The Experts below are selected from a list of 321 Experts worldwide ranked by ideXlab platform
Arnaldo Caruso - One of the best experts on this subject based on the ideXlab platform.
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role of autophagy in von willebrand factor secretion by endothelial cells and in the in vivo thrombin antithrombin complex formation promoted by the hiv 1 matrix Protein P17
International Journal of Molecular Sciences, 2020Co-Authors: Antonella Bugatti, Cinzia Giagulli, Pietro Mazzuca, Stefania Marsico, Kai Schulze, Thomas Ebensen, Mark Slevin, Esther Pena, Lina Badimon, Arnaldo CarusoAbstract:Although the advent of combined antiretroviral therapy has substantially improved the survival of HIV-1-infected individuals, non-AIDS-related diseases are becoming increasingly prevalent in HIV-1-infected patients. Persistent abnormalities in coagulation appear to contribute to excess risk for a broad spectrum of non-AIDS defining complications. Alterations in coagulation biology in the context of HIV infection seem to be largely a consequence of a chronically inflammatory microenvironment leading to endothelial cell (EC) dysfunction. A possible direct role of HIV-1 Proteins in sustaining EC dysfunction has been postulated but not yet investigated. The HIV-1 matrix Protein P17 (P17) is secreted from HIV-1-infected cells and is known to sustain inflammatory processes by activating ECs. The aim of this study was to investigate the possibility that P17-driven stimulation of human ECs is associated with increased production of critical coagulation factors. Here we show the involvement of autophagy in the P17-induced accumulation and secretion of von Willebrand factor (vWF) by ECs. In vivo experiments confirmed the capability of P17 to exert a potent pro-coagulant activity soon after its intravenous administration.
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hiv 1 matrix Protein P17 and its variants promote human triple negative breast cancer cell aggressiveness
Infectious Agents and Cancer, 2017Co-Authors: Francesca Caccuri, Arnaldo Caruso, Cinzia Giagulli, Pietro Mazzuca, Francesca Giordano, Ines Barone, Sebastiano Ando, Stefania MarsicoAbstract:The introduction of cART has changed the morbidity and mortality patterns affecting HIV-infected (HIV+) individuals. The risk of breast cancer in HIV+ patients has now approached the general population risk. However, breast cancer has a more aggressive clinical course and poorer outcome in HIV+ patients than in general population, without correlation with the CD4 or virus particles count. These findings suggest a likely influence of HIV-1 Proteins on breast cancer aggressiveness and progression. The HIV-1 matrix Protein (P17) is expressed in different tissues and organs of successfully cART-treated patients and promotes migration of different cells. Variants of P17 (vP17s), characterized by mutations and amino acid insertions, differently from the prototype P17 (refP17), also promote B-cell proliferation and transformation. Wound-healing assay, matrigel-based invasion assay, and anchorage-independent proliferation assay were employed to compare the biological activity exerted by refP17 and three different vP17s on the triple-negative human breast cancer cell line MDA-MB 231. Intracellular signaling was investigated by western blot analysis. Motility and invasiveness increased in cells treated with both refP17 and vP17s compared to untreated cells. The effects of the viral Proteins were mediated by binding to the chemokine receptor CXCR2 and activation of the ERK1/2 signaling pathway. However, vP17s promoted MDA-MB 231 cell growth and proliferation in contrast to refP17-treated or not treated cells. In the context of the emerging role of the microenvironment in promoting and supporting cancer cell growth and metastatic spreading, here we provide the first evidence that exogenous P17 may play a crucial role in sustaining breast cancer cell migration and invasiveness, whereas some P17 variants may also be involved in cancer cell growth and proliferation.
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role of autophagy in hiv 1 matrix Protein P17 driven lymphangiogenesis
Journal of Virology, 2017Co-Authors: Pietro Mazzuca, Arnaldo Caruso, Cinzia Giagulli, Stefania Marsico, Kai Schulze, Stefania Mitola, Marina C Pils, Carlos A Guzman, Francesca CaccuriAbstract:ABSTRACT AIDS-related lymphomas (ARLs) are expected to increase in the future since combined antiretroviral therapy (cART) enhances the life expectancy of HIV-1-infected (HIV + ) patients but does not affect the occurrence of ARLs to the same extent as that of other tumors. Lymphangiogenesis is essential in supporting growth and metastatic spreading of ARLs. HIV-1 does not infect the neoplastic B cells, but HIV-1 Proteins have been hypothesized to play a key role in sustaining a prolymphangiogenic microenvironment in lymphoid organs. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the germinal centers of lymph nodes of HIV + patients under successful cART. The viral Protein displays potent lymphangiogenic activity in vitro and in vivo . This is, at least in part, mediated by the secretion of the lymphangiogenic factor endothelin-1, suggesting that activation of a secretory pathway sustains the lymphangiogenic activity of P17. Here, we show that the P17 lymphangiogenic activity occurs on human lymph node-derived lymphatic endothelial cells (LN-LECs) under stress conditions only and relies entirely on activation of an autophagy-based pathway. In fact, induction of autophagy by P17 promotes lymphangiogenesis, whereas pharmacological and genetic inhibition of autophagy inhibits P17-triggered lymphangiogenesis. Similarly, the vasculogenic activity of P17 was totally inhibited in autophagy-incompetent mice. Our findings reveal a previously unrecognized role of autophagy in lymphangiogenesis and open the way to identify novel treatment strategies aimed at inhibiting aberrant tumor-driven lymphangiogenesis in HIV + patients. IMPORTANCE AIDS-related lymphomas (ARLs) are the most common malignancies in HIV-1-infected (HIV + ) patients after the introduction of combined antiretroviral therapy (cART). Lymphangiogenesis is of critical importance in sustaining growth and metastasis of ARLs. Indeed, enhanced lymphangiogenesis occurs in the lymph nodes of HIV + patients under successful cART. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the lymph node germinal centers even in the absence of virus replication. Several findings suggest a key role for P17 as a microenvironmental factor capable of promoting lymphangiogenesis. Here, we show that P17 promotes lymphangiogenesis of human lymph node-derived lymphatic endothelial cells (LN-LECs). The lymphangiogenic activity of P17 is sustained by an autophagy-based pathway that enables LN-LECs to release prolymphangiogenic factors into the extracellular microenvironment. Our findings indicate that specific targeting of autophagy may provide an important new tool for treating ARLs.
