The Experts below are selected from a list of 20856 Experts worldwide ranked by ideXlab platform
Ramsés Reina - One of the best experts on this subject based on the ideXlab platform.
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Post-entry blockade of Small Ruminant lentiviruses by wild Ruminants
Veterinary Research, 2016Co-Authors: Leticia Sanjosé, Giuseppe Bertoni, E Berriatua, Idoia Glaria, Helena Crespo, Damián De Andrés, Beatriz Amorena, Laure Blatti-cardinaux, Carlos Martínez-carrasco, Ramsés ReinaAbstract:Small Ruminant lentivirus (SRLV) infection causes losses in the Small Ruminant industry due to reduced animal production and increased replacement rates. Infection of wild Ruminants in close contact with infected domestic animals has been proposed to play a role in SRLV epidemiology, but studies are limited and mostly involve hybrids between wild and domestic animals. In this study, SRLV seropositive red deer, roe deer and mouflon were detected through modified ELISA tests, but virus was not successfully amplified using a set of different PCRs. Apparent restriction of SRLV infection in cervids was not related to the presence of neutralizing antibodies. In vitro cultured skin fibroblastic cells from red deer and fallow deer were permissive to the SRLV entry and integration, but produced low quantities of virus. SRLV got rapidly adapted in vitro to blood-derived macrophages and skin fibroblastic cells from red deer but not from fallow deer. Thus, although direct detection of virus was not successfully achieved in vivo, these findings show the potential susceptibility of wild Ruminants to SRLV infection in the case of red deer and, on the other hand, an in vivo SRLV restriction in fallow deer. Altogether these results may highlight the importance of surveilling and controlling SRLV infection in domestic as well as in wild Ruminants sharing pasture areas, and may provide new natural tools to control SRLV spread in sheep and goats.
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Small Ruminant lentivirus infections and diseases
Veterinary Microbiology, 2015Co-Authors: E. Minguijón, I. Leginagoikoa, M. Villoria, Ramsés Reina, Hugo Ramírez, M Perez, L Polledo, Juan Jose Badiola, J F Garciamarin, D De AndresAbstract:Small Ruminant lentiviruses include viruses with diverse genotypes that frequently cross the species barrier between sheep and goats and that display a great genetic variability. These characteristics stress the need to consider the whole host range and to perform local surveillance of the viruses to opt for optimum diagnostic tests, in order to establish control programmes. In the absence of effective vaccines, a comprehensive knowledge of the epidemiology of these infections is of major importance to limit their spread. This article intends to cover these aspects and to summarise information related to characteristics of the viruses, pathogenesis of the infection and description of the various syndromes produced, as well as the diagnostic tools available, the mechanisms involved in transmission of the pathogens and, finally, the control strategies that have been designed until now, with remarks on the drawbacks and the advantages of each one. We conclude that there are many variables influencing the expected cost and benefits of control programs that must be evaluated, in order to put into practice measures that might lead to control of these infections.
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Small Ruminant macrophage polarization may play a pivotal role on lentiviral infection
Veterinary Research, 2013Co-Authors: Helena Crespo, Idoia Glaria, Luigi Bertolotti, Magda Juganaru, Damián De Andrés, Beatriz Amorena, Sergio Rosati, Ramsés ReinaAbstract:Small Ruminant lentiviruses (SRLV) infect the monocyte/macrophage lineage inducing a long-lasting infection affecting body condition, production and welfare of sheep and goats all over the world. Macrophages play a pivotal role on the host’s innate and adaptative immune responses against parasites by becoming differentially activated. Macrophage heterogeneity can tentatively be classified into classically differentiated macrophages (M1) through stimulation with IFN-γ displaying an inflammatory profile, or can be alternatively differentiated by stimulation with IL-4/IL-13 into M2 macrophages with homeostatic functions. Since infection by SRLV can modulate macrophage functions we explored here whether ovine and caprine macrophages can be segregated into M1 and M2 populations and whether this differential polarization represents differential susceptibility to SRLV infection. We found that like in human and mouse systems, ovine and caprine macrophages can be differentiated with particular stimuli into M1/M2 subpopulations displaying specific markers. In addition, Small Ruminant macrophages are plastic since M1 differentiated macrophages can express M2 markers when the stimulus changes from IFN-γ to IL-4. SRLV replication was restricted in M1 macrophages and increased in M2 differentiated macrophages respectively according to viral production. Identification of the infection pathways in macrophage populations may provide new targets for eliciting appropriate immune responses against SRLV infection.
