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Biomedical subjects

F Ameglio

Publications and source records attributed to F Ameglio.

At least 73 records · Page 4Linked to original sources
PubMed1994

Mutual interactions between HIV-1 and cytokines in adherent cells during acute infection.

The production of cytokines by HIV-infected cells from adherent tissues as well as their effects on HIV replication in the same cells were investigated. CD4-transfected HeLa-T4-6c epithelial cells, CD4-positive normal lung fibroblasts and CD4-negative RD rhabdomyosarcoma cells were infected with HIV-1. All cultures were permissive for virus replication, which was completed within 48-72 h by Hela-T4-6c and RD cells and 2-3 weeks in normal fibroblasts. During the course of HIV replication, a series of cytokines (particularly IL-6 and TNF alpha) was produced and released in parallel to the peak of virus growth, in amounts varying with the cell system studied. Treatment of cultures with recombinant cytokines given at concentrations in the range of those induced by HIV-1 indicated that IL-6 and TNF alpha caused an increase of: i) CD4 expression, ii) HIV absorption to uninfected cells, and iii) release of infectious virions by infected cells. The fact that HIV-1 absorption and spread can be mediated by HIV-induced cytokines may be relevant in the pathogenesis of the in vivo disease, as it may constitute a possible self-enhancing model of HIV infection also in the solid tissues.

CD4 Antigens↗
PubMed1994

Autoreactive response in seronegative homosexual men at high risk for HIV infection.

Peripheral autoreactive T cell response was evaluated by limiting dilution analysis of autologous mixed lymphocyte reaction cultures in 15 subjects at high risk for HIV infection and in 20 normal individuals. The two groups did not show a quantitative difference of peripheral autoreactive T cells, but they showed different kinetics. While controls provided a straight line passing through the origin, the majority of high risk individuals showed a curve with a limited linear portion at high cell concentration, indicating that different mechanisms regulate the autoreactive response in the two groups studied. A follow-up study performed in three high risk and three normal individuals revealed a time-dependent increase of peripheral autoreactive T cells only in high risk subjects. Such increase correlates with the decrease of CD4+ cell number and CD4+/CD8+ cell ratio. Furthermore, the proliferative response of the same three subjects to gp160 peptides suggests a specific cellular reactivity to HIV components. This work has potential importance in understanding some of the early events in HIV infection.

Autoimmunity↗
PubMed1994

Serum reactivity against an immunoregulatory sequence of HIV p24 in HIV-1-infected subjects.

The aim of this study was to assess the antibody reactivity in HIV-infected subjects against an HIV-1 p24 sequence, p226 (aa226-237), including a seven amino acid epitope showing immunosuppressive activity in vitro and to evaluate the relationship between anti-peptide antibody levels and disease progression. Sera of HIV-infected subjects, at different stages of disease, were compared to control sera in a retrospective evaluation. Recombinant HIV-1 p24 and p24- and control-peptides were used in an enzyme immunoassay as targets for antibodies present in the sera. Antibodies directed against the whole p24 protein and its peptides were found in all the sera studied but at different levels. The anti-p226 reactivity was not significantly different at different clinical stages. Nevertheless, it was inversely correlated to the reactivity directed against the whole protein, that was lower in subjects characterized by low CD4 cell numbers.

Amino Acid Sequence↗
PubMed1994

Use of discriminant analysis to assess disease activity in pulmonary tuberculosis with a panel of specific and nonspecific serum markers.