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hiv 1 matrix Protein P17 and its receptors
Current Drug Targets, 2015Co-Authors: Francesca Caccuri, Simona Fiorentini, Arnaldo Caruso, Stefania Marsico, Cinzia GiagulliAbstract:The HIV-1 matrix Protein P17 (P17) plays a crucial role in the virus life cycle. It is released in the extracellular space from HIV-1-infected cells and accumulates in the tissues of patients, even in those successfully treated with highly active antiretroviral therapy. Extracellular P17 deregulates the biological functions of many different cells that are directly or indirectly implicated in AIDS pathogenesis. All P17 actions depend on interaction between its functional epitope (AT20), located at the Protein N-terminal region, and different receptors expressed on target cells. This finding corroborates the importance of impeding P17/P17 receptors interaction as a contribution to block AIDS. In this article we review the interaction of P17 with heparan sulfate proteoglycans (HSPGs) and with the chemokine (C-X-C motif) receptor 1 (CXCR1) and 2 (CXCR2). We provide details on how P17 interacts with its receptors and how these interactions are central to the P17 biological activities. Moreover, we highlight the existence of a P17 variant, named S75X, which displays opposite effects on B-cell proliferation as compared to P17. A two-site model for P17 interaction with G-coupled receptors provides a possible explanation on how mutations naturally occurring within the primary amino acid structure can lead S75X to activate the Akt signaling pathway and to promote B-cell growth and transformation. Identification of P17 interaction with HSPGs, CXCR1 and CXCR2 as a fundamental event in supporting its activity could help to find new treatment approaches aimed at blocking all P17/P17 receptors interactions and, consequently, P17 detrimental activities.
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angiogenic lymphangiogenic and adipogenic effects of hiv 1 matrix Protein P17
Pathogens and Disease, 2015Co-Authors: Arnaldo Caruso, Francesca Caccuri, Daniele Basta, Olga Latinovic, Mark K Lafferty, Joseph Bryant, Wuyuan Lu, Robert C Gallo, Alfredo GarzinodemoAbstract:Abstract Lymphangiogenesis and concurrent angiogenesis are essential in supporting proliferation and survival of AIDS-related lymphomas, which are often metastatic. In vitro studies suggest a candidate angiogienic and lymphangiogenic factor encoded by HIV: the matrix Protein P17. P17 accumulates in lymph nodes of patients even when they are undergoing highly active antiretroviral therapy. P17 has been found to affect immune cells, and recent data showed that a variant P17, called S75X, induces cell growth by triggering MAPK/ERK and PI3K/AKT pathways. We tested the in vivo angiogenic activity of P17 by injecting it in Matrigel plugs in nude mice. Plugs were retrieved 7 days after injection, and assessed macroscopically, and by light and confocal microscopy. Our data revealed that both reference and S75X variant P17 promote angiogenesis and lymphangiogenesis in vivo. Our results suggest that the induction of angiogenesis and lymphangiogenesis by HIV-1 P17 may generate a favorable microenvironment that could trigger tumor growth and maintenance. Moreover, the presence of adipocytes infiltration observed at the histological level suggests a possible interplay between angiogenesis, lymphangiogenesis and adipogenesis. These findings offer new opportunities for the development of treatment strategies to combat HIV-related cancers.
Simona Fiorentini - One of the best experts on this subject based on the ideXlab platform.
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in depth analysis of compartmentalization of hiv 1 matrix Protein P17 in pbmc and plasma
New Microbiologica, 2017Co-Authors: Marina Selleri, Francesca Caccuri, Emanuela Giombini, Riccardo Dolcetti, Gabriella Rozera, Isabella Abbate, Debora Martorelli, Alessia Mammone, Stefania Zanussi, Simona FiorentiniAbstract:HIV-1 P17 plays an important role in the virus life-cycle and disease pathogenesis. Recent studies indicated a high heterogeneity of P17. A high number of insertions in the P17 carboxy-terminal region have been more frequently detected in patients with non-Hodgkin lymphoma (NHL), suggesting a role of altered P17 in lymphomagenesis. Based on P17 heterogeneity, possible PBMC/plasma compartmentalization of P17 variants was explored by ultra-deep pyrosequencing in five NHL patients. The high variability of P17 with insertions at the carboxy-terminal region was confirmed in plasma and observed for the first time in proviral genomes. Quasispecies compartmentalization was evident in 4/5 patients. Further studies are needed to define the possible role of P17 quasispecies compartmentalization in lymphomagenesis.
