Beyond pathogens: the intriguing genetic legacy of endogenous retroviruses in host physiology.

The notion that viruses played a crucial role in the evolution of life is not a new concept. However, more recent insights suggest that this perception might be even more expansive, highlighting the ongoing impact of viruses on host evolution. Endogenous retroviruses (ERVs) are considered genomic remnants of ancient viral infections acquired throughout vertebrate evolution. Their exogenous counterparts once infected the host's germline cells, eventually leading to the permanent endogenization of their respective proviruses. The success of ERV colonization is evident so that it constitutes 8% of the human genome. Emerging genomic studies indicate that endogenous retroviruses are not merely remnants of past infections but rather play a corollary role, despite not fully understood, in host genetic regulation. This review presents some evidence supporting the crucial role of endogenous retroviruses in regulating host genetics. We explore the involvement of human ERVs (HERVs) in key physiological processes, from their precise and orchestrated activities during cellular differentiation and pluripotency to their contributions to aging and cellular senescence. Additionally, we discuss the costs associated with hosting a substantial amount of preserved viral genetic material.

Epidemiological and clinicopathological findings of feline immunodeficiency virus and feline leukemia virus infections in domestic cats from the Brazilian semiarid region.

Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses of great importance for domestic cats with a worldwide distribution. A retrospective study was conducted to determine the epidemiological and clinicopathological aspects of the infection by FIV and FeLV in cats from the Brazilian semiarid region. Cats treated between 2011 and 2021 at the teaching veterinary hospital of the Federal Rural University of the Semi-Arid Region that were submitted to a point-of-care (POC) test to detect anti-FIV IgG antibodies and FeLV antigen were enrolled in the study. Overall, 454 cats were selected, of which 30.2% [95% CI = 26.0% - 34.3%] were FIV-positive, 1.1% [95% CI = 0.9% - 1.2%] were FeLV-positive, and 0.7% [95% CI = 0.1% - 1.3%] were coinfected by both retroviruses. No statistical association was found between the studied retroviruses (P = 0.144). Multivariable analysis detected significant associations between FIV infection and male sex [OR = 5.7, 95% CI = 3.0-10.7, P < 0.0001), age between 19 and 78 months [OR = 5.2, 95% CI = 2.2-12.1, P < 0.0001], age greater than 78 months [OR = 12.8, 95% CI = 5.1-31.9, P < 0.0001], crossbreed [OR = 4.1, 95% CI = 1.2-13.4, P = 0.021], the presence of oral disease [OR = 2.1, 95% CI = 1.3-3.4, P = 0.004], reduced red blood cell (RBC) count [OR = 3.7, 95% CI = 1.9-7.2, P < 0.0001], and an albumin:globulin (A:G) ratio lower than 0.6 [OR = 3.4, 95% CI = 1.6-7.1, P = 0.001]. No statistical analyses were performed for FeLV infection due to the low number of positive animals. In the quantitative analyses of hematological parameters, FIV-positive cats presented lower values for RBC, hemoglobin, hematocrit, lymphocytes, and platelets compared to the negative animals. In the biochemical profile, cats infected with FIV showed higher creatinine, urea, total protein, and globulin values, while lower values for albumin and A:G ratio were observed (P < 0.05). The findings of this study characterized the prevalence, clinicopathological findings, and risk factors associated with FIV and FeLV in cats from the Brazilian semiarid region. They may help support veterinary practitioners in diagnosing feline retroviruses. The FIV prevalence observed is among the highest reported in Brazil, demonstrating the need for prevention and control strategies for this retrovirus.

Evidence of SARS-CoV-2 infection and co-infections in stray cats in Brazil.

The zoonotic virus SARS-CoV-2, which causes severe acute respiratory syndrome in humans (COVID-19), has been identified in cats. Notably, most positive cases were in cats that had close contact with infected humans, suggesting a role for humans in animal transmission routes. Previous studies have suggested that animals with immune depletion are more susceptible to SARS-CoV-2 infection. To date, there is limited evidence of SARS-CoV-2 infections in stray and free-range cats affected by other pathogens. In this study, we investigated infections caused by SARS-CoV-2, Leishmania spp., Toxoplasma gondii, Mycoplasma spp., Bartonella spp., Feline leukemia virus (FeLV), and Feline immunodeficiency virus (FIV) in stray cats from an urban park in Brazil during the COVID-19 pandemic. From February to September 2021, 78 mixed-breed cats were tested for SARS-CoV-2 and hemopathogens using molecular analysis at Américo Renné Giannetti Municipal Park, Belo Horizonte, Minas Gerais, Brazil. An enzyme-linked immunosorbent assay (ELISA) was used to detect IgG in T. gondii. None of the animals in this study showed any clinical signs of infections. The SARS-CoV-2 virus RNA was detected in 7.7 % of cats, and a whole virus genome sequence analysis revealed the SARS-CoV-2 Delta lineage (B.1.617.2). Phylogenetic analysis showed that SARS-CoV-2 isolated from cats was grouped into the sublineage AY.99.2, which matches the epidemiological scenario of COVID-19 in the urban area of our study. Leishmania infantum was detected and sequenced in 9 % of cats. The seroprevalence of T. gondii was 23.1 %. Hemotropic Mycoplasma spp. was detected in 7.7 % of the cats, with Mycoplasma haemofelis and Candidatus Mycoplasma haemominutum being the most common. Bartonella henselae and Bartonella clarridgeiae were detected in 38.5 % of the cats, FeLV was detected in 17,9 %, and none of the cats studied tested positive for FIV. This study reports, for the first time, the SARS-CoV-2 infection with whole-genome sequencing in stray cats in southeastern Brazil and co-infection with other pathogens, including Bartonella spp. and Feline leukemia virus. Our study observed no correlation between SARS-CoV-2 and the other detected pathogens. Our results emphasize the importance of monitoring SARS-CoV-2 in stray cats to characterize their epidemiological role in SARS-CoV-2 infection and reinforce the importance of zoonotic disease surveillance.

