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F Facchetti

Publications and source records attributed to F Facchetti.

At least 55 records · Page 3Linked to original sources
PubMed1999

Characterization of type II intracellular IL-1 receptor antagonist (IL-1ra3): a depot IL-1ra.

Three molecular forms of the IL-1 receptor antagonist (IL-1ra) have been identified and cloned. Secreted IL-1ra (sIL-1ra or IL-1ra1) contains a classical leader peptide giving a released mature protein. Two intracellular isoforms, icIL-1ra type I (IL-1ra2) and icIL-1ra type II (IL-1ra3), have no leader sequence, thus predicting that these proteins remain intracellular. In an effort to define its biological role, we structurally and functionally characterized IL-1ra3. Endogenous immunoreactive IL-1ra3 was detected in a variety of inflammatory cells and tissues. We used a gene transfer strategy to explore the possible intracellular functions of IL-1ra3 (and IL-1ra2) and the cell-associated agonist IL-1alpha. The intracellular IL-1ra3 isoform, as well as IL-1ra2, does not block the action of exogenous and endogenous IL-1 under these conditions. Intact IL-1ra3 was released from the cells killed by NK effectors. The intracellular isoforms may represent a reservoir of IL-1ra, released upon cell death, whose function is to limit the pro-inflammatory action of cell debris.

Animals↗
PubMed1999

Chilblain lupus erythematosus is associated with antibodies to SSA/Ro.

Chillblain Lupus Erythematosus (CL) of Hutchinson is a subtype of Lupus Erythematosus characterized by erythematous lesions symmetrically distributed on the face, nose, fingers and toes, knees and heels. The lesions are induced by cold, damp climates. A number of patients affected by CL eventually develop features of Systemic Lupus Erythematosus (SLE). We report here 7 patients, all but one affected by SLE, with chilblain cutaneous lesions on their hands, feet and face. The onset of CL preceded the diagnosis of SLE, from 1 to 10 years in 3 cases, it was concurrent in one case and was subsequent in the other 2 cases. Six out of the seven patients referred typical Raynaud's phenomenon and one had acrocyanosis. CL lesions developed and were aggravated by the cold during autumn and winter, they improved during summer. Skin biopsy performed in 5 patients from the lesions showed, on histology, a typical pattern of alterations with granular deposits at the dermo-epidermal junction on direct immunofluorescence. Laboratory findings showed: ANA and anti-SSA/Ro were detected in all the patients, anti-SSA/Ro were isolated in 4 patients and associated with anti-Sm in one case, anti-U1 RNP in one case and with anti-Sm and anti-RNP in a third case. Complement consumption was observed in 5 patients, anti-dsDNA in the six patients with SLE, hypergammaglobulinemia in 4 and rheumatoid factor in one. The fine specificity of anti-SSA/Ro as determined by immunoblotting using a human spleen extract as a substrate, showed: anti-60kD and anti-52 kD in two sera, anti-60kD isolated in 2 sera, anti-52kD isolated in one serum (from the patient without SLE) while 2 sera did not blotted. In conclusion, our study confirms the previous report of anti-SSA/Ro antibodies in association with CL. This clinical and serologic association widens the spectrum of cutaneous disease that is associated with antibodies to SSA/Ro to include conditions such as to SCLE, hypergammaglobulinemic purpura and neonatal lupus.

Adult↗
PubMed1999

Expression of inducible nitric oxide synthase in human granulomas and histiocytic reactions.

