Variabilidade genética do vírus da leucemia viral felina (FeLV) e avaliação de fatores virais e do hospedeiro na infecção pelos vírus da imunodeficiência felina (FIV) e FeLV

Os retrovírus são patógenos mundialmente distribuídos com grande importância na medicina veterinária e humana. Em felinos domésticos existem dois retrovírus que causam doenças: o vírus de leucemia felina (FeLV) e o vírus da imunodeficiência felina (FIV). Tanto o FIV quanto o FeLV estão associado a síndromes imunossupressoras, apresentação de doenças oportunistas e desenvolvimento de tumores. O FeLV é uma das principais causas de doença e morte em gatos, sendo assim mais patogênico do que o FIV. Muitos aspectos importantes da patogênese do FeLV ainda não foram elucidados, mas sabe-se que o curso da doença desenvolvida varia entre indivíduos. Esta variação é determinada por fatores tanto virais quanto do próprio hospedeiro. Sobre o vírus, informações sobre variantes específicas são muitas vezes suficientes para prever o resultado da doença. Além disso, no caso dos retrovírus, a proteína do envelope é um fator chave que define o subtipo ou subgrupo viral. A glicoproteína do envelope possui duas subunidades: superfície (SU) e transmembrana (TM). A glicoproteína de superfície determina o tropismo celular e é estruturalmente conformada por regiões conservadas e variáveis que são importantes na interação vírus-células. Para estabelecer uma infecção eficiente, os retrovírus precisam neutralizar a atividade de diversas proteínas celulares, conhecidas como fatores de restrição, através de proteínas virais que interferem ou suprimem a dita atividade. Além disso, os fatores de restrição determinam em parte o repertório de hospedeiros e assim limitam a transmissão entre espécies. Os fatores de restrição são menos eficientes contra os vírus do hospedeiro natural. A tese apresenta dois estudos que visam contribuir para a compreensão do FeLV. O primeiro trabalho é um estudo in sílico de bioinformática e filogenética do gene de superfície do envelope (SU) onde propõe-se um método altamente suportado para a classificação genética do FeLV. O segundo trabalho é um trabalho in vitro sobre o efeito do fator de restrição SERINC5 humano e felino (huSER5 e feSER5) sobre a infecciosidade do vírus da imunodeficiência humana – 1 (HIV-1), FIV e FeLV. Além disso, foi avaliada a capacidade de contra atacar o efeito inibitório das SER5s pelas proteínas virais Nef do HIV-1, glycoGag e Env do FeLV-A e do FeLV-B.Retroviruses are globally distributed pathogens with great importance in veterinary and human medicine. In domestic cats there are two retroviruses that cause disease: feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV). Both FIV and FeLV are associated with immunosuppressive syndromes, opportunistic diseases and tumors development. FeLV is a major cause of disease and death in cats and thus is more pathogenic than FIV. Many important aspects of the pathogenesis of FeLV remain to be unveiled, but it is known that the course of the disease varies between individuals. This variation is determined by both viral and host factors. Viral aspects, such as information on specific variants is often sufficient to predict the outcome of the disease. Furthermore, in retroviruses the envelope protein is a key factor defining the viral subtype or subgroup. The envelope glycoprotein possesses two subunits: surface (SU) and transmembrane (TM). The surface glycoprotein determines cell tropism and is structurally conformed by conserved and variable regions that are important in the virus-cell interaction. To establish an efficient infection, retroviruses need to neutralize the activity of several cellular proteins known as restriction factors. Viral proteins are capable of interfere with or suppress these host mechanisms. In addition, restriction factors partly determine the host repertoire and thus limit transmission between species. However, restriction factors are less efficient against natural host viruses. This thesis presents two studies that aim at contributing to the understanding of FeLV. The first work is a bioinformatics and phylogenetic study in silico of the envelope surface gene (SU). This paper proposes a highly supported method for genetic classification of FeLV. The second work is an in vitro study on the effect of the restriction factors human and the feline SERINC5 (huSER5 and feSER5) on the human immunodeficiency virus-1 (HIV-1), FIV and FeLV infectivity. In addition, the ability to counteract the inhibitory effect of SER5s by the viral proteins Nef from HIV-1, glycoGag and Env from FeLV-A and FeLV-B was studied

