
PubMedDate not supplied

Susceptibility of human immunodeficiency virus to antiviral agents measured by infectious virus yield reduction.

Under single growth cycle conditions in C8166 lymphoblastoid cells human immunodeficiency virus shows a replication curve which is completed at 24 h post-infection. At lower multiplicity of infection virus yield peaks at approximately 72 h post-infection but in both cases the titer of the virus released in the medium is negligible with respect to that which remains cell-associated. A method based on back-titration of virus in cryolysates of C8166 cells infected with HIV and treated with antiviral compounds has been used to evaluate HIV sensitivity to such agents. Under single growth cycle conditions dose response curves appear linear and permit rapid and accurate determination of the endpoint activity. Under multiple growth cycle conditions the inhibitory activity may be measured during the exponential growth phase, at 48 h post-infection. This method, which directly measures production of infectious virus rather than indirect probes of viral replication such as reverse transcriptase or antigen production, offers the advantage of a precise determination of the degree of activity of antivirals also acting on viral assembly or release.

Antiviral Agents↗
PubMedDate not supplied

Effects of IFN alpha on late stages of HIV-1 replication cycle.

IFN alpha causes a modest reduction of HIV-1 expression in chronically infected monocytoid U937 cells. However, the ratio between cell-associated and shed viral p24 antigen is altered, being the cell-associated fraction dose-dependently enhanced by IFN. Furthermore, a significant decrease of infectivity of both cell-associated and shed material is observed. Transmission electron microscopy of IFN-treated cells revealed virus assembly being strongly inhibited, with the production of morphologically altered (tear-drop shaped) virus particles. Proteolytic processing of gag proteins appeared to be normal in IFN-treated cultures. However, virions shed from IFN-treated cells showed a markedly reduced incorporation of virus-specific gp120 and cell-derived ICAM-1 by the virus envelope. Additionally, these particles showed a significantly decreased ability to become bound to CD4+ target cells, accounting for, at least in part, the observed decrease of infectivity. Taken together, the data suggest that, in chronically infected cells, IFN alpha can affect late stages of HIV-1 replication, by inhibiting virus assembly and release, and by reducing the infectivity of shed virions. The latter effect seems to be due, at least in part, to altered incorporation of surface glycoproteins and defective particle formation. The relationship between impaired gp120 incorporation and altered morphogenesis of HIV-1 virions is under investigation.

Antiviral Agents↗
PubMedDate not supplied

Detection of TT virus in lymph node biopsies of B-cell lymphoma and Hodgkin's disease, and its association with EBV infection.

Human TT virus (TTV) recently isolated from the serum of a patient with post-transfusion hepatitis does seem to have only hepatopathic effect. The virus can also infect the serum, peripheral blood mononuclear cells (PBMC) and bone marrow cells (BMC ). Additional evidence has indicated that TTV is also present in the serum of people with hematopoietic malignancies. A significant increase in the incidence of lymphoma has recently been observed worldwide. We have investigated the presence of TTV DNA in lymph node biopsies of Italian patients affected with the most common lymphoma types in Western Countries: follicular lymphoma (FL), diffuse large B-cell lymphoma (DLBCL) and nodular sclerosis Hodgkin's disease (NS-HD). The possible role of a co-infection with Epstein-Barr virus (EBV) has also been investigated. DNA was extracted from 73 paraffin-embedded and 38 snap-frozen tissue specimens. From these, only 67 samples (29 paraffin-embedded and 38 snap-frozen tissues) from a total of 56 patients, were suitable for PCR analysis. TTV and EBV were detected by PCR using primers from two different conserved region in TTV and EBV genomes respectively. TTV DNA was detected in 30.0-50.0% of FL, 30.8% of DLBCL and 30.0-50.0% of NS-HD cases, depending on the primers used. All cases of non-specific reactive lymphoid hyperplasia (RLH), used as a putative control, were negative. The two major TTV genotypes circulating in Italy (G1 and G2) were detected in the analysed lymphoid neoplasms. EBV DNA was detected in 40.0% of FL, in 72.7%of DLBCL, in 80.0% of SN-HD and in 40.0% of RLH cases. EBV co-infection was found in 90% of TTV positive cases. The in situ hybridization assay was performed in TTV positive frozen samples. The significant prevalence of TTV DNA in lymphocytes circulating in the lymph nodes of both B-cell lymphomas and HD reported herewith suggests an implication of TTV infection in the development of these lymphoproliferative disorders.