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hiv 1 matrix Protein P17 and its receptors
Current Drug Targets, 2015Co-Authors: Francesca Caccuri, Simona Fiorentini, Arnaldo Caruso, Stefania Marsico, Cinzia GiagulliAbstract:The HIV-1 matrix Protein P17 (P17) plays a crucial role in the virus life cycle. It is released in the extracellular space from HIV-1-infected cells and accumulates in the tissues of patients, even in those successfully treated with highly active antiretroviral therapy. Extracellular P17 deregulates the biological functions of many different cells that are directly or indirectly implicated in AIDS pathogenesis. All P17 actions depend on interaction between its functional epitope (AT20), located at the Protein N-terminal region, and different receptors expressed on target cells. This finding corroborates the importance of impeding P17/P17 receptors interaction as a contribution to block AIDS. In this article we review the interaction of P17 with heparan sulfate proteoglycans (HSPGs) and with the chemokine (C-X-C motif) receptor 1 (CXCR1) and 2 (CXCR2). We provide details on how P17 interacts with its receptors and how these interactions are central to the P17 biological activities. Moreover, we highlight the existence of a P17 variant, named S75X, which displays opposite effects on B-cell proliferation as compared to P17. A two-site model for P17 interaction with G-coupled receptors provides a possible explanation on how mutations naturally occurring within the primary amino acid structure can lead S75X to activate the Akt signaling pathway and to promote B-cell growth and transformation. Identification of P17 interaction with HSPGs, CXCR1 and CXCR2 as a fundamental event in supporting its activity could help to find new treatment approaches aimed at blocking all P17/P17 receptors interactions and, consequently, P17 detrimental activities.
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long lasting humoral immune response induced in hiv 1 infected patients by a synthetic peptide at20 derived from the hiv 1 matrix Protein P17 functional epitope
Hiv Clinical Trials, 2015Co-Authors: Emanuele Foca, Simona Fiorentini, Cinzia Giagulli, Francesca Caccuri, Marialuisa Iaria, Davide Motta, Francesco Castelli, Arnaldo CarusoAbstract:Objective: A therapeutic vaccination based on a synthetic peptide (AT20) representative of the HIV-1 matrix Protein P17 (P17) functional region, coupled to keyhole limpet hemocyanin (KLH) AT20-KLH was capable of inducing the production of high-avidity antibodies (Abs) toward a previous untargeted P17 hotspot of functional activity in highly active antiretroviral therapy (HAART)-treated HIV-1-infected patients. Since avidity of Abs after immunization and the retention of antigens are important in sustaining the long-lasting production of specific humoral responses, we asked whether AT20-KLH vaccination would result in development of a long-lived immune response. Methods: The long-term duration of Ab response to AT20-KLH has been evaluated in 10 patients previously enrolled for the AT20-KLH vaccination trial at day 898 post-immunization. Ab titer and their avidity was assessed using specifically designed ELISA assays, whereas their neutralizing capacity was estimated in vitro using a ‘wound sealing assay’. ...
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detection of hiv 1 matrix Protein P17 quasispecies variants in plasma of chronic hiv 1 infected patients by ultra deep pyrosequencing
Journal of Acquired Immune Deficiency Syndromes, 2014Co-Authors: Emanuela Giombini, Simona Fiorentini, Francesca Caccuri, Riccardo Dolcetti, Marina Selleri, Gabriella Rozera, Isabella Abbate, Barbara Bartolini, Debora Martorelli, Cinzia GiagulliAbstract:Background:The HIV-1 matrix Protein P17 (P17MA) is a pleiotropic Protein that plays a key role in the HIV-1 life cycle. It has been long believed to have a highly conserved primary amino acid sequence and a well-preserved structural integrity to avoid severe fitness consequences. However, recent dat
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synthetic hiv 1 matrix Protein P17 based at20 klh therapeutic immunization in hiv 1 infected patients receiving antiretroviral treatment a phase i safety and immunogenicity study
BMC Infectious Diseases, 2014Co-Authors: Arnaldo Caruso, Cinzia Giagulli, Francesca Caccuri, Marialuisa Iaria, Simona FiorentiniAbstract:Therapeutic vaccination is a promising approach to treat HIV-1+ people by boosting or redirecting immune system to neutralize HIV-1 antigens whose effects are relevant to viral pathogenesis. HIV-1 matrix Protein P17 is a structural Protein that, through the interaction of its NH2-residing epitope AT20 with specific receptor(s), acts extracellularly as a viral toxin. In fact, P17 is able to deregulate biological activities of different cells involved in AIDS pathogenesis. To induce neutralizing antibodies (Abs) to P17 we developed a peptide-based immunogen (AT20-KLH) and evaluated its safety and immunogenicity.
Cinzia Giagulli - One of the best experts on this subject based on the ideXlab platform.
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role of autophagy in von willebrand factor secretion by endothelial cells and in the in vivo thrombin antithrombin complex formation promoted by the hiv 1 matrix Protein P17
International Journal of Molecular Sciences, 2020Co-Authors: Antonella Bugatti, Cinzia Giagulli, Pietro Mazzuca, Stefania Marsico, Kai Schulze, Thomas Ebensen, Mark Slevin, Esther Pena, Lina Badimon, Arnaldo CarusoAbstract:Although the advent of combined antiretroviral therapy has substantially improved the survival of HIV-1-infected individuals, non-AIDS-related diseases are becoming increasingly prevalent in HIV-1-infected patients. Persistent abnormalities in coagulation appear to contribute to excess risk for a broad spectrum of non-AIDS defining complications. Alterations in coagulation biology in the context of HIV infection seem to be largely a consequence of a chronically inflammatory microenvironment leading to endothelial cell (EC) dysfunction. A possible direct role of HIV-1 Proteins in sustaining EC dysfunction has been postulated but not yet investigated. The HIV-1 matrix Protein P17 (P17) is secreted from HIV-1-infected cells and is known to sustain inflammatory processes by activating ECs. The aim of this study was to investigate the possibility that P17-driven stimulation of human ECs is associated with increased production of critical coagulation factors. Here we show the involvement of autophagy in the P17-induced accumulation and secretion of von Willebrand factor (vWF) by ECs. In vivo experiments confirmed the capability of P17 to exert a potent pro-coagulant activity soon after its intravenous administration.
