Detection of Gammaherpesvirus 1 in Domestic Cat Saliva: Prevalence, Risk Factors, and Attempted Virus Isolation.

gammaherpesvirus 1 (FcaGHV1) infects domestic cats worldwide, yet it has not been successfully propagated in cell culture, and little is known about how it is shed and transmitted. To investigate the salivary shedding of FcaGHV1, we quantified FcaGHV1 DNA in feline saliva by qPCR. For FcaGHV1-positive saliva, we sequenced a portion of the viral glycoprotein B (gB) gene and attempted to isolate the infectious virus by passage in several felid and non-felid cell lines.

Targeting the MR1-MAIT cell axis improves vaccine efficacy and affords protection against viral pathogens.

Mucosa-associated invariant T (MAIT) cells are MR1-restricted, innate-like T lymphocytes with tremendous antibacterial and immunomodulatory functions. Additionally, MAIT cells sense and respond to viral infections in an MR1-independent fashion. However, whether they can be directly targeted in immunization strategies against viral pathogens is unclear.

Monovalent and trivalent VSV-based COVID-19 vaccines elicit neutralizing antibodies and CD8 T cells against SARS-CoV-2 variants.

Recombinant vesicular stomatitis virus (rVSV) vaccines expressing spike proteins of Wuhan, Beta, and/or Delta variants of SARS-CoV-2 were generated and tested for induction of antibody and T cell immune responses following intramuscular delivery to mice. rVSV-Wuhan and rVSV-Delta vaccines and an rVSV-Trivalent (mixed rVSV-Wuhan, -Beta, -Delta) vaccine elicited potent neutralizing antibodies (nAbs) against live SARS-CoV-2 Wuhan (USAWA1), Beta (B.1.

Correction: A vesicular stomatitis virus-based prime-boost vaccination strategy induces potent and protective neutralizing antibodies against SARS-CoV-2.

[This corrects the article DOI: 10.1371/journal.ppat.

A vesicular stomatitis virus-based prime-boost vaccination strategy induces potent and protective neutralizing antibodies against SARS-CoV-2.

The development of safe and effective vaccines to prevent SARS-CoV-2 infections remains an urgent priority worldwide. We have used a recombinant vesicular stomatitis virus (rVSV)-based prime-boost immunization strategy to develop an effective COVID-19 vaccine candidate. We have constructed VSV genomes carrying exogenous genes resulting in the production of avirulent rVSV carrying the full-length spike protein (SF), the S1 subunit, or the receptor-binding domain (RBD) plus envelope (E) protein of SARS-CoV-2.

Expression of APOBEC3 Lentiviral Restriction Factors in Cats.

Feline immunodeficiency virus (FIV) is a naturally occurring T-cell tropic lentiviral disease of felids with many similarities to HIV/AIDS in humans. Similar to primate lentiviral-host interactions, feline APOBEC3 (A3) has been shown to inhibit FIV infection in a host-specific manner and feline A3 degradation is mediated by FIV Vif. Further, infection of felids with non-native FIV strains results in restricted viral replication in both experimental and naturally occurring infections.

Feline Foamy Virus Infection: Characterization of Experimental Infection and Prevalence of Natural Infection in Domestic Cats with and without Chronic Kidney Disease.

Foamy viruses (FVs) are globally prevalent retroviruses that establish apparently apathogenic lifelong infections. Feline FV (FFV) has been isolated from domestic cats with concurrent diseases, including urinary syndromes. We experimentally infected five cats with FFV to study viral kinetics and tropism, peripheral blood mononuclear cell (PBMC) phenotype, urinary parameters, and histopathology.

Identification of a Novel Gammaherpesvirus in Canada lynx ().

Gammaherpesviruses (GHVs) infect many animal species and are associated with lymphoproliferative disorders in some. Previously, we identified several novel GHVs in North American felids; however, a GHV had never been identified in Canada lynx (). We, therefore, hypothesized the existence of an unidentified GHV in lynx.

Identification of gammaherpesvirus infection in free-ranging black bears (Ursus americanus).

Herpesvirus infection was investigated in black bears (Ursus americanus) with neurological signs and brain lesions of nonsuppurative encephalitis of unknown cause. Visible cytopathic effects (CPE) could only be observed on days 3-5 post-infection in HrT-18G cell line inoculated with bear tissue extracts. The observed CPE in HrT-18G cells included syncytia, intranuclear inclusions, and cell detachments seen in herpesvirus infection in vitro.