Several cell activation markers, acute phase reactants, enzymes, and antituberculous antibody serum levels have been proposed as possible markers to monitor disease activity in patients with tuberculosis. They have all shown limited sensitivity or specificity. The authors therefore attempted to generate a canonical variable using discriminant analysis, including sensitive and specific parameters, to be a reliable marker in classifying patients correctly during the course of pulmonary tuberculosis. The following parameters were selected: two soluble cell activation markers (soluble interleukin-2 receptor and sCD8); the levels of immunoglobulin (Ig) G and IgM antibodies against the A60 antigen complex; and the presence of specific antibodies directed to eight different A60 components, revealed by Western blot analysis. The tests were performed on sera from three groups of patients with pulmonary tuberculosis. The first group comprised 25 patients with onset tuberculosis, clinically active (OTCA), evaluated at the time of admission. The second group included 28 patients with chemotherapy-treated tuberculosis, clinically active (CTCA), 2 months after therapy had begun. The third group included 20 patients with tuberculosis, nonclinically active (TNCA), who had had at least 1 year of effective therapy. The authors obtained an 80.9% rate of correct classification for the three groups and a rate of 100% when OTCA and TNCA were compared. The patients with CTCA were scarcely differentiated and tended to be distributed into the two other groups. To improve the separation between patients with CTCA and those with OTCA, a second canonical variable was generated with a 91.7% rate of correct classification, as compared with 71% obtained using the sCD8 as the best single variable. The mean values of the last canonical variable were statistically different (Mann-Whitney test, P = .049) when stratified for acid fast bacilli-positive or negative CTCA patients (microscopic detection). Three patients, followed during the entire course their disease, were, as expected, correctly positioned with respect to the subsequent disease phases.

Adult↗
PubMed1994

A simple and reliable method to detect cell membrane proteins on infectious human immunodeficiency virus type 1 particles.

Identification of cell-derived molecules on infectious human immunodeficiency virus type 1 (HIV-1) particles may be helpful in investigating mechanisms of HIV infection and in vaccine studies. Some of these molecules were detected on HIV-1 virions in previous studies, but rather elaborate methods were used. The method presented here allows an extensive characterization of the cell surface molecules associated with HIV-1 by capturing virus particles on monoclonal antibodies to cell membrane antigens bound to plastic wells. Binding of infectious virus was assessed by adding permissive target cells (C8166) and determining viral replication. With this procedure, beta 2-microglobulin, HLA-DR, intercellular adhesion molecule-1, and leukocyte function antigen-1 were found on HIV-1 particles from laboratory strains and primary clinical isolates. In contrast, CD19, CD4, and CD8 molecules were not detected.

Antigens, Surface↗
PubMed1994

Biochemotherapy with thymosin alpha 1, interleukin-2 and dacarbazine in patients with metastatic melanoma: clinical and immunological effects.

BACKGROUND: DTIC and interleukin-2 (IL-2), as single agents, have a limited anti-tumor activity in patients with metastatic melanoma. Experimentally, thymosin alpha 1 (TA1) may modulate the action of IL-2. We investigated the clinical and immunological effects of a combination with these three agents. PATIENTS AND METHODS: Forty-six patients with measurable metastatic melanoma were treated with DTIC 850 mg IV on day 1, TA1 2 mg s.c. on days 4 to 7, and IL-2 18 MU/m2/d by continuous intravenous infusion on days 8 to 12. Cycles were repeated every 3 weeks. RESULTS: Objective responses were obtained in 15 (36%) of 42 evaluable patients (CI at 95%: 22%-50%). Two patients experienced complete responses, and stable disease was observed in five. The median time to progression was 5.5 months and median survival was 11 months. Side effects were predominantly caused by IL-2. Treatment was tolerated reasonably well, and there was no overlapping toxicity or interference between chemotherapy and biotherapy. Baseline sCD4 levels seem to correlate to tumor burden. Patients benefiting from treatment had lower sCD4 and higher sCD8 than did progressing patients. CONCLUSIONS: The combination of DTIC + TA1 + IL-2 is active in the treatment of advanced melanoma, with acceptable toxicity. However, even more active regimens are needed, and the interactions between thymic hormones and cytokines should be further explored.

Adult↗
PubMed1994

Correlated increases of tumour necrosis factor-alpha, interleukin-6 and granulocyte monocyte-colony stimulating factor levels in suction blister fluids and sera of psoriatic patients--relationships with disease severity.

