RESUMO
Bovines infected by bovine leukemia virus (BLV) are characterized by presenting low proviral load (LPL) or high proviral load (HPL). It is reported that animals with HPL in peripheral blood mononuclear cells (PBMCs) present a decrease in apoptosis, an increase in viability and the proliferation rate, while animals that maintain an LPL have an intrinsic ability to control the infection, presenting an increased apoptosis rate of their PBMCs. However, there is little information on the effect of BLV on these mechanisms when the virus infects somatic milk cells (SC). This study investigates the mechanisms underlying apoptosis in milk and blood from BLV-infected animals with HPL and LPL. Relative levels of mRNA of tumor necrosis factor-α (TNF-α), TNF receptor 1 (TNF-RI), TNF receptor 2 (TNF-RII), anti-apoptotic B-cell lymphoma 2 protein (Bcl-2), and pro-apoptotic Bcl-2-like protein 4 (Bax) were measured in SC and PBMCs using quantitative reverse transcription-polymerase chain reaction (RT-qPCR) assay. A significant decrease in the expression of TNF-α in SC from HPL animals vs non-infected bovines was observed, but the infection in SC with BLV did not show a modulation on the expression of TNF receptors. A significant increase in TNF-RI expression in PBMCs from HPL bovines compared to LPL bovines was observed. No significant differences in PBMCs between HPL and LPL compared to non-infected animals concerning TNF-α, TNF-RI, and TNF-RII expression were found. There was a significant increase of both Bcl-2 and Bax in SC from LPL compared to non-infected bovines, but the Bcl-2/Bax ratio showed an anti-apoptotic profile in LPL and HPL bovines compared to non-infected ones. Reduced mRNA expression levels of Bax were determined in the PBMCs from HPL compared to LPL subjects. In contrast, BLV-infected bovines did not differ significantly in the mRNA expression of Bax compared to non-infected bovines. Our data suggest that the increased mRNA expression of Bax corresponds to the late lactation state of bovine evaluated and the exacerbated increase of mRNA expression of Bcl-2 may be one of the mechanisms for the negative apoptosis regulation in the mammary gland induced by BLV infection. These results provide new insights into the mechanism of mammary cell death in HPL and LPL BLV-infected bovine mammary gland cells during lactation.
Assuntos
Doenças dos Bovinos , Leucose Enzoótica Bovina , Vírus da Leucemia Bovina , Animais , Bovinos , Feminino , Apoptose , Proteína X Associada a bcl-2/metabolismo , Proliferação de Células , Leucócitos Mononucleares/metabolismo , Leite , Provírus/genética , Provírus/metabolismo , Receptores Tipo II do Fator de Necrose Tumoral/metabolismo , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Production of antimicrobial peptides cathelicidins, interferons and cytokines is an important feature in airway epithelial host defense. The innate immune response to alpha-herpesvirus infection at the sites of primary replication has not been fully studied. Thus, the aim of this study was to determine the expression of innate immune components, cathelicidins, IFNß, TNFα and TNF receptors (TNFRI and TNFRII) during acute infection and reactivation of bovine herpesvirus type 1 (BoHV-1) and 5 (BoHV-5) in the respiratory tract and lymphoid tissue of their natural host. We found that BoHV infection modulates mainly the expression of BMAP28, a key cathelicidin in cattle. It was downregulated by both viruses in retropharyngeal lymph nodes of acutely infected-calves, and it was accompanied by a lower expression of IFNß, TNFα and TNFRI. BoHV-5 showed a pronounced role in the downregulation of BMAP28, even in nasal mucosa and lung. However, during reactivation, BoHV-5 upregulated both BMAP28 and IFNß in retropharyngeal lymph nodes. Acute replication induced also TNFα mRNA and protein synthesis, and expression of TNFRI and II was positively regulated during both acute infection and reactivation, particularly in the trachea. Moreover, BMAP27 was detected during BoHV-1 reactivation suggesting a potential role at this stage. Thus, cathelicidins are implicated in alpha-herpesvirus infections of the bovine respiratory system and the response is distinct during BoHV-1 and BoHV-5 acute infection and reactivation. This demonstrates that these viruses modulate differentially the components of innate immune response, possibly influencing their pathogenesis. This study provides an initial pilot analysis of factors that might be implicated in alpha-herpesvirus infection of the bovine respiratory system.
