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Biomedical subjects

Marco De Andrea

Publications and source records attributed to Marco De Andrea.

13 recordsLinked to original sources
PubMed2006

Alpha- and betapapillomavirus E6/E7 genes differentially modulate pro-inflammatory gene expression.

Keratinocytes, the target cell of human papillomavirus (HPV) infection, can produce numerous cytokines and pro-inflammatory molecules which are important for the generation of an effective immune response. How this biological response, which involves the tumor stroma, is affected by the HPV oncoproteins within the epithelial cell itself is not clear. Here it is shown that oncoproteins of different HPV genotypes (alpha- versus beta-HPV genus) alter the expression of pro-inflammatory molecules in early passage primary human keratinocytes and the immortalized cell line HaCaT. HPV5 E6/E7 oncoproteins significantly induced interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and intercellular adhesion molecule-1 (ICAM-1) expression. By contrast, the same molecules were down-regulated or not modulated in HPV16 E6/E7 transduced keratinocytes. Interestingly, HPV38 oncoproteins expression resulted in a lower induction of pro-inflammatory molecules, resembling the behavior displayed by the mucosal carcinogenic HPV16. Finally, inducible nitric oxide synthase (iNOS) expression levels and nitric oxide (NO) production were induced at similar levels by all the HPV genotypes tested. These results further emphasize the different biological activities among HPV genotypes, and offer new insights into HPV-associated skin diseases.

Alphapapillomavirus↗
PubMed2006

The expression of p16INK4a tumor suppressor is upregulated by human cytomegalovirus infection and required for optimal viral replication.

The human cytomegalovirus (HCMV) induces a replicative senescence program after arresting host cell cycle progression so as to create a favorable environment for its replication. Here, we report that HCMV infection stimulates the expression of p16(INK4a), a direct effector of the senescence phenotype. The increase in p16(INK4a) gene expression was due to an increase in gene transcription, since the expression of a reporter gene driven by the p16(INK4a)-encoding CDKN2A gene promoter was strongly induced by HCMV infection. The results of deletion and mutational analysis of the CDKN2A promoter further suggest the involvement of Ets transcription factors in HCMV-mediated stimulation of p16(INK4a) gene expression. The significance of p16(INK4a) upregulation during the HCMV replicative cycle is underscored by the finding that virus replication was severely impaired in fibroblasts homozygous for an intragenic deletion in CDKN2A locus and devoid of functional p16(INK4a). Moreover, a retrovirus-mediated p16(INK4a) small interfering RNA (p16-siRNA) effectively reduced viral replication, thus providing direct evidence that p16(INK4a) upregulation plays a positive role for HCMV replication.

Artificial Gene Fusion↗
PubMed2006

A novel autoantigen to differentiate limited cutaneous systemic sclerosis from diffuse cutaneous systemic sclerosis: the interferon-inducible gene IFI16.

OBJECTIVE: To investigate the presence and clinical significance of autoantibodies against the interferon-inducible gene IFI16 in systemic sclerosis (SSc), systemic lupus erythematosus (SLE), and other autoimmune diseases. METHODS: Immunohistochemical analysis was used to evaluate the expression of IFI16 in skin biopsy specimens obtained from patients with SSc and patients with SLE. Levels of antibodies against IFI16 in sera from 82 patients with SSc and 100 patients with SLE were determined by enzyme-linked immunosorbent assay. Other autoimmune diseases such as primary Sjögren's syndrome (SS), rheumatoid arthritis (RA), chronic urticaria, and hepatitis C virus (HCV) infection were also examined. RESULTS: Expression of IFI16 was greatly increased and was ubiquitous in all layers of the epidermis and in the dermal inflammatory infiltrates of lesional skin from both patients with SLE and patients with SSc. Patients with SLE, those with primary SS, and those with SSc exhibited significantly higher anti-IFI16 IgG antibody levels compared with normal controls (for SLE, P < 0.002; for primary SS, P < 0.001; for SSc, P < 0.0005). Anti-IFI16 titers above the ninety-fifth percentile for control subjects were observed in 26% of the patients with SLE, 50% of those with primary SS, and 21% of those with SSc (28% of patients with limited cutaneous SSc [lcSSc] versus 4% of patients with diffuse cutaneous SSc [dcSSc]). In contrast, the prevalence of anti-IFI16 was 4% in patients with RA, 5% in those with chronic urticaria, and 13% in those with HCV infection. CONCLUSION: The results of this study provide evidence that an IFN-inducible gene, IFI16, may be involved in the pathophysiologic mechanisms of connective tissue disorders such as SSc. Moreover, a strict correlation with lcSSc was also demonstrated, thus providing a novel tool in the differential diagnosis of lcSSc from dcSSc.