Tumour necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and granulocyte monocyte-colony stimulating factor (GM-CSF) were measured in serum and involved and uninvolved skin blister fluids of 20 psoriatic patients and 10 healthy subjects, by enzyme immunoassay. TNF-alpha and IL-6 were always detectable in involved skin blister fluids, while GM-CSF was detected only in 45% of these samples. TNF-alpha, IL-6 and GM-CSF were detected in 95, 100 and 10% of uninvolved skin blister fluid samples, respectively. TNF-alpha and IL-6 were found in 50 and 30% of control blister fluids, while GM-CSF was never detected. In serum, TNF-alpha was detected in 75% of patients and in 70% of controls; IL-6 in 45% of patients and in no controls; and GM-CSF in 35% of patients and in 20% of the controls. The median TNF-alpha and IL-6 levels in involved skin were statistically higher than those of both uninvolved and control skin blister fluids. TNF-alpha and IL-6 levels in blister fluids obtained from both involved and uninvolved skin were higher than those of the patients' sera. GM-CSF, when present in involved skin blister fluids, showed correlated levels with the other cytokines (TNF-alpha: R = 0.85, P = 0.004; IL-6: R = 0.72, P = 0.03). TNF-alpha was highly correlated with IL-6 (R = 0.78, P < 0.00001) in involved skin blister fluids. TNF-alpha and IL-6 levels of involved skin blister fluids showed significant correlations with the psoriasis area and severity index scores in the patients, suggesting a direct relationship between these cytokines and the clinical manifestations of the disease. Moreover, the TNF-alpha levels were particularly related to the erythema scores in the patients, further supporting evidence of their role in the pathogenesis of the disease.

Adolescent↗
PubMed1994

Recombinant gp120 induces IL-10 in resting peripheral blood mononuclear cells; correlation with the induction of other cytokines.

Immunological abnormalities present in HIV-1-infected individuals often reflect an imbalance of cytokine production. The HIV-1 gp120 has the ability to induce a number of cytokines, and to enhance immunoglobulin release by normal peripheral blood mononuclear cells (PBMC) in vitro, in the absence of IL-2 production and of lymphoproliferation. This study provides evidence that gp120 is a potent IL-10 inducer in normal PBMC cultures. The pattern of other cytokines induced by gp120 includes interferon-alpha (IFN-alpha) and IFN-gamma, tumour necrosis factor-alpha (TNF-alpha), IL-6, IL-1 alpha and -beta, and not IL-2 and IL-4. These findings further define the pattern of cytokine release induced by gp120 on human resting PBMC. Furthermore, the present findings roughly parallel those observed both in the sera of patients and in the mononuclear cells from HIV+ individuals early after infection, suggesting that gp120 could be a good candidate as one of the agents responsible for cytokine dysregulation observed in HIV-1-infected individuals.

Biopterins↗
PubMed1994

Selection of patients with monoclonal gammopathy of undetermined significance is mandatory for a reliable use of interleukin-6 and other nonspecific multiple myeloma serum markers.

Serum levels of various immunochemical markers of clinical interest, as interleukin-6 (IL-6), C-reactive protein (CRP) and beta 2-microglobulin (beta 2M), were measured in sera from 98 subjects affected with monoclonal gammopathy of undetermined significance (MGUS; 80% of which bearing cancer too) and from 39 patients with multiple myeloma (MM). In addition, the ratio between serum IgG/IgA amounts (GAR) was also calculated in monoclonal gammopathies of IgG type. Consistent with our previous investigations, we found that tumor presence significantly influenced the serum levels of the various markers (except GAR) in MGUS patients; in fact, only when comparing MGUS without tumor and MM patients, was a clear difference observed for all markers considered. The data presented discourage the use of IL-6, CRP and beta 2M as discriminant indices between MGUS and MM patients, unless a careful selection of MGUS subjects is performed. Further investigations on these potential markers are therefore needed for a more rational clinical application.

Adult↗
PubMed1994

Interleukin-6 and tumour necrosis factor levels decrease in the suction blister fluids of psoriatic patients during effective therapy.

BACKGROUND: Involvement of various cytokines in psoriasis pathomechanisms has previously been reported. OBJECTIVE: To better define the relationship between the disease severity and interleukin-6 and tumour necrosis factor alpha skin levels, these two cytokines were measured in suction blister fluids obtained from involved and uninvolved skin areas of psoriatic patients treated with UVB, beta-methasone dipropionate and salicylic acid ointment. METHODS: Determinations were performed by ELISA in fluids obtained from 6 patients with the Kiistala method, every 1-2 weeks for at least 1 month. RESULTS: During the observation period, all the patients showed disease improvement (median PASI score declined from 13.4 to 3.9) and significant decreases in the cytokine levels in all samples. CONCLUSION: These results are in agreement with a functional involvement of these two cytokines in the pathogenesis of the disease and their possible use as follow-up markers.

Administration, Topical↗
PubMed1994

Soluble intercellular adhesion molecule-1 and procollagen III peptide are reliable markers of disease severity in psoriasis.