Assuntos
Catelicidinas/imunologia , Doenças dos Bovinos/imunologia , Infecções por Herpesviridae/imunologia , Herpesvirus Bovino 1/imunologia , Interferon beta/imunologia , Fator de Necrose Tumoral alfa/imunologia , Animais , Bovinos , Citocinas/imunologia , Infecções por Herpesviridae/veterinária , Imunidade Inata/imunologia , Projetos Piloto , RNA Mensageiro/imunologia , Receptores do Fator de Necrose Tumoral/imunologia , Sistema Respiratório/imunologia , Sistema Respiratório/virologia , Regulação para Cima/imunologiaRESUMO
Due to the wide dissemination of bovine leukemia virus (BLV) infection among dairy cattle, control and eradication programs based on serological detection of infected cattle and subsequent culling face a major economic task. In Argentina, genetic selection of cattle carrying alleles of the bovine leukocyte antigen (BoLA) DRB3.2 gene associated with BLV-infection resistance, like *0902, emerges as the best additional tool toward controlling virus spread. A potential risk in expanding or segregating BoLA selected populations of cattle is that it might increase susceptibility to other common viruses. Special concern raises the strong association found between low proviral load and low antibody titer against major BLV structural proteins. This phenomenon might depend on host genetic factors influencing other viruses requiring, unlike BLV, strong and long-lasting humoral immune response to prevent infection. In this study, we demonstrate that there is no association among neutralizing antibody titers against foot and mouth disease virus, bovine viral diarrhea virus, or bovine herpesvirus type 1 and polymorphism of the BoLA DRB3.2 gene. Conversely, there is strong association between BoLA DRB3.2*0902 and low antibody titers against 2 BLV structural proteins--env gp51 and gag p24--to date, the best BLV resistance marker. There is also significant association between low antibody titers against gp51 and p24 and BoLA DRB3.2*1701 and low antibody titers against p24 and BoLA DRB3.2*1101 or 02. Our data suggest that increasing BoLA-selected BLV-resistant cattle or segregating BoLA-associated alleles to BLV susceptibility would not affect the resistance or the predisposition to bovine viral diarrhea virus, bovine herpesvirus type 1, or foot and mouth disease virus infection.
Assuntos
Anticorpos Antivirais/imunologia , Formação de Anticorpos/imunologia , Antígenos Virais/imunologia , Leucose Enzoótica Bovina , Antígenos HLA , Imunidade Inata/genética , Vírus da Leucemia Bovina/imunologia , Animais , Anticorpos Antivirais/sangue , Doença das Mucosas por Vírus da Diarreia Viral Bovina/genética , Bovinos , Vírus da Diarreia Viral Bovina Tipo 1/imunologia , Leucose Enzoótica Bovina/genética , Leucose Enzoótica Bovina/imunologia , Feminino , Febre Aftosa/genética , Vírus da Febre Aftosa/imunologia , Genótipo , Antígenos HLA/genética , Antígenos HLA/imunologia , Infecções por Herpesviridae/genética , Herpesvirus Bovino 1/imunologia , Polimorfismo GenéticoRESUMO
The aim of this study was to evaluate the prevalence of human immunodeficiency virus (HIV)-Trypanosoma cruzi co-infection in a Buenos Aires health center. A retrospective analysis of the clinical charts of 602 HIV-infected patients was performed. Only 51.3% of the patients were evaluated against T. cruzi. The global co-infection prevalence was 4.2%, being more frequent among injectable drug users (IDU) (8.9% vs. 2.6%, < 0.05). The indication of T. cruzi testing should be stressed for HIV-infected patients, especially in those centers where IDU are assisted.
Assuntos
Doença de Chagas/complicações , Doença de Chagas/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Argentina , Feminino , Humanos , Masculino , Prevalência , Estudos RetrospectivosRESUMO
Se evaluó la prevalencia de coinfección virus de la inmunodeficiencia humana (VIH)- Trypanosoma cruzi ( T. cruzi) en pacientes atendidos en un centro asistencial de Buenos Aires, Argentina. Se realizó un análisis retrospectivo de las historias clínicas de 602 individuos VIH positivos. Sólo en el 51,3% de estos pacientes se había investigado la presencia de T. cruzi. La prevalencia global de coinfección fue del 4,2%, siendo más elevada en usuarios de drogas inyectables (UDI) (8,9% vs. 2,6%, p<0,05). Sobre la base de estos resultados, concluimos que debería enfatizarse el cumplimiento de la indicación de diagnóstico para la enfermedad de Chagas en pacientes VIH positivos, especialmente en UDI.
