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C Carini

Publications and source records attributed to C Carini.

At least 37 records · Page 2Linked to original sources
PubMed1992

Discrete subcellular localization of phosphoinositidase C beta, gamma and delta in PC12 rat pheochromocytoma cells.

Phosphoinositidase C activity was revealed in nuclei isolated from PC12 rat pheochromocytoma cells incubated with tritiated phosphatidylinositol, phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate. Phosphoinositide breakdown was found to be optimal at neutral pH and Ca++ concentrations ranging from endogenous levels to millimolar values. To characterize the enzymes involved, three monoclonal antibodies directed against the beta, gamma and delta phosphoinositidase C isoforms were employed. A combination of Western blot immunochemical analysis on cytoplasmic and nuclear fractions and of in situ immunocytochemistry on intact cells and isolated nuclei indicated that phosphoinositidase C gamma, though predominantly cytoplasmic, was present in both cell compartments. On the contrary, phosphoinositidase C beta was exclusively localized in the nucleus, whereas phosphoinositidase C delta was restricted to the cytoplasm. These data suggest that inositol lipid breakdown is controlled by different phosphoinositidase C isozymes in the various cell compartments, and support the notion that a separate phosphoinositide signalling system is located in the nucleus.

Animals↗
PubMed1992

Glycosylation-inhibiting factor from human T cell hybridomas constructed from peripheral blood lymphocytes of a bee venom-sensitive allergic patient.

Human T cell hybridomas, which constitutively secrete glycosylation inhibiting factor (GIF), were constructed from PBL of an allergic individual who was sensitive to honey bee venom. PBMC of the patient were stimulated with either denatured or cyanogen bromide-treated bee venom phospholipase A2 (PLA2), and Ag-activated cells were propagated by IL-2 in the presence of human recombinant lipocortin I. T cells obtained in the cultures were fused with a HAT-sensitive mutant of the human lymphoblastoid cell line CEM. Approximately one-third of hybridoma clones constitutively secreted GIF. The GIF-producing hybridomas were CD3+ and bore TCR-alpha beta. GIF formed by unstimulated hybridomas lacked affinity for bee venom PLA2. Upon cross-linking of CD3, however, a majority of the GIF-producing hybridomas formed IgE-binding factors and GIF, the latter of which had affinity for bee venom PLA2. Both nonspecific GIF and Ag-binding GIF from the hybridomas bound to an immunosorbent coupled with the anti-lipomodulin mAb 141-B9. Using an affinity-purified GIF as an immunogen, we established mouse B cell hybridomas that secreted monoclonal anti-human GIF. In order to characterize human nonspecific GIF, one of the GIF-producing hybridomas was adapted to a serum-free medium, and culture supernatant was fractionated by DEAE-Sepharose column chromatography and by gel filtration. The majority of nonspecific GIF in the culture supernatant was recovered from DEAE-Sepharose by elution of the column with 10 mM Tris-HCl buffer, pH 8.0, containing 50 mM NaCl. Affinity-purification of GIF in the DEAE Sepharose fraction by using anti-GIF-coupled Affigel, and analysis of the purified GIF by SDS-PAGE revealed that human GIF is a single polypeptide chain of 14 to 15 kDa. Gel filtration of both crude and affinity-purified GIF preparations confirmed the molecular size of the cytokine.

Antibodies, Monoclonal↗
PubMed1992

Increased phosphorylation of nuclear substrates for rat brain protein kinase C in regenerating rat liver nuclei.

Protein phosphorylation catalysed by rat brain protein kinase C (PKC) has been studied in nuclei isolated from normal and regenerating rat liver. Histone H1 and a 40,000 molecular weight protein were hyperphosphorylated at all the explored regeneration times, ranging from 3 to 22 h after partial hepatectomy. Phosphorylation of the two substrates was totally dependent on calcium and lipids and was abolished by low concentration of staurosporine. The observed early change of phosphate content of histone H1 and of the 40,000 molecular weight protein on the time scale of liver regeneration suggests that PKC might be involved in the initial nuclear events leading to cell proliferation.

Animals↗
PubMed1992

Isotypic distribution of HIV-1-specific antibodies in individuals from central Africa.

