G Carra

University of Verona, Verona, Veneto, Italy

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Publications (33)242.69 Total impact

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    ABSTRACT: Interleukin-12 (IL-12) and IL-23 share a common chain. Yet, their production in response to pathogens is differentially regulated, and their functions are distinct and often antithetic. IL-12 is involved in the induction or amplification of the T-helper (Th) type 1 response, whereas IL-23 has been associated with the generation of the Th17 response and IL-17 production. Mycobacterium tuberculosis and yeast zymosan induce IL-23, but in the absence of other stimuli, no IL-12 is induced in human dendritic cells (DCs). The stimulation of IL-23 by M. tuberculosis was mostly explained by the triggering of Toll-like receptor (TLR2) and the cytoplasmic receptor nucleotide oligomerization domain (NOD)-containing protein 2, whereas zymosan induces IL-23 primarily by stimulating the beta-glucan receptor dectin-1 alone or in combination with TLR2. IL-23, IL-6, transforming growth factor (TGF-beta1), and IL-1beta in supernatants from activated human DCs induce human naive CD4(+) T cells to produce IL-17. These data are consistent with various recent reports that TGF-beta is an inducer of IL-17 production both in human and in mouse cells. However, IL-1 is necessary in combination with some or all of the other cytokines to induce IL-17 production in human T cells. The ability of various stimuli to induce Th17 cells depends not only on their induction of IL-23, IL-6, and TGF-beta production in DCs but also on their ability to activate directly or indirectly the inflammasome and to induce IL-1beta.
    Immunological Reviews 01/2009; 226:112-31. · 12.16 Impact Factor
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    ABSTRACT: We analyzed interleukin (IL) 12 and IL-23 production by monocyte-derived dendritic cells (mono-DCs). Mycobacterium tuberculosis H37Rv and zymosan preferentially induced IL-23. IL-23 but not IL-12 was efficiently induced by the combination of nucleotide-binding oligodimerization domain and Toll-like receptor (TLR) 2 ligands, which mimics activation by M. tuberculosis, or by the human dectin-1 ligand beta-glucan alone or in combination with TLR2 ligands, mimicking induction by zymosan. TLR2 ligands inhibited IL-12 and increased IL-23 production. DC priming with interferon (IFN) gamma strongly increased IL-12 production, but was not required for IL-23 production and inhibited IL-23 production induced by beta-glucan. The pattern of IL-12 and IL-23 induction was reflected in accumulation of the IL-12p35 and IL-23p19 transcripts, respectively, but not IL-12/23p40. Although IL-23, transforming growth factor beta, and IL-6 contained in the supernatants of activated mono-DCs played a role in the induction of IL-17 by human CD4(+) T cells, IL-1beta, in combination with one or more of those factors, was required for IL-17 production, and its production determined the differential ability of the stimuli used to elicit mono-DCs to produce soluble factors directing IL-17 production. Thus, the differential ability of pathogens to induce antigen-presenting cells to produce cytokines regulates the immune response to infection.
    Journal of Experimental Medicine 07/2008; 205(6):1447-61. · 13.21 Impact Factor
  • International Journal of Cancer 07/2006; 48(3):473 - 475. · 6.20 Impact Factor
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    ABSTRACT: A reciprocal activating interaction between NK cells and dendritic cells (DC) has been suggested to play a role in the functional regulation of these cells in immunity, but it has been studied only using in vitro generated bone marrow- or monocyte-derived DC. We report that human peripheral blood plasmacytoid DC (pDC) and myeloid DC are necessary to induce NK cell function depending on the type of microbial stimulus. pDC and myeloid DC are required for strongly increased NK cytolytic activity and CD69 expression, in response to inactivated influenza virus or CpG-containing oligonucleotides and poly(I:C), respectively. Secreted type I IFN is required and sufficient for the augmentation of NK cell cytolytic activity in the coculture with pDC or myeloid DC, whereas CD69 expression is dependent on both type I IFN and TNF. In addition, in response to poly(I:C), myeloid DC induce NK cells to produce IFN-gamma through a mechanism dependent on both IL-12 secretion and cell contact between NK cells and myeloid DC, but independent of type I IFN. IL-2-activated NK cells have little to no cytolytic activity for immature myeloid DC and pDC, but are able to induce maturation of these cells. Moreover, IL-2-activated NK cells induce, in the presence of a suboptimal concentration of CpG-containing oligonucleotides, a strong IFN-alpha and TNF production. These data suggest that the reciprocal functional interaction between NK cells and either pDC or myeloid DC may play an important physiological role in the regulation of both innate resistance and adaptive immunity to infections.
