Bovine Viral Diarrhea Virus Infects Monocyte-Derived Bovine Dendritic Cells by an E2-Glycoprotein-Mediated Mechanism and Transiently Impairs Antigen Presentation

Abstract

Infection of professional antigen presenting cells by viruses can have a marked effect on these cells and important consequences for the generation of subsequent immune responses. In this study, we demonstrate that different strains of bovine viral diarrhea virus (BVDV) infect bovine dendritic cells differentiated from nonadherent peripheral monocytes (moDCs). BVDV did not cause apoptosis in these cells. Infection of moDC was prevented by incubating the virus with anti-E2 antibodies or by pretreating the cells with recombinant E2 protein before BVDV contact, suggesting that BVDV infects moDC through an E2-mediated mechanism. Virus entry was not reduced by incubating moDC with Mannan or ethylenediaminetetraacetic acid (EDTA) before infection, suggesting that Ca(2+) and mannose receptor-dependent pathways are not mediating BVDV entry to moDC. Infected moDC did not completely upregulate maturation surface markers. Infection, but not treatment with inactivated virus, prevented moDC to present a third-party antigen to primed CD4(+) T cells within the first 24 hours postinfection (hpi). Antigen-presenting capacity was recovered when viral replication diminished at 48 hpi, suggesting that active infection may interfere with moDC maturation. Altogether, our results suggest an important role of infected DCs in BVDV-induced immunopathogenesis.

In-vivo Activity of IFN-λ and IFN-α Against Bovine-Viral-Diarrhea Virus in a Mouse Model

“…Unpublished data from our laboratory analyzing the infection of murine splenocytes and cultured bone marrow-derived dendritic cells (DCs) have suggested that the DCs may be responsible for sustaining the infection in these animals. In fact, bovine DCs are not killed by BVDV infection (29). A role of the DCs in BVDV infection in mice-or even simply the extent of the action of those cells in persistent infection and the lack of IFN synthesis-needs to be confirmed by experiments aimed at this specific purpose.…”

“…FBS was also controlled for the BVDV genome by RT-PCR following a standard protocol (see below). The absence of live virus in the FBS was further corroborated by serial passage in MDBK cells followed by immunofluorescent staining as previously described (29).…”

A direct high-throughput in Cell-ELISA for measuring infectivity of cytopathic and non-cytopathic bovine viral diarrhoea virus strains applied to the assessment of antiviral activity

“…Virus monocitotrópicos como VDVB son capaces de infectar células presentadoras de antígeno y sus efectos dependen de la población celular infectada. Células dendríticas (CD) y monocitos son susceptibles a la infección con VDVB CP y NCP [29]; sin embargo, solo los monocitos sufren lisis celular cuando están infectados con VDVB cp. El mecanismo por el cual la CD sobrevive a la infección por VDVB CP aún no está completamente claro, sin embargo se ha sugerido que la infección de las CD con VDVB podría interferir con su funcionalidad [30] ya que se observa supresión de la respuesta inmune e inducción de apoptosis sin infección de los linfocitos.…”

“…Las células dendríticas de ganglios linfáticos, las cuales constituyen la población más importante de APC, no se afectaron en su capacidad de presentar antígenos a las células Th o expresar MHC II en su superficie luego de la infección con la cepa PE515 cp ó ncp aislada previamente de un caso de enfermedad de las mucosas [30]. Nuestro grupo ha demostrado que la incapacidad de las CD infectadas de presentar otros antígenos se mantiene durante las primeras 24h posteriores a la infección [29]. Monocitos infectados in vitro con las cepas NY-1 NCP ó NADL CP por 1 hora, mostraron un aumento en los niveles del ARN mensajero (ARNm) de TLR-3.…”

“…Se colectaron las CMSP en un cónico de 50 ml y para remover el Histopaque ® se hicieron dos lavados resuspendiendo las CMSP en 50 ml de PBS y centrifugando a 300 xg durante 10 min a 4°C.VIRUSLas cepas de referencia Singer y NADL fueron obtenidas de la ATCC ® . El resto de las cepas forman parte del cepario del Instituto de Virología de INTA[21],[29],[123]-[126] que cuenta con 30 aislamientos Argentinos y 8 cepas de referencia del VDVB. El Virus de Fiebre Aftosa (VFA) A-24 Cruzeiro[127] y el Virus de la Estomatitis Vesicular Bovina cepa New Jersey (VSV-NJ)[128] forman parte del Stock de INTA y fueron producidas en células BHK-21 y MDBK respectivamente.…”