Visualizing spatiotemporal dynamics of apoptosis after G1 arrest by human T cell leukemia virus type 1 Tax and insights into gene expression changes using microarray-based gene expression analysis

BACKGROUND: Human T cell leukemia virus type 1 (HTLV-1) Tax is a potent activator of viral and cellular gene expression that interacts with a number of cellular proteins. Many reports show that Tax is capable of regulating cell cycle progression and apoptosis both positively and negatively. However, it still remains to understand why the Tax oncoprotein induces cell cycle arrest and apoptosis, or whether Tax-induced apoptosis is dependent upon its ability to induce G1 arrest. The present study used time-lapse imaging to explore the spatiotemporal patterns of cell cycle dynamics in Tax-expressing HeLa cells containing the fluorescent ubiquitination-based cell cycle indicator, Fucci2. A large-scale host cell gene profiling approach was also used to identify the genes involved in Tax-mediated cell signaling events related to cellular proliferation and apoptosis. RESULTS: Tax-expressing apoptotic cells showed a rounded morphology and detached from the culture dish after cell cycle arrest at the G1 phase. Thus, it appears that Tax induces apoptosis through pathways identical to those involved in G1 arrest. To elucidate the mechanism(s) by which Tax induces cell cycle arrest and apoptosis, regulation of host cellular genes by Tax was analyzed using a microarray containing approximately 18,400 human mRNA transcripts. Seventeen genes related to cell cycle regulation were identified as being up or downregulated \u3e 2.0-fold in Tax-expressing cells. Several genes, including SMAD3, JUN, GADD45B, DUSP1 and IL8, were involved in cellular proliferation, responses to cellular stress and DNA damage, or inflammation and immune responses. Additionally, 23 pro- and anti-apoptotic genes were deregulated by Tax, including TNFAIP3, TNFRS9, BIRC3 and IL6. Furthermore, the kinetics of IL8, SMAD3, CDKN1A, GADD45A, GADD45B and IL6 expression were altered following the induction of Tax, and correlated closely with the morphological changes observed by time-lapse imaging. CONCLUSIONS: Taken together, the results of this study permit a greater understanding of the biological events affected by HTLV-1 Tax, particularly the regulation of cellular proliferation and apoptosis. Importantly, this study is the first to demonstrate the dynamics of morphological changes during Tax-induced apoptosis after cell cycle arrest at the G1 phase

Seroprevalence of ruminant pestivirus in breeding sheep in the central sierra of Peru

El objetivo del presente estudio fue determinar la frecuencia de los virus de la Diarrea Viral Bovina (VDVB) y de la Enfermedad de la Frontera (VEF) en ovinos reproductores procedentes de una empresa ovejera de la sierra central del país. Se colectaron muestras de sangre de ovinos reproductores hembras (n=165) y machos (n=165) aparentemente sanos, con un promedio de edad de cuatro años, y criados en forma extensiva. Los anticuerpos contra VDVB y VEF se detectaron mediante la prueba de neutralización viral. El 2.1 ± 1.5% (7/330) y 28.5 ± 4.9% (94/330) de ovinos reproductores tuvieron anticuerpos contra el VDVB y VEF, respectivamente, con títulos de anticuerpos de 1:2 a 1:16. Se encontró asociación significativa entre el sexo del animal y la presencia de anticuerpos contra el VEF (hembras: 53.3 ± 7.6%; machos: 3.6 ± 2.9%) (p<0.05).The aim of the present study was to determine the prevalence of Bovine Viral Diarrhea virus (BVDV) and Border Disease virus (BDV) in breeding sheep from a large cooperative farm in the central highlands of Peru. Blood samples from apparently healthy sheep of 4 years old, both sexes (female = 165; male = 165) were collected for antibodies detection against BVDV and BDV using the virus neutralisation test. The 2.1 ± 1.5% (7/330) and 28.5 ± 4.9% (94/330) of breeding sheep had antibodies against BVDV and BDV respectively, with antibodies titers of 1:2 and 1:16. There was significant association between sex and presence of antibodies against BDV (females: 53.3 ± 7.6%; males: 3.6 ± 2.9%) (p<0.05)

FRECUENCIA DE Leptospira spp EN PORCINOS DE CRIANZA TECNIFICADA Y DE TRANSPATIO BENEFICIADOS EN DOS MATADEROS DE LIMA.

