O vírus da imunodeficiência felina (FIV) é um membro da subfamília Lentivirinae da família Retroviridae. A infecção é caracterizada por imunodepressão com um declíneo progressivo dos linfócitos T CD4+, propiciando, desta maneira, o surgimento de infecções oportunistas. Já o vírus da leucemia viral felina (FeLV) pertence a subfamília Oncovirinae da família Retroviridae. Este vírus é um importante patógeno dos gatos domésticos que causa uma variedade de desordens neoplásicas e degenerativas e também apresenta distribuição mundial. O presente estudo compreendeu um levantamento da prevalência das infecções por FIV e FeLV no Município de Porto Alegre. Foram analisadas 65 amostras de gatos sadios e doentes. A detecção destas viroses foi realizada utilizando um “kit” comercial de ELISA para ambas as viroses e um protocolo de reação em cadeia da polimerase aninhada (Nested-PCR) para detecção do FIV. Os resultados demonstraram que 21,5% (14/65) dos gatos foram positivos para FIV combinado os resultados de ambos os testes, 10,8% (7/65) foram positivos para FeLV e 6,1% (4/65) foram positivos para ambos os vírus. Foram também realizados hemogramas de 48 animais, dos quais 8 apresentaram resultados positivos para FIV na Nested-PCR. Através do teste T de Student, verificou-se que não houve diferença significativa nos valores hematológicos destes animais. Conclui-se que a utilização do ELISA com a PCR dobrou a chance de detecção de gatos FIV positivos. Desta forma, a prevalência de FIV foi aproximadamente o dobro do que a de FeLV, ao contrário do que ocorre na maior parte de outros locais estudados. / Feline immunodeficiency virus (FIV) belongs to the Lentivirinae subfamily of the Retroviridae family. The infection is characterized by immunodepression and progressive decline in CD4+ T cells that may render the animal susceptible to opportunistic infections. Feline leukemia virus (FeLV) belongs to subfamily Oncovirinae of the Retroviridae family. The virus also affects domestic cats, being an important pathogen that causes a variety of neoplastic disorders and degenerative diseases. Both viruses have a worldwide distribution. The present study aims to determine the prevalence of infection with FIV and FeLV in Porto Alegre municipality. A total of 65 cats were tested, comprising healthy and sick cats. A commercial ELISA kit was used to detect anti-FIV antibodies and FeLV antigen. A nested polymerase chain reaction (Nested-PCR) was also used for FIV provirus detection. The results showed that 21.5% of the sampled cats were positive for FIV in the ELISA and Nested-PCR, 10.8% were positive for FeLV in the ELISA and 6.1% were positive for both viruses. Haemogram of 48 animals were performed but it was not found any significant association between hematologic values of FIV positive and negative animals. It was concluded that the use of ELISA and Nested-PCR increased the possibility to detect FIV positive cats. The prevalence of FIV infected cats was higher than the prevalence of FeLV positive cats, the opposite of what is normally found in studies performed in other regions.

Com o objetivo de avaliar a freqüência de infecção por micoplasmas hemotrópicos em gatos com linfoma e seu impacto na ocorrência de anemias nesses animais, foram analisadas amostras sangüíneas de 14 animais com diagnóstico de linfoma, sem qualquer tratamento prévio e 14 amostras de sangue de gatos hígidos, por meio da técnica de PCR-Nested. Utilizaram-se primers que amplificam fragmentos do gene 16S rRNA dos micoplasmas. Eritrograma e bioquímica sérica foram realizados, assim como testes sorológicos imunoenzimáticos (ELISA) para ambos os retrovírus. Anemia foi observada em 28,6% (4/14) dos gatos com linfoma. Em dois a anemia foi classificada como normocítica normocrômica não regenerativa, e em outros dois como macrocitica normocrômica não regenerativa. A freqüência de infecção pelos micoplasmas hemotrópicos felinos nos gatos com linfoma foi de 7,14% (1/14). Após seqüenciamento e posterior prova de identidade no GenBank, o agente foi identificado como M. haemofelis, número de acesso FJ544859. A freqüência de infecção pelos retrovírus foi de 21,42% para o FeLV e 7,14% (3/14) para o FIV. O animal infectado pelo M. haemofelis não apresentou anemia, ainda que apresentasse infecção concomitante pelo FeLV. O grupo controle não apresentou infecção por micoplasmas ou retrovírus. Nas condições em que este estudo foi realizado, concluiu-se que a anemia observada nos gatos com linfoma não foi ocasionada pela infecção por micoplasmas hemotrópicos, mas provavelmente em decorrência das alterações hematológicas promovidas pelo processo neoplásico, associadas ou não à infecção pelo FeLV. Portanto, a infecção pelos micoplasmas não apresentou um impacto direto na ocorrência de anemias em gatos com linfoma. / To evaluate the