Immune responses to influenza D virus in calves previously infected with bovine viral diarrhea virus 2

Bovine viral diarrhea virus (BVDV) induces immunosuppression and thymus depletion in calves. This study explores the impact of prior BVDV-2 exposure on the subsequent immune response to influenza D virus (IDV). Twenty 3-week-old calves were divided into four groups. Calves in G1 and G3 were mock-treated on day 0, while calves in G2 and G4 received BVDV. Calves in G1 (mock) and G2 (BVDV) were necropsied on day 13 post-infection. IDV was inoculated on day 21 in G3 calves (mock + IDV) and G4 (BVDV + IDV) and necropsy was conducted on day 42. Pre-exposed BVDV calves exhibited prolonged and increased IDV shedding in nasal secretions. An approximate 50% reduction in the thymus was observed in acutely infected BVDV calves (G2) compared to controls (G1). On day 42, thymus depletion was observed in two calves in G4, while three had normal weight. BVDV-2-exposed calves had impaired CD8 T cell proliferation after IDV recall stimulation, and the α/β T cell impairment was particularly evident in those with persistent thymic atrophy. Conversely, no difference in antibody levels against IDV was noted. BVDV-induced thymus depletion varied from transient to persistent. Persistent thymus atrophy was correlated with weaker T cell proliferation, suggesting correlation between persistent thymus atrophy and impaired T cell immune response to subsequent infections.Veterinary PathobiologyDean of Veterinary Medicin

Investigation of Bovine Herpesvirus-1 Determinants of Neuronal Infectivity in Novel Bovine Neuronal Cell Systems for Development of a Safer Viral Vaccine Vector

Bovine herpesvirus-1 (BoHV-1) is the causative agent of infectious bovine rhinotracheitis and a component of the bovine respiratory disease complex. BoHV-1 is a significant burden on the cattle industry in the United States causing severe respiratory disease, abortions, loss of calves (“shipping fever”). BoHV-1 belongs to the alphaherpesvirus subfamily of Herpesviridae. Alphaherpesviruses enter axons of sensory nerves and establish life-long latency in trigeminal and dorsal root ganglionic neurons after primary infection of the oronasal or genital epithelium respectively. Modified live attenuated vaccines for BoHV-1 are commercially available but are limited in their protection while retaining the ability to establish latency in neurons and are increasingly recognized as causing disease in vaccinated animals. BoHV-1 viruses containing mutations in proteins conserved among alphaherpesviruses involved in entry or transport at various stages of neuroinvasion have been created throughout this project. A virus with a deletion of amino acids 31-84 encompassing two N-glycosylation sites at the amino terminus of glycoprotein K (gK) involved in the modulation of fusion machinery alters entry rendering the mutant virus reliant on clathrin-mediated endocytosis as demonstrated by inhibition of entry into MDBK cells in the presence of Pitstop-2. Viral tegument proteins released into the cytoplasm following fusion ultimately enable invasion of neurons by aiding transport of viral capsids or muting early innate responses. A virus containing a deletion of the amino terminal portion of tegument protein UL37 has been generated, a region identified in other alphaherpesvirus as essential for retrograde neuronal transport, and this mutant effects egress and productive infection in neurons. ICP0 is a virus tegument protein which degrades IRF3 thereby inhibiting type I interferon responses. Of two BoHV-1 viruses with deletions in predicted nuclear localization signals of ICP0, deletion of amino acids 620- 629 prevents replication in differentiated FBBC-1 neuronal cells. In addition, Cell lines of bovine origin have been used to characterize entry mechanisms, to visualize transport and provide a system for capsid tracking in neurons with the aim of informing the creation of safer vaccines and vaccine vector candidates for BoHV-1 and other pathogens of cattle

Development of a reliable bovine neuronal cell culture system and labeled recombinant bovine herpesvirus type-1 for studying virus-host cell interactions

Bovine herpesvirus type 1 (BoHV-1) is the viral causative agent of infectious bovine rhinotracheitis and a component of the bovine respiratory complex commonly referred to as shipping fever in calves. BoHV-1 is also responsible for losses of aborted calves and reductions in dairy productivity. BoHV-1 belongs to the neurotropic alphaherpesviruses which have a predilection to infect and establish latency in sensory neurons. Neuronal cell cultures provide a useful platform for experiments investigating neuronal entry, retrograde and anterograde transport, and the establishment of latency. Rodent neuronal cell lines and primary rabbit neuronal cells have been utilized for BoHV-1, though a reliable host-specific neuronal cell culture system has not been developed. In this study, BoHV-1 readily infected bovine-derived immortalized neuronal progenitor cells (FBBC-1) differentiated in cell culture producing neurite-like projections and exhibiting neuronal cell markers NeuN and L1CAM. FBBC-1 cells expressed both nectin-1 and nectin-2 alphaherpesvirus receptors on their cell surfaces, however, nectin-2 was detected in much greater abundance than nectin-1. To facilitate investigations of BoHV-1 infection, a recombinant BoHV-1 virus expressing the green fluorescent protein (GFP) cloned into a bacterial artificial chromosome (BAC) was used to generate an mCherry-VP26 fusion protein. The BoHV-1 GFP expressing VP26mCherry labeled virus infected differentiated FBBC-1 cells as evidenced by the production of infectious virions and the expression of both GFP and mCherry fluorophores. Time-lapse live cell microscopy revealed the presence of mCherry fluorescent capsids in neuronal projections immediately after virus entry moving retrograde in a saltatory manner. Proximity ligation assays (PLA) using MDBK cells demonstrated that BoHV-1 glycoprotein D (gD) interacted more efficiently with nectin-1 than nectin-2. However, the gD interaction with nectin-2 predominated in differentiated FBBC-1 cells in comparison to the gD nectin-1 interaction. The efficiently differentiated FBBC-1 neuronal cell line and fluorescently labeled BoHV-1 virions will assist experimentation aiming to elucidate specific mechanisms of virus entry and transport in a homologous bovine neuronal cell culture system