Filodinâmica do vírus da imunodeficiência felina no Brasil e análise de sequências dos genes virais VIF e ENV e do gene A3Z3 em felinos domésticos naturalmente infectados na cidade de Porto Alegre

O vírus da imunodeficiência felina (FIV), membro da família Retroviridae, é um vírus mundialmente distribuído em gatos domésticos. Até o momento foram descritos sete subtipos de FIV em várias regiões do mundo. No Brasil, os estudos revelam a presença unicamente do subtipo B do FIV (FIV-B). Entretanto, o baixo número de sequências genômicas disponíveis nos bancos de dados dificulta a realização de estudos filogenéticos. Com a finalidade de compreender melhor alguns aspectos da epidemiologia molecular de FIV, trinta e uma amostras de gatos positivos para FIV, coletadas entre 2012 e 2016 no município de Porto Alegre-RS, foram submetidas à amplificação e sequenciamento da região C5-V4 do gene env, importante na subtipificação viral. Todas as sequências obtidas pertencem ao FIV-B. No entanto, 4 sequências (13 %) apresentaram um grupamento diferente das demais, confirmando a ocorrência de eventos de recombinação. Além disso, observou-se a existência de cinco clados altamente suportados nas sequências brasileiras, sugerindo cinco eventos independentes de introdução do vírus no Brasil. Por fim, os resultados obtidos sugerem que a epidemia de FIV-B se remonta a 1942 e, no Brasil, as cinco entradas do vírus aconteceram entre 1981-1991. Além disso, foi feita uma análise visando compreender a relação entre a frequência de mutações nos genes env e vif do FIV e gene A3Z3 do hospedeiro, um importante fator de restrição que induz hipermutações no vírus. Foram identificados 5 dos 7 haplótipos no gene A3Z3 descritos previamente e se encontrou um baixo ou indetectável nível de hipermutações nos genes virais analisados.Feline immunodeficiency virus (FIV), a member of the Retroviridae family, is a widespread virus in domestic cats. To date, seven FIV subtypes have been described in different regions of the world. In Brazil, the studies show only the presence of FIV subtype B (FIV-B). However, the low number of available genomic sequences in the databases is a challenge for phylogenetic studies. In order to better understand some aspects of the molecular epidemiology of FIV, thirty-one samples of FIV positive cats collected between 2012 and 2016 in Porto Alegre-RS, were submitted to amplification and sequencing of the C5-V4 region of the env gene, used to viral subtyping. All sequences obtained belong to FIV-B. However, 4 sequences (13%) presented a different grouping pattern when compared to other sequences, confirming the occurrence of recombination events. In addition, we observed the existence of five clades highly supported in the Brazilian sequences, suggesting five independent events of introduction of the virus in Brazil. Finally, the results obtained suggest that the FIV-B epidemic dates back to 1942 and, in Brazil, the five entries of the virus occurred from 1981 to 1991. In addition, an analysis was developed to understand the relationship between the frequency of mutations in the env and vif genes of the virus and A3Z3 host gene, an important restriction factor that induces hypermutations in the virus. Five of the 7 haplotypes in the A3Z3 gene described previously were identified and a low or undetectable level of hypermutations was found in the analyzed viral genes

Feline immunodeficiency virus Vif N-Terminal residues selectively counteract feline APOBEC3s

Feline immunodeficiency virus (FIV) Vif protein counteracts feline APOBEC3s (FcaA3s) restriction factors by inducing their proteasomal degradation. The functional domains in FIV Vif for interaction with FcaA3s are poorly understood. Here, we have identified several motifs in FIV Vif that are important for selective degradation of different FcaA3s. Cats (Felis catus) express three types of A3s: single-domain A3Z2, single-domain A3Z3, and double-domain A3Z2Z3. We proposed that FIV Vif would selectively interact with the Z2 and the Z3 A3s. Indeed, we identified two N-terminal Vif motifs (12LF13 and 18GG19) that specifically interacted with the FcaA3Z2 protein but not with A3Z3. In contrast, the exclusive degradation of FcaA3Z3 was regulated by a region of three residues (M24, L25, and I27). Only a FIV Vif carrying a combination of mutations from both interaction sites lost the capacity to degrade and counteract FcaA3Z2Z3. However, alterations in the specific A3s interaction sites did not affect the cellular localization of the FIV Vif protein and binding to feline A3s. Pulldown experiments demonstrated that the A3 binding region localized to FIV Vif residues 50 to 80, outside the specific A3 interaction domain. Finally, we found that the Vif sites specific to individual A3s are conserved in several FIV lineages of domestic cat and nondomestic cats, while being absent in the FIV Vif of pumas. Our data support a complex model of multiple Vif-A3 interactions in which the specific region for selective A3 counteraction is discrete from a general A3 binding domain