Individuals infected with human immunodeficiency virus type 1 (HIV-1) develop a humoral immune response to the virus's major structural gene products env, gag, and pol. The distribution of antibodies to env, gag, and pol proteins in Central African populations is of interest as they have a high level of immune system activation compared to non-African populations. Using the Western blot technique, we analyzed the isotypic distribution of anti-HIV antibodies in 45 HIV-1-infected individuals from Central Africa that were either symptomatic or asymptomatic. We observed two basic differences between the isotypic profile of individuals from Central Africa and non-African populations. Central African individuals had a strong polyisotypic response to gag and pol, which has only been observed for gag in American and European populations. In addition, individuals from Central Africa had a high frequency of IgG4 to gag and pol, 75 and 51%, respectively, as compared to 29 and 6% in a non-African population. The elevated IgG4 response may result from the high basal level of immune stimulation seen in Africans due to multiple and frequent exposures to viral, bacterial, and parasitic antigens.

Africa, Central↗
PubMed1992

Detection of IgG subclasses with anti-IgE activity in patients with atopic diseases.

Significantly increased levels of IgG anti-IgE were seen in atopic patients as compared with controls. A correlation was observed between the levels of anti-IgE autoantibodies and serum IgE in the groups of atopic patients studied. No significant correlation was found between IgG anti-IgE levels and severity of the disease or between IgG subclasses with anti-IgE activity and clinical status. Analysis of IgG subclasses with anti-IgE activity showed that IgG1 and IgG4 were clearly factors in differentiating the atopics from the controls. IgG2 and IgG3 anti-IgE levels were not statistically significantly elevated. The lack of these autoantibodies may be explained by the presence of immune complexes or the lack of specificity of the monoclonal antibodies used in this study. These observations have not yet determined whether these autoantibodies and the isotypic selection and restriction observed play a role in the dysregulation of the immune response and in the evolution towards atopy.

Adolescent↗
PubMed1991

Nuclear protein kinases in rat liver: evidence for increased histone H1 phosphorylating activity during liver regeneration.

Comparison of protein kinase activity in normal and regenerating rat liver nuclei indicates that exogenous histone H1 is hyperphosphorylated in 22-h regenerating nuclei. The protein kinase involved is not sensitive to protein kinase A inhibitor, is inhibited by staurosporine and by an anti-PKC polyclonal antibody, utilizes only ATP, and also phosphorylates the C-terminal fragment of histone H1. These data suggest that protein kinase C is responsible for the observed effects, in agreement with the presence of this enzyme in normal and regenerating nuclei demonstrated by immunoblotting.

Adenosine Triphosphate↗
PubMed1991

Evidence for IgE immune complexes and distribution of IgG subclasses with anti-IgE activity in patients with atopic dermatitis.

The anti-IgE autoantibody was detected, using a radioimmunoassay, in 17 out of 35 (48.6%) of patients with atopic dermatitis. Significant increased levels of IgG-anti-IgE were seen in the patients studied compared with the control group. The specificity of the anti-IgE autoantibody was confirmed by competitive inhibition assay using IgG, IgM, IgE myeloma. A correlation was observed between the levels of IgG-anti-IgE and serum IgE but not between the IgG subclasses with anti-IgE activity and the clinical status. These data demonstrate that the IgG subclass distribution with anti-IgE activity belongs mostly to the IgG1 and IgG4 subclasses compared with the controls. Moreover, ultracentrifugation analysis indicated that the IgG-anti-IgE in the serum samples from the patients with atopic dermatitis was present in the form of an immune complex with self-IgE. These observations may suggest that the anti-IgE complexes may play a broader role in the modulation of the immune response and that this autoantibody may mask recognition of IgE in conventional assays.

Adolescent↗
PubMed1990

A method to generate antigen-specific suppressor T cells in vitro from peripheral blood T cells of honey bee venom-sensitive, allergic patients.