Adult↗
PubMed2005

A cell-based high-throughput assay for screening inhibitors of human papillomavirus-16 long control region activity.

Cervical carcinomas express human papillomavirus (HPV) E6 and E7 oncoproteins, which are required to maintain the proliferative state of cancer cells. Repression of E6 and E7 expression results in acquisition of senescent phenotype and in the rescue of functional p53 and p105(Rb) pathways; therefore, therapies directed against either viral protein may be beneficial. However, the systems to study HPV in vitro are technically difficult and not convenient for screening of antiviral compounds. This has hampered the discovery of drugs against HPV. Here we describe the generation and use of a high-throughput screening system based on keratinocytes stably transfected with a reporter construct containing the regulatory sequence of E6 and E7 gene transcription (LCR) that allows easy detection of inhibitors of E6 and E7 expression in libraries of synthetic or biological compounds. The assay was used to screen a wide panel of cytokines: among them, IL-4, IL-13, TGF-beta1, TGF-beta2, TGF-beta3, TNF-alpha, IFN-alpha, and IFN-beta were found to induce a strong inhibition of the LCR activity. Our assay provides a validated tool in the search for drugs against HPV-associated cervical carcinomas and allowed the first systematic analysis of the effect of cytokines on the HPV-16 LCR transcriptional activity.

Cell Line↗
PubMed2004

The interferon-inducible IFI16 gene inhibits tube morphogenesis and proliferation of primary, but not HPV16 E6/E7-immortalized human endothelial cells.

Immunohistochemical analysis has demonstrated that the human IFI16 gene, in addition to the hematopoietic tissues, is highly expressed in endothelial cells and squamous stratified epithelia. In this study, we have developed a reliable HSV-derived replication-defective vector (TO-IFI16) to efficiently transduce IFI16 into primary human umbilical vein endothelial cells (HUVEC), which are usually poorly transfectable. HUVEC infection with TO-IFI16 virus suppressed endothelial migration, invasion and formation of capillary-like structures in vitro. In parallel, sustained IFI16 expression inhibited HUVEC cell cycle progression, accompanied by significant induction of p53, p21, and hypophosphorylated pRb. Further support for the involvement of these pathways in IFI16 activity came from the finding that infection with TO-IFI16 virus does not impair the in vitro angiogenic activity and cell cycle progression of HUVEC immortalized by HPV16 E6/E7 oncogenes, which are known to inactivate both p53 and pRb systems. This use of a reliable viral system for gene delivery into primary human endothelial cells assigns a potent angiostatic activity to an IFN-inducible gene, namely IFI16, and thus throws further light on antiangiogenic therapy employing IFNs.

Angiogenesis Inhibitors↗
PubMed2003

Influence of drug-induced apoptotic death on processing and presentation of tumor antigens by dendritic cells.

Here we have studied the effects of apoptotic cell death induced by chemotherapic agents on tumor phagocytosis by dendritic cells (DC) and presentation of the relevant antigen to T lymphocytes. Annexin-V-FITC (Ann-V) and propidium iodide (PI) staining was used to assess early apoptotic (Ann-V(+)/PI(-)) vs. late apoptotic/secondary necrotic (Ann-V(+)/PI(+)) death after a 24 hr observation of untreated and drug-treated gastric carcinoma cells. After treatments, the HLA-A*0201(+) tumor cell line KATO III was exposed for 24 hr to allogeneic, HLA-related GM-CSF, IL-4-driven immature (i) DC. Tumor-loaded iDC were tested for IL-12 release in an ELISA assay, incubated with the DC-maturating factor TNF-alpha and used as stimulators for autologous T lymphocytes. Generation of antitumor T response against KATO cells was evaluated in an anti-MHC class I MAb-blocked Interferon-gamma ELISPOT assay. After treatment with Cis-platin (cis), all dying cells were in early apoptosis, whereas secondary necrosis was the prevalent death pattern observed after epirubicin (epi) and doxorubicin (doxo). Doxo and epi increased tumor expression of heat shock protein (hsp) 70 and uptake of tumor cell components by DC, whereas cis treatment had no effect on hsp70 and was associated with poor tumor uptake by DC. Significant upmodulation of IL-12 was observed by DC that had taken up the doxo- and epi-treated tumors (p< 0.005 and p< 0.01, respectively). Increased IFN-gamma release was also observed after stimulation of T lymphocytes with DC loaded with doxo- and epi-treated (p< 0.02 and p< 0.005, respectively) but not with cis-treated DC. These data show that the products of early apoptosis cannot efficiently cross-activate MHC class I-restricted anti-tumor lymphocytes even in the presence of DC maturating factors, whereas secondary necrosis is associated with robust T cell response.

