VIROLOGY

Author: MORILLA VAZQUEZ GABRIEL.
Year: 2003.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The disease is caused by several species of begomovirus: virus DNA chain easily transmitted by the whitefly Bemisia tabaci Genn. In the Mediterranean basin, two species cause disease: Tomato yellow leaf curl virus Sardinia (TYLCSV and Tomato yellow leaf curl virus (TYLCV-Mld). TYLCSV was first described as a causative agent of big losses in southern Spain in the tomato crops in 1992. The second kind virual, TYLCV, was detected in 1997. crops often are tomato plants that are infected by both strains of the virus. order to analyze the potential impact of ocexistencia of these two viruses , became infected in the laboratory tomato plants and N.benthamiana with the two strains. The amount of viral DNA that accumulates was the same as that which occurs in the simple infections. in situ hybridization of tissue was infected showed that the virus was only found in the phloem in the two plant species. This distribution is not changed when the virus injects both on the same floor. proportion of nuclei containing viral DNA was the same in plants infected with TYLCSV, TYLCV or both. Hybridization of nuclei isolated from plants infected with the two viruses, revealed that at least one fifth of the nuclei containing DNA from the two species viral. The high number of co-infected nuclei might explain why recombination between different species of geminivirus is so prevalent. In a second part of the work has been found that plants pepper (Capsicum annuum) collected in cash crops in the province of Almeria, are infected with two strains of TYLCV: TYLCV-Mld (not described earlier in the Iberian Peninsula) and TYLCV. infective clones were obtained from the two strains of the virus and has analyzed the susceptibility of pepper plants, N.benthamiana, beans and tomato to these two viruses mediant. The results indicate that both isolates are capable of infect pepper. in the latter part of the work we have developed a GFP expression cassette containing elements bengomovirus monopartito TYLCSV. With this construction were obtained plants N.benthamiana containing a single copy of the tape consists of a stable in its genome. When these transgenic plants are infected with TYLCSV occur copies extracromosomicas of transgene to be retained as episomas. Forming episomas correlated with a change in the pattern of expression of GFP in these plants. been an increase in the fluorescence green the veins of all the leaves that are above point of inoculation, and in the tissues transport roots and shoots. Therefore, this system could be used to detect replication TYLCSV at the plant, and identify proteins necessary for cell the occurrence of the infection. To confirm this hypothesis we silenced by VIGS PCNA (proliferating cell nuclear antigen). inhibicón of PCNA prevented the change in the expression of GFP, and reduced the accumulation of viruses.

Author: GUIX ARNAU SUSANA.
Year: 2003.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE BIOLOGÍA (ub).
Place of preparation: UNVIERSIDAD DE BARCELONA.

Summary: The astrovirus are some viruses icosaédricos small with a genome RNA monocatenario of positive polarity and 3 patterns open reading (ORF1a and ORF1b for non-structural proteins, and ORF2 for structural proteins). Considered the third leading cause of non-bacterial gastroenteritis in children as in adults. In this thesis, is characterized one of the non-structural proteins of the virus coded by the ORF1a, protein nsP1 / 4. The use of a mouse polyclonal antibody produced in the laboratory against a synthetic peptide corresponding to the region hidrofílica more of the protein, found that the protein nsP1 / 4 has a molecular weight of between 24 and 26 kDa, which accumulates in the region perinuclear colocalizando with the RNA and viral membranes of the endoplasmic reticulum, and that it may suffer multiple changes post-traduccionales by glycosylation and / or phosphorylation. In addition, it also marked the genetic variability of a region hipervariable contained in the protein nsP1 / 4 and the associated variability in different capacities replicating virus, as well as different types of viral particles in the feces of infected children. Therefore, an indirect relationship between a variable nsP1 / 4 and potentially pathogenic viral properties. The main features of this genetic variability were the presence of numerous Gross deletions and insertions that preserve the pattern of reading and a high tolerance to amino acid substitutions. Given the importance of this relationship between the variability of the protein nsP1 / 4 and properties potentially virulent virus, developed a system of diagnosis and typing by RT-PCR and analysis fragment length polymorphism (RFLP) restricted to astrovirus and applied this method in a large-scale epidemiological study over 3 years on the pediatric population in the region of Barcelona. The incidence of astrovirus observed was 4.9% and 3.6% for genogrupos A and B respectively, and the detection rate was highest in children between 2 and 4 years. There was a biannual distribution and an increased incidence of infections astrovirus during the winter months. It was also noted as the incidences of each serotype and each subgenotipo vary each year, suggesting that there is no cross immunity between different serotypes. Finally, we explored some of the relationships that occur between virus and host cell using cell line intestina human CaCo-2 and was seen as a response apoptotic cells developed after infection astrovirus. The characterization of this apoptotic response enabled say that the percentage of apoptotic cells is directly proportional to the multiplicity of infection used and that there is a direct relationship between the expression of non-structural proteins of the virus-encoded by the ORF1a and apoptosis. It identifies a potential domain death domain (DD) in the protein nsP 1a / 4 of the virus. Finally, it identifies the activation of caspase 8 in the induction of apoptosis and presents a model to explain the biological significance of this induction of apoptosis by the virus, suggesting that apoptosis is necessary for proper maturation of proteins the capsid.