Inducible nitric oxide synthase (iNOS) is required in immune response against infections and is involved in granuloma formation in animals; in murine macrophages, iNOS is induced by lipopolysaccharide and interferon-gamma. In contrast, the role of iNOS in human immune response against infections is still questioned, and its expression in granulomas is poorly investigated. Using Western blotting and immunohistochemistry, we investigated iNOS expression in human lymph nodes with nonspecific reactions and in tissues containing granulomas caused by mycobacteria, Toxoplasma, Cryptococcus neoformans, Leishmania, Bartonella, noninfectious granulomas (sarcoidosis, foreign body), and other hystiocitic reactions (Kikuchi's disease, Omenn syndrome). iNOS was undetectable in nonspecific reactive lymphadenitis, foreign-body granulomas, and Omenn syndrome, whereas it was strongly expressed in infectious granulomas, sarcoidosis, and Kikuchi's diseases. Immunohistochemistry demonstrated that iNOS was selectively expressed by the epithelioid and multinucleated giant cells within the granulomas. Use of an anti-nitrotyrosine antibody, recognizing nitrosilated amino acid residues derived from nitric oxide production, revealed a consistent positivity within the cells expressing iNOS, thus suggesting that iNOS is functionally active. Detection of cytokines by reverse transcriptase-polymerase chain reaction demonstrated that tissues that were positive for iNOS, also expressed the Thl-type cytokine interferon-gamma mRNA, but not the Th2-type cytokine interleukin-4. Taken together, these results indicate that iNOS is involved in different human immune reactions characterized by histiocytic/granulomatous inflammation and associated with Th1-type cytokine secretion.

Adult↗
PubMed1999

Linker for activation of T cells (LAT), a novel immunohistochemical marker for T cells, NK cells, mast cells, and megakaryocytes: evaluation in normal and pathological conditions.

LAT (linker for activation of T cells) is an integral membrane protein of 36-38 kd that plays an important role in T cell activation. Using a rabbit polyclonal antibody generated against the cytosolic portion of LAT, we investigated the immunohistochemical expression of LAT in normal and pathological hematolymphoid tissues. LAT reacts with human T cells in paraffin sections, including decalcified bone marrow trephines. LAT appears early in T cells at the thymocyte stage and before TdT expression in embryos, and is expressed in peripheral lymphoid tissues, without restriction to any T cell subpopulations. In addition to T cells, natural killer (NK) cells (evaluated with flow cytometry), megakaryocytes and mast cells are also LAT-positive, whereas B cells and other myeloid and monocytic derived cells are negative. Tested on a total of 264 paraffin-embedded tissue biopsies, LAT reacted with the great majority (96.8%) of T/NK-cell neoplasms, covering the full range of T cell maturation. Although antibodies to both LAT and CD3 had a similarly high sensitivity in the staining of T/NK-cell lymphomas, when used in conjunction, they successfully identified a higher number of cases (98.4%). Atypical megakaryocytes from different hematological disorders, as well as mast cells in mastocytosis were also LAT-positive, but all neoplasms of B cell origin, Hodgkin's lymphomas, and several nonlymphoid malignancies were negative. These data indicate that the anti-LAT antibody may be of value to diagnostic histopathologists for the identification of T cell neoplasms.

Adaptor Proteins, Signal Transducing↗
PubMed1999

Plasmacytoid monocytes migrate to inflamed lymph nodes and produce large amounts of type I interferon.

We have identified two cell subsets in human blood based on the lack of lineage markers (lin-) and the differential expression of immunoglobulin-like transcript receptor 1 (ILT1) and ILT3. One subset (lin-/ILT3+/ILT1+) is related to myeloid dendritic cells. The other subset (lin-/ILT3+/ILT1+) corresponds to 'plasmacytoid monocytes'. These cells are found in inflamed lymph nodes in and around the high endothelial venules. They express CD62L and CXCR3, and produce extremely large amounts of type I interferon after stimulation with influenza virus or CD40L. These results, with the distinct cell phenotype, indicate that plasmacytoid monocytes represent a specialized cell lineage that enters inflamed lymph nodes at high endothelial venules, where it produces type I interferon. Plasmacytoid monocytes may protect other cells from viral infections and promote survival of antigen-activated T cells.

Antigens, CD↗
PubMed1999

Retrovirus-mediated WASP gene transfer corrects defective actin polymerization in B cell lines from Wiskott-Aldrich syndrome patients carrying 'null' mutations.