HERVs Role in the Pathogenesis, Diagnosis or Prognosis of Aging Diseases: A Systematic Review.

INTRODUCTION: HERVs are human endogenous retroviruses, which represent about 8% of the human genome, and have various physiological functions, especially in pregnancy, embryo development and placenta formation. However, their involvement in diseases is not well defined. Some studies have observed changes in HERV expression according to age. OBJECTIVE: Therefore, the aim of this systematic review was to analyze their role in pathogenesis and usage as diagnosis or prognosis biomarkers in aging disorders. METHODS: In this study, a search on the Pubmed interface was performed for papers published from January 1953 to June 1st, 2021. RESULTS: 45 articles have been included, which matched the eligibility criteria and evaluated the following diseases: breast cancer, prostate cancer, amyotrophic lateral sclerosis (ALS), osteoarthritis, Alzheimer's disease, immuno-senescence, cognitive impairment, cataract, glaucoma and hypertension. CONCLUSION: In conclusion, the results suggested that HERVs play a role in the pathogenesis and can be used as biomarkers for the diagnosis or prognosis of aging disorders.

Modulation of HERV Expression by Four Different Encephalitic Arboviruses during Infection of Human Primary Astrocytes.

Human retroelements (HERVs) are retroviral origin sequences fixed in the human genome. HERVs induction is associated with neurogenesis, cellular development, immune activation, and neurological disorders. Arboviruses are often associated with the development of encephalitis. The interplay between these viruses and HERVs has not been fully elucidated. In this work, we analyzed RNAseq data derived from infected human primary astrocytes by Zika (ZikV), Mayaro (MayV), Oropouche (OroV) and Chikungunya (ChikV) viruses, and evaluated the modulation of HERVs and their nearby genes. Our data show common HERVs expression modulation by both alphaviruses, suggesting conserved evolutionary routes of transcription regulation. A total of 15 HERVs were co-modulated by the four arboviruses, including the highly upregulated HERV4_4q22. Data on the upregulation of genes nearby to these elements in ChikV, MayV and OroV infections were also obtained, and interaction networks were built. The upregulation of 14 genes common among all viruses was observed in the networks, and 93 genes between MayV and ChikV. These genes are related to cellular processes such as cellular replication, cytoskeleton, cell vesicle traffic and antiviral response. Together, our results support the role of HERVs induction in the transcription regulation process of genes during arboviral infections.

Undetectable proviral DNA and viral RNA levels after raltegravir administration in two cats with natural feline leukemia virus infection.

Feline leukemia virus (FeLV) infection was discovered over 50 years ago; however, the serious clinical changes associated with FeLV infection still have great importance in the diagnosis, prevention, and clinical management of symptomatic patients. Progressive infection with FeLV leads to a reduction in the patient's life expectancy and quality of life. This report describes the use of an antiretroviral integrase inhibitor, raltegravir, in two cats with natural FeLV infection. Raltegravir was administered orally at a dose of 40 mg/cat every 12 h in both cases. In case one, 13 weeks after starting raltegravir, RNA loads were undetectable, while proviral DNA loads were still detectable. In case two, proviral DNA loads were undetectable after 32 weeks of medication, while RNA loads were undetectable throughout the treatment. No adverse effects or laboratory test abnormalities were detected with the use of raltegravir in either patient. The patients are currently clinically healthy, still receiving the drug, and are under close observation. To our knowledge, this is the first report describing the use of raltegravir in naturally infected FeLV-positive cats and its effects on circulating viral load. Moreover, the patients described here were followed-up for a longer period than those in previously reported cases.

