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R Cattaneo

Publications and source records attributed to R Cattaneo.

At least 19 recordsLinked to original sources
PubMed2001

Single-chain antibody displayed on a recombinant measles virus confers entry through the tumor-associated carcinoembryonic antigen.

To redirect the tropism of the vaccine strain of measles virus (MV), Edmonston B, to a targeted cell population, we displayed on the viral hemagglutinin (H) a single-chain antibody (scAb) specific for the tumor-associated carcinoembryonic antigen (CEA). We generated H fusion proteins with three forms of the scAb appended, differing in the lengths of the linkers separating the VH and VL domains and thus in the oligomerization states of the scAbs. All proteins were stable, appeared properly folded, and were transported to the cell surface, but only H displaying the long-linker form of scAb was functional in supporting cell-cell fusion. This protein induced extensive syncytia in cells expressing the normal virus receptor CD46 and also in CD46-negative cells expressing the targeted receptor, human CEA. Replication-competent MV with H replaced by H displaying the long-linker form of scAb was recovered and replicated efficiently in both CD46-positive and CD46-negative, CEA-positive cells. Thus, MV not only tolerates the addition of a scAb on its H protein but also infects cells via a novel interaction between the scAb and its targeted receptor.

Animals↗
PubMed2000

Fusogenic membrane glycoproteins as a novel class of genes for the local and immune-mediated control of tumor growth.

We report here the use of viral fusogenic membrane glycoproteins (FMGs) as a new class of therapeutic genes for the control of tumor growth. FMGs kill cells by fusing them into large multinucleated syncytia, which die by sequestration of cell nuclei and subsequent nuclear fusion by a mechanism that is nonapoptotic, as assessed by multiple criteria. Direct and bystander killing of three different FMGs were at least one log more potent than that of herpes simplex virus thymidine kinase or cytosine deaminase suicide genes. Transduction of human tumor xenografts with plasmid DNA prevented tumor outgrowth in vivo, and cytotoxicity could be regulated through transcriptional targeting. Syncytial formation is accompanied by the induction of immunostimulatory heat shock proteins, and tumor-associated FMG expression in immunocompetent animals generated specific antitumor immunity.

Animals↗
PubMed2000

Characterization of gammadelta T cells expressing CD158b, a killer cell inhibitory receptor, in a patient with chronic CD4(+) lymphocytopenia and disseminated Mycobacterium intracellulare infection.

A population of Vdelta1(+)Vgamma9(-) gammadelta T cells that represented almost the totality (84%) of circulating lymphocytes in a patient with chronic, non-HIV-related, CD4 lymphocytopenia complicated by a disseminated Mycobacterium intracellulare infection was characterized. These gammadelta(+) T cells expressed a single killer inhibitory receptor (CD158b) and their phenotype (CD8(+)CD57(+)CD27(-)CD28(-)) indicated that, although CD45RA(+), they were not naive. However, the absence of large granular lymphocyte morphology, the impaired proliferative activity, the high susceptibility to apoptosis, and the total lack of cytotoxic ability suggested that these gammadelta cells were in a resting state. A high percentage of the cells did not harbor the CD11b integrin alpha chain and exhibited a decreased capability to bind endothelial cells. This defect might represent the mechanism whereby they remained trapped in the circulation.

Antigens, CD↗
PubMed2000

Recombinant measles virus requiring an exogenous protease for activation of infectivity.

Proteolytic cleavage of the fusion protein (F) is an important control mechanism of the biological activity of paramyxoviruses. The sequence R-R-H-K-R(112) at the cleavage site of the F protein of measles virus (MV) was altered by site-directed mutagenesis to R-N-H-N-R(112), which is not recognized by the ubiquitous cellular protease furin. When transiently expressed in cell cultures standard F protein was cleaved, whereas the mutant remained in the uncleaved form. Syncytium formation by the mutant that was analysed after coexpression with haemagglutinin protein depended on the presence of trypsin. Recombinant MV containing the mutation required trypsin activation for fusion and infectivity in cell culture. Intranasal infection of transgenic mice susceptible to MV infection (Ifnar(tm)-CD46Ge) resulted in a moderately productive infection and inflammation of the lung. In contrast to parental virus, intracerebral inoculation did not induce neural disease. The possible effects of the change in cleavage activation on tissue tropism and pathogenicity are discussed.

Amino Acid Sequence↗
PubMed2000

Characterization of a region of the measles virus hemagglutinin sufficient for its dimerization.