Author: TAPIA SECO NATALIA.
Year: 2004.
University: AUTÓNOMA DE BARCELONA [www.uab.es].
Place of defense: HOSPITAL UNIVERSITARI GERMANS TRIAS I PUJOL.
Place of preparation: ESCUELA DE POSTGRADO.

Author: CARMONA HIDALGO ROCÍO.
Year: 2004.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: INSTITUTO DE SALUD CARLOS III.

Summary: This Doctoral thesis demonstrates for the first time the existence and frequency of natural resistance to the new fusion inhibitors in patients infected with different genetic forms of HIV-1 and thus demonstrate the importance of cuasiespecies viral reservoirs variants implicated in response to therapy with new fámacos. It is also noteworthy detection of new mutations in HR2, in addition to those already proven in HR1 and its relationship with virologic failure, suggesting its potential role in the resistance to the drug and pose for the optimization of treatment with inhibitors merger would convenient studying resistance in the same way as is now done in connection with reverse transcriptase inhibitors and protease.

Author: CANO CEJAS IRENE.
Year: 2004.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS - UNIVERSIDAD DE MÁLAGA.

Summary: The disease linfocitis produces epizootic outbreaks in many fish species cultivated among them is the golden (Sparus aurata, L.), one of the most economically important species in the Autonomous Andaluza. The causative agent of this disease is the disease virus linfocsitis (LCDV), a member of the genus Lymphocistivirus, one of four genera currently described in the family Iridoviridae. The detection of LCDV confined to the technical standards cultivation in cell lines, and subsequent identification through viral serological techniques. This methodology has been applied only to confirm the diagnosis in sick fish and seems to have a limited applicability due mainly to its low sensitivity. The objective of this work has been the development and evaluation of diagnostic methods for detecting specific and sensitive LCDV in golden cultivated, and the application of these methods in the study of the pathogenesis of the disease. The detection techniques developed are appropriate for the specific identification of LCDV in sick animals (and inmunoblot in blot hybridization), as for the detection of the virus in asymptomatic carriers (nested-PCR followed by hybridization blot in confirming the diagnosis). The results obtained in studies of the pathogenesis reveal persistent nature of the infection, as well as the prevalence of asymptomatic infections in populations of golden grown. Moreover, it has been determined that the LCDV produces a systemic infection in gold, as evidenced by the detection of the virus in different organs analyzed.

Author: ACOSTA GALLO BELÉN.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE CIENCIAS BIOLÓGICAS.
Place of preparation: UNIVERSIDAD COMPLUTENSE DE MADRID.