A Mismatch Between Patient Education Materials About Sickle Cell Disease and the Literacy Level of Their Intended Audience

Introduction Despite the first goal of the 2010 National Action Plan to Improve Health Literacy, the literacy demands of much health information exceeds the reading skills of most US adults. The objective of this study was to assess the health literacy level of publicly available patient education materials for people with sickle cell disease (SCD). Methods We used 5 validated tools to evaluate 9 print and 4 online patient education materials: the simple measure of gobbledygook (SMOG) to assess reading grade level, the Peter Mosenthal and Irwin Kirsch readability formula (PMOSE/IKIRSCH) to assess structure and density, the Patient Education Materials Assessment Tool (PEMAT) to assess actionability (how well readers will know what to do after reading the material) and understandability, the Centers for Disease Control and Prevention’s (CDC’s) Clear Communication Index (Index) to obtain a comprehensive literacy demand score, and the Printed Cancer Education Materials for African Americans Cultural Sensitivity Assessment Tool. Results Materials’ scores reflected high reading levels ranging from 8th grade to 12th grade, appropriate (low) structural demand, and low actionability relative to understandability. CDC suggests that an appropriate Index score should fall in or above the 90th percentile. The scores yielded by materials evaluated in this assessment ranged from the 44th to the 76th percentiles. Eight of the 13 materials scored within the acceptable range for cultural sensitivity. Conclusion Reading levels of available patient education materials exceed the documented average literacy level of the US adult population. Health literacy demands should be a key consideration in the revision and development of patient education materials for people with SCD

Development of a mouse salivary gland-derived mesenchymal cell line for immunological studies of murine cytomegalovirus

The salivary glands are a crucial site of replication for human cytomegalovirus (HCMV) and its murine counterpart, murine cytomegalovirus (MCMV). Studies of MCMV often involve the use of BALB/c strain mice, but most in vitro assays are carried out in the NIH 3T3 cell line, which is derived from Swiss Albino mice. This report describes a BALB/c-derived mouse salivary gland cell line immortalized using the SV40 large T antigen. Cells stained positive for PDGFR1 and negative for E-cadherin and PECAM-1, indicating mesenchymal origin. This cell line, which has been named murine salivary gland mesenchymal (mSGM), shows promise as a tool for ex vivo immunological assays due to its MHC haplotype match with the BALB/c mouse strain. In addition, plaque assays using mSGM rather than NIH 3T3 cells are significantly more sensitive for detecting low concentrations of MCMV particles. Finally, it is demonstrated that mSGM cells express all 3 BALB/c MHC class I isotypes and are susceptible to T cell-mediated ex vivo cytotoxicity assays, leading to many possible uses in immunological studies of MCMV

Two Sides to Every Story: Herpes Simplex Type-1 Viral Glycoproteins gB, gD, gH/gL, gK, and Cellular Receptors Function as Key Players in Membrane Fusion

Herpes simplex virus type-1 (HSV-1) and type-2 (HSV-2) are prototypical alphaherpesviruses that are characterized by their unique properties to infect trigeminal and dorsal root ganglionic neurons, respectively, and establish life-long latent infections. These viruses initially infect mucosal epithelial tissues and subsequently spread to neurons. They are associated with a significant disease spectrum, including orofacial and ocular infections for HSV-1 and genital and neonatal infections for HSV-2. Viral glycoproteins within the virion envelope bind to specific cellular receptors to mediate virus entry into cells. This is achieved by the fusion of the viral envelope with the plasma membrane. Similarly, viral glycoproteins expressed on cell surfaces mediate cell-to-cell fusion and facilitate virus spread. An interactive complex of viral glycoproteins gB, gD/gH/gL, and gK and other proteins mediate these membrane fusion phenomena with glycoprotein B (gB), the principal membrane fusogen. The requirement for the virion to enter neuronal axons suggests that the heterodimeric protein complex of gK and membrane protein UL20, found only in alphaherpesviruses, constitute a critical determinant for neuronal entry. This hypothesis was substantiated by the observation that a small deletion in the amino terminus of gK prevents entry into neuronal axons while allowing entry into other cells via endocytosis. Cellular receptors and receptor-mediated signaling synergize with the viral membrane fusion machinery to facilitate virus entry and intercellular spread. Unraveling the underlying interactions among viral glycoproteins, envelope proteins, and cellular receptors will provide new innovative approaches for antiviral therapy against herpesviruses and other neurotropic viruses