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Small Ruminant lentiviruses genetic variability tropism and diagnosis
Viruses, 2013Co-Authors: Hugo Ramírez, Ramsés Reina, Damián De Andrés, Beatriz Amorena, Humberto A MartinezAbstract:Small Ruminant lentiviruses (SRLV) cause a multisystemic chronic disease affecting animal production and welfare. SRLV infections are spread across the world with the exception of Iceland. Success in controlling SRLV spread depends largely on the use of appropriate diagnostic tools, but the existence of a high genetic/antigenic variability among these viruses, the fluctuant levels of antibody against them and the low viral loads found in infected individuals hamper the diagnostic efficacy. SRLV have a marked in vivo tropism towards the monocyte/macrophage lineage and attempts have been made to identify the genome regions involved in tropism, with two main candidates, the LTR and env gene, since LTR contains primer binding sites for viral replication and the env-encoded protein (SU ENV), which mediates the binding of the virus to the host’s cell and has hypervariable regions to escape the humoral immune response. Once inside the host cell, innate immunity may interfere with SRLV replication, but the virus develops counteraction mechanisms to escape, multiply and survive, creating a quasi-species and undergoing compartmentalization events. So far, the mechanisms of organ tropism involved in the development of different disease forms (neurological, arthritic, pulmonary and mammary) are unknown, but different alternatives are proposed. This is an overview of the current state of knowledge on SRLV genetic variability and its implications in tropism as well as in the development of alternative diagnostic assays.
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Mannose receptor may be involved in Small Ruminant lentivirus pathogenesis
Veterinary Research, 2012Co-Authors: Helena Crespo, Idoia Glaria, Damián De Andrés, Beatriz Amorena, Leticia Sanjosé, L Polledo, Paula Jauregui, Juan F García-marín, Lluís Luján, Ramsés ReinaAbstract:Thirty-one sheep naturally infected with Small Ruminant lentiviruses (SRLV) of known genotype (A or B), and clinically affected with neurological disease, pneumonia or arthritis were used to analyse mannose receptor (MR) expression (transcript levels) and proviral load in virus target tissues (lung, mammary gland, CNS and carpal joints). Control sheep were SRLV-seropositive asymptomatic ( n = 3), seronegative ( n = 3) or with chronic listeriosis, pseudotuberculosis or parasitic cysts ( n = 1 in each case). MR expression and proviral load increased with the severity of lesions in most analyzed organs of the SRLV infected sheep and was detected in the affected tissue involved in the corresponding clinical disease (CNS, lung and carpal joint in neurological disease, pneumonia and arthritis animal groups, respectively). The increased MR expression appeared to be SRLV specific and may have a role in lentiviral pathogenesis.
Sergio Rosati - One of the best experts on this subject based on the ideXlab platform.
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Small Ruminant macrophage polarization may play a pivotal role on lentiviral infection
Veterinary Research, 2013Co-Authors: Helena Crespo, Idoia Glaria, Luigi Bertolotti, Magda Juganaru, Damián De Andrés, Beatriz Amorena, Sergio Rosati, Ramsés ReinaAbstract:Small Ruminant lentiviruses (SRLV) infect the monocyte/macrophage lineage inducing a long-lasting infection affecting body condition, production and welfare of sheep and goats all over the world. Macrophages play a pivotal role on the host’s innate and adaptative immune responses against parasites by becoming differentially activated. Macrophage heterogeneity can tentatively be classified into classically differentiated macrophages (M1) through stimulation with IFN-γ displaying an inflammatory profile, or can be alternatively differentiated by stimulation with IL-4/IL-13 into M2 macrophages with homeostatic functions. Since infection by SRLV can modulate macrophage functions we explored here whether ovine and caprine macrophages can be segregated into M1 and M2 populations and whether this differential polarization represents differential susceptibility to SRLV infection. We found that like in human and mouse systems, ovine and caprine macrophages can be differentiated with particular stimuli into M1/M2 subpopulations displaying specific markers. In addition, Small Ruminant macrophages are plastic since M1 differentiated macrophages can express M2 markers when the stimulus changes from IFN-γ to IL-4. SRLV replication was restricted in M1 macrophages and increased in M2 differentiated macrophages respectively according to viral production. Identification of the infection pathways in macrophage populations may provide new targets for eliciting appropriate immune responses against SRLV infection.