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identification of amino acid residues critical for the b cell growth promoting activity of hiv 1 matrix Protein P17 variants
Biochimica et Biophysica Acta, 2019Co-Authors: Wangxiao He, Cinzia Giagulli, Pietro Mazzuca, Stefania Marsico, Antonella Bugatti, Marco Rusnati, Kristen M Varney, Weirong Yuan, Alfredo Cagnotto, Luisa DiomedeAbstract:Abstract Background HIV-1 matrix Protein P17 variants (vP17s) detected in HIV-1-infected patients with non-Hodgkin's lymphoma (HIV-NHL) display, differently from the wild-type Protein (refP17), B cell growth-promoting activity. Biophysical analysis revealed that vP17s are destabilized as compared to refP17, motivating us to explore structure-function relationships. Methods We used: biophysical techniques (circular dichroism (CD), nuclear magnetic resonance (NMR) and thermal/GuHCL denaturation) to study Protein conformation and stability; Surface plasmon resonance (SPR) to study interactions; Western blot to investigate signaling pathways; and Colony Formation and Soft Agar assays to study B cell proliferation and clonogenicity. Results By forcing the formation of a disulfide bridge between Cys residues at positions 57 and 87 we obtained a destabilized P17 capable of promoting B cell proliferation. This finding prompted us to dissect refP17 to identify the functional epitope. A synthetic peptide (F1) spanning from amino acid (aa) 2 to 21 was found to activate Akt and promote B cell proliferation and clonogenicity. Three positively charged aa (Arg15, Lys18 and Arg20) proved critical for sustaining the proliferative activity of both F1 and HIV-NHL-derived vP17s. Lack of any interaction of F1 with the known refP17 receptors suggests an alternate one involved in cell proliferation. Conclusions The molecular reasons for the proliferative activity of vP17s, compared to refP17, relies on the exposure of a functional epitope capable of activating Akt. General significance Our findings pave the way for identifying the receptor(s) responsible for B cell proliferation and offer new opportunities to identify novel treatment strategies in combating HIV-related NHL.
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hiv 1 matrix Protein P17 and its variants promote human triple negative breast cancer cell aggressiveness
Infectious Agents and Cancer, 2017Co-Authors: Francesca Caccuri, Arnaldo Caruso, Cinzia Giagulli, Pietro Mazzuca, Francesca Giordano, Ines Barone, Sebastiano Ando, Stefania MarsicoAbstract:The introduction of cART has changed the morbidity and mortality patterns affecting HIV-infected (HIV+) individuals. The risk of breast cancer in HIV+ patients has now approached the general population risk. However, breast cancer has a more aggressive clinical course and poorer outcome in HIV+ patients than in general population, without correlation with the CD4 or virus particles count. These findings suggest a likely influence of HIV-1 Proteins on breast cancer aggressiveness and progression. The HIV-1 matrix Protein (P17) is expressed in different tissues and organs of successfully cART-treated patients and promotes migration of different cells. Variants of P17 (vP17s), characterized by mutations and amino acid insertions, differently from the prototype P17 (refP17), also promote B-cell proliferation and transformation. Wound-healing assay, matrigel-based invasion assay, and anchorage-independent proliferation assay were employed to compare the biological activity exerted by refP17 and three different vP17s on the triple-negative human breast cancer cell line MDA-MB 231. Intracellular signaling was investigated by western blot analysis. Motility and invasiveness increased in cells treated with both refP17 and vP17s compared to untreated cells. The effects of the viral Proteins were mediated by binding to the chemokine receptor CXCR2 and activation of the ERK1/2 signaling pathway. However, vP17s promoted MDA-MB 231 cell growth and proliferation in contrast to refP17-treated or not treated cells. In the context of the emerging role of the microenvironment in promoting and supporting cancer cell growth and metastatic spreading, here we provide the first evidence that exogenous P17 may play a crucial role in sustaining breast cancer cell migration and invasiveness, whereas some P17 variants may also be involved in cancer cell growth and proliferation.
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role of autophagy in hiv 1 matrix Protein P17 driven lymphangiogenesis
Journal of Virology, 2017Co-Authors: Pietro Mazzuca, Arnaldo Caruso, Cinzia Giagulli, Stefania Marsico, Kai Schulze, Stefania Mitola, Marina C Pils, Carlos A Guzman, Francesca CaccuriAbstract:ABSTRACT AIDS-related lymphomas (ARLs) are expected to increase in the future since combined antiretroviral therapy (cART) enhances the life expectancy of HIV-1-infected (HIV + ) patients but does not affect the occurrence of ARLs to the same extent as that of other tumors. Lymphangiogenesis is essential in supporting growth and metastatic spreading of ARLs. HIV-1 does not infect the neoplastic B cells, but HIV-1 Proteins have been hypothesized to play a key role in sustaining a prolymphangiogenic microenvironment in lymphoid organs. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the germinal centers of lymph nodes of HIV + patients under successful cART. The viral Protein displays potent lymphangiogenic activity in vitro and in vivo . This is, at least in part, mediated by the secretion of the lymphangiogenic factor endothelin-1, suggesting that activation of a secretory pathway sustains the lymphangiogenic activity of P17. Here, we show that the P17 lymphangiogenic activity occurs on human lymph node-derived lymphatic endothelial cells (LN-LECs) under stress conditions only and relies entirely on activation of an autophagy-based pathway. In fact, induction of autophagy by P17 promotes lymphangiogenesis, whereas pharmacological and genetic inhibition of autophagy inhibits P17-triggered lymphangiogenesis. Similarly, the vasculogenic activity of P17 was totally inhibited in autophagy-incompetent mice. Our findings reveal a previously unrecognized role of autophagy in lymphangiogenesis and open the way to identify novel treatment strategies aimed at inhibiting aberrant tumor-driven lymphangiogenesis in HIV + patients. IMPORTANCE AIDS-related lymphomas (ARLs) are the most common malignancies in HIV-1-infected (HIV + ) patients after the introduction of combined antiretroviral therapy (cART). Lymphangiogenesis is of critical importance in sustaining growth and metastasis of ARLs. Indeed, enhanced lymphangiogenesis occurs in the lymph nodes of HIV + patients under successful cART. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the lymph node germinal centers even in the absence of virus replication. Several findings suggest a key role for P17 as a microenvironmental factor capable of promoting lymphangiogenesis. Here, we show that P17 promotes lymphangiogenesis of human lymph node-derived lymphatic endothelial cells (LN-LECs). The lymphangiogenic activity of P17 is sustained by an autophagy-based pathway that enables LN-LECs to release prolymphangiogenic factors into the extracellular microenvironment. Our findings indicate that specific targeting of autophagy may provide an important new tool for treating ARLs.