The objective of this study was to determine the frequency of antibodies against Leptospira spp in pigs reared in five well-managed farms (n=163) and from 11 backyard breeding (n=133) owners in the Lima valley, Peru. Blood samples (n=296) were collected in two slaughterhouses for antibody detection against eight serovars of Leptospira by microaglutination test. The 85.8 ± 3.9% (254/296) of samples had antibodies against one or more serovars of Leptospira. The 89.6 ± 4.7% (146/163) and 82.1 ± 6.5% (108/133) of samples from well-managed farms and from backyard breeding pigs showed antibodies against Leptospira spp. The serovars icterohaemorrhagiae, pomona, and georgia were the most frequently detected in both groups of pigs. No antibodies were detected against serovars bratislava and grippothyphosa. Antibody titres ranged from 100 to 400, being the highest titles (800 to 1600) detected more frequently in backyard breeding pigs. Serovars icterohaemorrhagiae and pomona were the most common mixed infections found for both type of breeding systems. There were no association between antibodies against Leptospira and type of pig breeding system.El objetivo del estudio fue determinar la frecuencia de anticuerpos contra Leptospira spp en porcinos provenientes de crianza tecnificada (5 granjas, n=163) y de traspatio (11 criaderos, n=133) del valle de Lima. Se colectaron muestras de sangre de porcinos (n=296) durante el beneficio en dos mataderos de la ciudad de Lima, para la detección de anticuerpos contra ocho serovares de Leptospira mediante la prueba de microaglutinación. El 85.8 ± 3.9% (254/296) de las muestras fue positivo a uno o más serovares de Leptospira. El 89.6 ± 4.7% (146/163) y el 82.1 ± 6.5% (108/133) de las muestras de porcinos de crianza tecnificada y de traspatio, respectivamente, tuvieron anticuerpos contra Leptospira. Los serovares icterohaemorrhagiae, pomona y georgia fueron los más frecuentes en ambos tipos de crianza. No se detectaron anticuerpos contra los serovares bratislava y grippothyphosa. Los títulos de anticuerpos tuvieron un rango entre 100 a 400 en ambos tipos de crianza, pero títulos de anticuerpos de 800 a 1600 fueron detectados con mayor frecuencia en animales de traspatio. La combinación icterohaemorrhagiae y pomona fue la más común en ambos tipos de crianza. No hubo asociación entre la presencia de anticuerpos contra Leptospira y la procedencia de los porcinos evaluados

DINÁMICA DE SEROCONVERSIÓN EN HEMBRAS BOVINAS POST ELIMINACIÓN DE ANIMALES PORTADORES DEL VIRUS DE LA DIARREA VIRAL BOVINA