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in vitro properties of Small Ruminant lentivirus genotype e
Virology, 2011Co-Authors: Magda Juganaru, Ramsés Reina, Luigi Bertolotti, Beatriz Amorena, Margherita Profiti, Maria Cristina Stella, M Armentano, E Bollo, Sergio RosatiAbstract:Abstract Small Ruminant lentivirus genotype E lacks the dUTPase subunit and vpr-like gene. Two strains (Roccaverano and Seui) with identical genetic organization have been described, with the env HV1–HV2 domains being the most divergent. Although dUTPase and vpr-like deletions have been involved in the RT fidelity in non dividing cells, both strains were able to replicate efficiently in blood derived macrophages (BDM), while virus production of E1 subtype was reduced or abrogated in replicating fibroblastic-like cells. The transcriptional activity of genotype E was similar in these two cellular populations. When viral pseudotypes were generated with the env of both viruses, Roccaverano pseudotype displayed a paranuclear localization on BDM, suggesting a different mechanism of entry. Polymorphic GAS and TAS sites in the U3 region, further suggest that a population different from classically activated macrophages can be infected by these viruses, opening new insights into lentiviruses with low or null pathogenic potential.
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Development of specific diagnostic test for Small Ruminant lentivirus genotype E
Veterinary Microbiology, 2009Co-Authors: Ramsés Reina, Idoia Glaria, Beatriz Amorena, Elena Grego, Margherita Profiti, Patrizia Robino, Antonio Quasso, Sergio RosatiAbstract:Small Ruminant lentivirus (SRLV) belonging to the highly divergent genotype E has recently been identified in the Italian goat breed Roccaverano. In this report we have developed a specific serological test based on recombinant matrix/capsid antigen fusion protein. Performance has been evaluated and compared with a similar test based on genotype B antigen. Herds under study were selected according to the infectious status characterized by blood PCR and sequencing. Results clearly showed that B and E based recombinant ELISA only detected homologous infection and an apparent cross-reactivity was recorded in a herd in which co-infection was present. Three commercially available ELISAs showed different abilities in detecting genotype E infection, being the whole virus-based immunoassay the best choice. Genotype E-recombinant antigen was not detected in ELISA by three commercially available Mabs known to be cross-reactive among CAEV and MVV capsid antigens, further supporting the high divergence of the E genotype from others. Finally, a SRLV-free herd according to commercial ELISA testing, was analysed in the same area where genotype E was identified and few animals belonging to Roccaverano breed were found slightly reactive with the E antigens. Our results suggest that the prevalence of genotype E in other Small Ruminant populations may be conveniently estimated using a comparative assay based on a combination of genotype specific recombinant antigens and may highlight a wider space in which SRLVs evolve.
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genetic heterogeneity of Small Ruminant lentiviruses involves immunodominant epitope of capsid antigen and affects sensitivity of single strain based immunoassay
Clinical and Vaccine Immunology, 2002Co-Authors: Elena Grego, Margherita Profiti, Monica Giammarioli, Laura Giannino, D Rutili, C J Woodall, Sergio RosatiAbstract:The pol and gag gene fragments of Small Ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed. Phylogenetic analysis revealed that the majority of ovine isolates form a distinct cluster more similar to caprine lentivirus prototypes than to the visna virus prototype. These findings confirm and extend those reported by Leroux et al. (Arch. Virol., 142:1125-1137, 1997). Moreover, we observed that a variable region of Gag, included in the fragment analyzed, corresponded to one of the three major capsid antigen epitopes, which suggests that the antibody response to this epitope may be type specific. To test this hypothesis, two recombinant peptides, derived from the Icelandic prototype K1514 and this novel genotype, were expressed and used in an enzyme-linked immunosorbent assay to screen a panel of ovine and caprine sera collected from different geographical locations in Italy. Several sera reacted in a type-specific manner, indicating that in a diagnostic setting the combination of at least these two type-specific peptides is necessary to cover a wide range of infections. Additionally, these results support the hypothesis of cross-species transmission based on the phylogenetic analysis described above. This has implications for the control and eradication of Small Ruminant lentivirus infections.