The aim of this study was to evaluate the prevalence of human immunodeficiency virus (HIV)- Trypanosoma cruzi co-infection in a Buenos Aires health center. A retrospective analysis of the clinical charts of 602 HIV-infected patients was performed. Only 51.3% of the patients were evaluated against T. cruzi. The global co-infection prevalence was 4.2%, being more frequent among injectable drug users (IDU) (8.9% vs. 2.6%, p<0.05). The indication of T. cruzi testing should be stressed for HIV-infected patients, especially in those centers where IDU are assisted.
Assuntos
Feminino , Humanos , Masculino , Doença de Chagas/complicações , Doença de Chagas/epidemiologia , Infecções por HIV/complicações , Infecções por HIV/epidemiologia , Abuso de Substâncias por Via Intravenosa/complicações , Abuso de Substâncias por Via Intravenosa/epidemiologia , Argentina , Prevalência , Estudos RetrospectivosRESUMO
Bovine leukaemia virus (BLV) causes lymphosarcoma and persistent lymphocytosis (PL). Some MHC class II gene polymorphisms have been associated with resistance and susceptibility to the development of lymphosarcoma and PL, as well as with a reduced number of circulating BLV-infected lymphocytes. Previously, 230 BLV-infected Holstein cattle were classified into two infection profiles characterized by low and high proviral loads (LPL and HPL respectively). Here, the influence of the polymorphism at the BoLA-DRB3.2* gene of these animals was examined. After genotyping, the association between the BoLA-DRB3.2* alleles and the BLV infection profile was determined as the odds ratio (OR). Two subtypes of allele *11 were identified (ISAG*0901 and *0902). Allele ISAG*0902 showed a stronger association with the LPL profile (OR = 8.24; P < 0.0001) than allele *11 itself (OR = 5.82; P < 0.0001). Allele ISAG*1701 (*12) also showed significant association with the LPL profile (OR = 3.46; P < 0.0055). Only one allele, ISAG*1501 or 03 (*16), showed significant association with HPL (OR = 0.36; P < 0.0005). The DRB3.2* alleles were assigned to three categories: resistant (R), susceptible (S) and neutral (N). Based on their DRB3 genotypes, cattle were classified as homozygous or heterozygous. The RR and RN genotypes were associated with the LPL profile, while the SS and NS genotypes were associated with the HPL profile. The RS genotype could not be associated with any particular profile. Our results show that allele ISAG*0902 appears to be the best BLV resistance marker in Holstein cattle.
Assuntos
Bovinos/genética , Leucose Enzoótica Bovina/genética , Antígenos de Histocompatibilidade Classe II/genética , Vírus da Leucemia Bovina/genética , Alelos , Animais , Bovinos/imunologia , Bovinos/virologia , Leucose Enzoótica Bovina/imunologia , Leucose Enzoótica Bovina/virologia , Feminino , Predisposição Genética para Doença , Genótipo , Antígenos de Histocompatibilidade Classe II/imunologia , Imunidade Inata , Vírus da Leucemia Bovina/imunologia , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Carga ViralRESUMO
Since the appearance of resistance to antiretroviral treatment is unavoidable, the host cell's transcription factor NF-kappaB is a novel HIV target. The goal of this study was to characterize the effect of two immunomodulators, curcumin (Cur) and sulfasalazine (Sul), with a protease inhibitor, indinavir (IDV), on HIV-1 persistently infected CD4+ T-cells. Viral p24 antigen production, viral infectivity (tested on MAGI cells) and viral relative infectivity (viral infectivity/p24) were analysed. When used alone, both immunomodulators were able to reduce viral infectivity. When in combination, both 10 microM IDV plus 10 microM Cur and 10 microM IDV plus 250 microM Sul showed a significant reduction in viral infectivity and viral relative infectivity when compared to the reduction produced by IDV alone. Thus, the use of immunomodulators with IDV could help to reduce HIV-1 production in persistently infected cells.