Annexin A5↗
PubMed2002

The interferon-inducible gene, Ifi204, acquires malignant transformation capability upon mutation at the Rb-binding sites.

p204 overexpression in retinoblastoma (Rb)-/- mouse embryo fibroblasts or transfection of p204 mutated at both Rb-binding sites confer growth advantages, resulting in a significantly higher number of foci in a cell focus assay. To investigate the possibility that mutated p204 acquires malignant transformation capability, NIH3T3 cells were stably transfected with the expression vector pRcRSV204 double-mutant (p204dm) harboring both the C-terminal deletion up to amino acid 568 and the point mutation from glutamic acid to lysine at position 427, and analyzed for markers typical of cell immortalization and transformation. We detected a greater abundance of cell colonies in soft agar with p204dm-expressing cells than vector control cells. The p204dm-transfected cells also displayed two other characteristics associated with malignant transformation, i.e. growth under low-serum conditions and formation of tumors in athymic nude mice. Moreover, their telomerase activity was significantly higher than in the vector control cells. It would thus seem that p204, devoid of functional Rb-binding motifs, can become oncogenic.

3T3 Cells↗
PubMed2002

The interferon system: an overview.

Interferons are a family of related and naturally occurring signal proteins grouped in three major species (alpha, beta and gamma) according to their cellular origin and inducing agents and historically described for their antiviral activity. Upon binding to specific receptors they lead to the activation of a signal transduction pathway that activates a broad range of genes, that are now known involved not only in antiviral but also in immunomodulatory and antiproliferative activities. The inhibition of virus growth and/or cell proliferation by interferons is associated with several physiological changes, some of which depend on the activity of specific proteins that are interferon-inducible. This review will attempt to illustrate the history and main properties of the interferon system, taking a look at recent discoveries about some interferon-inducible genes.

Animals↗
PubMed2002

Immunohistochemical expression analysis of the human interferon-inducible gene IFI16, a member of the HIN200 family, not restricted to hematopoietic cells.

This is the first description of an extensive immunohistochemical analysis of interferon (IFN)-inducible gene IFI16 expression in normal tissues. Immunohistochemical detection of IFI16 in paraffin-embedded tissues is achieved by using a polyclonal antibody raised against its C-terminal fragment that recognizes its three closely migrating isoforms in Western blotting. The results clearly indicate that IFI16 expression is not restricted to the hematopoietic compartment. In normal adult human tissues, it is prominent in stratified squamous epithelia and particularly intense in parabasal cells in the proliferating compartments, but it gradually decreases in the more differentiated suprabasal layers. Understanding of IFI16 expression in vivo is essential for interpretation of the results obtained from in vitro studies and elucidation of its physiologic role. The constitutive expression and wider distribution of IFI16 in normal human tissues, not restricted to the hematopoietic compartment, strongly support the possibility of an important role in cell differentiation that can be further modulated by other stimuli, such as IFN.

Blotting, Western↗
PubMed2002

The mouse interferon-inducible gene Ifi204 product interacts with the Tpr protein, a component of the nuclear pore complex.