Beatriz Amorena - One of the best experts on this subject based on the ideXlab platform.
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Post-entry blockade of Small Ruminant lentiviruses by wild Ruminants
Veterinary Research, 2016Co-Authors: Leticia Sanjosé, Giuseppe Bertoni, E Berriatua, Idoia Glaria, Helena Crespo, Damián De Andrés, Beatriz Amorena, Laure Blatti-cardinaux, Carlos Martínez-carrasco, Ramsés ReinaAbstract:Small Ruminant lentivirus (SRLV) infection causes losses in the Small Ruminant industry due to reduced animal production and increased replacement rates. Infection of wild Ruminants in close contact with infected domestic animals has been proposed to play a role in SRLV epidemiology, but studies are limited and mostly involve hybrids between wild and domestic animals. In this study, SRLV seropositive red deer, roe deer and mouflon were detected through modified ELISA tests, but virus was not successfully amplified using a set of different PCRs. Apparent restriction of SRLV infection in cervids was not related to the presence of neutralizing antibodies. In vitro cultured skin fibroblastic cells from red deer and fallow deer were permissive to the SRLV entry and integration, but produced low quantities of virus. SRLV got rapidly adapted in vitro to blood-derived macrophages and skin fibroblastic cells from red deer but not from fallow deer. Thus, although direct detection of virus was not successfully achieved in vivo, these findings show the potential susceptibility of wild Ruminants to SRLV infection in the case of red deer and, on the other hand, an in vivo SRLV restriction in fallow deer. Altogether these results may highlight the importance of surveilling and controlling SRLV infection in domestic as well as in wild Ruminants sharing pasture areas, and may provide new natural tools to control SRLV spread in sheep and goats.
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Small Ruminant macrophage polarization may play a pivotal role on lentiviral infection
Veterinary Research, 2013Co-Authors: Helena Crespo, Idoia Glaria, Luigi Bertolotti, Magda Juganaru, Damián De Andrés, Beatriz Amorena, Sergio Rosati, Ramsés ReinaAbstract:Small Ruminant lentiviruses (SRLV) infect the monocyte/macrophage lineage inducing a long-lasting infection affecting body condition, production and welfare of sheep and goats all over the world. Macrophages play a pivotal role on the host’s innate and adaptative immune responses against parasites by becoming differentially activated. Macrophage heterogeneity can tentatively be classified into classically differentiated macrophages (M1) through stimulation with IFN-γ displaying an inflammatory profile, or can be alternatively differentiated by stimulation with IL-4/IL-13 into M2 macrophages with homeostatic functions. Since infection by SRLV can modulate macrophage functions we explored here whether ovine and caprine macrophages can be segregated into M1 and M2 populations and whether this differential polarization represents differential susceptibility to SRLV infection. We found that like in human and mouse systems, ovine and caprine macrophages can be differentiated with particular stimuli into M1/M2 subpopulations displaying specific markers. In addition, Small Ruminant macrophages are plastic since M1 differentiated macrophages can express M2 markers when the stimulus changes from IFN-γ to IL-4. SRLV replication was restricted in M1 macrophages and increased in M2 differentiated macrophages respectively according to viral production. Identification of the infection pathways in macrophage populations may provide new targets for eliciting appropriate immune responses against SRLV infection.