frequency of infection by hemotropic mycoplasmas in cats with lymphoma and its impact in the development of anaemia in those animals, blood samples from 14 animals diagnosed with Lymphoma and without any previous treatment and 14 blood samples from healthy cats were analyzed by means of the PCR-Nested technique. Primers were utilized and selectively amplified fragments of 16SrRNA gene of mycoplasma. Haematology, serum biochemical profile and FeLV/FIV ELISA were performed in all 28 cats. Anaemia was observed in 28.6% (4/14) of the cats with lymphoma. In two of them, anaemia was classified as normocytic-normochromic nonregenerative and in the other two as macrocytic-normochromic nonregenerative. The frequency of feline haemotropic mycoplasmas infection in cats with lymphoma was 7.14% (1/14). After sequencing and identity proof by the GenBank, the agent was identified as M. haemofelis, access number FJ544859. The frequency of retrovirus infection among all the cats with lymphoma was 21.42% (3/14) for FeLV and 7.14% (1/14) for FIV. The cat infected by M. haemofelis was also infected with FeLV, but was not anaemic. The 14 cats used as control did not exhibited infection by mycoplasmas or retrovirus infections. Under the conditions in which this study was developed, one can conclude that the anaemia observed in cats with lymphoma may not be related to hemotropic microplasmas infection, but to haematologyc alterations promoted by the associated neoplasic process and/or the occurrence or of FeLV infection. Therefore, the infection by the mycoplasmas did not present a direct impact in the occurrence of anaemies in cats with limphoma.

A infecção de trato respiratório superior em gatos é uma afecção muito frequente em indivíduos que vivem em abrigos, com elevada morbidade e em alguns casos, fatal. O herpesvírus felino tipo1 (FHV-1) e a Chlamydophila felis estão entre os principais causadores. O FHV-1 ocasiona quadros de espirros, secreção nasal e alterações oculares como conjuntivite. A C. felis é responsável pelos piores casos de conjuntivite e apresenta um plasmídeo críptico como possível fator de virulência. A presença dos retrovírus da leucemia felina (FeLV) e/ou imunodeficiência dos felinos (FIV) debilita a função do sistema imunológico, causando imunossupressão e consequentemente aumento no índice de morbidade e mortalidade. Neste trabalho foram avaliados quatro abrigos, três gatis particulares não-comercias (um localizado em Osasco/SP e outros dois São Paulo/SP). Os gatis possuiam alta densidade populacional e a procedência dos gatos alojados era desconhecida. A detecção de FHV-1, como de C. felis e de três genes do plasmídeo criptico foram realizadas por PCR em amostras de mucosa oral e de conjuntiva ocular de ambos os olhos obtidas com swabs de algodão, secos e estéreis. Amostras de sangue foram coletadas para a detecção do FIV e FeLV por meio de teste imunoenzimático. O sintomas clínicos dos animais foram classificados de 1 a 4, sendo 4 atribuído àqueles que apresentavam pior sintomatologia. A ocorrência de FIV e FeLV no 1° gatil foi de 4,63% e 3,70%, no 2° gatil foi de 0% e 6,45%, enquanto que no 3° gatil foi 75% e 0% respectivamente, estes vírus não foram detectados no 4° gatil. FHV-1 foi observado em 61,11% dos gatos no 1° gatil; 90,32% no 2° gatil, 100% no 3° gatil e em 89,74% dos animais do 4° gatil. No 1° gatil, 7,41% das amostras apresentavam C. felis, no 2° gatil, 58,06%; no 4° gatil, 23,08%; enquanto que no 3° gatil o agente não foi detectado. Dentre as amostras positivas para C. felis, os genes do plasmídeo críptico foram detectados; no 1o gatil o gene 1 estava presente em 62,50% das amostras, o gene 2 e 3 em 75%, para o 2° gatil obteve-se 61,11% de positividade para os genes 1 e 2 e 55,56% para o gene 3; no 4° gatil o gene 1 e 3 estavam presentes em 77,78% das amostras, o gene 2 em 55,56%. Os óbitos relatados no período do estudo foram de animais classificados com sintomas 3 ou 4 e positivos para C. felis e para o plasmídeo críptico. No presente trabalho foi observada uma elevada ocorrência de C. felis e de seu plasmídeo críptico, apesar da baixa ocorrência de FIV e FeLV nos gatis. / The infection of upper respiratory disease in cats is very common in individuals that living in shelters, with high morbidity, and in some cases, fatal. The feline herpesvirus type 1 (FHV- 1) and Chlamydophila felis are agents the main causes. The FHV- 1 causes sneezing, nasal discharge and ocular abnormalities such as conjunctivitis. The C. felis is responsible for the worst cases of conjunctivitis and features a cryptic plasmid as a possible virulence factor. The presence of the feline leukemia virus (FeLV) and/or vírus of feline immunodeficiency (FIV) weaken the function of the immune system, causing immunosuppression and therefore increased morbidity and