    The Journal of Immunology 02/2005; 174(2):727-34. · 5.52 Impact Factor
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    ABSTRACT: We have isolated a novel cell surface molecule, the human homolog of osteoclast-associated receptor (OSCAR). Unlike mouse OSCAR, hOSCAR is widely transcribed in cells of the myeloid lineage. Notably, hOSCAR is expressed on circulating blood monocytes and CD11c(+) dendritic cells but not on T and B cells. hOSCAR is continually expressed during differentiation of CD14(+) monocytes into dendritic cells and maintained after maturation. hOSCAR associates with the FcRgamma as shown by translocation of FcRgamma to the cell surface in presence of hOSCAR and coimmunoprecipitation from transfected cell lines and ex vivo cells. Engagement of hOSCAR with specific mAb leads to Ca(2+) mobilization and cytokine release, indicators of cellular activation. Endocytosis of the receptor in dendritic cells was observed, followed by passage of the internalized material into Lamp-1(+) and HLA-DR(+) compartments, suggesting a role in antigen uptake and presentation. Dendritic cells were able to stimulate a T-cell clone specific for an epitope of mouse IgG1 after uptake and processing of the hOSCAR-specific antibody, demonstrating the capacity of this receptor to mediate antigen presentation. hOSCAR thus represents a novel class of molecule expressed by dendritic cells involved in the initiation of the immune response.
    Blood 10/2004; 104(5):1386-95. · 9.78 Impact Factor
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    ABSTRACT: Interleukin-12 (IL-12) is a heterodimeric cytokine that induces interferon-g (IFN-g) production by natural killer and T-lymphocytes. IL-12 also activates human B-cells through the IL-12 receptor (IL-12R) complex. Here we review the expression and function of IL-12 and IL-12R in human B-cells and in their malignant counterparts. The information provided derives from results both published and unpublished obtained in the laboratories of the Authors, and from a comprehensive review of all the pertinent articles published so far in Medline. The two components of the IL-12R, i.e. the b 1 and b 2 chains, were found to be constitutively expressed in human naive, germinal center and memory tonsil B-cells; however, only naive B-cells were activated following interaction with IL-2. Here we show that the IL-12Rb2 gene is not expressed in EBV-transformed normal B-lymphocytes and in Burkitt's lymphoma B-cell lines. IL-12 p35 and p40 transcripts were detected in all tonsil B-cell subsets, but only naive and memory B-cells produced IL-12. In this study, biosynthesis of IL-12 was investigated in tonsil B-cells, showing that the molecular weight of the mature heterodimeric IL-12 was similar to that of monocyte-derived IL-12, with minor differences possibly related to glycosylation. Finally, malignant B-cells from follicular and marginal zone lymphomas expressed IL-12 p35 and p40 transcripts, whereas only p35 mRNA was detected in mantle cell lymphoma. Taken together, the studies herein reviewed indicate that human B-cells, at variance with their murine counterparts, can produce IL-12 following CD40 ligation. IL-12 p35 and p40 transcripts are found in B-cells from different lymphoproliferative disorders, but the evidence that the cytokine is produced at the protein level is poor. IL-12R is expressed in the main human B-cell subsets, but it is functional only in naive B-cells. Finally, the failure of transformed B-cell lines to express IL-12Rb2 mRNA opens up new perspectives in the investigation of B-cell malignant transformation.