DNA Virus Infections↗
PubMedDate not supplied

T-Cell response profiling to biological threat agents including the SARS coronavirus.

The emergence of pathogens such as SARS and the increased threat of bioterrorism has stimulated the development of novel diagnostic assays for differential diagnosis. Rather than focusing on the detection of an individual pathogen component, we have developed a T cell profiling system to monitor responses to the pathogens in an array format. Using a matrix of antigens specific for different pathogens, a specific T cell profile was generated for each individual by monitoring the intracellular production of interferon-gamma by flow cytometry. This assay allows for the testing of multiple proteins or peptides at a single time and provides a quantitative and phenotypic assessment of CD4(+) and CD8(+) responding cells. We present profiling examples for several positive individuals, including those vaccinated with the smallpox and anthrax vaccines. We also show antigen optimization for the SARS-hCoV, as studies revealed that these proteins contain peptides which cross-react with more common coronaviruses, a cause of the common cold. The T cell array is an early and sensitive multiplex measure of active infection, exposure to a pathogen, or effective, recent vaccination.

Antigens, Viral↗
PubMedDate not supplied

Cervicovaginal shedding of TT virus in HIV-infected women.

OBJECTIVE: TT virus (TTV) is frequently detected in the serum and in other body fluids of humans. Recently TTV-specific deoxyribonucleic acid has been detected in cervical specimens from apparently healthy women and in seminal fluid, suggesting that sexual transmission may be common. STUDY DESIGN/METHODS: TT virus-deoxyribonucleic acid prevalence was assessed in paired samples of blood and cervical smears from 110 human immunodeficiency virus-positive women. Detection and typing of human papillomavirus (HPV) present in cervical smears was also performed. RESULTS: The prevalence of TTV-deoxyribonucleic acid in cervical smears was 16.4%, without significant difference (p = 0.81) between HPV-positive (18.6%) and -negative (14.9%) samples. The distribution of high/middle and low-risk HPV types was similar in TTV-positive and -negative samples. On the contrary, women with multiple HPV infections had a significantly higher TTV-deoxyribonucleic acid prevalence (60.0%) than HPV-negative women (p = 0.04). CONCLUSIONS: TT virus excretion in the female genital tract of human immunodeficiency virus-infected women is common, further supporting sexual transmission of this virus.

AIDS-Related Opportunistic Infections↗
PubMedDate not supplied

Prevalence of human herpesvirus (HHV)-8 infection among carriers of cardiovascular disease.

Infectious agents, such as herpesviruses, have been hypothesized to be involved in development of atheromatous plaque. The study aim was to evaluate the possibility that HHV-8 infection could be an additional risk factor for the establishment of cardiovascular disease. HHV-8 seroprevalence was determined by immunofluorescence in a population of cardiovascular disease patients (n=50) as compared to an age- and sex-matched group of control subjects (n=47); HHV-8 genome was detected in DNA extracted from circulating PBMC and from atheromatous lesions by PCR with primers specific for the minor virus capsid gene (ORF 26). The seroprevalence of HHV-8 was significantly increased in the patients as compared to the control population, while the presence of HHV-8 genome was observed in PBMC from 2 patients and 1 control. Virus-specific DNA was found in 2 out of 4 atheromatous plaques. The higher seroprevalence in patients suffering from vascular diseases as compared to age-and sex-matched controls suggests that HHV-8 infection could be an additional risk factor for the establishment of cardiovascular disease, although the data on the persistence of viral DNA in PBMC or in the arterial lesions are too exiguous to definitively support this hypothesis. More extensive studies are needed to define the exact role of HHV-8 infection in the establishment and progression of atheromatous lesions.

Aged↗
PubMedDate not supplied

Heterogeneity of HVR-1 quasispecies is predictive of early but not sustained virological response in genotype 1b-infected patients undergoing combined treatment with PEG- or STD-IFN plus RBV.