A infecção pelo vírus da leucemia felina foi descoberta há mais de 50 anos, mas as graves alterações clínicas associadas à infecção pelo FeLV, ainda denotam grande importância no diagnóstico, nas medidas de prevenção e no manejo clínico de pacientes sintomáticos. A infecção progressiva pelo FeLV acarreta na redução do tempo e qualidade de vida do paciente. Este relato descreve o uso de um antirretroviral inibidor da integrase, o raltegravir, em dois gatos com infecção natural pelo FeLV. O raltegravir foi utilizado na dose de 40 mg/gato por via oral a cada 12 horas em ambos os casos. No primeiro caso após treze semanas do uso do raltegravir, a quantificação de RNA foi indetectável e no segundo caso, após trinta e duas semanas o número de cópias de DNA pró-viral foi indetectável. A carga de RNA nunca foi detectada neste paciente. Nenhum efeito adverso, nem alterações laboratoriais foram detectadas com o uso do raltegravir em ambos os casos. Atualmente, os pacientes encontram-se clinicamente saudáveis, fazem uso do antiretroviral com monitorização contínua. Este é o primeiro relato que descreve o uso do raltegravir em gatos infectados naturalmente pelo FeLV e seus efeitos na carga viral circulante. Além disso, os pacientes descritos aqui foram acompanhados por um período maior que os trabalhos anteriores descritos.

Off-Target Effect of Activation of NF-κB by HIV Latency Reversal Agents on Transposable Elements Expression.

Many drugs have been evaluated to reactivate HIV-1 from cellular reservoirs, but the off-target effects of these latency reversal agents (LRA) remain poorly defined. Transposable elements (TEs) are reactivated during HIV-1 infection, but studies of potential off-target drug effects on TE expression have been limited. We analyzed the differential expression of TEs induced by canonical and non-canonical NF-κB signaling. We evaluated the effect of PKC agonists (Bryostatin and Ingenol B) on the expression of TEs in memory CD4+ T cells. Ingenol B induced 38 differentially expressed TEs (17 HERV (45%) and 21 L1 (55%)). Interestingly, TE expression in effector memory CD4+ T cells was more affected by Bryostatin compared to other memory T-cell subsets, with 121 (107 upregulated and 14 downregulated) differentially expressed (DE) TEs. Of these, 31% (n = 37) were HERVs, and 69% (n = 84) were LINE-1 (L1). AZD5582 induced 753 DE TEs (406 HERV (54%) and 347 L1 (46%)). Together, our findings show that canonical and non-canonical NF-κB signaling activation leads to retroelement expressions as an off-target effect. Furthermore, our data highlights the importance of exploring the interaction between LRAs and the expression of retroelements in the context of HIV-1 eradication strategies.

Reflection About the Ancient Emergence of HTLV-2 Infection.

During millions of years, viruses have emerged and reemerged, with imbalance of photogenicity and transmissivity overtime. This letter describes that sometimes the nomenclature is uncertain what may actually happen during retrovirus evolution nowadays. This article discusses a possibility that human T-lymphotropic virus type 2 (HTLV-2) has been processed to incorporate the human genome in the last millions of years. Persistent viruses such as human immunodeficiency virus type 1 (HIV-1), HIV-2, and human T cell lymphotropic type 2 may also have potential of endogenization instead of a cytolytic process in a long time.

Generalized and fatal felid alphaherpesvirus-1 natural infection with liver involvement in a feline leukaemia virus-positive adult cat: a case report.

Generalized and fatal felid alphaherpesvirus-1 (FeHV-1) natural infection with liver involvement is rarely reported in cats, and the occurrence of herpesvirus viraemia with internal organ histologic lesions in adult cats is unknown. A 1.5-year-old cat, female, mixed breed, positive for feline leukaemia virus (FeLV) presented in a veterinary teaching hospital with sneezing, nasal discharge, anorexia, and diarrhoea after two weeks, evolving to inspiratory dyspnoea. Complete blood count and serum biochemistry analysis showed marked leukopenia and thrombocytopenia. After clinical worsening and lack of treatment response, the cat was euthanized. Pathological findings included hepatic necrosis, fibrinonecrotic tracheitis, and bronchointerstitial pneumonia. Marked amounts of coccobacillary bacteria were observed covering the necrotic tracheal and bronchial mucosa, at the cytoplasm of alveolar macrophages, and free in alveoli lumen, mimicking a primary bacterial tracheitis and pneumonia. Both lung and tracheal bacteria exhibited marked immunolabeling in anti-Escherichia coli immunohistochemistry. In addition, rare epithelial cells of bronchi contained round, eosinophilic, intranuclear viral inclusion bodies (4-7 µm) that marginate the chromatin, characteristic of FeHV-1 infection. Strong multifocal anti-FeHV-1 immunolabeling was observed in necrotic epithelial cells of the liver, trachea, and lungs. Generalized herpesvirus infection with the occurrence of acute hepatic necrosis and severe respiratory illness is a potential differential diagnosis in FeLV-positive cats with respiratory signs. The immunodepression in these cats probably favours a FeHV-1 viraemia in addition to the development of opportunistic bacterial infections, such as Escherichia coli, and it is associated with a poor outcome.