Peripheral blood mononuclear cells of patients allergic to honey bee venom were stimulated with denatured bee venom phospholipase A2, and the antigen-activated T cells were propagated for 4 days by human IL-2 in the presence or absence of recombinant human lipocortin I. Upon antigenic stimulation with the denatured phospholipase A2 and autologous monocytes or by cross-linking of CD3 by anti-CD3 antibody, the activated T cells, which had propagated by IL-2 alone, formed N-glycosylated IgE-binding factors and glycosylation enhancing factor (GEF), while those propagated in the presence of lipocortin formed unglycosylated IgE-binding factors and glycosylation inhibiting factor (GIF). The GEF and GIF formed by the antigen- or anti-CD3-stimulated T cells had affinity for bee venom phospholipase A2 and could be purified by using anti-lipomodulin Sepharose. In the mouse lymphocyte system, the major cell source of GIF is antigen-specific suppressor T cells, and the antigen-binding GIF from the cells suppressed the in vivo antibody response in an antigen (carrier)-specific manner. In view of the findings in the mouse system, the present results may provide an immunological maneuver to generate allergen-specific suppressor T cells, and to obtain allergen-specific suppressor factor from T cell populations in the peripheral blood of allergic patients.

Annexins↗
PubMed1989

Interleukin-2, interleukin-2 receptor and gamma-interferon synthesis by peripheral blood mononuclear cells in chronic hepatitis delta virus infection.

The behaviour of the immune system during liver damage caused by chronic hepatitis delta virus (HDV) infection was evaluated by assessing, in 16 patients with HBsAg+ chronic liver disease and HDV superinfection (15 HBeAg-, 1 HBeAg+), phytohaemagglutinin (PHA)-induced interleukin-2 synthesis and interleukin-2 receptor expression, PHA and staphylococcal enterotoxin B (SEB)-induced gamma-interferon synthesis and, in some cases, the presence of hepatitis B virus DNA (HBV-DNA) within peripheral blood mononuclear cells (PBMC). The results were compared to those obtained in 13 patients without HBV replication (i.e., serum HBV-DNA and liver HBcAg-negative), in 15 with HBV replication (i.e., serum HBV-DNA and/or liver HBcAg-positive) with chronic liver disease without HDV superinfection, and in 15 HBsAg-negative healthy control subjects. The lymphokine pattern in HDV infection was comparable to that of healthy subjects and of HBV non-replicating patients without HDV superinfection. Interleukin-2 receptor expression and gamma-interferon synthesis were however significantly decreased in HDV-negative patients with active HBV replication. HBV-DNA was detected in PBMC from 8 of 23 patients, without any correlation with the lymphokine pattern. Our results suggest that in HDV-related chronic liver disease, immune system alterations are unlikely. HDV superinfection does not affect the occurrence of HBV-DNA sequences within the leukocytes. HBV-DNA in PBMC does not interfere with the interleukin-2 system nor with the gamma-interferon response in HBV- and HDV-related chronic liver disease.

Adult↗
PubMed1989

Complement activation is associated with the presence of specific human immunodeficiency virus (HIV)-anti-HIV immune complexes in patients with acquired immunodeficiency syndrome-related complex or lymphoadenopathy syndrome.

The complement system was examined in a group of eight patients (six with lymphoadenopathy syndrome (LAS); two with acquired immunodeficiency syndrome (AIDS)-related complex (ARC], who were found to be human immunodeficiency virus (HIV)-positive, for the presence of specific HIV-anti-HIV complexes. A significant impairment of the classical and/or alternative pathway was found associated with the presence of cleavage fragments of C3 and/or B and a significant reduction in the complement factors studied. Ultracentrifugation fractions of serum samples obtained from one of the patients were assessed for the detection of specific HIV-anti-HIV (GP41-anti-GP41) complexes and were incubated with normal human serum to determine their complement activation capacity. A clear complement activation was found with the fraction in which a clear peak of HIV-anti-HIV (GP41-anti-GP41) immune complexes was present. The results demonstrate that specific immune complexes and complement activation are sometimes concomitantly present in patients with AIDS-related disease and that specific immune complexes may be one of the causal factors of the pathogenesis of complement activation in these patients. Possible consequences for the severe immune regulation with relevance to the dramatic failure in treating the virus effectively are discussed.

AIDS-Related Complex↗
PubMed1989

Formation of IgE-binding factors by lymphocytes of HIV-infected patients.

Peripheral blood mononuclear cells of human immunodeficiency virus infected patients were cultured in the presence or absence of 10 micrograms/ml human IgE, and culture filtrates were fractionated on IgE-Sepharose. IgE-binding factors were assessed in the acid eluate fraction from IgE-Sepharose by both rosette inhibition assay and radioimmunoassay. Among 22 cases studied, mononuclear cells from 9 patients formed IgE-binding factors in the absence of IgE, and those of 13 cases formed the factors upon incubation with IgE. The major cell source of IgE-binding factors was T cells. In 2 cases of human immunodeficiency virus infection, Fc epsilon receptors were detected on both Leu-2+ and Leu-3+ T cells.