mortality. This study evaluated four shelters, three catteries private non-commercial (one located in Osasco/SP and two in São Paulo/SP). Catteries possessed high population density and cats housed origin was unknown. The detection of FHV- 1 as three genes of the C. felis and cryptic plasmid was performed by PCR in oral mucosa and the ocular conjunctiva of both eyes obtained with cotton swabs, dried and sterile. Blood samples were collected for the detection of FeLV and FIV by enzyme immunoassay. The clinical symptoms of animals were classified from 1 to 4 , with 4 assigned to worst symptoms. The presence of the FIV and FeLV was in the first cattery 4.63% and 3.70%, in the second cattery was 0% and 6.45%, while in the third cattery was 75% and 0%, respectively, these viruses do not were detected in the 4th cattery. FHV- 1 was observed in 61.11 % of the cats in the first cattery; 90.32 % in the second cattery 100 % in the third and 89.74% of the animals of the fourth cattery. In the first cattery, 7.41% of the samples had C. felis, the second cattery, 58.06 %, in the fourth cattery, 23.08%, while the third cattery the agent was not detected. Among the samples positive for C. felis genes were detected cryptic plasmid; in the first cattery, the first gene was present in 62.50%, gene 2 and 3 in 75% of the samples; for the second cattery was obtained 61.11 % positive for 1 and 2 genes and 55.56 % to the third gene; in fourth cattery the first and the third genes were present at 77.78% of the samples in the second gene was in 55.56%. The deaths reported during the study period were classified in animals with symptoms 3 or 4 and positive for C. felis and the cryptic plasmid. In this study we observed a high incidence of C. felis and the cryptic plasmid, despite the low occurrence of FIV and FeLV in catteries.

Made available in DSpace on 2014-08-20T14:37:48Z (GMT). No. of bitstreams: 1 Dissertacao_fabio_silva.pdf: 518189 bytes, checksum: 5328c1b56ef14ad739bd14cb751dcd72 (MD5) Previous issue date: 2012-02-24 / The feline immunodeficiency virus belongs to the Retroviridae family, Lentivirus gennus and presents molecular structure and pathogenicity similar to the human immunodeficiency virus (HIV), therefore it is not transmissible to humans, being susceptible only the domestic and feral cats. FIV is classified in five phylogenetically different subtypes from A to E spread worldwide, apart from recombinant strains among the subtypes. Recently, two new subtypes were described, the subtype F identified in the United States and Portugal, and the subtype U-NZenv in New Zealand. Considering that the retroviruses have the ability to integrate the cell genome, under double stranded DNA form, it is possible to detect the provirus in infected leucocytes through the polymerase chain reaction (PCR) technique. The present report investigated the occurrence of the feline immunodeficiency virus infection between 2010 and 2011 in domestic cats submitted to medical treatment at the Hospital of Veterinary Clinics of the Federal University of Pelotas and private clinics from Pelotas, RS. Blood samples of seventy animals, healthy or sick, were collected and subjected to the nested-PCR technique. The tested cats were classified in two groups taking into account their clinical condition: the group 1 represented 28 FIV suspect cats with lymphadenomegaly, neurological disorders or chronic and recurring infections. The results pointed out a FIV infection frequency of 15,7% (11/70). Eight of the positive samples were subjected to molecular characterization, being all of them into the subtype B. The most diagnosed clinical manifestations in the cats that developed disease related to FIV were bronchopulmonar (4/10) and cutaneous (3/10) secondary infections. Another clinical disorders observed in the positive animals were gingivitis, uveitis, anemia and icterus. The FIV infected cats presented 30% of lethality during the period of study. Most of the infected cats were up to 10 years of age. Faced with the data shown in this report we could conclude that the subtype B of the feline immunodeficiency virus presents circulation in the domestic cat population of the south region of Rio Grande do Sul and elderly animals affected by chronic or recurring infections must be FIV tested. / O vírus da imunodeficiência felina pertence à família Retroviridae, gênero Lentivirus e apresenta estrutura molecular e patogenia similar ao vírus da imunodeficiência humana (HIV), entretanto não é transmissível ao homem, sendo suscetíveis somente os felinos domésticos e selvagens. O FIV é classificado em cinco subtipos filogeneticamente diferentes de A a E, distribuídos mundialmente, além de cepas com recombinações entre os subtipos. Recentemente dois novos subtipos foram descritos, o subtipo F identificado nos Estados