Protocolo para diagnóstico molecular de imunodeficiência e leucemia em gatos domésticos / Protocol for molecular diagnosis of immunodeficiency and leukemia, in domestic cats

Diversas afecções que acometem os felinos domésticos, como as retroviroses, não possuem tratamento efetivo. Tal fato torna relevante o estudo dessas doenças, em virtude da baixa eficácia de cura e caráter majoritariamente vitalício. Entre as retroviroses que mais acometem os felinos estão a imunodeficiência felina (FIV) e a leucemia felina (FeLV). O diagnóstico é obtido pela associação do exame clínico, geralmente inconclusivo, com exames laboratoriais complementares. Testes moleculares, como a reação em cadeia da polimerase (PCR), são eficientes para a detecção do DNA proviral e podem ser utilizados na rotina diagnóstica. Diante disso, o objetivo deste estudo foi comprovar a eficiência do protocolo molecular Nested PCR para diagnosticar FIV e FeLV. Para tal, amostras de sangue e/ou medula de 41 gatos domésticos foram coletadas por meio de punção venosa ou de medula e encaminhadas ao laboratório Oncells Biotecnologia. Os seguintes pares de primers foram adotados para o Nested PCR: FF1 e FF2 para o primeiro ciclo, com um amplicon de 1325pb para FIV e 490pb para a FeLV. Para o segundo foi utilizada a combinação F14, F15, FE4 e FE7, com um amplicon de 1138pb para FIV e 306pb para FeLV. As bandas correspondentes às esperadas para FeLV foram detectadas pela observação dos géis, porém, além de outras bandas inespecíficas, não foram observadas bandas correspondentes à FIV. Os resultados confirmam a capacidade de detecção do patógeno da FeLV pela técnica empregada. No entanto, novos ajustes do protocolo são necessários.

Several affections that affect domestic cats, such as retroviruses, do not have effective treatment. This fact makes the study of these diseases relevant, due to the low healing efficacy and mostly lifelong character. Among the retroviruses that most affect felines are feline immunodeficiency (FIV) and feline leukemia (FeLV). The diagnosis is obtained by associating the clinical examination, which is generally inconclusive, with complementary laboratory tests. Molecular tests, such as the polymerase chain reaction (PCR), are efficient for proviral DNA detection and can be used in the diagnostic routine. Therefore, this study aimed to prove the efficiency of the molecular protocol Nested PCR to diagnose FIV and FeLV. For this purpose, blood and/ or bone marrow samples from 41 domestic cats were collected through venipuncture or bone marrow and sent to the Oncells Biotechnology laboratory. The following primer pairs were adopted for the Nested PCR: FF1 and FF2 for the first cycle, with an amplicon of 1325bp for FIV and 490bp for FeLV. For the second, the combination F14, F15, FE4, and FE7 was used, with an amplicon of 1138bp for FIV and 306bp for FeLV. The bands corresponding to those expected for FeLV were detected by observing the gels; however, in addition to other non-specific bands, bands corresponding to FIV were not observed. The results confirm the ability to detect the FeLV pathogen by the technique employed. Nevertheless new protocol adjustments are required.

Disseminated Histoplasmosis in Persons with HIV/AIDS, Southern Brazil, 2010-2019.

We evaluated disseminated histoplasmosis (DH) in HIV patients over 10 years in southern Brazil. The incidence was 12 cases/1,000 hospitalizations (2010-2019); the mortality rate was 35%. Tuberculosis frequently obscured the diagnosis of DH. We emphasize the need in our region to suspect and investigate DH using more sensitive methods.

The role of IFN-γ production during retroviral infections: an important cytokine involved in chronic inflammation and pathogenesis

ABSTRACT Interferon-gamma (IFN-γ) plays a crucial role in viral infections by preventing viral replication and in the promotion of innate and adaptive immune responses. However, IFN-gamma can exert distinct effects in different persistent viral infections. The long-term overproduction of IFN-γ in retroviral infections, such as the human immunodeficiency virus (HIV), human T-lymphotropic virus type 1 (HTLV-1), and human endogenous retroviruses (HERVs), resulting in inflammation, may cause neuronal damage. This review is provocative about the role of IFN-γ during persistent retroviral infections and its relationship with the causation of some neurological disorders that are important for public health.

ERVs-TLR3-IRF axis is linked to myelodysplastic syndrome pathogenesis.