Attachment of measles virus (MV) to its cellular receptor is mediated by the viral envelope glycoprotein hemagglutinin (H). H exists at the viral surface as a disulfide-linked dimer which may associate into a tetramer. We aimed to define regions of H essential for its homo-oligomerization. To delineate these more precisely, we have generated a series of H ectodomain truncation mutants and studied their abilities to form both homotypic complexes and heterotypic complexes with full-length H. We define a "minimal unit" which is sufficient for MV H dimerization as that encompassing residues 1 to 151. This unit forms both homodimers and heterodimers with full-length H protein, although neither is transported to the cell surface even in the presence of other MV proteins. We show that cysteine residues at positions 139 and 154 are both critical in mediating covalent dimerization, not only of the truncated H mutants but also of full-length MV H protein. Even those cysteine mutants unable to form covalent intermolecular interactions are biologically active, mediating the formation of syncytia, albeit at a reduced rate. We demonstrate that this impaired capacity to mediate cell-to-cell fusion is based mainly on a reduced transport rate of the mutant molecules to the cell surface, indicating a role for covalent intermolecular interactions in efficient transport of MV H dimers to the cell surface.

Animals↗
PubMed2000

In vitro and in vivo infection of neural cells by a recombinant measles virus expressing enhanced green fluorescent protein.

This study focused on the in vitro infection of mouse and human neuroblastoma cells and the in vivo infection of the murine central nervous system with a recombinant measles virus. An undifferentiated mouse neuroblastoma cell line (TMN) was infected with the vaccine strain of measles virus (MVeGFP), which expresses enhanced green fluorescent protein (EGFP). MVeGFP infected the cells, and cell-to-cell spread was studied by virtue of the resulting EGFP autofluorescence, using real-time confocal microscopy. Cells were differentiated to a neuronal phenotype, and extended processes, which interconnected the cells, were observed. It was also possible to infect the differentiated neuroblastoma cells (dTMN) with MVeGFP. Single autofluorescent EGFP-positive cells were selected at the earliest possible point in the infection, and the spread of EGFP autofluorescence was monitored. In this instance the virus used the interconnecting processes to spread from cell to cell. Human neuroblastoma cells (SH-SY-5Y) were also infected with MVeGFP. The virus infected these cells, and existing processes were used to initiate new foci of infection at distinct regions of the monolayer. Transgenic animals expressing CD46, a measles virus receptor, and lacking interferon type 1 receptor gene were infected intracerebrally with MVeGFP. A productive infection ensued, and the mice exhibited clinical signs of infection, such as ataxia and an awkward gait, identical to those previously observed for the parental virus (Edtag). Mice were sacrificed, and brain sections were examined for EGFP autofluorescence by confocal scanning laser microscopy over a period of 6 h. EGFP was detected in discrete focal regions of the brain and in processes, which extended deep into the parenchyma. Collectively, these results indicate (i) that MVeGFP can be used to monitor virus replication sensitively, in real time, in animal tissues, (ii) that infection of ependymal cells and neuroblasts provides a route by which measles virus can enter the central nervous system in mouse models of encephalitis, and (iii) that upon infection, the virus spreads transneuronally.

Animals↗
PubMed2000

Recombinant measles viruses efficiently entering cells through targeted receptors.

We sought proof of principle that one of the safest human vaccines, measles virus Edmonston B (MV-Edm), can be genetically modified to allow entry via cell surface molecules other than its receptor CD46. Hybrid proteins consisting of the epidermal growth factor (EGF) or the insulin-like growth factor 1 (IGF1) linked to the extracellular (carboxyl) terminus of the MV-Edm attachment protein hemagglutinin (H) were produced. The standard H protein gene was replaced by one coding for H/EGF or H/IGF1 in cDNA copies of the MV genome. Recombinant viruses were rescued and replicated to titers approaching those of the parental strain. MV displaying EGF or IGF1 efficiently entered CD46-negative rodent cells expressing the human EGF or the IGF1 receptor, respectively, and the EGF virus caused extensive syncytium formation and cell death. Taking advantage of a factor Xa protease recognition site engineered in the hybrid H proteins, the displayed domain was cleaved off from virus particles, and specific entry in rodent cells was abrogated. These studies prove that MV can be engineered to selectively eliminate cells expressing a targeted receptor and provide insights into the mechanism of MV entry.

3T3 Cells↗
PubMed2000

Lymphatic dissemination and comparative pathology of recombinant measles viruses in genetically modified mice.