Unidos e Portugal, e o subtipo U-NZenv na Nova Zelândia. Considerando-se que os retrovírus têm a capacidade de integrar-se ao genoma celular, sob a forma de DNA de dupla fita, é possível a detecção do provírus em leucócitos infectados, através da técnica de reação em cadeia da polimerase (PCR). O presente trabalho investigou a ocorrência de infecção pelo vírus da imunodeficiência felina, entre os anos de 2010 e 2011, em gatos domésticos levados para atendimento médico no Hospital de Clínicas Veterinária da Universidade Federal de Pelotas e clínicas privadas da cidade de Pelotas, RS. Amostras de sangue de 70 animais, entre hígidos e doentes, foram colhidas e submetidas à técnica de nested-PCR. Os gatos testados foram classificados em dois grupos quanto à condição clínica: o grupo 1 foi representado por 28 felinos suspeitos de FIV, diagnosticados com linfoadenomegalia, sinais neurológicos ou com infecções crônicas e recidivantes; o grupo 2 representado por 42 animais livres de sintomatologia relacionada a FIV. Os resultados apontaram uma frequência de infecção pelo FIV de 15,7% (11/70). Das amostras positivas, 8 foram submetidas à caracterização molecular, sendo todas alocadas dentro do subtipo B. As manifestações clínicas mais diagnosticadas nos felinos que desenvolveram doença relacionada a FIV, foram as infecções secundárias broncopulmonares (4/10) e cutâneas (3/10). Outras alterações clínicas identificadas em animais positivos foram gengivite, uveíte, anemia e icterícia. Os animais infectados por FIV apresentaram letalidade de 30% durante o período de estudo. Em relação à faixa etária a maior proporção de felinos infectados apresentava idade superior a 10 anos. Diante dos dados apresentados conclui-se que o subtipo B do vírus da imunodeficiência felina apresenta circulação na população de gatos domésticos da região sul do Rio Grande do Sul, e que animais idosos acometidos por infecções crônicas ou recidivantes devem ser testados para esse agente.

Thesis (M.Med. (Radiation Oncology)) -- University of Limpopo, 2020 / Introduction Invasive cervical cancer (ICC) constitutes almost 50% of all cancer conditions diagnosed and treated at the Polokwane/Mankweng Hospital Complex (PMHC). HIV infection is also a very common condition. There is no consensus on the relationship between the two clinical conditions among patients treated at PMHC. There is a need to describe the simultaneous occurrence of the two clinical conditions among these patients to define a rational approach to these conditions’ clinical management. Methodology This was a retrospective review of medical records of patients diagnosed with ICC who were treated at PMHC in Limpopo Province, South Africa in 2013. Results Three hundred and twenty-nine medical records were reviewed in this study; 64% of the patients were HIV-negative, and only 35% were HIV-positive. Thirty-five percent of the patients were younger than 50 years of age, followed by those aged 50–59 years (23%). Among women in the age group 30–59 years, the most common ICC stages were IIB and IIIB. In women older than 60 years, stages IIB, IIIA, IIIB and IVA were the most common. In the HIV-positive women, 18% had a CD4 cell count of less than 200/μL, compared to 2% in the HIV-negative women (p <0.05). Among the HIV-negative women, stages IIIB (49.8%) and IIB (24.6%) were the most common, where as among those who were HIV-positive, stages IIIB (55.6%) and IIB (22.6%) dominated. Conclusion This retrospective study did not find any relationship between HIV infection and ICC in patients treated at PMHC. However, it indicated that a significant proportion of HIV-positive women with ICC had lower CD4 cell counts compared to those of HIV-negative women. KEY CONCEPTS: Invasive cervical cancer, Human immunodeficiency virus, Stage, Prevalence, CD4 cell count, Age, Polokwane/Makweng Hospital Complex

Shelters often make euthanasia or adoption decisions based on the results of FeLV-FIV point-of-care tests but given the low estimated prevalence of these diseases and imperfect test performance, this might not be a good practice because of diagnostic error. The objectives of this study were to determine the true prevalence of FeLV and FIV in apparently healthy and sick shelter cats in Mississippi, estimate predictive value of the Zoetis Witness FeLV-FIV Rapid ImmunoMigration test results at the estimated true prevalences through Bayesian latent class modeling, and formulate testing recommendations for shelters. One chapter will review the literature on FeLV and FIV. The bulk of this thesis will focus on determining the true prevalence of retroviral infection in Mississippi shelter cat populations. The last chapter will use Bayesian modeling to estimate test performance and predictive value of test results in healthy and sick shelter cat populations.