ISDR mutation pattern and HVR-1 quasispecies were analyzed in HCV genotype 1b-infected patients treated with either PEG- or STD-IFN plus ribavirin, in order to find virological correlates of therapy outcome. ISDR region analysis, performed at baseline (T0) and at 4 weeks of therapy (T1), indicated that ISDR mutation pattern was not predictive of response to treatment. Moreover, no selection of putative resistant strains in the first month of therapy was observed. Viral load was not correlated with any parameter of HVR-1 heterogeneity. Among the HVR-1 heterogeneity parameters considered, complexity was inversely correlated to viral load decline at T1. In univariate analysis, complexity, proportion of non synonymous substitutions (NS) and NS/S ratio were lower in patients showing virological response at 6 months of treatment. Complexity was the only parameter independently associated with both decline of viral load at T1 and virological response after 6 months, even after adjustment for confounding variables. At the end of treatment or later, these correlations were lost. Evolution pattern of the HVR-1 quasispecies indicated a strong selective pressure in sustained responders, with complete substitution of pre-existing quasispecies, while minor changes occured in non responders. In relapsers both patterns were present at a similar rate. In conclusion, this study shows that HVR-1 heterogeneity may be involved in the early response to combined IFN-RBV therapy. The loss of correlation between viral heterogeneity and therapy outcome at 6 months of therapy, or later, suggests that other factors may play a role in maintaining sustained response to treatment.

Antiviral Agents↗
PubMedDate not supplied

Infection with Epstein-Barr virus and cancer: an epidemiological review.

The Epstein-Barr virus (EBV) is ubiquitous worldwide, with greater than 80% of people over the age of 30 having been infected. Once EBV infection has occurred, it remains for the lifetime of the individual, making EBV one of the most persistant viruses that infect humans. EBV is strongly associated with the development of several cancers, in particular with Burkitt's lymphoma, Hodgkin's disease, and lymphoproliferative disorders which complicate immune suppression conditions. These EBV-associated neoplasms are characterized by peculiar geographic distributions and distinctive epidemiologic features. In this review, the main epidemiological aspects of the relationship between EBV infection and cancer are outlined, and recent advances in the mechanisms underlying EBV-induced growth transformation are summarized.

Adolescent↗
PubMedDate not supplied

Role of glycosilation in the susceptibility of "acid labile" interferon alpha to acid treatment.

Mononuclear cells from blood of healthy donors produce acid-labile interferon (IFN) alpha when stimulated with HIV-infected cells. A large proportion of this IFN appears to be glycosilated, as treatment with neuraminidase causes a shift of the isoelectric point (IP) from pH = 5.2-5.4 to pH = 5.8-6.2. To assess the role of glycosilation in determining the instability of antiviral activity after exposure to acid (pH lower than 4) peripheral blood mononuclear cells (PBMC) were induced to produce IFN with HIV-infected cells in the presence of tunicamycin, an inhibitor of glycosilation. The IFN produced under such experimental conditions (tu-IFN) was acid-stable. Tu-IFN was compared to a standard acid-labile IFN by affinity chromatography on Con A-sepharose. The elution pattern showed that tu-IFN does not bind to the gel, whereas the acid-labile IFN is eluted in two fractions, one unbound, which is stable at pH2, and one bound, which retains the initial acid-lability. These results suggest that acid-labile IFN alpha is largely glycosilated, and that the presence of glycosilated molecules contribute to render the IFN molecule unstable at acidic pH. It is to be determined whether some glycosilated molecule present in the IFN preparation, or glycosilation of the IFN molecule per se, is responsible for acid-lability of the antiviral activity.

Chromatography, Affinity↗
PubMedDate not supplied

Membrane interactions involved in the induction of acid labile interferon alpha.

Human normal peripheral blood mononuclear cells (PBMC) produce acid-labile interferon (IFN) alpha when stimulated in vitro with HIV-infected cells fixed with glutaraldehyde. The cells responsible for IFN production are mainly B lymphocytes. The present study was aimed to further elucidate the cellular source of this IFN and to analyze the membrane interactions involved in the induction process. To this purpose PBMC were stimulated with inducers of acid labile IFN alpha in the presence or absence of a panel of monoclonal antibodies (MoAbs) against antigens of the lymphocyte membrane, namely HLA Class I and II and CD4. The results indicate that both HLA Class II and CD4 antigens are involved in the induction process. Conversely B cell lines seem capable of producing conventional alpha IFN but they fail to produce acid labile IFN alpha even in the presence of cooperating CD4 positive T cell lines. Furthermore PBMC cultured for more than 20 hours prior to stimulation lose the ability to produce acid labile IFN alpha, while remaining fully capable of producing conventional IFN alpha and gamma. It remains to be established whether this phenomenon reflects the disappearance of some membrane structure necessary for acid labile IFN alpha induction, or whether it is due to some early appearing functional alteration of B cells.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Acid-labile alpha interferon produced by peripheral blood mononuclear cells stimulated by cells infected by HIV].