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Small Ruminant lentiviruses genetic variability tropism and diagnosis
Viruses, 2013Co-Authors: Hugo Ramírez, Ramsés Reina, Damián De Andrés, Beatriz Amorena, Humberto A MartinezAbstract:Small Ruminant lentiviruses (SRLV) cause a multisystemic chronic disease affecting animal production and welfare. SRLV infections are spread across the world with the exception of Iceland. Success in controlling SRLV spread depends largely on the use of appropriate diagnostic tools, but the existence of a high genetic/antigenic variability among these viruses, the fluctuant levels of antibody against them and the low viral loads found in infected individuals hamper the diagnostic efficacy. SRLV have a marked in vivo tropism towards the monocyte/macrophage lineage and attempts have been made to identify the genome regions involved in tropism, with two main candidates, the LTR and env gene, since LTR contains primer binding sites for viral replication and the env-encoded protein (SU ENV), which mediates the binding of the virus to the host’s cell and has hypervariable regions to escape the humoral immune response. Once inside the host cell, innate immunity may interfere with SRLV replication, but the virus develops counteraction mechanisms to escape, multiply and survive, creating a quasi-species and undergoing compartmentalization events. So far, the mechanisms of organ tropism involved in the development of different disease forms (neurological, arthritic, pulmonary and mammary) are unknown, but different alternatives are proposed. This is an overview of the current state of knowledge on SRLV genetic variability and its implications in tropism as well as in the development of alternative diagnostic assays.
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Mannose receptor may be involved in Small Ruminant lentivirus pathogenesis
Veterinary Research, 2012Co-Authors: Helena Crespo, Idoia Glaria, Damián De Andrés, Beatriz Amorena, Leticia Sanjosé, L Polledo, Paula Jauregui, Juan F García-marín, Lluís Luján, Ramsés ReinaAbstract:Thirty-one sheep naturally infected with Small Ruminant lentiviruses (SRLV) of known genotype (A or B), and clinically affected with neurological disease, pneumonia or arthritis were used to analyse mannose receptor (MR) expression (transcript levels) and proviral load in virus target tissues (lung, mammary gland, CNS and carpal joints). Control sheep were SRLV-seropositive asymptomatic ( n = 3), seronegative ( n = 3) or with chronic listeriosis, pseudotuberculosis or parasitic cysts ( n = 1 in each case). MR expression and proviral load increased with the severity of lesions in most analyzed organs of the SRLV infected sheep and was detected in the affected tissue involved in the corresponding clinical disease (CNS, lung and carpal joint in neurological disease, pneumonia and arthritis animal groups, respectively). The increased MR expression appeared to be SRLV specific and may have a role in lentiviral pathogenesis.
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in vitro properties of Small Ruminant lentivirus genotype e
Virology, 2011Co-Authors: Magda Juganaru, Ramsés Reina, Luigi Bertolotti, Beatriz Amorena, Margherita Profiti, Maria Cristina Stella, M Armentano, E Bollo, Sergio RosatiAbstract:Abstract Small Ruminant lentivirus genotype E lacks the dUTPase subunit and vpr-like gene. Two strains (Roccaverano and Seui) with identical genetic organization have been described, with the env HV1–HV2 domains being the most divergent. Although dUTPase and vpr-like deletions have been involved in the RT fidelity in non dividing cells, both strains were able to replicate efficiently in blood derived macrophages (BDM), while virus production of E1 subtype was reduced or abrogated in replicating fibroblastic-like cells. The transcriptional activity of genotype E was similar in these two cellular populations. When viral pseudotypes were generated with the env of both viruses, Roccaverano pseudotype displayed a paranuclear localization on BDM, suggesting a different mechanism of entry. Polymorphic GAS and TAS sites in the U3 region, further suggest that a population different from classically activated macrophages can be infected by these viruses, opening new insights into lentiviruses with low or null pathogenic potential.
Michael L Clawson - One of the best experts on this subject based on the ideXlab platform.