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a single amino acid substitution confers b cell clonogenic activity to the hiv 1 matrix Protein P17
Scientific Reports, 2017Co-Authors: Cinzia Giagulli, Francesca Caccuri, Stefania Marsico, Wangxiao He, Kristen M Varney, Pasqualina Dursi, Simone Zorzan, Alessandro Orro, Benoit Otjacques, Carlo LaudannaAbstract:Recent data highlight the presence, in HIV-1-seropositive patients with lymphoma, of P17 variants (vP17s) endowed with B-cell clonogenicity, suggesting a role of vP17s in lymphomagenesis. We investigated the mechanisms responsible for the functional disparity on B cells between a wild-type P17 (refP17) and a vP17 named S75X. Here, we show that a single Arginine (R) to Glycine (G) mutation at position 76 in the refP17 backbone (P17R76G), as in the S75X variant, is per se sufficient to confer a B-cell clonogenic potential to the viral Protein and modulate, through activation of the PTEN/PI3K/Akt signaling pathway, different molecules involved in apoptosis inhibition (CASP-9, CASP-7, DFF-45, NPM, YWHAZ, Src, PAX2, MAPK8), cell cycle promotion and cancer progression (CDK1, CDK2, CDK8, CHEK1, CHEK2, GSK-3 beta, NPM, PAK1, PP2C-alpha). Moreover, the only R to G mutation at position 76 was found to strongly impact on Protein folding and oligomerization by altering the hydrogen bond network. This generates a conformational shift in the P17 R76G mutant which enables a functional epitope(s), masked in refP17, to elicit B-cell growth-promoting signals after its interaction with a still unknown receptor(s). Our findings offer new opportunities to understand the molecular mechanisms accounting for the B-cell growth-promoting activity of vP17s.
Francesca Caccuri - One of the best experts on this subject based on the ideXlab platform.
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hiv 1 matrix Protein P17 and its variants promote human triple negative breast cancer cell aggressiveness
Infectious Agents and Cancer, 2017Co-Authors: Francesca Caccuri, Arnaldo Caruso, Cinzia Giagulli, Pietro Mazzuca, Francesca Giordano, Ines Barone, Sebastiano Ando, Stefania MarsicoAbstract:The introduction of cART has changed the morbidity and mortality patterns affecting HIV-infected (HIV+) individuals. The risk of breast cancer in HIV+ patients has now approached the general population risk. However, breast cancer has a more aggressive clinical course and poorer outcome in HIV+ patients than in general population, without correlation with the CD4 or virus particles count. These findings suggest a likely influence of HIV-1 Proteins on breast cancer aggressiveness and progression. The HIV-1 matrix Protein (P17) is expressed in different tissues and organs of successfully cART-treated patients and promotes migration of different cells. Variants of P17 (vP17s), characterized by mutations and amino acid insertions, differently from the prototype P17 (refP17), also promote B-cell proliferation and transformation. Wound-healing assay, matrigel-based invasion assay, and anchorage-independent proliferation assay were employed to compare the biological activity exerted by refP17 and three different vP17s on the triple-negative human breast cancer cell line MDA-MB 231. Intracellular signaling was investigated by western blot analysis. Motility and invasiveness increased in cells treated with both refP17 and vP17s compared to untreated cells. The effects of the viral Proteins were mediated by binding to the chemokine receptor CXCR2 and activation of the ERK1/2 signaling pathway. However, vP17s promoted MDA-MB 231 cell growth and proliferation in contrast to refP17-treated or not treated cells. In the context of the emerging role of the microenvironment in promoting and supporting cancer cell growth and metastatic spreading, here we provide the first evidence that exogenous P17 may play a crucial role in sustaining breast cancer cell migration and invasiveness, whereas some P17 variants may also be involved in cancer cell growth and proliferation.
