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Biomedical subjects

F Puppo

Publications and source records attributed to F Puppo.

At least 37 records · Page 2Linked to original sources
PubMed1999

Immune regulatory properties of corticosteroids: prednisone induces apoptosis of human T lymphocytes following the CD3 down-regulation.

Glucocorticoid hormones (GCH) induce apoptosis in PHA-primed peripheral blood T lymphocytes (PBL) and down-regulate membrane-bound proteins involved in the immune response. We have analyzed whether GCH are able to affect the expression of the TCR-associated molecules CD3, CD4, and CD8 on PBL-PHA, and whether the modulation of those receptors is related to the GCH-driven apoptosis of the PBL-PHA. Lymphocytes were cultured with PHA or with PHA plus prednisone (PDN) 10(-3), 10(-6), and 10(-9) M. Then expression of CD2, CD3, CD4, CD8, and CD56 antigens was studied by cytofluorimetric assay using propidium iodide (PI) staining and annexin procedure, and by gel electrophoresis of low molecular weight DNA. PDN, at a pharmacological concentration (10(-6) M), was able to inhibit the CD3 expression on T cells. The kinetics of CD3 decrement and of apoptosis show that the down-regulation of CD3 molecules precedes DNA fragmentation and that the cells lacking CD3 are those prone to PDN-induced apoptosis. The inhibition of CD3 is not related to a transcriptional or posttranscriptional phenomenon, because both PBL-PHA and PBL-PHA-PDN expressed the same amount of intracytoplasmic CD3 molecule. PDN also induced a down-regulation of the CD4 and CD8 molecules that resulted sooner in more intense CD8. In vitro PDN is able to induce apoptosis in PBL-PHA through a down-regulation of CD3 molecules.

Adrenal Cortex Hormones↗
PubMed1999

Possible differences in the mechanism(s) of action of different glucocorticoid hormone compounds.

Different glucocorticoid hormones (GCH) show differences in the intensity and in the kinetics of their immunomodulating activity. The mechanism(s) of action of GCH is under investigation, but is has been noted that they exert immune activity via the genomic pathway. We have studied the effects of prednisone (PDN), deflazacort (DFC), and dexamethasone (DXM) on the production of cytokines (IL-2, IL-6, TNF-alpha, IL-10) by peripheral T lymphocytes, and the effects on the inhibition of NF-kB DNA binding activity by activated Jurkat cell line. The data obtained show that the three GCH molecules exert an immunosuppression on cytokine production by T lymphocytes and a strong decrease in the nuclear translocation of NF-kB in Jurkat cells; moreover, (a) not all the cytokines investigated were affected, and not with the same intensity, by the three GCH and (b) DXM inhibited the binding activity of NF-kB less than that of DFC and PDN. These data are in agreement with the concept that different GCH compounds might differ in their binding and affinity properties, tissue-specific metabolism, and interaction with transcription factor.

Adult↗
PubMed1999

Soluble HLA class I, HLA class II, and Fas ligand in blood components: a possible key to explain the immunomodulatory effects of allogeneic blood transfusions.

The immunomodulatory effect of allogeneic blood transfusions (ABT) has been known for many years. However, a complete understanding of the effects of ABT on the recipient's immune system has remained elusive. Soluble HLA class I (sHLA-I), HLA class II (sHLA-II), and Fas ligand (sFasL) molecules may play immunoregulatory roles. We determined by double-determinant immunoenzymatic assay (DDIA) sHLA-I, sHLA-II, and sFasL concentrations in different blood components. sHLA-I and sFasL levels in red blood cells (RBCs) stored for up to 30 days and in random-donor platelets are significantly (P <.001) higher than in other blood components and their amount is proportionate to the number of residual donor leukocytes and to the length of storage. Blood components with high sHLA-I and sFasL levels play immunoregulatory roles in vitro as in allogeneic mixed lymphocyte responses (MLR) and antigen-specific cytotoxic T-cell (CTL) activity, and induce apoptosis in Fas-positive cells. These data suggest that soluble molecules in blood components are functional. If these results are paralleled in vivo, they should be taken into account in transfusion practice. Blood components that can cause immunosuppression should be chosen to induce transplantation tolerance, whereas blood components that lack immunosuppressive effects should be preferred to reduce the risk of postoperative complications and cancer recurrence.