Summary: The carbon from the plant biomass is the support of the energy stored continuously biosphere. The social concern for the destruction of forests and the burning of fossil fuels have to do with the depletion of this energy and the release of oxidized carbon to the atmosphere. The carbon must be absorbed by the oceans and continents, but the relative importance of each of these sinks, both its geographical distribution as the mechanisms involved, have not been easy to quantify at this stage. In this context, pastoral systems provide data novel of great interest. The novelty of exploring the interrelationships Reviewed systems pasture Mediterranean is evident, can be compared with other peer systems, such as tropical, for which it has been suggested as an important role as a carbon sink. This study devotes much of its attention to compare aerial and below-ground biomass accumulated in the grassland in different environmental conditions. It was considered a gradient natural water availability, both altitudinal -variación moisture and temperatura- as geomorphological -zonas export and accumulation hillside in the gradiente-. In the cases that have been referred to the grass is the subject of traditional consumption by herbivores and has also simulated the abandonment by his initial pilot exclusion of livestock in all positions and geomorphological heights studied. In grasslands considered in the present study biomass accumulated increases with the decrease of water stress, leading to record more than 50 t / ha. The biomada groundwater is the primary carbon reserves accumulated in the plant performance, representing 90% of the plant biomass. More than 80% of this below-ground biomass is in the top 10 cm of soil.

Author: SIERRA GARCÍA MARÍA.
Year: 2005.
University: COMPLUTENSE DE MADRID [www.ucm.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: AIDS is caused by two retrovirus belonging to the subfamily of the lentivirus, HIV-1 and HIV-2, in which HIV-1 presents worldwide distribution. The virión HIV-1 contains two copies of genomic RNA and viral protein associated with a capsid and surrounded by a lipid embroiled in which they reside viral glycoproteins and the host cell. The high variability presents HIV-1 is due to a combination of several factors which can highlight the high frequency of recombination, which is an intrinsic part of the cycle replicativo of retroviruses because each virión contains two viral genomes that can serve alternately mold for IT during the proviral DNA synthesis. Its importance in the HIV-1 can be seen increasingly with the increasing detection of recombinant forms in multiple geographies. Nine have been defined within the group M subtypes of HIV-1, each of them has a geographical feature, but all except B are represented in Central Africa. In areas where circulating different subtypes of HIV-1, can cause forms recombinant intersubtipo in individuals infected with two or more different virus subtype, which become circulating when individuals are isolated in three different unrelated epidemiological (CRFs). Taking into account the implications of the genetic diversity of HIV-1 in general and recombination in particular, the goals that arise in this Doctoral Thesis are as follows: 1-Analysis of the structures in mosaic virus genomes recombinant intersubtipo BF America (or South American origin) and BG Cuba. 2-Study of potential phylogenetic relationships among themselves and with other recombinant described in the literature. 3-Identifying new ways reconviertes circulating. 4, - Survey of the distribution of recombination points along the genome. 5-Identification of the parent strains of recombinant analyzed. We have analyzed 37 samples: 8 of Brazil, 5 from Argentina, 3 of Chile, 1 in Venezuela, 13 in Cuba and 7 from Spain. The methodology is summarized below: extraction of plasma RNA or DNA from peripheral blood mononuclear cells, amplified by PCr genome nearly complete with 4 fragments solapantes and sequencing. Phylogenetic analysis by the method of bootscanning and phylogenetic trees using MEGA and Puzzle. The phylogenetic analysis of recombinant BF Brazilians indicate a possible origin independent of each doubles infections in individuals with subtype ByF, and who have no connection with the CRF12_BF circulating in Argentina. The recombinant BF of Brazil presents a variable frequency points recombination intersubtipo along the genome, with an increased frequency of recombination in the segment 5 'pol and env minor. The rest of recombinant BF, except for P526, A068 and X1679 are phylogenetically related to the CRF12_BF as evidenced by recombination points in common, clustering in the phylogenetic tree of representatives of subtype F and the presence of nucleotide and amino acids characteristic in this manner. Two of the recombinant analyzed, presented a single recombinant structure, which is similar but not identical to the CRF12_BF, and grouped them in between phylogenetic trees of partial sequences, which could represent a new CRF although it would be necessary to characterize a third with an identical structure to recombinant able to define it. An examination of structures and recombinant lso phylogenetic analysis suggest a model generation recombinant BF (including CRF12_BF) in Argentina and possibly in other countries of Latin America (except Brazil) through recombination with successive virus subtype Bu 8 other r 78b ecombinantes BF along various storylines from a common ancestor, probably of Brazilian origin. The HIV-1 in Cuba is characterized by a wide range of alternatives among which must be emphasized two new CRFs of African origin (CRF18_cpx and CRF19_cpx) and a large number of recombinants unique, in addition to Cubans By G. The results make it possible to identify three new CRFs in Cuba, which have expanded recently in Havana's homosexuals, which have increased from 0% in infections diagnosed in 1999 to 31.4% in those diagnosed in 2003. These three new CRFs are recombinants between subtype B (2 virus) and G (3 viruses), 3 presents 5 points of recombination in common and fall into the phylogenetic tree of partial sequences, indicating a possible common origin. The high genetic diversity of HIV-1 detected in Cuba is unprecedented outside of Central Africa, and makes this country a very appropriate place for the study of the implications of the genetic diversity of HIV-1 including recombination, pathogenesis, transmission , protective immune responses and responses to antiretroviral therapy.