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hiv 1 matrix Protein P17 misfolding forms toxic amyloidogenic assemblies that induce neurocognitive disorders
Scientific Reports, 2017Co-Authors: Yasmin Zeinolabediny, Francesca Caccuri, Laura Colombo, Federica Morelli, Margherita Romeo, Alessandro Rossi, Silvia Schiarea, Carlotta Ciaramelli, Cristina Airoldi, Ria WestonAbstract:Human immunodeficiency virus type-1 (HIV-1)-associated neurocognitive disorder (HAND) remains an important neurological manifestation that adversely affects a patient’s quality of life. HIV-1 matrix Protein P17 (P17) has been detected in autoptic brain tissue of HAND individuals who presented early with severe AIDS encephalopathy. We hypothesised that the ability of P17 to misfold may result in the generation of toxic assemblies in the brain and may be relevant for HAND pathogenesis. A multidisciplinary integrated approach has been applied to determine the ability of P17 to form soluble amyloidogenic assemblies in vitro. To provide new information into the potential pathogenic role of soluble P17 species in HAND, their toxicological capability was evaluated in vivo. In C. elegans, capable of recognising toxic assemblies of amyloidogenic Proteins, P17 induces a specific toxic effect which can be counteracted by tetracyclines, drugs able to hinder the formation of large oligomers and consequently amyloid fibrils. The intrahippocampal injection of P17 in mice reduces their cognitive function and induces behavioral deficiencies. These findings offer a new way of thinking about the possible cause of neurodegeneration in HIV-1-seropositive patients, which engages the ability of P17 to form soluble toxic assemblies.
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role of autophagy in hiv 1 matrix Protein P17 driven lymphangiogenesis
Journal of Virology, 2017Co-Authors: Pietro Mazzuca, Arnaldo Caruso, Cinzia Giagulli, Stefania Marsico, Kai Schulze, Stefania Mitola, Marina C Pils, Carlos A Guzman, Francesca CaccuriAbstract:ABSTRACT AIDS-related lymphomas (ARLs) are expected to increase in the future since combined antiretroviral therapy (cART) enhances the life expectancy of HIV-1-infected (HIV + ) patients but does not affect the occurrence of ARLs to the same extent as that of other tumors. Lymphangiogenesis is essential in supporting growth and metastatic spreading of ARLs. HIV-1 does not infect the neoplastic B cells, but HIV-1 Proteins have been hypothesized to play a key role in sustaining a prolymphangiogenic microenvironment in lymphoid organs. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the germinal centers of lymph nodes of HIV + patients under successful cART. The viral Protein displays potent lymphangiogenic activity in vitro and in vivo . This is, at least in part, mediated by the secretion of the lymphangiogenic factor endothelin-1, suggesting that activation of a secretory pathway sustains the lymphangiogenic activity of P17. Here, we show that the P17 lymphangiogenic activity occurs on human lymph node-derived lymphatic endothelial cells (LN-LECs) under stress conditions only and relies entirely on activation of an autophagy-based pathway. In fact, induction of autophagy by P17 promotes lymphangiogenesis, whereas pharmacological and genetic inhibition of autophagy inhibits P17-triggered lymphangiogenesis. Similarly, the vasculogenic activity of P17 was totally inhibited in autophagy-incompetent mice. Our findings reveal a previously unrecognized role of autophagy in lymphangiogenesis and open the way to identify novel treatment strategies aimed at inhibiting aberrant tumor-driven lymphangiogenesis in HIV + patients. IMPORTANCE AIDS-related lymphomas (ARLs) are the most common malignancies in HIV-1-infected (HIV + ) patients after the introduction of combined antiretroviral therapy (cART). Lymphangiogenesis is of critical importance in sustaining growth and metastasis of ARLs. Indeed, enhanced lymphangiogenesis occurs in the lymph nodes of HIV + patients under successful cART. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the lymph node germinal centers even in the absence of virus replication. Several findings suggest a key role for P17 as a microenvironmental factor capable of promoting lymphangiogenesis. Here, we show that P17 promotes lymphangiogenesis of human lymph node-derived lymphatic endothelial cells (LN-LECs). The lymphangiogenic activity of P17 is sustained by an autophagy-based pathway that enables LN-LECs to release prolymphangiogenic factors into the extracellular microenvironment. Our findings indicate that specific targeting of autophagy may provide an important new tool for treating ARLs.
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a single amino acid substitution confers b cell clonogenic activity to the hiv 1 matrix Protein P17
Scientific Reports, 2017Co-Authors: Cinzia Giagulli, Francesca Caccuri, Stefania Marsico, Wangxiao He, Kristen M Varney, Pasqualina Dursi, Simone Zorzan, Alessandro Orro, Benoit Otjacques, Carlo LaudannaAbstract:Recent data highlight the presence, in HIV-1-seropositive patients with lymphoma, of P17 variants (vP17s) endowed with B-cell clonogenicity, suggesting a role of vP17s in lymphomagenesis. We investigated the mechanisms responsible for the functional disparity on B cells between a wild-type P17 (refP17) and a vP17 named S75X. Here, we show that a single Arginine (R) to Glycine (G) mutation at position 76 in the refP17 backbone (P17R76G), as in the S75X variant, is per se sufficient to confer a B-cell clonogenic potential to the viral Protein and modulate, through activation of the PTEN/PI3K/Akt signaling pathway, different molecules involved in apoptosis inhibition (CASP-9, CASP-7, DFF-45, NPM, YWHAZ, Src, PAX2, MAPK8), cell cycle promotion and cancer progression (CDK1, CDK2, CDK8, CHEK1, CHEK2, GSK-3 beta, NPM, PAK1, PP2C-alpha). Moreover, the only R to G mutation at position 76 was found to strongly impact on Protein folding and oligomerization by altering the hydrogen bond network. This generates a conformational shift in the P17 R76G mutant which enables a functional epitope(s), masked in refP17, to elicit B-cell growth-promoting signals after its interaction with a still unknown receptor(s). Our findings offer new opportunities to understand the molecular mechanisms accounting for the B-cell growth-promoting activity of vP17s.