Adjuvants, Immunologic↗
PubMed1999

Beta2-micro-free HLA class I heavy chain levels in sera of healthy individuals. Lack of association with beta2-micro-associated HLA class I heavy chain levels and HLA phenotype.

We have applied a double-determinant immune assay (DDIA) to measure soluble beta2-microglobulin (beta2-micro)-free HLA class I heavy chains in serum. The mean concentration of beta2-micro-free HLA class I heavy chains in serum from 120 healthy subjects was 0.21+/-0.24 microg/ml. The individual serum levels of beta2-micro-free HLA class I heavy chains had a wide distribution, did not seem to be related with HLA phenotype, were stable over time and did not change with age. The serum levels of soluble beta2-micro-free HLA class I heavy chains did not correlate with those of soluble beta2-micro-associated HLA class I heavy chains, suggesting that their release is independently regulated. Three forms of soluble beta2-micro-free HLA class I heavy chains, with apparent molecular masses of 44, 39 and 37-35 kD, respectively, circulate in human serum. These results provide a useful background to assess the serum level of soluble beta2-micro-free HLA class I heavy chains in pathological conditions and to evaluate their putative immunoregulatory function.

Adolescent↗
PubMed1999

Cyclosporin A and iloprost treatment of systemic sclerosis: clinical results and interleukin-6 serum changes after 12 months of therapy.

OBJECTIVES: The main aim was to analyse the long-term therapeutic effects on systemic sclerosis (SSc) patients of treatment with either (i) iloprost alone or (ii) low-dose oral cyclosporin A (CyA) associated with iloprost. A secondary aim was to analyse interleukin-6 (IL-6) serum levels in SSc patients before and after 1 yr of treatment. METHODS: A clinical trial was performed in which 20 consecutive SSc patients were alternately randomized into two homogeneous groups receiving either monthly i.v. iloprost (1 ng/kg/min in 6 h i.v. infusion, for 5 consecutive days, 1 week per month) (Group I) or low-dose CyA (2.5 mg/kg/day) associated with iloprost administration (Group II). IL-6 concentrations were evaluated by ELISA in the sera of each patient before and after 1 yr of therapy and in 20 healthy subjects. RESULTS: After 1 yr of therapy, a significant improvement of skin (P=0.008), microvascular (P=0.004) and oesophageal (P=0.05) morphological and functional parameters was observed only in Group II patients. Furthermore, after 1 yr of treatment, a significant reduction (P=0.007) of IL-6 serum concentration was observed only in Group II patients. CONCLUSIONS: Collectively, our data suggest that the combination of low-dose CyA with iloprost administration may be of clinical utility in SSc and that a mechanism of action of CyA in SSc may include the decrease in IL-6 production.

Adolescent↗
PubMed1998

Double-stranded deoxyribonucleic acid binds to HLA class II molecules and inhibits HLA class II-mediated antigen presentation.

CD4+ T cells proliferating in response to purified double-stranded deoxyribonucleic acid (dsDNA) have been recently demonstrated in peripheral blood mononuclear cells of patients with systemic lupus erythematosus. Their activation was inhibited by anti-HLA class II (HLA-II) monoclonal antibodies; thus, the existence of a molecular interaction between dsDNA and HLA-II is conceivable. In this report we show that dsDNA specifically bind to HLA-II. After preincubating cells with purified dsDNA or synthetic oligonucleotides, dsDNA was detected on the cell membrane and in the lysates of HLA-II+ but not of isogenic HLA-II- cell lines. We demonstrate that dsDNA binding inhibits that of a specific peptide to HLA-II. Mixed lymphocyte reaction and antigen-specific T cell proliferation were inhibited by the preincubation of stimulator cells or antigen-presenting cells with dsDNA. These results suggest the existence of a novel mechanism of down-modulation of the CD4+ T cell function generated by lack of stimulation due to the HLA-II presenting molecules being "occupied" by dsDNA.