    Haematologica 05/2002; 87(4):434-42. · 5.94 Impact Factor
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    ABSTRACT: We analyzed the interaction between human peripheral blood natural killer (NK) cells and monocyte-derived immature dendritic cells (DC). Fresh NK cells were activated, as indicated by the induced expression of the CD69 antigen, and their cytolytic activity was strongly augmented by contact with lipopolysaccharide (LPS)-treated mature DC, or with immature DC in the presence of the maturation stimuli LPS, Mycobacterium tuberculosis or interferon (IFN)-alpha. Reciprocally, fresh NK cells cultured with immature DC in the presence of the maturation stimuli strongly enhanced DC maturation and interleukin (IL)-12 production. IL-2--activated NK cells directly induced maturation of DC and enhanced their ability to stimulate allogeneic naive CD4(+) T cells. The effects of NK cells were cell contact dependent, although the secretion of IFN-gamma and TNF also contributed to DC maturation. Within peripheral blood lymphocytes the reciprocal activating interaction with DC was restricted to NK cells, because the other lymphocyte subsets were neither induced to express CD69, nor induced to mature in contact with DC. These data demonstrated for the first time a bidirectional cross talk between NK cells and DC, in which NK cells activated by IL-2 or by mature DC induce DC maturation.
    Journal of Experimental Medicine 03/2002; 195(3):327-33. · 13.21 Impact Factor
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    ABSTRACT: IL-12 is a heterodimeric proinflammatory cytokine consisting of a light alpha-chain, formerly defined as p35, disulfide-linked to a heavier beta-chain, formerly defined as p40. The beta-chain is also produced in large excess in a free form, and disulfide-linked beta-chain homodimers with anti-inflammatory effects are produced in the mouse. We analyzed the biosynthesis and glycosylation of IL-12 in human monocytes, and in a cell line stably transfected with IL-12 alpha and beta genes (P5-0.1). The IL-12 heterodimer and free beta-chain were immunoprecipitated from supernatants and cell lysates of metabolically labeled cells and resolved in SDS-PAGE. Whereas the beta-chain showed similar pI pattern whether in the free form or associated in the heterodimer, either in the secreted or intracellular form, the alpha-chain in the secreted heterodimer was much more acidic than that present in the intracellular heterodimer. Deglycosylation experiments with neuraminidase and Endo-F combined with two-dimensional PAGE of single bands of the intracellular vs extracellular IL-12 heterodimer revealed that the alpha-chain was extensively modified with sialic acid adducts to N-linked oligosaccharides before secretion. N-glycosylation inhibition by tunicamycin (TM) did not alter free beta-chain secretion, while preventing the IL-12 heterodimer assembling and secretion. Pulse-chase experiments indicated that IL-12 persists intracellularly for a long period as an immature heterodimer, and that glycosylation is the regulatory step that determines its secretion. beta-chain disulfide-linked homodimers were observed in TM-treated P5-0.1 cells, but in neither TM-treated nor untreated monocytes.
    The Journal of Immunology 06/2000; 164(9):4752-61. · 5.52 Impact Factor
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    ABSTRACT: For a better understanding of the regulation of prostaglandin and nitric oxide (NO) synthesis in circumstances in which the gastric mucosa is inflamed, we have examined the ex vivo production of NO and prostaglandin E2 and the protein expression of inducible nitric oxide synthase (iNOS) and 2 cyclo-oxygenase (COX) isoforms in gastric biopsies from nine Helicobacter pylori-infected patients with active gastritis and six Helicobacter pylori (HP)-negative patients. The results indicate a significant increased of NO and PGE2 in patients with HP infection compared with uninfected samples. These findings were paralleled by marked increases in iNOS and in COX-1 and COX-2 protein expression. Expression of iNOS and COX-2 protein was absent in the mucosa of HP-negative controls. We have demonstrated that iNOS protein is expressed in the gastric mucosa of patients with HP infection. It is likely that iNOS expression and the corresponding high release of NO may play an important role in gastric inflammation associated with HP infection. However, the expression of COX-1 and COX-2 and the parallel increase of prostaglandin E2 could imply that these factors could limit the extend of mucosal damage. In previous reports NO has been shown to stimulate the COX activity, so we think that the role of NO could be both in the regulation of normal function and in the genesis of diseases.
    Prostaglandins & other lipid mediators 09/1999; 58(1):9-17. · 2.42 Impact Factor
  • Prostaglandins 01/1999; 58(1).