Transcriptome Analysis and In Situ Hybridization for FcaGHV1 in Feline Lymphoma.

Lymphoma is one of the most common malignancies in domestic cats. The lymphomagenic potential of gammaherpesvirus 1 (FcaGHV1), a common infection in domestic cats, is unknown. In other species, including humans, cellular transformation by gammaherpesviruses is typically mediated by viral genes expressed during latency.

A Preliminary Proteomic Investigation of Circulating Exosomes and Discovery of Biomarkers Associated with the Progression of Osteosarcoma in a Clinical Model of Spontaneous Disease.

Circulating cancer exosomes are microvesicles which originate from malignant cells and other organs influenced by the disease and can be found in blood. The exosomal proteomic cargo can often be traced to the cells from which they originated, reflecting the physiological status of these cells. The similarities between cancer exosomes and the tumor cells they originate from exhibit the potential of these vesicles as an invaluable target for liquid biopsies.

Feline Leukemia Virus (FeLV) Disease Outcomes in a Domestic Cat Breeding Colony: Relationship to Endogenous FeLV and Other Chronic Viral Infections.

Exogenous feline leukemia virus (FeLV) is a feline gammaretrovirus that results in a variety of disease outcomes. Endogenous FeLV (enFeLV) is a replication-defective provirus found in species belonging to the genus, which includes the domestic cat (). There have been few studies examining interaction between enFeLV genotype and FeLV progression.

High prevalence of gammaherpesvirus 1 in wild Vermont bobcats.

Gammaherpesviruses (GHVs) are host specific DNA viruses that infect a large range of mammalian species. These viruses preferentially target host lymphocyte cell populations and infection may lead to morbidity or mortality in immunocompromised, co-infected, or non-adapted hosts. In this study, we tested for the presence of gammaherpesvirus 1 (LruGHV1) in a northeastern United States population of wild bobcats ().

Replacement of feline foamy virus bet by feline immunodeficiency virus vif yields replicative virus with novel vaccine candidate potential.

Background: Hosts are able to restrict viral replication to contain virus spread before adaptive immunity is fully initiated. Many viruses have acquired genes directly counteracting intrinsic restriction mechanisms. This phenomenon has led to a co-evolutionary signature for both the virus and host which often provides a barrier against interspecies transmission events.

FIV vaccine with receptor epitopes results in neutralizing antibodies but does not confer resistance to challenge.

Feline immunodeficiency virus (FIV) is the feline analogue to human immunodeficiency virus (HIV) and utilizes parallel modes of receptor-mediated entry. The FIV surface glycoprotein (SU) is an important target for induction of neutralizing antibodies, and autoantibodies to the FIV binding receptor (CD134) block infection ex vivo; thus highlighting the potential for immunotherapies which utilize anti-receptor antibodies to block viral infection. To determine whether vaccination with CD134-SU complexes could induce protection against FIV infection, cats ( = 5 per group) were immunized with soluble CD134, recombinant FIV-SU protein, and/or CD134+SU complexes.

Prior Puma Lentivirus Infection Modifies Early Immune Responses and Attenuates Feline Immunodeficiency Virus Infection in Cats.

We previously showed that cats that were infected with non-pathogenic Puma lentivirus (PLV) and then infected with pathogenic feline immunodeficiency virus (FIV) (co-infection with the host adapted/pathogenic virus) had delayed FIV proviral and RNA viral loads in blood, with viral set-points that were lower than cats infected solely with FIV. This difference was associated with global CD4⁺ T cell preservation, greater interferon gamma (IFN-γ) mRNA expression, and no cytotoxic T lymphocyte responses in co-infected cats relative to cats with a single FIV infection. In this study, we reinforced previous observations that prior exposure to an apathogenic lentivirus infection can diminish the effects of acute infection with a second, more virulent, viral exposure.

Exosomes from Osteosarcoma and normal osteoblast differ in proteomic cargo and immunomodulatory effects on T cells.