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complete genome sequences of two genotype a2 Small Ruminant lentiviruses isolated from infected u s sheep
Genome Announcements, 2017Co-Authors: Aspen M Workman, Aaron M Dickey, Michael P Heaton, Michael L Clawson, Timothy P L SmithAbstract:ABSTRACT Two distinct subgroups of genotype A2 Small Ruminant lentiviruses (SRLVs) have been identified in the United States that infect sheep with specific host transmembrane protein 154 (TMEM154) diplotypes. Here, we report the first two complete genome sequences of SRLV strains infecting U.S. sheep belonging to genotype A2, subgroups 1 and 2.
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Genetic subgroup of Small Ruminant lentiviruses that infects sheep homozygous for TMEM154 frameshift deletion mutation A4^Δ53
Veterinary Research, 2015Co-Authors: Michael L Clawson, Michael P Heaton, Timothy P L Smith, Reid Redden, Gennie Schuller, Aspen Workman, Carol G Chitko-mckown, Kreg A LeymasterAbstract:Small Ruminant lentivirus (SRLV) infections of sheep are influenced by genetics on both the host and pathogen sides. Genetic variation in the ovine transmembrane 154 ( TMEM154 ) gene associates with infection susceptibility, and distinct SRLV genetic subgroups infect sheep in association with their TMEM154 diplotypes. In this study, a novel SRLV subgroup was identified that naturally infected sheep with various TMEM154 diplotypes, including those homozygous for a rare frameshift mutation (A4 delta53), which is predicted to abolish TMEM154 protein function. Thus, these SRLVs may infect sheep that lack functional TMEM154, and may not be restricted by TMEM154 diplotypes in establishing infections.
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Small Ruminant lentivirus genetic subgroups associate with sheep TMEM154 genotypes
Veterinary Research, 2013Co-Authors: Lucia H Sider, Michael P Heaton, Timothy P L Smith, Carol G Chitko-mckown, Kreg A Leymaster, Greg P Harhay, William W Laegreid, Michael L ClawsonAbstract:Small Ruminant lentiviruses (SRLVs) are prevalent in North American sheep and a major cause of production losses for the U.S. sheep industry. Sheep susceptibility to SRLV infection is influenced by genetic variation within the ovine transmembrane 154 gene ( TMEM154 ). Animals with either of two distinct TMEM154 haplotypes that both encode glutamate at position 35 of the protein (E35) are at greater risk of SRLV infection than those homozygous with a lysine (K35) haplotype. Prior to this study, it was unknown if TMEM154 associations with infection are influenced by SRLV genetic subgroups. Accordingly, our goals were to characterize SRLVs naturally infecting sheep from a diverse U.S. Midwestern flock and test them for associations with TMEM154 E35K genotypes. Two regions of the SRLV genome were targeted for proviral amplification, cloning, sequence analysis, and association testing with TMEM154 E35K genotypes: gag and the transmembrane region of env . Independent analyses of gag and env sequences showed that they clustered in two subgroups (1 and 2), they were distinct from SRLV subtypes originating from Europe, and that subgroup 1 associated with hemizygous and homozygous TMEM154 K35 genotypes and subgroup 2 with hemi- and homozygous E35 genotypes ( gag p < 0.001, env p = 0.01). These results indicate that SRLVs in the U.S. have adapted to infect sheep with specific TMEM154 E35K genotypes. Consequently, both host and SRLV genotypes affect the relative risk of SRLV infection in sheep.
Margherita Profiti - One of the best experts on this subject based on the ideXlab platform.
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in vitro properties of Small Ruminant lentivirus genotype e
Virology, 2011Co-Authors: Magda Juganaru, Ramsés Reina, Luigi Bertolotti, Beatriz Amorena, Margherita Profiti, Maria Cristina Stella, M Armentano, E Bollo, Sergio RosatiAbstract:Abstract Small Ruminant lentivirus genotype E lacks the dUTPase subunit and vpr-like gene. Two strains (Roccaverano and Seui) with identical genetic organization have been described, with the env HV1–HV2 domains being the most divergent. Although dUTPase and vpr-like deletions have been involved in the RT fidelity in non dividing cells, both strains were able to replicate efficiently in blood derived macrophages (BDM), while virus production of E1 subtype was reduced or abrogated in replicating fibroblastic-like cells. The transcriptional activity of genotype E was similar in these two cellular populations. When viral pseudotypes were generated with the env of both viruses, Roccaverano pseudotype displayed a paranuclear localization on BDM, suggesting a different mechanism of entry. Polymorphic GAS and TAS sites in the U3 region, further suggest that a population different from classically activated macrophages can be infected by these viruses, opening new insights into lentiviruses with low or null pathogenic potential.