Toll-like receptors are mutated or overexpressed in up to 50% of patients with myelodysplastic syndrome (MDS). Endogenous retroviruses (ERV) trigger TLR3 leading to interferon regulatory genes (IRFs) activation. We evaluated if the ERVs-TLR3-IRF axis activation would be linked to MDS pathogenesis and we also conducted a detailed cancer analysis of the ERVs, TLR3 and IRFs gene expression in 30 cancer types using GEPIA database. Seventy-nine bone marrow samples from patients with MDS were evaluated for cytogenetics and quantitative real­time PCR of TLR3, ERVK6, ERVW-1, ERV3-1, IRF3 and IRF7. Patients with dyserythropoiesis showed higher TLR3 (p = 0.035), ERVK6 (p = 0.001), ERVW1 (p = 0.045) and ERV3-1 (p = 0.016) expression than patients without dyserythropoiesis. Upregulation of Interferon Regulatory Factors, IRF3 and IRF7, was associated with poor prognostic markers in MDS such as > 10% of blasts (p = 0.003-IRF3; p = 0.009-IRF7), low platelets count (< 50.000/mm3) (p = 0.001-IRF3; p = 0.021-IRF7), transfusion dependence (p = 0.014-IRF3) and chromosomal abnormalities (p = 0.036-IRF7). We found strong correlations between ERVK6-ERVW1 (r = 0.800; r2 = 0.640; p = 0.000), ERVW1-ERV3-1 (r = 0.715; r2 = 0.511; p = 0.000), and IRF7-IRF3 (r = 0.567; r2 = 0.321; p = 0.000) and moderate correlation between ERVK6-ERV3-1(r = 0.485; r2 = 0.235; p = 0.000), ERVW1-IRF7 (r = 0.389; r2 = 0.151; p = 0.001), ERVW1-IRF3 (r = 0.357; r2 = 0.127; p = 0.004), ERV3-1-IRF7 (r = 0.314; r2 = 0.098; p = 0.009), and ERV3-1-IRF3 (r = 0.324; r2 = 0.104; p = 0.007). Using GEPIA Database in 30 cancer types, we detected a typical pattern of upregulation as here presented in MDS. We suggest TLR3 activation by ERVs is linked to MDS pathogenesis leading to bone marrow failure. Abnormal double-stranded RNA (dsRNA) expression of Endogenous Retroviruses (ERV) triggers TLR3 hyperactivation. This induces IRF3, IRF7, and NF-kB to translocate to the nucleus and activate transcription of IFNα/ß which binds to the type I-IFN receptor promoting interferon response. Thus, just as TLR4 induces a crucial myeloid shift, the ERVs-TLR3 axis may play an important role in establishing one of the most striking characteristics in MDS, dyserythropoiesis.

Is the human T-cell lymphotropic virus type 2 in the process of endogenization into the human genome?

Human T-cell lymphotropic virus type 2 (HTLV-2) infection has been shown to be endemic among intravenous drug users in parts of North America, Europe and Southeast Asia and in a number of Amerindian populations. Despite a 65% genetic similarity and common host humoral response, the human T-cell lymphotropic viruses type 1 (HTLV-1) and 2 display different mechanisms of host interaction and capacity for disease development. While HTLV-1 pathogenicity is well documented, HTLV-2 etiology in human disease is not clearly established. From an evolutionary point of view, its introduction and integration into the germ cell chromosomes of host species could be considered as the final stage of parasitism and evasion from host immunity. The extraordinary abundance of endogenous viral sequences in all vertebrate species genomes, including the hominid family, provides evidence of this invasion. Some of these gene sequences still retain viral characteristics and the ability to replicate and hence are potentially able to elicit responses from the innate and adaptive host immunity, which could result in beneficial or pathogenic effects. Taken together, this data may indicate that HTLV-2 is more likely to progress towards endogenization as has happened to the human endogenous retroviruses millions of years ago. Thus, this intimate association (HTLV-2/human genome) may provide protection from the immune system with better adaptation and low pathogenicity.

Donor-Derived Transmission of Cryptococcus gattii sensu lato in Kidney Transplant Recipients.

We describe cases of donor-derived transmission of Cryptococcus deuterogattii in 2 kidney transplant recipients in Brazil and published information on other cases. Prompt reduction of immunosuppression and initiation of antifungal therapy was required to successfully control the fungal infections and preserve engraftment.

Microtubule Retrograde Motors and Their Role in Retroviral Transport.

Following entry into the host cell, retroviruses generate a dsDNA copy of their genomes via reverse transcription, and this viral DNA is subsequently integrated into the chromosomal DNA of the host cell. Before integration can occur, however, retroviral DNA must be transported to the nucleus as part of a 'preintegration complex' (PIC). Transporting the PIC through the crowded environment of the cytoplasm is challenging, and retroviruses have evolved different mechanisms to accomplish this feat. Within a eukaryotic cell, microtubules act as the roads, while the microtubule-associated proteins dynein and kinesin are the vehicles that viruses exploit to achieve retrograde and anterograde trafficking. This review will examine the various mechanisms retroviruses have evolved in order to achieve retrograde trafficking, confirming that each retrovirus has its own strategy to functionally subvert microtubule associated proteins.