We have used yeast two-hybrid screening to isolate cDNA-encoding proteins interacting with the protein encoded by the interferon (IFN)-inducible gene Ifi204. Four independent overlapping clones were isolated from an NIH3T3 cDNA library. The largest clone encoded a protein (1203 amino acids in length) sharing 94% identity with the C-terminal portion of the human translocated promoter region (Tpr) protein. Northern blot analysis revealed a 7.5-kilobase mRNA present in both mouse and human cell lines. In addition, in vivo interaction was demonstrated by coimmunoprecipitation experiments. Anti-Tpr polyclonal monospecific antibodies (Ab) used for immunofluorescence staining labeled the nuclear envelope (NE) in a punctate pattern characteristic of nucleoporins and also yielded staining throughout the nuclear interior. The intranuclear Tpr occurred in apparently discrete foci. When superimposed on optical sections obtained with anti-p204 Abs, these colocalized, with the sole exception of the nucleolar compartment stained by the anti-p204 Abs only. Although the specific function of Tpr is not defined, it appears to mediate p204 translocation from the cytoplasmic to the nuclear compartment following IFN treatment.

3T3 Cells↗
PubMed2002

Cell cycle arrest by human cytomegalovirus 86-kDa IE2 protein resembles premature senescence.

Primary human embryo lung fibroblasts and adult diploid fibroblasts infected by the human cytomegalovirus (HCMV) display beta-galactosidase (beta-Gal) activity at neutral pH (senescence-associated beta-Gal [SA-beta-Gal] activity) and overexpression of the plasminogen activator inhibitor type 1 (PAI-1) gene, two widely recognized markers of the process designated premature cell senescence. This activity is higher when cells are serum starved for 48 h before infection, a process that speeds and facilitates HCMV infection but that is insufficient by itself to induce senescence. Fibroblasts infected by HCMV do not incorporate bromodeoxyuridine, a prerequisite for the formal definition of senescence. At the molecular level, cells infected by HCMV, beside the accumulation of large amounts of the cell cycle regulators p53 and pRb, the latter in its hyperphosphorylated form, display a strong induction of the cyclin-dependent kinase inhibitor (cdki) p16(INK4a), a direct effector of the senescence phenotype in fibroblasts, and a decrease of the cdki p21(CIP1/WAF). Finally, a replicative senescence state in the early phases of infection significantly increased the number of cells permissive to virus infection and enhanced HCMV replication. HCMV infection assays carried out in the presence of phosphonoformic acid, which inhibits the virus DNA polymerase and the expression of downstream genes, indicated that immediate-early and/or early (alpha) genes are sufficient for the induction of SA-beta-Gal activity. When baculovirus vectors expressing HCMV IE1-72 or IE2-86 proteins were inoculated into fibroblasts, the increase of p16(INK4a) (observed predominantly with IE2-86) was similar to that observed with the whole virus, as was the induction of SA-beta-Gal activity, suggesting that the viral IE2 gene leads infected cells into senescence. Altogether our results demonstrate for the first time that HCMV, after arresting the cell cycle and inhibiting apoptosis, triggers the cellular senescence program, probably through the p16(INK4a) and p53 pathways.

Cell Cycle↗
PubMed2002

High prevalence of autoantibodies against the nuclear high mobility group (HMG) protein SSRP1 in sera from patients with systemic lupus erythematosus, but not other rheumatic diseases.

OBJECTIVE: To evaluate the presence of autoantibodies to the high mobility group (HMG) structure specific recognition protein I (SSRP1) in sera from patients with systemic lupus erythematosus (SLE) or other rheumatic diseases. METHODS: Antibodies to SSRP1(anti-SSRP1) were measured in sera from patients with SLE, Sjogren's syndrome (SS), ulcerative colitis (UC), systemic sclerosis (SSc), rheumatoid arthritis (RA), and sera from healthy individuals by both an enzyme-linked immunoassay (ELISA) and Western blotting (WB) using the recombinant SSRP1 N-terminus as antigen. RESULTS: We found 28.8% of the sera from patients with SLE contained anti-SSRPI by both ELISA and WB assay, compared to 8.3% of the sera from healthy individuals. When the 40 sera from patients with other autoimmune diseases were tested, only 2 sera (5%) from individuals with SS showed a moderate reactivity to SSRPI in both ELISA and WB assays. CONCLUSION: The results show that anti-SSRPI can be identified in sera from patients with SLE, but not with other rheumatic diseases and may thus help the diagnosis of SLE in the presence of appropriate clinical findings.

Antibody Specificity↗