The dissemination of the Edmonston measles virus (Ed-MV) vaccine strain was studied with genetically modified mice defective for the alpha/beta interferon receptor and expressing human CD46 with human-like tissue specificity and efficiency. A few days after intranasal infection, macrophages expressing Ed-MV RNA were detected in the lungs, in draining lymph nodes, and in the thymus. In lymph nodes, large syncytia which stained positive for viral RNA and for macrophage surface marker proteins were found and apoptotic cell death was monitored. In the thymus, smaller syncytia which stained positive for macrophage and dendritic cell markers were detected. Thus, macrophages appear to be the main vectors for dissemination of MV infection in these mice; human macrophages may have a similar function in the natural host. We then compared the pathogenicities of two recombinant viruses lacking the C or V nonstructural proteins to that of the parental strain, Ed-MV. These viruses were less effective in spreading through the lymphatic system and, unlike Ed-MV, were not detected in the liver. After intracerebral inoculation the recombinant viruses caused lethal disease less often than Ed-MV and induced distinctive patterns of gliosis and inflammation. Ed-MV was reisolated from brain tissue, but its derivatives were not. C- and V-defective viruses should be considered as more-attenuated MV vaccine candidates.

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

Antiperinuclear factor in psoriatic arthropathy.

BACKGROUND: Antiperinuclear factor (APF) is an autoantibody directed against (pro)-filaggrin molecules. OBJECTIVE: We evaluated whether APF determination is useful for the diagnosis of psoriatic arthritis (PA). METHODS: We determined APF titers in sera from patients with PA (n = 76), psoriasis vulgaris (n = 38), noninflammatory rheumatic diseases (NIRDs, n = 119), rheumatoid arthritis (RA, n = 159) both with negative (n = 36) and positive (n = 123) rheumatoid factor (RF) tests, as well as from 204 healthy controls. We used an indirect immunofluorescence test on epithelial cells from human buccal mucosa as a substrate. RESULTS: In patients with PA, 7.9% of the serum samples were APF-positive. The incidence was greater than in healthy controls (1.0%; P < .01), similar to those with uncomplicated psoriasis (2.6%; P = NS) and NIRDs (4.0%; P = NS), and lower than in RF-negative (52.7%; P < .001) and RF-positive (90.2%; P < .001) patients with RA. Three APF-positive patients with PA had symmetric joint involvement and 3 had pustulotic arthroosteitis. CONCLUSION: The APF test may be useful in differentiating PA from RA, and APF may be specific for two PA subgroups.

Antibodies, Antinuclear↗
PubMed1999

Immune reconstitution after bone marrow transplantation for combined immunodeficiencies: down-modulation of Bcl-2 and high expression of CD95/Fas account for increased susceptibility to spontaneous and activation-induced lymphocyte cell death.

We have studied the regeneration of T cell subsets and function after BMT in 21 children affected by combined immunodeficiency after BMT. In the first months, the striking predominance of CD4+ cells displayed the primed CD45R0+ phenotype and a high number of activated (HLA-DR+) T cells were observed. Regeneration of naive CD4+CD45RA+ cells correlated with the recovery of proliferative responses to mitogens (r = 0.64, P<0.001). Peripheral blood lymphocytes circulating after BMT undergo an increased process of in vitro cell death, resulting from two mechanisms: spontaneous apoptosis (SA), a consequence of defective production of IL-2 and down-regulation of Bcl-2 (P = 0.02 vs. healthy controls), and high susceptibility to activation-induced cell death (AICD) after restimulation with mitogens. In accordance with the role of CD95/Fas in this latter process, we have observed a high level of CD95 expression (P<0.001 vs. healthy controls), correlated with AICD (P<0.001) but not with SA, and decreasing with time after BMT (P<0.001). Both SA and AICD levels correlated with the presence of activated T cells and decreased with the progressive recovery of T cell proliferative response. Therefore, the lymphocyte hyperactivated status might explain their susceptibility to apoptosis and contribute to the genesis of immunodeficiency that follows BMT.

Adolescent↗
PubMed1999

A recombinant measles virus expressing hepatitis B virus surface antigen induces humoral immune responses in genetically modified mice.

It has been shown previously that measles virus (MV) can be successfully used to express foreign proteins (M. Singh and M. A. Billeter, J. Gen. Virol. 80:101-106, 1998). To develop an inexpensive MV-based vaccine, we generated recombinant MVs that produce structural proteins of hepatitis B virus (HBV). A recombinant virus that expressed the HBV small surface antigen (HBsAg) was analyzed in terms of its replication characteristics, its genetic stability in cell culture, and its immunogenic potential in genetically modified mice. Although this virus showed a progression of replication slightly slower than that of the parental MV, it appeared to stably maintain the added genetic information; it uniformly expressed the appropriately glycosylated HBsAg after 10 serial passages. Genetically modified mice inoculated with this recombinant MV produced humoral immune responses against both HBsAg and MV proteins.

Animals↗
PubMed1999

Measles virus spread by cell-cell contacts: uncoupling of contact-mediated receptor (CD46) downregulation from virus uptake.