Oral lesions and retroviruses in shelter cats / Afecções orais e retroviroses em gatos de abrigo

Oral lesions are common problems in feline medicine worldwide, and may be associated with different causes, such as infectious agents. There are only a few studies reporting the chief oral diseases and the results for retrovirus tests in shelter cats in Brazil, especially in the South region. This study aimed to identify the main inflammatory oral lesions in shelter cats and verify the test results for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections. Forty-three felines from private shelters in the central region of Rio Grande do Sul state (RS) that presented clinically evident oral lesions, regardless of age, breed, sex, and neuter status, were used in this survey. Serological tests for FIV and FeLV were performed in all cats, and data regarding the rearing system were collected. Sixteen cats (37.2%) were reared in a free system, whereas 27 (62.8%) were kept under a restrict system. Of the 43 cats with oral lesions, 29 (67.44%) presented only one type of lesion, characterized as periodontitis (n=22, 51.16%), followed by gingivitis (n=6, 13.95%), and stomatitis (n=1, 2.32%). Concomitant stomatitis and periodontitis were found in the 14 remaining cats (100%). With respect to the test results for retrovirus infections, nine (20.93%) of the 43 felines were positive for FIV alone. Co-infection with both viruses was observed in seven cats (16.28%). No cat was seropositive for FeLV valone. None of the six cats that presented gingivitis was positive for FIV and FeLV; one cat with stomatitis was positive for FIV and FeLV; of the 22 cats with periodontitis, six (27.27%) were FIV positive and two (9.09%) were FIV/FeLV positive; and of the 14 cats that presented stomatitis and periodontitis, three (21.43%) were FIV positive and four (28.57%) were FIV/FeLV positive. As for diagnosis, 28 cats (65.1%) presented solely periodontal disease (PD), one cat (2.32%) had feline chronic gingivostomatitis (FCG) alone, and 14 (32.5%) had both PD and FCG. The results obtained show that the main oral lesions found in shelter cats in the central region of RS were gingivitis, stomatitis, and periodontitis. Periodontitis, in association or not with stomatitis, was the most frequently observed oral cavity lesion in FIV- and/or FeLV-positive cats. Other factors may contribute to installation of inflammatory oral diseases in shelter cats because most cats with oral cavity lesions tested negative for retrovirus infections.(AU)

As afecções orais são problemas comuns em medicina felina em diferentes locais do mundo e podem estar relacionadas a diferentes causas, como agentes infecciosos. Poucos estudos foram encontrados no Brasil sobre o levantamento das principais doenças orais e dos resultados de testes para retrovírus em gatos de abrigos, principalmente na região Sul. Diante disso, o objetivo deste artigo foi identificar as principais afecções orais inflamatórias em gatos de abrigos e verificar os resultados dos testes para o vírus da imunodeficiência felina (FIV) e o vírus da leucemia felina (FeLV). Foram incluídos 43 felinos provenientes de abrigos privados localizados na região central do Rio Grande do Sul (RS) que apresentavam lesões orais clinicamente evidentes, independente de idade, raça, gênero e estado reprodutivo. Em todos os gatos foram realizados testes sorológicos para FIV e FeLV e obtidas informações referentes ao sistema de criação. Em 16 gatos (37,2%), o sistema de criação era livre, enquanto em 27 (62,8%) era restrito. Dos 43 gatos com lesões orais, em 29 (67,44%) foi verificado somente um tipo de lesão, caracterizado como periodontite (n=22, 51,16%), seguido de gengivite (n=6, 13,95%) e estomatite (n=1, 2,32%). Lesões concomitantes de estomatite e periodontite foram encontradas nos 14 gatos (100%) restantes. Quanto aos resultados dos testes para retrovírus, nove (20,93%) dos 43 felinos testados, foram positivos somente para FIV. Em sete gatos (16,28%) foi observada coinfecção pelos dois vírus. Em nenhum gato foi observado soropositividade somente para FeLV. Dos seis gatos com gengivite, nenhum foi positivo para FIV e FeLV; um gato com estomatite foi positivo para FIV e FeLV; dos 22 gatos com periodontite, seis (27,27%) foram FIV positivos e dois (9,09%) FIV/FeLV positivos; e dos 14 com estomatite e periodontite, três (21,43%) foram FIV positivos e quatro (28,57%) FIV/FeLV positivos. Quanto ao diagnóstico, em 28 gatos (65,1%) foi observada somente doença periodontal (DP), em um (2,32%) somente gengivoestomatite crônica felina (GECF) e em 14 gatos (32,5%) DP e GECF. Diante dos resultados obtidos, pode-se concluir que as principais lesões orais encontradas em gatos de abrigos da região central do RS foram gengivite, estomatite e periodontite; a periodontite associada ou não a estomatite foi a lesão oral mais frequente nos gatos positivos para FIV e/ou FeLV. Acredita-se que outros fatores possam contribuir na instalação de doenças orais em gatos de abrigos, já que houve predomínio de gatos com resultados negativos nos testes para os retrovírus.(AU)

Oral lesions and retroviruses in shelter cats / Afecções orais e retroviroses em gatos de abrigo