Background: Canine osteosarcoma (OSA) is the most common cancer of the appendicular skeleton and is associated with high metastatic rate to the lungs and poor prognosis. Recent studies have shown the impact of malignant-derived exosomes on immune cells and the facilitation of immune evasion. In the current study, we have characterized the proteomic profile of exosomes derived from healthy osteoblasts and osteosarcoma cell lines.

Feline Immunodeficiency Virus Cross-Species Transmission: Implications for Emergence of New Lentiviral Infections.

Owing to a complex history of host-parasite coevolution, lentiviruses exhibit a high degree of species specificity. Given the well-documented viral archeology of human immunodeficiency virus (HIV) emergence following human exposures to simian immunodeficiency virus (SIV), an understanding of processes that promote successful cross-species lentiviral transmissions is highly relevant. We previously reported natural cross-species transmission of a subtype of feline immunodeficiency virus, puma lentivirus A (PLVA), between bobcats () and mountain lions () for a small number of animals in California and Florida.

Domestic cats seropositive for Felis catus gammaherpesvirus 1 are often qPCR negative.

Felis catus gammaherpesvirus 1 (FcaGHV1) is a newly described virus that infects domestic cats. To identify FcaGHV1 antigens, we developed an immunofluorescent antibody assay by expressing FcaGHV1 open reading frames (ORFs) in feline cells and incubating fixed cells with sera from FcaGHV1-positive cats. Of the seven ORFs tested, ORF52 and ORF38 had the strongest, most consistent antibody responses.

Closing the gap on causal processes of infection risk from cross-sectional data: structural equation models to understand infection and co-infection.

Background: Epidemiological studies of disease exposure risk are frequently based on observational, cross-sectional data, and use statistical approaches as crucial tools for formalising causal processes and making predictions of exposure risks. However, an acknowledged limitation of traditional models is that the inferred relationships are correlational, cannot easily distinguish direct from indirect determinants of disease risk, and are often considerable simplifications of complex interrelationships. This may be particularly important when attempting to infer causality in patterns of co-infection through pathogen-facilitation.

First Complete Genome Sequence of Felis catus Gammaherpesvirus 1.

We sequenced the complete genome of Felis catus gammaherpesvirus 1 (FcaGHV1) from lymph node DNA of an infected cat. The genome includes a 121,556-nucleotide unique region with 87 predicted open reading frames (61 gammaherpesvirus conserved and 26 unique) flanked by multiple copies of a 966-nucleotide terminal repeat.

Bovine herpesvirus 4 DNA is not detected in free-ranging domestic cats from California, Colorado or Florida.

Objectives Several studies have reported that domestic cats can be naturally infected with bovine herpesvirus 4 (BHV4). Cats experimentally inoculated with BHV4 developed clinical signs involving the urinary tract, leading to the hypothesis that natural infection with BHV4 may be associated with feline lower urinary tract diseases. However, the question of whether BHV4 infection is common in cats remains equivocal.

Identification of Novel Gammaherpesviruses in Ocelots (Leopardus pardalis) and Bobcats (Lynx rufus) in Panama and Colorado, USA.

Gammaherpesviruses (GHVs) have been identified in many species and are often associated with disease. Recently, we characterized three novel felid GHVs in domestic cats (Felis catus), bobcats (Lynx rufus), and pumas (Puma concolor). We investigated whether free-ranging ocelots (Leopardus pardalis) and bobcats are infected with additional GHVs.

Interaction of Interferon gamma-induced reactive oxygen species with ceftazidime leads to synergistic killing of intracellular Burkholderia pseudomallei.

Burkholderia pseudomallei, a facultative intracellular pathogen, causes severe infections and is inherently refractory to many antibiotics. Previous studies from our group have shown that interferon gamma (IFN-γ) interacts synergistically with the antibiotic ceftazidime to kill bacteria in infected macrophages. The present study aimed to identify the underlying mechanism of that interaction.

Blocking phosphatidylcholine utilization in Pseudomonas aeruginosa, via mutagenesis of fatty acid, glycerol and choline degradation pathways, confirms the importance of this nutrient source in vivo.

Pseudomonas aeruginosa can grow to very high-cell-density (HCD) during infection of the cystic fibrosis (CF) lung. Phosphatidylcholine (PC), the major component of lung surfactant, has been hypothesized to support HCD growth of P. aeruginosa in vivo.