No description available.

De nombreux parasites circulent dans les populations naturelles. Au sein d’un hôte, souvent pluri-infecté, ils peuvent interagir, augmentant ou réduisant le risque d’infection et les symptômes d’autres pathogènes. L’étude de ces interactions commence seulement dans les populations naturelles. Les enjeux sont cruciaux : détecter les interactions d’intérêt, estimer la probabilité de coinfection, comprendre la cocirculation des parasites. La détection des interactions sur le terrain est compliquée par la nature des données (e.g., présence-absence) et les facteurs confondants créant des associations statistiques (fausses interactions). Ce travail visait à mener une réflexion transversale sur ces interactions et le multiparasitisme, avec des applications à des données sérologiques pour 4 virus félins suivis dans des populations rurales de chats domestiques. De nouvelles méthodes de modélisation dynamique et statistique ont été développées pour prendre en compte les facteurs générant de fausses interactions (effet cumulatif de l’âge, facteurs de risque communs) et évaluer le biais des méthodes classiques. Des synergies entre 3 couples de virus félins ont été révélées. On a aussi identifié des caractéristiques comportementales et physiologiques (modes de vie, niveau de testostérone), qui, en modulant l’exposition et la sensibilité aux pathogènes, génèrent une forte hétérogénéité entre les hôtes. Enfin, une vision intégrative des systèmes hôte-parasites est indispensable pour appréhender la complexité des communautés et évaluer l’impact de la multitude d’hôtes, de parasites et d’interactions sur la coévolution, la conservation des espèces et la gestion des maladies infectieuses / Numerous parasites circulate within natural host populations. Within a host, often pluri-infected, parasites can interact, increasing or decreasing the infection risk and/or symptoms’ severity of other pathogens. Studies of such interactions only start in natural populations. Their stakes are high: detecting interactions of interest, estimating coinfection probabilities and understanding the cocirculation of parasites. The detection of interactions in the field is however complicated by the nature of data (often presence-absence) and the existence of confounding factors that can create statistical associations (false interactions). This work aimed at having a cross-cutting reflection on those interactions and on multiparasitism, with applications on a rich dataset of four feline viruses followed in rural populations of domestic cats. New dynamical and statistical modeling methods were developed to take into account factors generating false interactions (cumulative effect of age, shared risk factors) and evaluate the biases of classical methods. Synergies between three pairs of feline viruses were revealed. In addition, we identified behavioral and physiological factors (e.g., way of life, testosterone levels) that, by modulating exposition and/or susceptibility to pathogens, generate strong heterogeneity between hosts. Finally, a more integrative approach to host-parasites systems is proposed. It now appears necessary if one wants to deal with communities’ complexity and further evaluate the impact of multiple hosts, multiple parasites and their interactions on their coevolution, species conservation and infectious diseases management

Dans la cellule, les ARN pré messagers contenant des introns sont normalement retenus au noyau par leur interaction avec des facteurs d’épissage. Cependant, les ARN partiellement et non épissés des rétrovirus doivent entrer dans le cytoplasme pour servir de matrice pour la synthèse de certaines protéines telles que Env, Gag et Gag-Pol ainsi que d’ARN génomique qui sera empaqueté dans les nouveaux virions. Un mécanisme post-transcriptionnel utilisé par les lentivirus pour éviter la séquestration nucléaire de ces ARNm dépend d’une protéine virale appelée Rev. Pour assurer sa fonction d’exportation, Rev doit transiter entre le noyau et le cytoplasme et doit aussi pouvoir former des multimères. Par conséquent, Rev est dotée de domaines fonctionnels lui procurant ces habiletés. On retrouve le domaine riche en arginines qui contient le domaine de liaison à l’ARN et le signal de localisation nucléaire (NLS), un second domaine, riche en leucines, porte le signal d’exportation nucléaire (NES) et finalement le domaine de