Oral lesions are common problems in feline medicine worldwide, and may be associated with different causes, such as infectious agents. There are only a few studies reporting the chief oral diseases and the results for retrovirus tests in shelter cats in Brazil, especially in the South region. This study aimed to identify the main inflammatory oral lesions in shelter cats and verify the test results for feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) infections. Forty-three felines from private shelters in the central region of Rio Grande do Sul state (RS) that presented clinically evident oral lesions, regardless of age, breed, sex, and neuter status, were used in this survey. Serological tests for FIV and FeLV were performed in all cats, and data regarding the rearing system were collected. Sixteen cats (37.2%) were reared in a free system, whereas 27 (62.8%) were kept under a restrict system. Of the 43 cats with oral lesions, 29 (67.44%) presented only one type of lesion, characterized as periodontitis (n=22, 51.16%), followed by gingivitis (n=6, 13.95%), and stomatitis (n=1, 2.32%). Concomitant stomatitis and periodontitis were found in the 14 remaining cats (100%). With respect to the test results for retrovirus infections, nine (20.93%) of the 43 felines were positive for FIV alone. Co-infection with both viruses was observed in seven cats (16.28%). No cat was seropositive for FeLV valone. None of the six cats that presented gingivitis was positive for FIV and FeLV; one cat with stomatitis was positive for FIV and FeLV; of the 22 cats with periodontitis, six (27.27%) were FIV positive and two (9.09%) were FIV/FeLV positive; and of the 14 cats that presented stomatitis and periodontitis, three (21.43%) were FIV positive and four (28.57%) were FIV/FeLV positive. As for diagnosis, 28 cats (65.1%) presented solely periodontal disease (PD), one cat (2.32%) had feline chronic gingivostomatitis (FCG) alone, and 14 (32.5%) had both PD and FCG. The results obtained show that the main oral lesions found in shelter cats in the central region of RS were gingivitis, stomatitis, and periodontitis. Periodontitis, in association or not with stomatitis, was the most frequently observed oral cavity lesion in FIV- and/or FeLV-positive cats. Other factors may contribute to installation of inflammatory oral diseases in shelter cats because most cats with oral cavity lesions tested negative for retrovirus infections.(AU)

As afecções orais são problemas comuns em medicina felina em diferentes locais do mundo e podem estar relacionadas a diferentes causas, como agentes infecciosos. Poucos estudos foram encontrados no Brasil sobre o levantamento das principais doenças orais e dos resultados de testes para retrovírus em gatos de abrigos, principalmente na região Sul. Diante disso, o objetivo deste artigo foi identificar as principais afecções orais inflamatórias em gatos de abrigos e verificar os resultados dos testes para o vírus da imunodeficiência felina (FIV) e o vírus da leucemia felina (FeLV). Foram incluídos 43 felinos provenientes de abrigos privados localizados na região central do Rio Grande do Sul (RS) que apresentavam lesões orais clinicamente evidentes, independente de idade, raça, gênero e estado reprodutivo. Em todos os gatos foram realizados testes sorológicos para FIV e FeLV e obtidas informações referentes ao sistema de criação. Em 16 gatos (37,2%), o sistema de criação era livre, enquanto em 27 (62,8%) era restrito. Dos 43 gatos com lesões orais, em 29 (67,44%) foi verificado somente um tipo de lesão, caracterizado como periodontite (n=22, 51,16%), seguido de gengivite (n=6, 13,95%) e estomatite (n=1, 2,32%). Lesões concomitantes de estomatite e periodontite foram encontradas nos 14 gatos (100%) restantes. Quanto aos resultados dos testes para retrovírus, nove (20,93%) dos 43 felinos testados, foram positivos somente para FIV. Em sete gatos (16,28%) foi observada coinfecção pelos dois vírus. Em nenhum gato foi observado soropositividade somente para FeLV. Dos seis gatos com gengivite, nenhum foi positivo para FIV e FeLV; um gato com estomatite foi positivo para FIV e FeLV; dos 22 gatos com periodontite, seis (27,27%) foram FIV positivos e dois (9,09%) FIV/FeLV positivos; e dos 14 com estomatite e periodontite, três (21,43%) foram FIV positivos e quatro (28,57%) FIV/FeLV positivos. Quanto ao diagnóstico, em 28 gatos (65,1%) foi observada somente doença periodontal (DP), em um (2,32%) somente gengivoestomatite crônica felina (GECF) e em 14 gatos (32,5%) DP e GECF. Diante dos resultados obtidos, pode-se concluir que as principais lesões orais encontradas em gatos de abrigos da região central do RS foram gengivite, estomatite e periodontite; a periodontite associada ou não a estomatite foi a lesão oral mais frequente nos gatos positivos para FIV e/ou FeLV. Acredita-se que outros fatores possam contribuir na instalação de doenças orais em gatos de abrigos, já que houve predomínio de gatos com resultados negativos nos testes para os retrovírus.(AU)

Cross-reactivity between myelin oligodendrocyte glycoprotein and human endogenous retrovirus W protein: nanotechnological evidence for the potential trigger of multiple sclerosis.