CD46, which serves as a receptor for measles virus (MV; strain Edmonston), is rapidly downregulated from the cell surface after contact with viral particles or infected cells. We show here that the same two CD46 complement control protein (CCP) domains responsible for primary MV attachment mediate its downregulation. Optimal downregulation efficiency was obtained with CD46 recombinants containing CCP domains 1 and 2, whereas CCP 1, alone and duplicated, induced a slight downregulation. Using persistently infected monocytic/promyelocytic U937 cells which release very small amounts of infectious virus, and uninfected HeLa cells as contact partners, we then showed that during contact the formation of CD46-containing patches and caps precedes CD46 internalization. Nevertheless, neither substances inhibiting capping nor the fusion-inhibiting peptide Z-D-Phe-L-Phe-Gly-OH (FIP) blocked CD46 downregulation. Thus, CD46 downregulation can be uncoupled from fusion and subsequent virus uptake. Interestingly, in that system cell-cell contacts lead to a remarkably efficient infection of the target cells which is only partially inhibited by FIP. The finding that the contact of an infected with uninfected cells results in transfer of infectious viral material without significant (complete) fusion of the donor with the recipient cell suggests that microfusion events and/or FIP-independent mechanisms may mediate the transfer of MV infectivity from cell to cell.

Animals↗
PubMed1999

Central nervous system involvement in systemic lupus erythematosus patients without overt neuropsychiatric manifestations.

OBJECTIVE: To verify whether features of CNS involvement can be detected in SLE patients without overt neuropsychiatric manifestations. METHODS: 114 SLE patients who had never received a diagnosis of neuropsychiatric lupus (never-NPSLE) were studied and compared to 65 SLE patients with known neuropsychiatric involvement (NPSLE). The study relied on evaluation of neurocognitive functions by means of a battery of neuropsychological tests, on psychiatric and neuropsychological assessments and on neuroimaging studies (computed tomography, magnetic resonance, single photon emission computed tomography (SPECT)). RESULTS: Clinical features, including disease duration/activity and pharmacological therapy, of never-NPSLE and NPSLE patients were similar. Short-term and long-term memory, visuo-spatial and verbal information processing were similarly compromised in never-NPSLE and in NPSLE patients; only attention was significantly more compromised in NPSLE patients. Psychiatric morbidity was higher than expected in never-NPSLE patients, although less than in the control neuropsychiatric group. Ischemic lesions, multiple small high intensity lesions and cortical atrophy, detected by CT and MR scans, as well as abnormal SPECT were also frequently detected in never-NPSLE patients. Interestingly, left parietal and occipital area hypoperfusion by SPECT was significantly more frequent in the patients with impaired visuo-spatial intelligence and short-term memory. CONCLUSIONS: Most abnormalities detected by available diagnostic tools and characteristics of neuropsychiatric SLE are also present in non-symptomatic patients. They may derive from an unexpected widespread involvement of the CNS and are not per se sufficient, in the absence of clinical manifestations, for a diagnosis of neuropsychiatric SLE.

Adult↗
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↗
PubMed1999

Photodynamic effects in vitro in fresh gynecologic tumors analyzed with a bioluminescence method.

Photodynamic therapy (PDT) is a promising alternative method for clinical cancer treatment. In the present study, cells from four breast carcinomas, seven ovarian carcinomas of various stages of differentiation, and ascites from a diffuse metastatic tumor were treated by PDT in vitro. Tetra(m-hydroxyphenyl)-chlorin (m-THPC) was used as the photosensitizer. Surviving cell rate was evaluated by the ATP-Cell-Viability-Assay (ATP-CVA), which measures light production as an interaction of intracellular ATP with the luciferin-luciferase complex. The most effective PDT of the tumor cells was achieved at an m-THPC concentration of 0.2 microgram/ml following incubation of the cells with photosensitizer for 24 hours. PDT toxicity resulted in a cell survival rate of 1% to 42% compared to untreated control cells (survival rate of control = 100%). The inhibitor concentration IC50 of m-THPC was determined both in the dark (dark toxicity) and in combination with laser irradiation. IC50 was defined as the concentration of photosensitizer which caused 50% of cell death. The IC50 values were heterogeneous in all tumor specimens examined. IC50 values for dark toxicity were on average 0.14 microgram m-THPC/ml for primary ovarian carcinoma, 2.16 micrograms m-THPC ml for refractory ovarian carcinoma and 0.3 microgram m-THPC/ml for breast carcinoma. After PDT, average IC50 value for refractory ovarian carcinoma was 0.04 microgram m-THPC/ml, for primary ovarian carcinoma 0.05 microgram m-THPC/ml and for breast carcinoma 0.03 microgram m-THPC/ml. These data might indicate that clinical PDT of gynecological carcinoma requires individual treatment conditions to achieve optimal results.

Breast Neoplasms↗