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Development of specific diagnostic test for Small Ruminant lentivirus genotype E
Veterinary Microbiology, 2009Co-Authors: Ramsés Reina, Idoia Glaria, Beatriz Amorena, Elena Grego, Margherita Profiti, Patrizia Robino, Antonio Quasso, Sergio RosatiAbstract:Small Ruminant lentivirus (SRLV) belonging to the highly divergent genotype E has recently been identified in the Italian goat breed Roccaverano. In this report we have developed a specific serological test based on recombinant matrix/capsid antigen fusion protein. Performance has been evaluated and compared with a similar test based on genotype B antigen. Herds under study were selected according to the infectious status characterized by blood PCR and sequencing. Results clearly showed that B and E based recombinant ELISA only detected homologous infection and an apparent cross-reactivity was recorded in a herd in which co-infection was present. Three commercially available ELISAs showed different abilities in detecting genotype E infection, being the whole virus-based immunoassay the best choice. Genotype E-recombinant antigen was not detected in ELISA by three commercially available Mabs known to be cross-reactive among CAEV and MVV capsid antigens, further supporting the high divergence of the E genotype from others. Finally, a SRLV-free herd according to commercial ELISA testing, was analysed in the same area where genotype E was identified and few animals belonging to Roccaverano breed were found slightly reactive with the E antigens. Our results suggest that the prevalence of genotype E in other Small Ruminant populations may be conveniently estimated using a comparative assay based on a combination of genotype specific recombinant antigens and may highlight a wider space in which SRLVs evolve.
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Serological characterization of the new genotype E of Small Ruminant lentivirus in roccaverano goat flocks
Veterinary Research Communications, 2009Co-Authors: Elena Grego, Margherita Profiti, D. Lacerenza, R. Reina Arias, S. RosatiAbstract:Maedi visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) are a heterogeneous group of infectious agents affecting sheep and goats. Due to their natural cross-species infection they are referred to as Small-Ruminant lentiviruses (SRLV). Recently a new genetic cluster, highly divergent from MVV and CAEV was identified in the north-west part of Italy. A panel of genotype E specific antigens was developed and evaluated in flocks infected with B1 and E strains. The results clearly indicate that a strain specific antigen is required to correctly identify animals infected with different genotypes.
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genetic heterogeneity of Small Ruminant lentiviruses involves immunodominant epitope of capsid antigen and affects sensitivity of single strain based immunoassay
Clinical and Vaccine Immunology, 2002Co-Authors: Elena Grego, Margherita Profiti, Monica Giammarioli, Laura Giannino, D Rutili, C J Woodall, Sergio RosatiAbstract:The pol and gag gene fragments of Small Ruminant lentivirus field isolates collected in the last decade in Italy were amplified, sequenced, and analyzed. Phylogenetic analysis revealed that the majority of ovine isolates form a distinct cluster more similar to caprine lentivirus prototypes than to the visna virus prototype. These findings confirm and extend those reported by Leroux et al. (Arch. Virol., 142:1125-1137, 1997). Moreover, we observed that a variable region of Gag, included in the fragment analyzed, corresponded to one of the three major capsid antigen epitopes, which suggests that the antibody response to this epitope may be type specific. To test this hypothesis, two recombinant peptides, derived from the Icelandic prototype K1514 and this novel genotype, were expressed and used in an enzyme-linked immunosorbent assay to screen a panel of ovine and caprine sera collected from different geographical locations in Italy. Several sera reacted in a type-specific manner, indicating that in a diagnostic setting the combination of at least these two type-specific peptides is necessary to cover a wide range of infections. Additionally, these results support the hypothesis of cross-species transmission based on the phylogenetic analysis described above. This has implications for the control and eradication of Small Ruminant lentivirus infections.