Animals↗
PubMed1998

Immunoregulatory role of soluble HLA molecules: a new skin for an old subject?

The available evidence suggests that measurement of the level of total sHLA-1 antigens and of donor-derived and recipient-derived allospecificities as well as the characterization of their variants in recipient's serum may provide useful information to differentiate graft rejections from infections in allograft recipients. Moreover, a significant progress has been made in our understanding of the functional properties of sHLA-I antigens in serum and of their potential role in the modulation of immune responses. If these preliminary results will be confirmed, then sHLA-I antigens are likely to become important reagents to monitor and treat graft recipients.

Histocompatibility Antigens Class I↗
PubMed1997

Downregulation of HLA class I antigen expression in CD4+ T lymphocytes from HIV type 1-infected individuals.

The expression of HLA class I antigens is downregulated in CD4+ T cells following in vitro HIV-1 infection. We determined whether the expression of HLA class I antigens is downmodulated in peripheral blood lymphocytes (PBLs) of HIV-1-positive subjects and whether this defect correlates with disease progression. A cohort of 62 HIV-1-seropositive individuals in different stages of disease was studied. Among these, four subjects were evaluated at yearly intervals for 6 years. The expression of HLA class I, HLA class II, and CD38 antigens was analyzed in PBLs and in CD4+ and CD8+ T lymphocyte subpopulations. The percentage of HLA class I-positive cells and the membrane density of HLA class I antigens were significantly lower in PBLs from HIV-1-positive individuals than in PBLs from HIV-negative controls, proportionally decreased with disease progression, and significantly correlated with the decrease in CD4+ T lymphocytes. Furthermore, the percentage of HLA class I-positive cells and the membrane density of HLA class I antigens were significantly lower in CD4+ T lymphocytes from AIDS patients with respect to CD4+ T lymphocytes from HIV-negative controls and to CD8+ T lymphocytes from HIV-negative controls and AIDS patients. By contrast, the expression of HLA class II and CD38 antigens was upregulated in CD4+ and CD8+ T lymphocytes from HIV-1-positive subjects. The defective expression of HLA class I antigens could impair the lysis of HIV-infected CD4+ cells by virus-specific HLA class I-restricted cytotoxic T lymphocytes and contribute to the progression of disease.

Adult↗
PubMed1997

Soluble HLA class I and class II molecule levels in serum and cerebrospinal fluid of multiple sclerosis patients.

Increased concentrations of soluble HLA class I and class II molecules (sHLA-I and sHLA-II) have been observed in infectious, inflammatory, and autoimmune diseases. Because autoimmune mechanisms are considered to play a role in the pathogenesis of multiple sclerosis (MS), we decided to dose sHLA-I and sHLA-II in serum and cerebrospinal fluid (CSF) of MS patients comparing their concentrations with those observed in serum and CSF of patients with other neurologic diseases (OND) without evidence of neuroradiologic involvement of central nervous system (CNS) and in serum of healthy donors. The serum concentrations of sHLA-I were higher in both MS and OND patients than in healthy donors (P < 0.05) whereas sHLA-II serum concentrations were lower in MS patients than in both OND patients and healthy donors (P < 0.01). Detectable amounts of sHLA-II were observed in the CSF of 45% of MS patients and in CSF of only 6% of OND patients (P < 0.001). In MS patients a significant correlation between sHLA-I serum and CSF concentrations was observed (P < 0.01), whereas sHLA-II serum and CSF levels did not correlate. In conclusion, alterations of sHLA-I and sHLA-II serum and CSF concentrations are present in MS patients and could be involved in the induction of enhanced susceptibility to develop MS or in MS pathogenesis.

Adolescent↗
PubMed1997

S-adenosil-L-methionine is able to reverse the immunosuppressive effects of chenodeoxycholic acid in vitro.