Boys affected with Wiskott-Aldrich syndrome (WAS) present with variable association of thrombocytopenia, eczema and immune deficiency. If untreated, WAS patients may succumb to intracerebral hemorrhages, severe infections or malignancies. Allogeneic bone marrow transplantation (BMT) can cure all aspects of the disease, but HLA-identical donors are not available to all patients and mismatched BMTs are unfortunately associated with high mortality and morbidity. The good success of HLA-matched BMT, however, makes WAS a potential candidate for hematopoietic stem cell gene therapy. WAS patients carry mutations of the Wiskott-Aldrich syndrome protein gene encoding WASP, a 502-amino acid proline-rich protein with demonstrated involvement in the organization of the actin cytoskeleton. To verify the feasibility of genetic correction for this disease, the WASP cDNA was expressed in EBV-immortalized B cell lines obtained from WAS patients using a retroviral vector. Transduced WAS cells showed levels of WASP expression similar to those found in cells from normal donors, without detectable effects on viability or growth characteristics. In addition, retrovirus-mediated expression of WASP led to improvement of cytoplasmic F-actin expression and formation of F-actin-positive microvilli, a process shown to be defective in untransduced WAS cell lines. These preliminary results indicate a potential use for retrovirus-mediated gene transfer as therapy for WAS.

Actins↗
PubMed1999

The spleen in the Wiskott-Aldrich syndrome: histopathologic abnormalities of the white pulp correlate with the clinical phenotype of the disease.

The Wiskott-Aldrich syndrome (WAS) is a X-linked hematologic disorder characterized by thrombocytopenia, eczema, and immunodeficiency of variable severity. Reported here are the results of a morphologic, morphometric, and immunophenotypic analysis of splenic lymphoid tissue in 12 WAS patients with documented molecular defect and with different disease severity. Spleens from 29 age-matched patients with different diseases were used as controls. Paraffin-embedded tissue (from all cases) and fresh-frozen samples (from 5 WAS patients and 4 control subjects) were used to study the different white pulp compartments by classic morphologic, immunophenotyping, and image analysis techniques. Data were statistically analyzed by both parametric and nonparametric tests. Spleens from WAS patients showed a significant depletion of the total white pulp (p = 0.0008), T cell (p < 0.05), and B cell (p = 0.0002) areas and marginal zone (MZ) thickness (p < 0.0001). Among WAS patients, a negative correlation was found between the score of severity of the disease and all variables considered (Spearman's rank correlation coefficient, r = -0.79, r = -0.73, r = -0.68, and r = -0.56, respectively). In conclusion, this study shows that in WAS a general depletion of the splenic white pulp occurs, supporting the evidence that WAS is characterized by a combined immune defect. The significant reduction of the MZ may explain the inability of WAS patients to mount a response to T-independent antigens.

Antigens, CD↗
PubMed1999

Chilblain lupus erythematosus is associated with antibodies to SSA/Ro.

Chilblain lupus erythematosus (CL) of Hutchinson is a subtype of lupus erythematosus (LE) characterized by erythematous lesions induced by cold, damp climates. A number of patients affected by CL eventually develop features of systemic lupus erythematosus (SLE). We report here 9 patients with chilblain cutaneous lesions, 6 of them were affected by SLE and 2 by SCLE. The onset of CL preceded the diagnosis of LE, from 1 to 10 years in 3 cases, it was concurrent in one case and was subsequent in the remaining 4 cases. Raynaud's phenomenon and photosensitivity were other prominent clinical features in patients with CL. Nailfold capillaroscopy revealed pathological changes in every patient examined. ANA and anti-SSA/Ro antibodies were detected in all nine patients. Anti-SSB/La were detected in 2 cases, anti-Sm in one case, and anti-Sm and anti-RNP in a one case. Antibodies to dsDNA and complement consumption were found in the six patients with SLE. The fine specificity of anti-SSA/Ro was determined by immunoblotting: anti-60kD and anti-52 kD were detected in three sera, anti-60kD alone in 5 sera, while one serum did not blot. In conclusion, the present study suggests that chilblain LE is associated with SSA/Ro autoantibodies, as is SCLE, hypergammaglobulinemic purpura and neonatal lupus erythematosus.

Adolescent↗
PubMed1998

Clonality of B-cells in portal lymphoid infiltrates of HCV-infected livers.