Could phylogenetic analysis be used for feline Leukemia Virus (FeLV) classification?

The surface envelope (SU) protein determines the cell tropism and consequently the pathogenesis of the feline leukemia virus (FeLV) in felids. Recombination of exogenous FeLV (exFeLV) with endogenous retroviruses (enFeLV) allows the emergence of more pathogenic variants. Currently, phenotypic testing through interference assays is the only method to distinguish among subgroups—namely, FeLV-A, -B, -C, -E, and -T. This study proposes a new method for FeLV classification based on molecular analysis of the SU gene. A total of 404 publicly available SU sequences were used to reconstruct a maximum likelihood tree. However, only 63 of these sequences had available information about phenotypic tests or subgroup assignments. Two major clusters were observed: (a) clade FeLV-A, which includes FeLV-A, FeLV-C, FeLV-E, and FeLV-T sequences, and (b) clade enFeLV, which includes FeLV-B and enFeLV strains. We found that FeLV-B, FeLV-C, FeLV-E, and FeLV-T SU sequences share similarities to FeLV-A viruses and most likely arose independently through mutation or recombination from this strain. FeLV-B and FeLV-C arose from recombination between FeLV-A and enFeLV viruses, whereas FeLV-T is a monophyletic subgroup that has probably originated from FeLV-A through combined events of deletions and insertions. Unfortunately, this study could not identify polymorphisms that are specifically linked to the FeLV-E subgroup. We propose that phylogenetic and recombination analysis together can explain the current phenotypic classification of FeLV viruses

Absence of A3Z3-related hypermutations in the env and vif proviral genes in FIV naturally infected cats

Apolipoprotein B mRNA-editing enzyme catalytic polypeptide-like 3 (APOBEC3; A3) proteins comprise an important family of restriction factors that produce hypermutations on proviral DNA and are able to limit virus replication. Vif, an accessory protein present in almost all lentiviruses, counteracts the antiviral A3 activity. Seven haplotypes of APOBEC3Z3 (A3Z3) were described in domestic cats (hap I–VII), and in-vitro studies have demonstrated that these proteins reduce infectivity of vif-defective feline immunodeficiency virus (FIV). Moreover, hap V is resistant to vif-mediated degradation. However, studies on the effect of A3Z3 in FIV-infected cats have not been developed. Here, the correlation between APOBEC A3Z3 haplotypes in domestic cats and the frequency of hypermutations in the FIV vif and env genes were assessed in a retrospective cohort study with 30 blood samples collected between 2012 and 2016 from naturally FIV-infected cats in Brazil. The vif and env sequences were analyzed and displayed low or undetectable levels of hypermutations, and could not be associated with any specific A3Z3 haplotype

A new marseillevirus isolated in Southern Brazil from Limnoperna fortunei

Members of the family Marseilleviridae are giant viruses that have the ability to infect amoebas. Such viruses were initially described in 2009. Since then, this family has grown, and diverse members have been found in different environments and geographic locations. Previous phylogenetic analyses suggested the existence of four marseillevirus lineages. A fourth lineage was described with the discovery of the Brazilian marseillevirus (BrMr), isolated from Pampulha Lake, Brazil. Here we describe the isolation and characterization of the Golden marseillevirus (GMar), a new marseillevirus isolated from golden mussels (Limnoperna fortunei) in South of Brazil. This new representative of Marseilleviridae has circular, double-stranded (dsDNA) that contains 360, 610 base pairs and encodes 483 open read frames (ORFs). The complete virus genome was sequenced and phylogenic analyses indicated clear differences between this virus and other marseilleviruses. In addition, this is the only marseillevirus so far that has been isolated from mussels, and this report expands the diversity of environments from which giant viruses could be recovered