Levels of soluble intercellular adhesion molecule-1 (sICAM-1) and procollagen III peptide (PIIIP) were measured respectively by enzyme immunoassay (EIA) and radioimmunoassay (RIA) methods in sera from 14 patients affected with psoriasis. The same determinations were also performed on suction blister fluids (BFs) obtained from lesional and non-lesional skin. Fourteen normal subjects were used as controls. Significant correlations were found between the serum levels and psoriasis area and severity index (PASI), (R = 0.62 for sICAM-1 and R = 0.73 for PIIIp, respectively). Of the PASI components, infiltration and erythema represented the variables most closely related to PIIIP (R = 0.85; R = 0.72 respectively). Differently from PIIIP, whose levels were significantly lower in the sera than in skin BFs (serum: median value 1.05, range 0.7-2.3 vs. lesional skin fluid: 11.8, 4.8-30 U/ml), sICAM-1 molecules were found predominantly in the sera (serum: median 316, range 117-579 vs lesional skin fluid: median 70, range 31-252 ng/ml). These data cannot exclude that sICAM-1 molecules detected in suction BFs may derive from serum contamination.

Adolescent↗
PubMed1994

Interleukin-1-beta, interleukin-6, and interferon-gamma in suction blister fluids of involved and uninolved skin and in sera of psoriatic patients.

Interleukin-1-beta (IL-1-beta), Interleukin-6 (IL-6) and Interferon-gamma (IFN-gamma) were measured by enzyme immunoassay (EIA) methods in blister fluids (BFs) obtained from both involved (ISBF) and non-involved skin (USBF) and in sera from 14 psoriatic patients. The same determinations were carried out in 14 sera and in 5 suction blister fluids from 14 normal subjects. IL-6 was always detectable in all skin fluids and in 3 psoriasis sera. IL-1-beta was measured only in 5 ISBFs and in 5 sera from the same patients. IFN-gamma was present in 11 ISBFs, in 5 USBFs and in 5 sera. The analysis of the levels found in the samples shows: 1) a local production of these cytokines, 2) the presence of detectable amounts of IL-6 and IFN-gamma in USBFs, and 3) a significant correlation between the IL-6 levels in the ISBFs and erythema score.

Adolescent↗
PubMed1993

Ferritin downregulation in HIV-infected cells.

Levels of serum ferritin are increased in AIDS patients in relation to the progression of the disease. To establish whether or not this in vivo increase could be due to a direct effect of the virus on the infected cells, three HIV-permissive cell lines, the CD4-positive HeLa-T4-6c and C8166 cells and the CD4-negative RD cells, were infected with HIV-1 strains. The expression of ferritin was followed during the course of acute infection, in parallel to other cellular components. Unexpectedly, all three cell lines showed a phase of decrease in their ferritin content after infection by HIV-1, not justified by the modest and late increase of ferritin in the fluids, due to disruption of infected cells. Since ferritin is involved in the control of cell growth and DNA synthesis, its downregulation may be implied both in cell toxicity and DNA abnormalities due to HIV infection.

CD4 Antigens↗
PubMed1993

Coordinate induction of interferon alpha and gamma by recombinant HIV-1 glycoprotein 120.

Similarly to HIV-infected cells, recombinant HIV-1 glycoprotein 120 induces acid-labile interferon production in peripheral blood mononuclear cells from healthy donors. Acid lability of this interferon is due to the presence of both IFN-alpha and -gamma molecules. In fact, although not revealed by neutralization of antiviral activity with antibody to IFN-gamma, the presence of IFN-gamma was shown both immunoenzymatically and by detection of specific mRNA in gp120-stimulated cells. The source of IFN-gamma appears to be a T cell present in the CD4-enriched subpopulation. Cultures treated with monoclonal antibodies to the ICAM-1 and LFA-1 adhesion molecules showed an impaired release of both IFN types after gp120 stimulation, suggesting a crucial role of cell-to-cell interactions in the process leading to IFN production. Our data suggest that the HIV envelope glycoprotein could be responsible for the induction of endogenous IFN-alpha and -gamma observed in AIDS patients.

Cell Adhesion Molecules↗
PubMed1993

Early abnormalities of the antibody response against Mycobacterium tuberculosis in human immunodeficiency virus infection.