Evidence has been accumulating in favour of a role for hepatitis C virus (HCV) in the pathogenesis of human lymphoproliferative disorders. HCV infection has been documented in the majority of patients with essential mixed cryoglobulinaemia type II (MC-II); in patients with HCV infection, B-cell clonal expansion have been detected in peripheral blood and bone marrow, and a high prevalence of B-cell non-Hodgkin's lymphomas has been documented. Liver biopsies in chronic hepatitis C frequently show portal lymphoid infiltrates with features of B follicles, whose clonality has not yet been investigated. This study has analysed the B-cell clonality of portal lymphoid infiltrates from 16 patients with chronic HCV hepatitis. Portal tracts showing obvious lymphoid infiltrates were microdissected from the paraffin-embedded liver tissue sections and the clonality of lymphoid B-cells was tested using a polymerase chain reaction (PCR) approach designed to identify immunoglobulin heavy chain gene (IgH) rearrangements. A successful IgH-PCR analysis was achieved in 35 lymphoid infiltrates from 11 patients (seven with the four without MC-II) and yielded a single band in 21 cases, two bands in ten cases, and three bands in four cases. Comparison of the IgH-PCR amplification bands obtained from the different lymphoid aggregates of the same biopsy revealed that they differed in size. This finding indicates that each aggregate derives from the proliferation of one or a few founder B-cells, which are not related to each other. The results obtained in patients with and without MC-II were similar, suggesting that the presence of B-cell clonal proliferations in liver biopsies is independent of the occurrence of B-cells producing monoclonal IgMk cryoglobulins.

B-Lymphocytes↗
PubMed1998

Defective actin polymerization in EBV-transformed B-cell lines from patients with the Wiskott-Aldrich syndrome.

The Wiskott-Aldrich syndrome (WAS) is a rare X-linked recessive disorder characterized by eczema, thrombocytopenia, and immunodeficiency. An allelic variant of the disease is characterized by isolated thrombocytopenia (XLT). The gene responsible for WAS/XLT (WASP) encodes for a 502 amino acid protein (WASP) that is possibly involved in actin binding and cytoskeleton organization. The expression of WASP and the distribution of F-actin and alpha-actinin (which binds to and stabilizes actin filaments) have been analysed in lymphoblastoid cell lines from six patients with WAS and one with XLT. Western blot and immunocytochemistry did not reveal WASP expression in four WAS patients, whereas two WAS patients (with a moderate clinical course) expressed trace amounts of mutant WASP. In contrast, the XLT patient expressed normal amounts of WASP. Furthermore, cell lines from WAS and XLT patients also markedly differed in F-actin polymerization and alpha-actinin distribution. In particular, severe defects of cytoplasmic F-actin expression and of F-actin-positive microvillus formation, and impaired capping of alpha-actinin, were observed in all patients who lacked WASP. As a whole, the degree of impairment of WASP protein expression in WAS/XLT seems to correlate with anomalies of cytoskeletal organization, strongly supporting a role for WASP in the regulation of F-actin polymerization.

Actinin↗
PubMed1997

Cholangiopathy and tumors of the pancreas, liver, and biliary tree in boys with X-linked immunodeficiency with hyper-IgM.

We report an association between X-linked immunodeficiency with hyper-IgM (XHIM) and carcinomas affecting the liver, pancreas, biliary tree, and associated neuroectodermal endocrine cells. The tumors were fatal in eight of nine cases and in most instances were preceded by chronic cholangiopathy and/or cirrhosis. An additional group of subjects with XHIM had chronic inflammation of the liver or bile ducts but no malignancy. Many patients with XHIM were infected with cryptosporidia. CD40 is normally expressed on regenerating or inflammed bile duct epithelium. A CD40+ hepatocellular carcinoma cell line, HepG2, susceptible to cryptosporidia and CMV infection became resistant when cell surface CD40 was cross-linked by a CD40 ligand fusion protein. Apoptosis was triggered in HepG2 cells if protein synthesis was blocked by cycloheximide or if the cells were infected by cryptosporidia. Ligation of CD40 on biliary epithelium may contribute to defense against infection by intracellular pathogens. We propose that the CD40 ligand mutations that cause XHIM deprive the biliary epithelium of one line of defense against intracellular pathogens and that malignant transformation in the biliary tree follows chronic infection or inflammation. The resulting tumors may then progress without check by an effective immune response. Patients with XHIM who have abnormal liver function tests should be considered at increased risk for cholangiopathy or malignancy.