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    ABSTRACT: Two-dimensional electrophoretic analysis (2D-PAGE) of cell surface human DP and DR class II antigens identified a glycoprotein, designated pX, that is associated at the cell surface with DP but not DR class II antigen in activated T, B and NK lymphocytes but not in resting B lymphocytes, Raji B lymphoma cells, activated thymic epithelial cells or activated monocytes. pX is a heavily glycosylated protein with an apparent molecular mass spanning between 38 kDa and 22 kDa, that is reduced, after deglycosylation with Endo-F, to 22 kDa. The pX structure appears nonpolymorphic and independent of DP polymorphism, as suggested by 2D-PAGE migrational pattern of 125I-labelled Endo-F deglycosylated DP immunoprecipitates from T cells blasts derived from four donors with different DP allotypes. The apparent absence of polymorphism of pX is further suggested by two-dimensional peptide mapping of a single spot derived from 2D-PAGE of 125I-labelled DP deglycosylated immunoprecipitates from two donors.
    Molecular Immunology 03/1996; 33(3):269-78. · 2.65 Impact Factor
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    ABSTRACT: Interleukin (IL) 12 is a proinflammatory cytokine produced by phagocytic cells, B cells, and other antigen-presenting cells that modulates adaptive immune responses by favoring the generation of T helper type 1 cells. IL-12 mediates some of its physiological activities by acting as a potent inducer of interferon (IFN) gamma production by T and natural killer cells. IFN-gamma enhances the ability of the phagocytic cells to produce IL-12 and other proinflammatory cytokines. Thus, IL-12-induced IFN-gamma acts in a positive feedback loop that represents an important amplifying mechanism in the inflammatory response to infections. We show here that IFN-gamma enhances IL-12 production mostly by priming phagocytic cells for lipopolysaccharide (LPS)-induced transcription of the IL-12 p40 gene, which encodes the heavy chain of the IL-12 heterodimer; furthermore, IFN-gamma directly induces transcription of the IL-12 p35 gene, which encodes the light chain of IL-12, and has at least an additive effect with LPS stimulation in inducing its transcription. The priming effect of IFN-gamma on the LPS-induced p40 gene transcription requires preincubation of the cells with IFN-gamma for at least 8 h to obtain a maximal effect. The priming effect of IFN-gamma for IL-12 production is predominantly at the transcriptional level for both the p40 and the p35 gene, and no evidence for a major role of posttranscriptional or translational mechanisms was found. A 3.3-kb human IL-12 p40 promoter construct transfected into cell lines recapitulated the tissue specificity of the endogenous gene, being silent in two human T cell lines, constitutively active in two human Epstein-Barr virus-positive B lymphoblastoid cell lines, and LPS inducible in the human THP-1 and mouse RAW264.7 monocytic cell lines. Because the RAW264.7 cell line is easily transfectable and regulates the endogenous IL-12 p40 gene in response to IFN-gamma or LPS similarly to human monocytes, it was used for analysis of the regulation of the cloned human IL-12 p40 promoter. A requirement for the region between -222 and -204 in both LPS responsiveness and IFN-gamma priming was established. This region contains an ets consensus sequence that was shown to mediate activation of the promoter by IFN-gamma and LPS, as well as by a cotransfected ets-2. The -222 construct was also regulated in a tissue-specific manner. Two other elements, IRF-1 located at -730 to -719, and NF-IL6 at -520 to -512, were also studied by deletion analysis, which did not result in decreased response to IFN-gamma and LPS stimulation.