Assuntos
Fármacos Anti-HIV/farmacologia , Linfócitos T CD4-Positivos/virologia , Curcumina/farmacologia , HIV-1/efeitos dos fármacos , Indinavir/farmacologia , Sulfassalazina/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Sinergismo Farmacológico , Inibidores Enzimáticos/farmacologia , Proteína do Núcleo p24 do HIV/metabolismo , Inibidores da Protease de HIV/farmacologia , HIV-1/fisiologia , Humanos , Proteínas Serina-Treonina Quinases/metabolismo , Quinase Induzida por NF-kappaBRESUMO
OBJECTIVE: To develop a blocking ELISA for detection of bovine leukemia virus (BLV) antibodies that is comparable to a radioimmunoprecipitation (RIP) assay, to evaluate use of this ELISA for identification of BLV-infected herds, and to develop a polymerase chain reaction (PCR) assay for direct diagnosis of infection with BLV. SAMPLE POPULATION: Serum samples and pooled bulk-tank milk samples from cattle. PROCEDURE: The blocking ELISA was developed, using BLV gp51 as antigen, captured by a selected bovine polyclonal serum. A nested PCR was conducted with primers specific for a segment of the pol region of the BLV genome. RESULTS: Sensitivity and specificity of the ELISA were comparable to those of the RIP assay. Use of the ELISA on pooled milk samples allowed identification of herds in which prevalence of BLV infection among lactating cows was as low as 2.5%. Pooled milk samples from BLV-free herds did not react in the ELISA. All cattle that had positive results for the nested PCR had BLV antibodies, but cattle with consistantly low antibody titers required examination of sequential DNA samples to detect viral sequences. None of the 63 antibody-negative cattle had positive results for the PCR. CONCLUSIONS AND CLINICAL RELEVANCE: This ELISA is a highly specific and sensitive assay for the detection of BLV antibodies in serum and milk samples of cattle. Examination of pooled milk samples with the ELISA provides a reliable, practical, and economic procedure for identification of BLV-infected herds. The nested PCR also constitutes a specific procedure for direct diagnosis of infection with BLV.
Assuntos
Leucose Enzoótica Bovina/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Vírus da Leucemia Bovina/isolamento & purificação , Reação em Cadeia da Polimerase/veterinária , Animais , Anticorpos Antivirais/sangue , Antígenos Virais/isolamento & purificação , Bovinos , DNA Viral/química , DNA Viral/isolamento & purificação , Leucose Enzoótica Bovina/sangue , Leucose Enzoótica Bovina/virologia , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Vírus da Leucemia Bovina/química , Vírus da Leucemia Bovina/genética , Leite/virologia , Curva ROC , Ensaio de Radioimunoprecipitação/veterinária , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
DNA was extracted from the peripheral blood of a seropositive, PCR-positive, BLV-infected Holstein cow (No. 38) from Argentina. The DNA was amplified via PCR with a series of overlapping primers encompassing the entire BLV proviral DNA. The amplified BLV ARG 38 DNA was cloned, sequenced, and compared phylogenetically to three other full-length BLV sequences. Characterization of its deduced proteins and its relationship to other members of the PTLV/BLV genus of retroviruses are discussed.
Assuntos
Bovinos/virologia , Leucose Enzoótica Bovina/virologia , Genoma Viral , Vírus da Leucemia Bovina/genética , Sequência de Aminoácidos , Animais , Argentina , Sequência Consenso , DNA Viral/classificação , DNA Viral/genética , Leucose Enzoótica Bovina/sangue , Feminino , Vírus da Leucemia Bovina/classificação , Dados de Sequência Molecular , Provírus/isolamento & purificação , Alinhamento de Sequência , Sequências Repetidas TerminaisRESUMO
The Cuenca Lechera Mar y Sierras (CLMS) includes about 300 dairy farms located in the counties of Tandil, Balcarce, Juarez, Ayacucho, General Pueyrredón, Gonzalez Chavez and Necochea, in the province of Buenos Aires. The purpose of this investigation was to determine the prevalence of infection caused by Bovine Leukemia Virus (BLV) in the CLMS. We investigated the presence of anti-BLV antibodies in 4,203 milk samples taken from 73 dairy farms belonging to the CLMS. An indirect ELISA, which is described and evaluated in this paper, was used to test the antibodies in milk. We classified the dairy farms according to their rate of infection. The percentage of dairy farms free of infection resulted in 31.50. On the other hand, 49.40% of the dairy farms showed a figure between 1% and 15% of infected cattle; 17.80% between 16% and 30%, and the remaining 1.30% turned out more than 30% of infected cattle. If compared with data obtained in the 1979-1981 period, which showed that 95.65% of the dairy farms was BLV-free, it is clear that a dramatic progress of the BLV infection has occurred for the last 15 years. Nevertheless, the CLMS is in a privileged position so as to incorporate an inexpensive control plan to eradicate the BLV infection, as almost 1/3 of its dairy farms is still BLV-free and 49.40% still has a low rate of BLV infection. Only about 20% of the dairy farms would require costly strategies of control.