Adolescent↗
PubMed1997

Fine-needle aspiration cytologic findings in a case of lymph node tumor of plasmacytoid monocytes.

We present a unique case of fine-needle aspiration (FNA) from a lymph node with subsequent histologic diagnosis of tumor of plasmacytoid monocytes (PMs). The patient had an associated myeloproliferative disease which terminated into an acute myelomonocytic leukemia. In a 95% ethanol-fixed, hematoxylin-eosin (H&E)-stained smear, the tumor cells appeared monomorphic, medium size, with oval to indented nuclei, finely stippled chromatin, and small nucleoli; the cytoplasm was scanty and slightly eccentric. The cytologic picture suggested some subtypes of small-cell non-Hodgkin's lymphomas or a leukemic infiltration. In the FNA specimen, the cells appeared immunocytochemically negative for some B- and T-cell markers (MB2, L26, LN1, and UCHL1) and strongly positive to KP1, a known histyocyte-macrophage and myeloid marker. The FNA differentiated diagnoses are discussed.

Biopsy, Needle↗
PubMed1997

In vitro cell death of activated lymphocytes in Omenn's syndrome.

Omenn's syndrome (OS) is characterized by erythrodermia, hepatosplenomegaly, lymphadenopathy, hypereosinophilia and elevated IgE levels associated with increased susceptibility to severe infections. Peripheral blood T cells, though usually present in normal number, show an activated phenotype (including an increased expression of CD95/Fas), a Th2 pattern of cytokine secretion and defective proliferative response to mitogens. In this report, we demonstrate that T cells from patients with OS undergo an excessive cell death in vitro resulting from two mechanisms. First, a substantial number of peripheral blood lymphocytes from OS patients die in unstimulated cultures (p = 0.009 vs. healthy controls). This spontaneous apoptosis is associated with reduced expression of bcl-2 gene product (p < 0.05) and can be prevented by addition of interleukin (IL)-2 (which also prevents down-modulation of bcl-2), while is independent from CD95 signaling. Second, lymphocytes from OS patients are highly susceptible to activation-induced cell death (AICD) induced with mitogens. This mechanism is largely independent from IL-2, while it can be significantly inhibited blocking CD95 with an IgG2b monoclonal antibody (mAb). The dependence of AICD from signals transduced via CD95 was confirmed showing that cross-linking CD95 with an IgM mAb induces a higher cell death in purified CD4+ CD45R0+ cells from OS patients than in controls (comparable for CD95 expression). Both mechanisms of cell death observed in this study result from lymphocyte hyperactivation occurring in vivo in these patients and may contribute to functional T cell defects of OS.

Apoptosis↗
PubMed1997

Histopathological changes in bone marrow biopsies from patients with chronic myeloid leukaemia after treatment with recombinant alpha-interferon.

AIMS: Recombinant alpha-interferon (r-IFN) is an effective therapy for chronic myeloid leukaemia (CML), inducing haematological and major cytogenetic response in 70% and 30% of patients, respectively. In this study we have evaluated the significance of bone marrow (BM) histology on the subsequent response to r-IFN therapy, as well as the morphological changes induced by r-IFN within BM. METHODS AND RESULTS: 73 BM biopsies were studied from 21 patients with Ph1-positive CML in chronic phase at diagnosis and at different times during r-IFN treatment. At diagnosis the probability of achieving a major or complete cytogenetic response was significantly higher in patients with a total marrow cellularity lower than 90% (P = 0.02). During therapy with r-IFN, significant BM changes included disappearance of the CML pattern (P = 0.0002), reduction of M:E ratio (P = 0.0009) and total cellularity (P = 0.0027), and increase in number of terminal megakaryocytes (P = 0.0009) and of fatty tissue regeneration (P = 0.037); only after long-term therapy (mean 20 months), did reticulin fibrosis increase significantly (P = 0.032). CONCLUSIONS: The overall BM morphology in response to treatment displayed different pictures, ranging from persistence of CML (25 biopsies out of 51), to reversion to normal histology (14 out of 51). Persistence of diffuse morphological abnormalities was associated with lack of cytogenetic responsiveness (P = 0.025).

Adolescent↗