Viral DNA genomes in sera of farrowing sows with or without stillbirths

A study was conducted to investigate the serum virome of sows with and without stillbirths after farrowing. Sera from sows with at least one stillbirth or with normal litters were collected immediately after farrowing. Viral DNA was extracted from serum pools and submitted to high throughput sequencing. No differences in the proportion of virus-related reads were found in both groups (p > 0.05). A variety of viral DNA genomes were identified, mostly representative of three viral families: Anelloviridae, Circoviridae and Smacoviridae. Besides, a number of novel unclassified circular Rep-encoding single stranded DNA (CRESS DNA) viruses were also identified. These findings suggest that the presence of such viral genomes in sows’ sera bears no correlation with stillbirths’ occurrence; it seems likely that these constitute part of the normal serum microbiome of sows at farrowing

Differential effects of the second SARS-CoV-2 mRNA vaccine dose on T cell immunity in naive and COVID-19 recovered individuals

The rapid development of mRNA-based vaccines against the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) led to the design of accelerated vaccination schedules that have been extremely effective in naive individuals. While a two-dose immunization regimen with the BNT162b2 vaccine has been demonstrated to provide a 95% efficacy in naive individuals, the effects of the second vaccine dose in individuals who have previously recovered from natural SARS-CoV-2 infection has not been investigated in detail. In this study, we characterize SARS-CoV-2 spike-specific humoral and cellular immunity in naive and previously infected individuals during and after two doses of BNT162b2 vaccination. Our results demonstrate that, while the second dose increases both the humoral and cellular immunity in naive individuals, COVID-19 recovered individuals reach their peak of immunity after the first dose. These results suggests that a second dose, according to the current standard regimen of vaccination, may be not necessary in individuals previously infected with SARS-CoV-2.Research reported in this publication was supported in part by the National Cancer Institute of the NIH (5R01HD102614-02; R01CA249204 and R01CA248984) and an ISMMS seed fund to E.G. The authors gratefully acknowledge use of the services and facilities of the Tisch Cancer Institute supported by a NCI Cancer Center Support Grant (P30 CA196521). M.S. was supported by a NCI training grant (T32CA078207). This work was supported by an ISMMS seed fund to J.O.; Instituto de Salud Carlos III (COV20-00668) to R.C.R.; the Instituto de Salud Carlos III, Spanish Ministry of Science and Innovation (COVID-19 research call COV20/00181) co-financed by the European Development Regional Fund “A way to achieve Europe” to E.P.; the Instituto de Salud Carlos III, Spain (COV20/00170); the Government of Cantabria, Spain (2020UIC22-PUB-0019) to M.L.H.; the Instituto de Salud Carlos III (PI16CIII/00012) to P.P.; the Fondo Social Europeo e Iniciativa de Empleo Juvenil YEI (Grant PEJ2018-004557-A) to M.P.E.; and by REDInREN 016/009/009 ISCIII. This project has received funding from the European Union Horizon 2020 research and innovation programs VACCELERATE and INsTRuCT under grant agreements 101037867 and 860003.S

Impact of mediterranean diet promotion on environmental sustainability: a longitudinal analysis

[EN]This article aims to estimate the differences in environmental impact (greenhouse gas [GHG] emissions, land use, energy used, acidification and potential eutrophication) after one year of promoting a Mediterranean diet (MD). Methods Baseline and 1-year follow-up data from 5800 participants in the PREDIMED-Plus study were used. Each participant's food intake was estimated using validated semi-quantitative food frequency questionnaires, and the adherence to MD using the Dietary Score. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The influence of diet on environmental impact was assessed through the EAT-Lancet Commission tables. The association between MD adherence and its environmental impact was calculated using adjusted multivariate linear regression models.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Formando educadores en el sur de Colombia : Investigación educativa en licenciatura en educación infantil.

Este libro ofrece al lector reflexión continua de los retos de la universidad en la formación de licenciados para la transformación y emancipación de Colombia hacia la construcción de paz, revela las realidades socio críticas del XXI en los programas académicos de licenciados y visualiza las niñeces como sujetos políticos y sociales, logrando un despliegue significativo de metodologías pertinentes para la formación de maestros en Colombia y Latinoamérica