El objetivo del presente estudio fue determinar el efecto de la eliminación de los animales portadores del virus de la diarrea viral bovina (VDVB) sobre la seroconversión contra el virus en la nueva generación de animales de un establo lechero de crianza intensiva en Arequipa. Se colectaron muestras de suero a vaquillas entre 6 a 12 meses de edad en cuatro periodos: enero (n=73), junio (n=48) y octubre (n=48) del 2003 y enero del 2004 (n=35) para la detección de anticuerpos contra el VDVB y para la detección de animales portadores (PI) del virus, mediante las pruebas de neutralizaciónviral y ELISA captura de antigeno, respectivamente. La seroprevalencia del VDVB fue de 80.8 + 9.0, 56.3 + 14.0,50.0+ 14.2 y 22.9+ 13.9%en el primero, segundo, tercero y cuarto periodo de muestreo, respectivamente. La prevalencia de animales portadores del virus fue de 2.7% (2173) y fueron detectados únicamente en el grupo muestreado en enero del 2003. La incidencia de infección de VDVB fue 121100 (24159) al mes en el periodo enero 2003 a enero 2004. Mediante la pruebas de regresión logística se demostró que la eliminación de animales PI en enero del 2003 redujo el riesgo de infección en los animales susceptibles en los siguientes periodos de muestreo. Además, la edad mostró ser un factor de riesgo para la infección con VDVB. Los resultados indican que la infección con VDVB es altamente prevalente en hatos que albergan animales portadores y que su eliminación reduce el riesgo de infección en el resto de animales, como se describe en la literatura. Los resultados sugieren que es posible el control y erradicación de la DVB en hatos lecheros de crianza intensiva mediante la identificación y eliminación de los animales portadores y sin vacunación pero manteniendo un alto nivel de bioseguridad en el establo.A study was conducted to determine the effect of culling BVDV carrier animals on the seroconversion against BVDV in the new generation of heifers from a dairy herd located in Arequipa, Peru. Blood samples were collected to 6-12 month old females in four sampling periods: January (n=73), June (n=48), October 2003 (n=48), and January 2004 (n=35) to evaluate their serological status against BVDV and to screen for carrier animals using the virus neutralization and antigen-capture ELISA tests, respectively. The prevalence of BVDV was 80.8 ± 9.0, 56.3 ± 14.0, 50.0 ± 14.2 and 22.9 ± 13.9% in the first, second, third and fourth sampling period, respectively. There were 2.7% (2/73) of carrier heifers in the group sampled in January 2003, and none in the subsequent sampling periods. The incidence of BVDV infection was 12/100 heifers per month from January 2003 till January 2004. The logistic regression test showed that culling of carrier animals in January 2003 reduced the risk of infection in subsequent months. In addition, age was a risk factor for VDVB infection in this group of animals. The results showed that BVDV infection is highly prevalent in herds having carrier animals, and that the culling of PI animals reduce the risk of infection in herd mates as indicated in the literature. The results also suggest that the control and eradication of BVDV in intensive management dairy herds may be possible by identifying and culling carrier animals and without vaccination but ensuring high level of biosecurity

A new genotype of bovine leukemia virus in South America identified by NGS-based whole genome sequencing and molecular evolutionary genetic analysis

Background: Bovine leukemia virus (BLV) is a member of retroviridae family, together with human T cell leukemia virus types 1 and 2 (HTLV-1 and -2) belonging to the genes deltaretrovirus, and infects cattle worldwide. Previous studies have classified the env sequences of BLV provirus from different geographic locations into eight genetic groups. To investigate the genetic variability of BLV in South America, we performed phylogenetic analyses of whole genome and partial env gp51 sequences of BLV strains isolated from Peru, Paraguay and Bolivia, for which no the molecular characteristics of BLV have previously been published, and discovered a novel BLV genotype, genotype-9, in Bolivia. Results: In Peru and Paraguay, 42.3 % (139/328) and over 50 % (76/139) of samples, respectively, were BLV positive. In Bolivia, the BLV infection rate was up to 30 % (156/507) at the individual level. In Argentina, 325/420 samples were BLV positive, with a BLV prevalence of 77.4 % at the individual level and up to 90.9 % at herd level. By contrast, relatively few BLV positive samples were detected in Chile, with a maximum of 29.1 % BLV infection at the individual level. We performed phylogenetic analyses using two different approaches, maximum likelihood (ML) tree and Bayesian inference, using 35 distinct partial env gp51 sequences from BLV strains isolated from Peru, Paraguay, and Bolivia, and 74 known BLV strains, representing eight different BLV genotypes from various geographical locations worldwide. The results indicated that Peruvian and Paraguayan BLV strains were grouped into genotypes-1, -2, and -6, while those from Bolivia were clustered into genotypes-1, -2, and -6, and a new genotype, genotype-9. Interestingly, these results were confirmed using ML phylogenetic analysis of whole genome sequences obtained by next generation sequencing of 25 BLV strains, assigned to four different genotypes (genotypes-1, -2, -6, and -9) from Peru, Paraguay, and Bolivia. Comparative analyses of complete genome sequences clearly showed some specific substitutions, in both structural and non-structural BLV genes, distinguishing the novel genotype-9 from known genotypes. Conclusions: Our results demonstrate widespread BLV infection in South American cattle and the existence of a new BLV genotype-9 in Bolivia. We conclude that at least seven BLV genotypes (genotypes-1, -2, -4, -5, -6, -7, and -9) are circulating in South America.Facultad de Ciencias VeterinariasInstituto de Genética Veterinari

A new genotype of bovine leukemia virus in South America identified by NGS-based whole genome sequencing and molecular evolutionary genetic analysis