multimérisation. Bien que les protéines Rev du virus de l’immunodéficience humaine de type 1 (VIH-1) et bovine (VIB) aient été caractérisées, aucune étude n’a été réalisée pour la protéine Rev du virus de la maladie de Jembrana (JDV) et très peu sur le virus de l’immunodéficience féline (VIF). Comme les domaines fonctionnels et la voie d’importation des protéines Rev déjà caractérisées sont différents, nous supposons que chaque protéine Rev possède une organisation qui lui est propre et que les mécanismes de transport nucléo-cytoplasmique diffèrent entre les virus. Ce projet a pour objectif de caractériser ces domaines pour la protéine Rev du JDV et ceux du VIF ainsi que les mécanismes permettant leur transport nucléaire. L’utilisation de mutants de la protéine Rev de ces virus couplés à la protéine de fluorescente verte (EGFP) exprimés dans des cellules appropriées et observés par microscopie a permis d’identifier des séquences NLS et NES différentes de celles déjà caractérisées. Le NLS de la protéine Rev du JDV a été identifié et est composé des résidus arginines de la séquence 76-RRPARRPPIRR-87 avec un NoLS composé des mêmes résidus en plus des arginines R74, R103 et R104. Son NES est composé des résidus hydrophobes de la séquence 116-MAELEERFEDLAL-128 et est du type de l’inhibiteur de la protéine kinase (PKI pour « protéine kinase inhibitor »). Pour la protéine Rev du VIF, son NLS est composé des résidus basiques de la séquence 84-KKKRQRRRRKKKAFKK-99. Le NoLS est composé des mêmes acides aminés en plus du résidu K82. De plus, les essais d’importation nucléaires et d’interaction semblent indiquer que les voies d’importation utilisées diffèrent entre les virus et que plusieurs voies peuvent être utilisées. Ces travaux pourront éventuellement servir de base pour identifier de nouvelles cibles thérapeutiques contre les lentivirus. / In the cell, pre-messenger RNAs containing introns are normally retained in the nucleus by their interaction with splicing factors. However, the partially and unspliced ​​RNAs of retroviruses must enter the cytoplasm to serve as a template for the synthesis of certain proteins such as Env, Gag and Gag-Pol as well as genomic RNA to be packaged in the new virions. A post-transcriptional mechanism used by lentiviruses to prevent nuclear sequestration of these mRNAs depends on a trans-activator, the viral protein Rev. To ensure its export function, Rev must be able to shuttle between the nucleus and the cytoplasm and to form multimers. As a result, Rev has functional domains that provide these abilities: the arginine-rich domain, which contains the RNA binding domain and the nuclear localization signal (NLS), a second domain, rich in leucine, corresponding to the nuclear export signal (NES) and finally the multimerization domain. Although the Rev proteins of the human and bovine immunodeficiency virus (HIV-1 and BIV respectively) have been characterized, no studies have been performed for the Jembrana disease virus (JDV) Rev protein and very little on the feline immunodeficiency virus (FIV). Since the functional domains and import pathway of the already characterized Rev proteins are different, we assume that each Rev protein has its own organization and that the nucleo-cytoplasmic transport mechanisms differ between viruses. The goal of this project is to characterize these domains for the JDV and FIV Rev proteins as well as to elucidate mechanisms for their nuclear transport. The use of Rev mutants fused to the EGFP expressed in appropriate cells and observed by microscopy has identified NLS and NES sequences that differ from those already characterized. JDV Rev NLS is composed of arginine residues in the 76-RRPARRPPIRR-87 sequence with a NoLS composed of the same residues with the addition of arginine R74, R103 and R104. JDV Rev NES is composed of hydrophobic residues in the 116-MAELEERFEDLAL-128 sequence and is of the protein kinase inhibitor type (PKI). For the FIV Rev protein, its NLS is composed of basic residues in the 84-KKKRQRRRRKKKAFKK-99 sequence. FIV Rev NoLS is composed of the same residues with the addition of the lysine at position 82. In addition, the nuclear import and interaction tests suggest that the import routes used by Rev differ between the different viruses studied and that more than one import pathway may be used. This work could serve as a basis for identifying new therapeutic targets against lentiviruses.