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in depth analysis of compartmentalization of hiv 1 matrix Protein P17 in pbmc and plasma
New Microbiologica, 2017Co-Authors: Marina Selleri, Francesca Caccuri, Emanuela Giombini, Riccardo Dolcetti, Gabriella Rozera, Isabella Abbate, Debora Martorelli, Alessia Mammone, Stefania Zanussi, Simona FiorentiniAbstract:HIV-1 P17 plays an important role in the virus life-cycle and disease pathogenesis. Recent studies indicated a high heterogeneity of P17. A high number of insertions in the P17 carboxy-terminal region have been more frequently detected in patients with non-Hodgkin lymphoma (NHL), suggesting a role of altered P17 in lymphomagenesis. Based on P17 heterogeneity, possible PBMC/plasma compartmentalization of P17 variants was explored by ultra-deep pyrosequencing in five NHL patients. The high variability of P17 with insertions at the carboxy-terminal region was confirmed in plasma and observed for the first time in proviral genomes. Quasispecies compartmentalization was evident in 4/5 patients. Further studies are needed to define the possible role of P17 quasispecies compartmentalization in lymphomagenesis.
Stefania Marsico - One of the best experts on this subject based on the ideXlab platform.
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role of autophagy in von willebrand factor secretion by endothelial cells and in the in vivo thrombin antithrombin complex formation promoted by the hiv 1 matrix Protein P17
International Journal of Molecular Sciences, 2020Co-Authors: Antonella Bugatti, Cinzia Giagulli, Pietro Mazzuca, Stefania Marsico, Kai Schulze, Thomas Ebensen, Mark Slevin, Esther Pena, Lina Badimon, Arnaldo CarusoAbstract:Although the advent of combined antiretroviral therapy has substantially improved the survival of HIV-1-infected individuals, non-AIDS-related diseases are becoming increasingly prevalent in HIV-1-infected patients. Persistent abnormalities in coagulation appear to contribute to excess risk for a broad spectrum of non-AIDS defining complications. Alterations in coagulation biology in the context of HIV infection seem to be largely a consequence of a chronically inflammatory microenvironment leading to endothelial cell (EC) dysfunction. A possible direct role of HIV-1 Proteins in sustaining EC dysfunction has been postulated but not yet investigated. The HIV-1 matrix Protein P17 (P17) is secreted from HIV-1-infected cells and is known to sustain inflammatory processes by activating ECs. The aim of this study was to investigate the possibility that P17-driven stimulation of human ECs is associated with increased production of critical coagulation factors. Here we show the involvement of autophagy in the P17-induced accumulation and secretion of von Willebrand factor (vWF) by ECs. In vivo experiments confirmed the capability of P17 to exert a potent pro-coagulant activity soon after its intravenous administration.
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identification of amino acid residues critical for the b cell growth promoting activity of hiv 1 matrix Protein P17 variants
Biochimica et Biophysica Acta, 2019Co-Authors: Wangxiao He, Cinzia Giagulli, Pietro Mazzuca, Stefania Marsico, Antonella Bugatti, Marco Rusnati, Kristen M Varney, Weirong Yuan, Alfredo Cagnotto, Luisa DiomedeAbstract:Abstract Background HIV-1 matrix Protein P17 variants (vP17s) detected in HIV-1-infected patients with non-Hodgkin's lymphoma (HIV-NHL) display, differently from the wild-type Protein (refP17), B cell growth-promoting activity. Biophysical analysis revealed that vP17s are destabilized as compared to refP17, motivating us to explore structure-function relationships. Methods We used: biophysical techniques (circular dichroism (CD), nuclear magnetic resonance (NMR) and thermal/GuHCL denaturation) to study Protein conformation and stability; Surface plasmon resonance (SPR) to study interactions; Western blot to investigate signaling pathways; and Colony Formation and Soft Agar assays to study B cell proliferation and clonogenicity. Results By forcing the formation of a disulfide bridge between Cys residues at positions 57 and 87 we obtained a destabilized P17 capable of promoting B cell proliferation. This finding prompted us to dissect refP17 to identify the functional epitope. A synthetic peptide (F1) spanning from amino acid (aa) 2 to 21 was found to activate Akt and promote B cell proliferation and clonogenicity. Three positively charged aa (Arg15, Lys18 and Arg20) proved critical for sustaining the proliferative activity of both F1 and HIV-NHL-derived vP17s. Lack of any interaction of F1 with the known refP17 receptors suggests an alternate one involved in cell proliferation. Conclusions The molecular reasons for the proliferative activity of vP17s, compared to refP17, relies on the exposure of a functional epitope capable of activating Akt. General significance Our findings pave the way for identifying the receptor(s) responsible for B cell proliferation and offer new opportunities to identify novel treatment strategies in combating HIV-related NHL.