Background: Bovine leukemia virus (BLV) is a member of retroviridae family, together with human T cell leukemia virus types 1 and 2 (HTLV-1 and -2) belonging to the genes deltaretrovirus, and infects cattle worldwide. Previous studies have classified the env sequences of BLV provirus from different geographic locations into eight genetic groups. To investigate the genetic variability of BLV in South America, we performed phylogenetic analyses of whole genome and partial env gp51 sequences of BLV strains isolated from Peru, Paraguay and Bolivia, for which no the molecular characteristics of BLV have previously been published, and discovered a novel BLV genotype, genotype-9, in Bolivia. Results: In Peru and Paraguay, 42.3 % (139/328) and over 50 % (76/139) of samples, respectively, were BLV positive. In Bolivia, the BLV infection rate was up to 30 % (156/507) at the individual level. In Argentina, 325/420 samples were BLV positive, with a BLV prevalence of 77.4 % at the individual level and up to 90.9 % at herd level. By contrast, relatively few BLV positive samples were detected in Chile, with a maximum of 29.1 % BLV infection at the individual level. We performed phylogenetic analyses using two different approaches, maximum likelihood (ML) tree and Bayesian inference, using 35 distinct partial env gp51 sequences from BLV strains isolated from Peru, Paraguay, and Bolivia, and 74 known BLV strains, representing eight different BLV genotypes from various geographical locations worldwide. The results indicated that Peruvian and Paraguayan BLV strains were grouped into genotypes-1, -2, and -6, while those from Bolivia were clustered into genotypes-1, -2, and -6, and a new genotype, genotype-9. Interestingly, these results were confirmed using ML phylogenetic analysis of whole genome sequences obtained by next generation sequencing of 25 BLV strains, assigned to four different genotypes (genotypes-1, -2, -6, and -9) from Peru, Paraguay, and Bolivia. Comparative analyses of complete genome sequences clearly showed some specific substitutions, in both structural and non-structural BLV genes, distinguishing the novel genotype-9 from known genotypes. Conclusions: Our results demonstrate widespread BLV infection in South American cattle and the existence of a new BLV genotype-9 in Bolivia. We conclude that at least seven BLV genotypes (genotypes-1, -2, -4, -5, -6, -7, and -9) are circulating in South America.Facultad de Ciencias VeterinariasInstituto de Genética Veterinari

A mature macrophage is a principal HIV-1 cellular reservoir in humanized mice after treatment with long acting antiretroviral therapy

BACKGROUND: Despite improved clinical outcomes seen following antiretroviral therapy (ART), resting CD4+ T cells continue to harbor latent human immunodeficiency virus type one (HIV-1). However, such cells are not likely the solitary viral reservoir and as such defining where and how others harbor virus is imperative for eradication measures. To such ends, we used HIV-1(ADA)-infected NOD.Cg-Prkdc (scid) Il2rg (tm1Wjl)/SzJ mice reconstituted with a human immune system to explore two long-acting ART regimens investigating their abilities to affect viral cell infection and latency. At 6 weeks of infection animals were divided into four groups. One received long-acting (LA) cabotegravir (CAB) and rilpivirine (RVP) (2ART), a second received LA CAB, lamivudine, abacavir and RVP (4ART), a third were left untreated and a fourth served as an uninfected control. After 4 weeks of LA ART treatment, blood, spleen and bone marrow (BM) cells were collected then phenotypically characterized. CD4+ T cell subsets, macrophages and hematopoietic progenitor cells were analyzed for HIV-1 nucleic acids by droplet digital PCR. RESULTS: Plasma viral loads were reduced by two log(10) or to undetectable levels in the 2 and 4ART regimens, respectively. Numbers and distributions of CD4+ memory and regulatory T cells, macrophages and hematopoietic progenitor cells were significantly altered by HIV-1 infection and by both ART regimens. ART reduced viral DNA and RNA in all cell and tissue compartments. While memory cells were the dominant T cell reservoir, integrated HIV-1 DNA was also detected in the BM and spleen macrophages in both regimen-treated mice. CONCLUSION: Despite vigorous ART regimens, HIV-1 DNA and RNA were easily detected in mature macrophages supporting their potential role as an infectious viral reservoir. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s12977-017-0344-7) contains supplementary material, which is available to authorized users