Acquired immunodeficiency syndrome (AIDS) is caused by infection with T-cell tropic retrovirus HIV. The disease is characterized by a profound defect in cell-mediated immunity and a number of serologic abnormalities. Among the serologic abnormalities, the presence of an unusual acid-labile interferon (IFN) has been repeatedly found, and it is considered to be a marker of infection HIV evolving toward illness. Because little is known about the relationships existing between the etiologic agent of AIDS (i.e. HIV) and acid-labile IFN alpha, we approached this problem by testing whether acid-labile IFN alpha is induced in vitro by this virus. In this paper we compared the IFN-inducing activity of free, infectious HIV to that of HIV-infected cells. A number of other enveloped viruses and virus-infected cells were used as controls. Interferon inducing activity by virions as compared to virus-infected cells was determined by incubating human PBMC either with VSV, HSV, and HIV or with cells infected with the same viruses. In this case cells were fixed with glutaraldehyde to prevent virus shedding. While VSV and HSV induced production of acid-stable IFN both as free virions and as virus-infected cells, HIV induced acid-stable IFN when applied as a viral suspension, but it did produce acid-labile IFN when virus-infected cells were used as the inducer. In fact the IFN produced under these circumstances lost more than 80% of its activity when treated to pH2, no matter whether H9/HIV or HIV infected PBMC were used as the inducer. Because acid-lability is a peculiar property of IFN gamma, whereas both native and cloned IFN alpha are completely stable under acid conditions, we compared the IFNs induced by either HIV and HIV-infected cells to standard IFN alpha and gamma preparations with respect to (i) acid stability (ii) neutralization with specific antisera (iii) apparent molecular weight estimated by gel filtration. Results indicate that HIV-induced IFN behaves exactly as standard IFN alpha, as it was completely stable at pH2, totally inactivated by anti-IFN alpha and not by anti-IFN gamma serum, and had apparent molecular weight of 20,000; conversely IFN induced by HIV-infected cells, both H9/HIV and PBMC/HIV, although sharing with IFN alpha both molecular weight and antigenic properties, was inactivated by acid treatment by more than 80%.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Serum IL-10 levels in HIV-positive subjects: correlation with CDC stages.

HIV-1 infection and the HIV gp120 have been shown to induce an IL-10 increase in cultured peripheral blood mononuclear cells. Furthermore, the expression of this cytokine has been reported to increase in lymphnodes of infected patients along the disease course, and a shift from the TH-1 towards the TH-0/TH-2 phenotypes (with subsequent IL-10 release) has been hypothesized to underly AIDS progression. In this study the serum IL-10 levels found in 30 HIV-negative controls and in 65 HIV-positive patients, untreated with AZT and negative for HBsAg and HCV-Ab have been compared, using a commercial, competitive ELISA method based on a polyclonal anti-IL-10 serum. With this test, HIV-positive sea showed IL-10 levels significantly higher than those found in the controls. In addition the IL-10 levels progressively increased in the subsequent CDC stages, without further changes from the stage III to the stage IV. Accordingly, patients evaluated two times in CDC stage II, with a time interval of at least one year, showed significant IL-10 increases, even more pronounced when the same patients passed from CDC stage II to stage III. Furthermore, a significant, negative correlation was observed between the circulating IL-10 levels and the patients' CD4/CD8 ratios. These data may be important from a clinical point of view since IL-10 monitoring could be considered as a surrogate marker for evaluating the disease progression. In addition, several immunological abnormalities present in HIV positive patients, such as the monocyte/macrophage impairment and the hypergammaglobulinemia could be related to the enhanced IL-10 expression.

Adult↗