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hiv 1 matrix Protein P17 and its variants promote human triple negative breast cancer cell aggressiveness
Infectious Agents and Cancer, 2017Co-Authors: Francesca Caccuri, Arnaldo Caruso, Cinzia Giagulli, Pietro Mazzuca, Francesca Giordano, Ines Barone, Sebastiano Ando, Stefania MarsicoAbstract:The introduction of cART has changed the morbidity and mortality patterns affecting HIV-infected (HIV+) individuals. The risk of breast cancer in HIV+ patients has now approached the general population risk. However, breast cancer has a more aggressive clinical course and poorer outcome in HIV+ patients than in general population, without correlation with the CD4 or virus particles count. These findings suggest a likely influence of HIV-1 Proteins on breast cancer aggressiveness and progression. The HIV-1 matrix Protein (P17) is expressed in different tissues and organs of successfully cART-treated patients and promotes migration of different cells. Variants of P17 (vP17s), characterized by mutations and amino acid insertions, differently from the prototype P17 (refP17), also promote B-cell proliferation and transformation. Wound-healing assay, matrigel-based invasion assay, and anchorage-independent proliferation assay were employed to compare the biological activity exerted by refP17 and three different vP17s on the triple-negative human breast cancer cell line MDA-MB 231. Intracellular signaling was investigated by western blot analysis. Motility and invasiveness increased in cells treated with both refP17 and vP17s compared to untreated cells. The effects of the viral Proteins were mediated by binding to the chemokine receptor CXCR2 and activation of the ERK1/2 signaling pathway. However, vP17s promoted MDA-MB 231 cell growth and proliferation in contrast to refP17-treated or not treated cells. In the context of the emerging role of the microenvironment in promoting and supporting cancer cell growth and metastatic spreading, here we provide the first evidence that exogenous P17 may play a crucial role in sustaining breast cancer cell migration and invasiveness, whereas some P17 variants may also be involved in cancer cell growth and proliferation.
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role of autophagy in hiv 1 matrix Protein P17 driven lymphangiogenesis
Journal of Virology, 2017Co-Authors: Pietro Mazzuca, Arnaldo Caruso, Cinzia Giagulli, Stefania Marsico, Kai Schulze, Stefania Mitola, Marina C Pils, Carlos A Guzman, Francesca CaccuriAbstract:ABSTRACT AIDS-related lymphomas (ARLs) are expected to increase in the future since combined antiretroviral therapy (cART) enhances the life expectancy of HIV-1-infected (HIV + ) patients but does not affect the occurrence of ARLs to the same extent as that of other tumors. Lymphangiogenesis is essential in supporting growth and metastatic spreading of ARLs. HIV-1 does not infect the neoplastic B cells, but HIV-1 Proteins have been hypothesized to play a key role in sustaining a prolymphangiogenic microenvironment in lymphoid organs. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the germinal centers of lymph nodes of HIV + patients under successful cART. The viral Protein displays potent lymphangiogenic activity in vitro and in vivo . This is, at least in part, mediated by the secretion of the lymphangiogenic factor endothelin-1, suggesting that activation of a secretory pathway sustains the lymphangiogenic activity of P17. Here, we show that the P17 lymphangiogenic activity occurs on human lymph node-derived lymphatic endothelial cells (LN-LECs) under stress conditions only and relies entirely on activation of an autophagy-based pathway. In fact, induction of autophagy by P17 promotes lymphangiogenesis, whereas pharmacological and genetic inhibition of autophagy inhibits P17-triggered lymphangiogenesis. Similarly, the vasculogenic activity of P17 was totally inhibited in autophagy-incompetent mice. Our findings reveal a previously unrecognized role of autophagy in lymphangiogenesis and open the way to identify novel treatment strategies aimed at inhibiting aberrant tumor-driven lymphangiogenesis in HIV + patients. IMPORTANCE AIDS-related lymphomas (ARLs) are the most common malignancies in HIV-1-infected (HIV + ) patients after the introduction of combined antiretroviral therapy (cART). Lymphangiogenesis is of critical importance in sustaining growth and metastasis of ARLs. Indeed, enhanced lymphangiogenesis occurs in the lymph nodes of HIV + patients under successful cART. The HIV-1 matrix Protein P17 is detected in blood and accumulates in the lymph node germinal centers even in the absence of virus replication. Several findings suggest a key role for P17 as a microenvironmental factor capable of promoting lymphangiogenesis. Here, we show that P17 promotes lymphangiogenesis of human lymph node-derived lymphatic endothelial cells (LN-LECs). The lymphangiogenic activity of P17 is sustained by an autophagy-based pathway that enables LN-LECs to release prolymphangiogenic factors into the extracellular microenvironment. Our findings indicate that specific targeting of autophagy may provide an important new tool for treating ARLs.
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a single amino acid substitution confers b cell clonogenic activity to the hiv 1 matrix Protein P17
Scientific Reports, 2017Co-Authors: Cinzia Giagulli, Francesca Caccuri, Stefania Marsico, Wangxiao He, Kristen M Varney, Pasqualina Dursi, Simone Zorzan, Alessandro Orro, Benoit Otjacques, Carlo LaudannaAbstract:Recent data highlight the presence, in HIV-1-seropositive patients with lymphoma, of P17 variants (vP17s) endowed with B-cell clonogenicity, suggesting a role of vP17s in lymphomagenesis. We investigated the mechanisms responsible for the functional disparity on B cells between a wild-type P17 (refP17) and a vP17 named S75X. Here, we show that a single Arginine (R) to Glycine (G) mutation at position 76 in the refP17 backbone (P17R76G), as in the S75X variant, is per se sufficient to confer a B-cell clonogenic potential to the viral Protein and modulate, through activation of the PTEN/PI3K/Akt signaling pathway, different molecules involved in apoptosis inhibition (CASP-9, CASP-7, DFF-45, NPM, YWHAZ, Src, PAX2, MAPK8), cell cycle promotion and cancer progression (CDK1, CDK2, CDK8, CHEK1, CHEK2, GSK-3 beta, NPM, PAK1, PP2C-alpha). Moreover, the only R to G mutation at position 76 was found to strongly impact on Protein folding and oligomerization by altering the hydrogen bond network. This generates a conformational shift in the P17 R76G mutant which enables a functional epitope(s), masked in refP17, to elicit B-cell growth-promoting signals after its interaction with a still unknown receptor(s). Our findings offer new opportunities to understand the molecular mechanisms accounting for the B-cell growth-promoting activity of vP17s.