Among human immunodeficiency virus (HIV)-infected persons, those who react against purified protein derivative (PPD) have higher risk of tuberculosis. Since PPD testing has limited predictive power in HIV-positive populations, new markers of antituberculous immunity were sought by analyzing antibodies to Mycobacterium tuberculosis antigens (PPD and its fraction A60) in 102 HIV-positive subjects, some PPD-positive and some PPD-negative, and in 23 HIV-positive tuberculosis patients. ELISA and Western blotting were used. Forty HIV-negative healthy subjects and 40 HIV-negative tuberculosis patients were evaluated as controls. While all those HIV-negative and PPD-positive had IgG antibodies recognizing the 38-, 28-, and 19-kDa M. tuberculosis antigens, only 26% of those HIV-positive and PPD-positive (all with < 400 CD4+ cells/mm3) and none of the HIV-positive tuberculosis patients recognized them, indicating that the lack of IgG against those antigens, in the presence of a specific IgM response, is a marker of immunodeficiency.

Adolescent↗
PubMed1993

Mycobacterial antigen complex A60-specific T-cell repertoire during the course of pulmonary tuberculosis.

The Mycobacterium bovis antigen complex A60 is known to be immunodominant in tuberculosis and to have a protective effect against experimental infection in vitro and in vivo. To identify immunodominant and possibly protective antigens in pulmonary tuberculosis, the T-cell repertoire directed to nitrocellulose-bound fractions of A60 antigen was analyzed in active tuberculosis patients during the course of the infection and after recovery. The results show that patients infected with Mycobacterium tuberculosis acquired complete A60-T-cell reactivity only in the late phases of infection. At disease onset, patients with active tuberculosis were characterized by (i) T-cell unresponsiveness to most A60 fractions, (ii) high tumor necrosis factor alpha production, and (iii) low gamma interferon (IFN-gamma) release. Several weeks after chemotherapy, the unresponsive state disappeared and the following reverse situation was observed: (i) high blastogenic response to almost all A60 fractions, (ii) low tumor necrosis factor alpha release, and (iii) high IFN-gamma production. In addition, 60% of these patients significantly responded against seven A60 fractions (61 to 58, 56 to 53, 49 to 46, 46 to 44, 35 to 33, 33 to 30, and 30 to 28 kDa), indicating that they included immunodominant antigens. Furthermore, only the fractions within the molecular mass ranges of 56 to 44 and 35 to 28 kDa induced IFN-gamma synthesis. One year after complete recovery from infection, more than 60% of past-active tuberculosis subjects had memory T cells specific for the immunodominant fractions of 61 to 58, 56 to 53, 49 to 46, and 33 to 30 kDa. Since the same fractions induced the strongest IFN-gamma production, known to exhibit antimycobacterial effects, it is suggested that these may represent the inducers of a protective immune response.

Adult↗
PubMed1993

Antibody repertoire against the A60 antigen complex during the course of pulmonary tuberculosis.

The A60 antigen complex is a Mycobacterium bovis (BCG) highly immunodominant antigen containing both B and T-cell epitopes. Clinical-serological studies show that elevated anti-A60 titres are present during tuberculosis. We wished to analyze in detail antibody responses against A60 components during the course of tuberculosis. A mixed longitudinal study was designed including individuals at the onset of tuberculosis, during treatment and after resolution of the disease. The anti-A60 repertoire was analyzed using a western blot assay with A60 as the antigen. While PPD- normals recognized only the 65 kDa heat shock protein (HSP), PPD+ normal individuals displayed low levels of anti-A60 antibodies against dominant antigens. There were immunoglobulin M (IgM) and immunoglobulin G (IgG) consistent with response to a latent infection. Onset tuberculosis was characterized by IgM and IgG antibodies against 52 to 28 kDa antigens; IgM response being limited to earlier phases of the disease. In contrast, IgM antibodies against 25 to 14 kDa antigens appeared only 2-6 months after disease onset. The antibody repertoire of chemotherapy-treated, resolved tuberculosis was exclusively IgG in isotype, as for a memory-type response. Thus, western blot analysis with A60 identifies typical antibody patterns associated with different clinical phases of tuberculosis infection. Such approach may help in identifying new single antigens for serologic diagnosis of active tuberculosis.

Adult↗