The study was conceived to evaluate if S-adenosil-L-methionine, a substance commonly used in the treatment of cholestasis in patients with cirrhosis and chronic hepatitis, exerts any immunological effect and of it is able to counterbalance bile acid-mediated immunosuppression. Proliferation and interleukin 2 and interferon-gamma secretion of human lymphocytes, collected from healthy subjects and exposed to mitogenic stimuli (phytohemagglutinin, pokeweed and anti-CD3 monoclonal antibodies), were analysed in the basal condition or after exposure to S-adenosil-L-methionine and/or chenodeoxycholic acid. Chenodeoxycholic acid inhibited phytohemagglutinin-induced lymphocyte proliferation and interferon-gamma secretion, and phytohemagglutinin and pokeweed-mediated interleukin 2 secretion. S-adenosil-L-methionine did not affect lymphocyte proliferation while it reduced interleukin 2 secretion upon phytohemagglutinin and pokeweed stimulation and interferon-gamma secretion upon all stimuli tested. Moreover, S-adenosil-L-methionine counteracted chenodeoxycholic acid-mediated inhibition of lymphocyte proliferation and interleukin 2 secretion. The results of our study confirm the immunosuppressive role of chenodeoxycholic acid on both secretive and proliferative lymphocyte functions and provide evidence of immunomodulatory activities of S-adenosil-L-methionine and its capacity to antagonize chenodeoxycholic acid-mediated inhibition of lymphocyte proliferation and interleukin 2 secretion.

Antibodies, Monoclonal↗
PubMed1997

Plicometer skin test: a new technique for the evaluation of cutaneous involvement in systemic sclerosis.

This study tries to establish a new method for the evaluation of skin lesion extension and progression in systemic sclerosis (SSc) patients. Plica thickness measurements of 200 healthy subjects and 19 SSc patients by plicometer were performed, and an arbitrary plicometer skin score was created. The plicometer skin score was compared to m-Rodnan's score on the same patients. The statistical association between the plicometer score and DLCO values in SSc patients was analysed. Plicometer plica thickness cut-off values of normality were established for nine skin areas. High specificity (95-99%) and a high negative predictive value (95.5-100%) were found. The sensitivity and the positive predictive value were 52.6-100% and 52.4-90.5%, respectively. The coefficient of variation of the plicometer score (0.05-0.14) was lower than that of the m-Rodnan score (0.22-0.33). A statistically significant association was found between skin score and DLCO. The study underlines the accuracy and reproducibility of the plicometer skin test, and suggests its utility in monitoring scleroderma progression.

Adolescent↗
PubMed1996

IL2 triggers a tumor progression process in a melanoma cell line MELP derived from a patient whose metastasis increased in size during IL2/INFalpha biotherapy.

Human melanomas may express both in vivo and in vitro functional IL-Rs and may be expected to directly respond to injected IL2. This may generate biological situations which may be favourable for the patient, but also for tumor progression. Here, we analyse the latter hypothesis. MELP is a melanoma cell line derived from a patient whose metastasis increased in size during IL2/IFN alpha biotherapy [correction of biotheraphy]. These cells have been characterized in vitro for their phenotype and for their sensitivity to IL2. In vitro MELP cells express an IL2-R alpha(+) beta(+) gamma(-) phenotype and IL2 treatment induces the acquisition of new functional characteristics represented (i) by the increased surface expression of two markers of metastatic evolution (ICAM-1 and CD44); (ii) by the stable induction of the IL2-R gamma with the appearance of functional IL2-R beta complex, which are also recognized by GM-CSF; (iii) by the inhibition of transcription of a regulatory cytokine such as IL6; (iv) by a differential effect of IL6 on CD44 surface expression in MELP cells treated or not with IL2 (MILG cells); (v) by the acquisition of faster growth rates and appearance of piling up and multilayer cellular organization; (vi) by the development of rapidly growing tumors in nude mice. IL2 induces in MELP cells a tumor progression process that could mimic the metastatic evolution observed in vivo during biotherapy. Therefore, MELP phenotype may help to define a subset of patients in which IL2 therapy may trigger unfavourable evolution.