AIDS-Related Complex↗
PubMed1988

Formation of IgE-binding factors by T cells of patients infected with human immunodeficiency virus type 1.

Peripheral blood mononuclear cells of 10 out of 26 patients with human immunodeficiency virus type 1 (HIV-1) released IgE-binding factors, as determined by two independent assays. The formation of the factors by the mononuclear cells was enhanced by incubation of the cells with homologous IgE. In the presence of IgE, peripheral blood mononuclear cells from 15 of the 26 patients formed a detectable amount of IgE-binding factors, whereas those of normal individuals of allergic rhinitis patients failed to do so. The major source of IgE-binding factors was the T cells of the HIV-1-infected patients. The CD8+ T cells from a HIV-1-infected patient formed IgE-binding factors upon incubation with IgE, and type II receptors for Fc epsilon were detected on both CD4+ T cells and CD8+ T cells in one of five patients studied. It was also found that culture supernatants of mononuclear cells from HIV-1-infected patients released soluble factors that induce normal human T cells to form IgE-binding factors. The results suggest that lymphocytes of some HIV-1-infected patients are activated to produce lymphokines regulating formation of IgE-binding factors.

AIDS-Related Complex↗
PubMed1988

IgG autoantibody to IgE in atopic patients.

An IgG type of antibody directed against IgE has been studied in serum from healthy and allergic individuals. The technique used is based on a solid phase paper radioimmunoassay in which the discs were sensitized with purified IgE myeloma. After incubation with patients' serum, human IgG labeled with iodine 125 was added. The anti-IgE antibodies were partially blocked by endogenous IgE in the serum and heating the serum samples at 56 degrees C disrupted the immune complexes (ie, IgG-aIgE:IgE), thereby increasing the detectable levels of IgG anti-IgE. The specificity of anti-IgE autoantibody was confirmed by both competitive inhibition and absorption experiments, using IgG, IgM, IgA, IgE, and rabbit anti-human IgG. Significantly raised levels of anti-IgE autoantibody were found in patients suffering from atopic disorders in comparison to the controls. These observations may suggest that the anti-IgE autoantibody could play a certain role in the modulation of IgE-mediated immune system and the pathogenesis of atopic diseases.

Adolescent↗
PubMed1987

Characterization of specific immune complexes in HIV-related disorders.

Eighty-seven seropositive subjects with HIV (human immunodeficiency virus) infection together with 20 normal controls with no history of any illness were investigated for the presence of circulating immune complexes (CIC) by the conglutinin binding assay (KgBA) and further studied for isotype characterization of CIC. Six out of 87 patients showing very high values for immune complexes (CIC) were studied for the presence of free antigen. In 3 out of 6 (1, IVc1; 1, III; 1, IVa) we could detect by ultracentrifugation analysis the presence of specific HIV (p15) anti-HIV (anti-p15) and gp41-anti-gp41 CIC. Evidence in favour of this finding is supported by: the presence of specific CIC (p15-anti-p15 or gp41-anti-gp41) seen only at pH 7.2; the apparent presence of free antigen and specific HIV antibodies were only at pH 4.0. The relevance of this finding lies in the attempt to explain the occurrence of false seronegativity seen occasionally in symptomatic patients. Thus, the presence of CIC might perhaps interfere in the routine assay (i.e. ELISA) making the diagnosis difficult. All these considerations will have to be taken into account in the future handling of this disease.

Acquired Immunodeficiency Syndrome↗
PubMed1987

IgE complexes in food allergy.

We have studied patients with the diagnoses of asthma, eczema, and arthralgia by monitoring the formation of immune complexes containing IgE after antigen egress from the gut before and after challenge with food. Following challenge, immune complexes containing IgE, IgG, and antigen are detectable in the circulation. Their appearance correlates with the production of symptoms. The effect of sodium cromoglycate was to prevent the appearance of complexes. This was associated with absence of symptoms. It is suggested that a local IgE-mediated mechanism acts as a "trigger" for the entry of antigen and the formation of immune complexes by altering the permeability of the gut mucosa. The resulting delayed onset symptoms could be viewed as a form of serum sickness with few or many target organs affected.

Adolescent↗