Multiple sclerosis (MS) is an autoimmune and inflammatory demyelinating disease of the central nervous system. Experimental evidence supports the reactivity of autoantibodies against components of myelin sheath including the myelin oligodendrocyte glycoprotein (MOG). The MS etiology is still unknown, but some risk factors associated with immune dysregulation, genetic susceptibility, and environmental factors are under investigation. The last consider the hypothesis of molecular mimicry mechanism, which is potentially triggered by viral antigen inducing MS autoimmunity. The Human Endogenous Retroviruses W family (HERV-W) is the subject of studies within this field, based on the detection of HERV-W envelope gene proteins in MS patients' samples. In the biomedical field of diagnosis and therapeutics, nanotechnology is of great use for the detailed study of molecular mechanisms involving specific interactions between biomolecules providing high specificity and sensitivity of response. In view of the significance of etiological aspects for the comprehension of MS mechanisms of action, we applied a nanotechnological approach designed for antibody detection. For this, we analyzed MOG peptide sequences similar to the HERV-W protein. These sequences were subjected to interaction with anti-HERV-W antibodies using atomic force spectroscopy (AFS) and silver nanoparticles (AgNPs) methods to survey the potential occurrence of molecular mimicry. Our results revealed the molecular recognition between the anti-HERV-W antibody and the HERV-W and MOG epitopes by AFS and AgNPs approaches. Specific non-linear shape of force curves and median adhesion force values within the expected range for an antigen-antibody interaction were obtained for HERV-W and MOG peptides, 163 pN and 178 pN, respectively, suggesting the occurrence of cross-reactivity in these systems.

Seroprevalence of feline immunodeficiency virus and feline leukemia virus in domestic cats of Fortaleza, Ceará / Soroprevalência do vírus da imunodeficiência felina e do vírus da leucemia felina em gatos domésticos de Fortaleza, Ceará

Feline Immunodeficiency Virus (FIV) and Feline Leukemia Virus (FeLV) are important etiologic agents of immunosuppressive diseases in felines. The objective of the present study was to determine the prevalence of these retroviruses in domestic cats in Fortaleza, Ceará and the epidemiological factors associated with these infections. Between 2015 and 2016, 138 blood samples were collected and tested for FIV and FeLV by the enzyme immunoadsorption assay (ELISA). Parameters such as breed, gender, age, reproductive status, multi-cat environment, outdoor access and clinical manifestations were evaluated. The results showed that 12.32% were positive for FIV, 5.80% for FeLV and 1.45% for co-infection (FIV/FeLV). FIV+ animals were mostly mixed breed, neutered male adult cats, with indoor lifestyle and living in a multi-cat household. The most common clinical manifestation observed was disorders of the oral cavity. Factors found to increase the risk for FeLV seropositivity include mixed breed, young, spayed female cats, indoor lifestyle living in a multi-cat household were the most common epidemiological factors observed. The most common clinical manifestation was anorexia and apathy. The prevalence of these viruses were relatively high, compared with other region of Brazil. This study demonstrated that mixed breed, castrated, multi-cat environment and indoor lifestyle animals are of greater relevance for FIV and FeLV infection diseases. Factors related to cat demographics and health such as age, sex and type of household are important predictors for seropositive status to FeLV or FIV in Fortaleza. High prevalence of FeLV or FIV observed in our study is of concern, in view of the immunosuppressive potential of the two pathogens.(AU)

O Vírus da Imunodeficiência Felina (FIV) e o Vírus da Leucemia Felina (FeLV) são importantes agentes etiológicos de doenças imunossupressoras em felinos. O objetivo do presente estudo foi determinar a prevalência desses retrovírus em gatos domésticos em Fortaleza, Ceará e os fatores epidemiológicos associados a essas infecções. Entre 2015 e 2016, foram coletadas 138 amostras de sangue e testadas para FIV e FeLV pelo ensaio de imunoadsorção enzimática (ELISA). Parâmetros como raça, gênero, idade, estado reprodutivo, ambiente com vários gatos, acesso ao ar livre e manifestações clínicas foram avaliados. Os resultados mostraram que 12,32% foram positivos para o FIV, 5,80% para o FeLV e 1,45% para a co-infecção (FIV/FeLV). Os animais FIV+ eram na sua maioria gatos machos castrados, adultos, de raça mista, com estilo de vida dentro de casa e vivendo em um ambiente com vários gatos. A manifestação clínica mais comum observada foi distúrbios da cavidade oral. Os fatores encontrados que aumentam o risco de soropositividade para FeLV incluem gatas fêmeas castradas, jovens, de raça mista, com estilo de vida dentro de casa e vivendo em um ambiente com vários gatos, foram os fatores epidemiológicos mais comuns observados. A manifestação clínica mais comum foi anorexia e apatia. A prevalência desses vírus foi relativamente alta em comparação com outras regiões do Brasil. Este estudo demonstrou que os animais de raça mista, castrados, vivendo em um ambiente com vários gatos e estilo de vida dentro de casa são de maior relevância para as doenças infecciosas por FIV e FeLV. Fatores relacionados à demografia e à saúde do gato, como idade, sexo e tipo de domicílio, são importantes preditores do estado soropositivo para FeLV ou FIV em Fortaleza. A alta prevalência de FeLV ou FIV observada em nosso estudo é preocupante, tendo em vista o potencial imunossupressor dos dois patógenos.(AU)