    Journal of Experimental Medicine 02/1996; 183(1):147-57. · 13.21 Impact Factor
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    ABSTRACT: The effect of rIL-12 on induction of CD69 antigen expression and cytolytic activity in purified human NK cells was evaluated in comparison to the effects of rIL-2 and rIFN-alpha. It was found that rIL-12 directly induced CD69 antigen expression in NK cells, although the period of incubation required by rIL-12 was longer than the period required by rIL-2 or by rIFN-alpha. Similarly, the cytolytic activity induced by rIL-12 in NK cells against the NK-resistant target cell line Raji was consistently lower than the cytolytic activity induced by rIL-2 or rIFN-alpha when measured after 6 hr of incubation, and increased during the following 18 hr of incubation. To compare the involvement of tyrosin kinases in activation of NK cells induced by rIL-2, rIL-12, and rIFN-alpha, the effect of the specific inhibitor of tyrosin kinases, genistein, was evaluated on induction of CD69 antigen expression and lytic function mediated by the three cytokines. It was found that genistein inhibited CD69 antigen expression induced by rIL-2 and by rIL-12, but not that induced by rIFN-alpha. Unlike the effect on CD69 antigen expression, the cytolytic activity induced by all three cytokines was inhibited by genistein. These results, together with the finding that CD69 antigen expression induced by rIL-2 but not by rIL-12 or rIFN-alpha was inhibited by addition of rIL-4, strongly suggest that IL-2, IL-12, and IFN-alpha mediate their effects, leading to induction of CD69 antigen expression through different activation pathways.
    Cellular Immunology 10/1993; 150(2):382-90. · 1.74 Impact Factor
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    ABSTRACT: In the present study, we have investigated the leukemic cells obtained from 16 patients with acute myeloid leukemia (AML) at diagnosis for the membrane expression of p55 (alpha) and p75 (beta) interleukin-2 receptor (IL-2R) chains using specific monoclonal antibodies (mAbs), as well as for the presence of their transcripts using Northern blot analysis. In addition, immunoprecipitation of the p75 membrane molecule with TU27 and Mik-beta 1 mAbs was carried out in selected cases. The p75 IL-2R beta transcripts were detected in all cases, whereas the membrane p75 molecule was demonstrable by flow cytometry in three cases. However, data from the immunoprecipitation analysis suggest that the lack of the p75 IL-2R detection by flow cytometry might be caused by the low density of molecules per cell rather than the fact that the specific mRNA is not translated into the p75 surface molecule. In addition, a consistent membrane positivity with an anti-p55/CD25 mAb, present on fresh uncultured blasts in 37.5% of the cases, became detectable after short-term culture in 75% of cases. In each individual case, a strict correlation was found between membrane CD25 reactivity and the expression of p55 mRNA. Taken together, our data suggest that the expression of both alpha (p55) and beta (p75) IL-2R molecules is a common feature of leukemic cells in AML, and provide new arguments for reassessing the possible role of IL-2 in leukemic growth.
    Leukemia 04/1993; 7(3):418-25. · 10.16 Impact Factor
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    ABSTRACT: Hairy cell leukemia is a chronic lymphoproliferative disorder characterized by the expansion of neoplastic B-cells expressing the p55 chain of the interleukin 2 receptor (IL-2R) system that is recognized by anti-CD25 monoclonal antibodies (mAb) and binds interleukin 2 (IL-2) with low affinity. In the present study we investigated leukemic hairy cells (HC) for the presence of the p75 IL-2R chain which binds IL-2 with intermediate affinity and plays a crucial role in transducing the message to the cell. For this purpose, we tested highly enriched leukemic HC from six hairy cell leukemia patients for the presence of IL-2R transcripts and for the expression of the p55 and p75 IL-2R chains on their surface membrane by flow cytometry and immunoprecipitation analyses. The functional role of IL-2 in the regulation of HC proliferation was also investigated. Our results indicate that freshly isolated HC express detectable messages for both the p75 IL-2R and the p55 IL-2R. Flow cytometry analysis demonstrated detectable levels of p75 IL-2R on the HC from all patients tested. A mixture of two specific mAb was able to immunoprecipitate detectable amounts of p75 IL-2R from leukemic HC. When leukemic HC were cultured in the presence of several concentrations of IL-2 a low proliferative response was observed. Moreover, the IL-2-driven proliferation of HC was markedly inhibited by anti-p75 IL-2R mAb and to a lesser extent by anti-p55 IL-2R mAb. These findings provide direct evidence of the expression of different IL-2 receptors on leukemic HC and suggest that these molecules might play a role in leukemic cell growth.