Author: RICO TORTOSA PATRICIA MARÍA.
Year: 2006.
University: POLITÉCNICA DE VALENCIA [www.upv.es].
Place of defense: Dep. Biotecnologia.
Place of preparation: Universidad Politécnica de Valencia.

Summary: The overall aim of this thesis has been to review relations estructura-función the virus breaking the color of the flower of Pelargonium (Pelargonium flower break viruses, PFBV), one of the viral pathogens most prevailing species of the genus Pelargonium. As a first step in carrying out this analysis it was determined the complete nucleotide sequence of RNA viral genomic (gRNA), which consists of 3923 nucleotides (nt) and contains five open reading patterns (ORFs). The ORF closer to the extreme 5 ', ORF1, encodes a protein of 27 kDa and ends with an amber codon reading through which to continue the translation to the stop codon of ORF2 resulting in a protein of 86 kDa that contains the reasons preserved the RNA polymerases RNA-dependientes viral (RdRps). Two small ORFs, located in the central part of the viral genome, encode polypeptides of 7 (p7) and 12 kDa (p12), respectively, which are presumably involved in the movement viral. Significantly, the p12 presents a cause for rack of leucinas which has not been previously described in related proteins. The ORF 3'-proximal encodes a protein of 37 kDa cover viral (COP). The gene of p12 is the same pattern of reading that the ORF that leads to p86, which could happen by a dual process of reading through that would lead to a protein of 99 kDa (p99). A comparative analysis of sequences showed that the p86, p7 and p12 showed higher homology with equivalent products from the Carnation mottle virus (Carnation mottle virus), which with other carmovirus, while the p27 and COP resembled more a protein associated virus Saguaro cactus (Saguaro cactus viruses). The resulting phylogenetic analysis confirmed secondment final PFBV gender Carmovirus.

Author: VEGA MARTIN LAUREANO DE LA.
Year: 2006.
University: CÓRDOBA [www.uco.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA.

Summary: In this thesis we have addressed the problem of viral latency, seeking new cellular proteins involved in the establishment and maintenance of dormancy. Here we present protein cutting and oliadenilación CPSF3 as a new transcriptional repressor of HIV-1. We have described this new repressor activity of the protein and a new site interaction CPSF3 with modulating the promoter region of HIV, we are proposing is responsible for its repressor activity. This new activity is found both in transient transfections as a model of viral latency in which the virus is integrated and permanently idle. Since it is described that the viral Tat protein increases the expression of CPSF3, we studied the ability of Tat to regulate this new activity, seeing that in the presence of Tat lost repression mediated CPSF3. It also explores the physical interaction between CPSF3 and viral protein Tat. Also present protein HIVEP-3 and its role as a repressor of transcription of HIV-1, regardless of his well-known ability to join sites B.