Adult↗
PubMed1996

Prednisone increases apoptosis in in vitro activated human peripheral blood T lymphocytes.

Glucocorticoid hormones (GCH) regulate, through the apoptotic process, the negative selection of immature T cells in the thymus. Because apoptosis seems to occur also in the maintenance of peripheral tolerance, we have investigated whether GCH may induce apoptosis in human mature lymphocytes. Peripheral blood lymphocytes (PBL) or peripheral CD4(+) and CD8(+) T cell subsets were cultured in the presence of phytohaemaglutinin (PHA) or PHA and prednisone (PDN) at 10(-3)-10(-12)M concentrations for 72, 96 and 120h. Cell cycle and membrane antigen expression were evaluated by flow cytometry and DNA degradation was detected by agarose gel electrophoresis. PDN blocks PBL growth in the G1 phase of cell cycle and inhibits both IL-2 receptor (IL-2R) expression and IL-2 secretion. Apoptosis is clearly increased by PDN in PHA-activated human PBL, and the apoptotic effect of PDN is stronger on CD8(+) than on CD4(+) T lymphocytes. All these effects are dose- and time-dependent. The addition of exogenous IL-2 did not rescue lymphocytes from PDN-increased apoptosis. These results show that PDN increases apoptosis in mature activated human peripheral blood lymphocytes, suggesting a possible role of GCH in the maintenance of immune tolerance at post-thymic level.

Adult↗
PubMed1996

Serum HLA class I antigen levels in allogeneic bone marrow transplantation: a possible marker of acute GVHD.

The levels of serum HLA class I antigens were determined at weekly intervals up to 5 weeks in 46 patients who had undergone allogeneic BMT. In patients with GVHD grade I or with GVHD grade I and fever of unknown origin (FUO), serum HLA class I antigen levels did not change during the observation period. In patients with GVHD grade II-IV serum HLA class I antigen level significantly increased in the week before the onset of GVHD, was maximal at the onset of GVHD and then persisted unchanged in the following 2 weeks. In patients with GVHD grade I or GVHD grade II-IV and infections whose onset coincided with that of acute GVHD a significant increase of serum HLA class I antigen level was found 2 weeks after the onset of the infectious episode. An increase of serum HLA class I antigen level was also found before the onset of repetitive GVHD grade II-IV episodes as well as during and after infectious episodes whose onset occurred after the onset of acute GVHD. The mean +/- s.d. concentrations of serum HLA class I antigens during GVHD grade II-IV episodes (9.4 +/- 3.4 micrograms/ml) and 2 weeks after the onset of infectious episodes (7.1 +/- 1.6 micrograms/ml) are significantly (P < 0.01 and P < 0.05, respectively) higher than that found 2 weeks before the onset of GVHD (3.0 +/- 0.5 micrograms/ml). The results of the present investigation suggest that measurement of serum HLA class I antigen level may be a possible marker to detect an acute GVHD following BMT.

Acute Disease↗
PubMed1996

[The immunological activity of corticosteroids].

Corticosteroids are among the most used anti-inflammatory and immunosuppressive drugs. The most recent reports have shown that the corticosteroids: A) modulate the lymphocyte recirculation and induce a lymphocyte depletion mainly regarding to the CD4 cells. B) Inhibit several lymphocyte activities, as well as their capacity to secrete cytokines and their clonal expansion under activating conditions. C) Induce apoptosis in primed T cells. D) Modulate the synthesis and activity of nuclear factors AP1 and NFkB. Moreover several data suggest that the molecular manipulations of cortisol, performed with the aim of improving its therapeutic efficiency, might change its capacity to bind the cytoplasmic receptor and/or generate CTS/CTS-R compounds that have different capacity to migrate through the nuclear membrane and/or to activate the nuclear responsive elements inducing different biologic responses.

Adrenal Cortex Hormones↗