    Cancer Research 11/1992; 52(19):5223-8. · 8.65 Impact Factor
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    ABSTRACT: The effect of rIL-4 on CD69 antigen expression induced by rIL-2 or by rINF-alpha on human resting NK cells and CD3+, CD4-, CD8- T lymphocytes has been investigated. rIL-4 drastically inhibited CD69 antigen expression induced by rIL-2 in both cell types. In contrast, rIL-4 did not alter rINF-alpha-induced CD69 antigen expression. Consistent results were obtained evaluating the cytolytic activity of NK cells against the Raji target cell line: rINF-alpha-induced lytic activity was not inhibited by rIL-4, while rIL-2-induced lytic activity was drastically inhibited. Proliferative activity of NK cells induced by rIL-2, in contrast, was only slightly reduced by rIL-4. rIL-4 did not alter the expression of the beta chain of IL-2 receptor, evaluated in NK cells by indirect immunofluorescence. Expression of the alpha chain of IL-2 receptor could not be detected in NK cells by indirect immunofluorescence. It can therefore be suggested that the selective inhibitory effect of rIL-4 on rIL-2-induced activation of NK cells is not mediated by downregulation of alpha and beta chains of IL-2 receptor.
    Cellular Immunology 06/1992; 141(2):342-51. · 1.74 Impact Factor
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    ABSTRACT: In this study we describe the generation and characterization of interspecies somatic cell hybrids between human activated mature T cells and mouse BW5147 thymoma cells. A preferential segregation of human chromosomes was observed in the hybrids. Phenotypic analysis of two hybrids and their clones demonstrated coexpression of CD4 and CD69 antigens in the same cells. Segregation analysis of an informative family of hybrids followed by molecular and karyotype studies clearly demonstrated that the locus encoding CD69 antigen mapped to human chromosome 12. Although the expression of CD69 antigen is an early event after T-lymphocyte activation and rapidly declines in absence of exogenous stimuli, in the hybrids described in this study the expression was constitutive, similarly to what was previously found in early thymocyte precursors and mature thymocytes. In this respect it was important to note that the behavior of the hybrids in culture strongly suggested a dominant influence of the thymus-derived mouse tumor cell genome in controlling the constitutive expression of human CD69. These hybrids may thus provide a system to study the genetic and molecular mechanisms controlling the expression and function of this activation antigen.
    Immunogenetics 05/1992; 36(2):117-120. · 2.89 Impact Factor
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    ABSTRACT: In this study we describe the generation and characterization of interspecies somatic cell hybrids between human activated mature T cells and mouse BW5147 thymoma cells. A preferential segregation of human chromosomes was observed in the hybrids. Phenotypic analysis of two hybrids and their clones demonstrated coexpression of CD4 and CD69 antigens in the same cells. Segregation analysis of an informative family of hybrids followed by molecular and karyotype studies clearly demonstrated that the locus encoding CD69 antigen mapped to human chromosome 12. Although the expression of CD69 antigen is an early event after T-lymphocyte activation and rapidly declines in absence of exogenous stimuli, in the hybrids described in this study the expression was constitutive, similarly to what was previously found in early thymocyte precursors and mature thymocytes. In this respect it was important to note that the behavior of the hybrids in culture strongly suggested a dominant influence of the thymus-derived mouse tumor cell genome in controlling the constitutive expression of human CD69. These hybrids may thus provide a system to study the genetic and molecular mechanisms controlling the expression and function of this activation antigen.
    Immunogenetics 02/1992; 36(2):117-20. · 2.89 Impact Factor
  • Folia allergologica 01/1992; 29:495-500.
  • International Journal of Cancer 06/1991; 48(3):473-5. · 6.20 Impact Factor

Publication Stats

2k Citations
242.69 Total Impact Points

Institutions

  • 1991–2009
    • University of Verona
      • • Section of Immunology
      • • Section of Urology
      • • Graduate School of Translational Biomedical Sciences
      Verona, Veneto, Italy
    • University of Ferrara
      Ferrare, Emilia-Romagna, Italy
  • 1996
    • Wistar Institute
      Philadelphia, Pennsylvania, United States
  • 1986
    • Ludwig Institute for Cancer Research
      La Jolla, California, United States