Domestic cat hepadnavirus detection in blood and tissue samples of cats with lymphoma

Intrauterine inoculation of pseudorabies virus impairs mouse embryo implantation via inducing inflammation and apoptosis in endometrium

Pseudorabies virus (PRV) is the pathogenic agent of pseudorabies, causing serious reproductive failure in swine. However, it is still unknown whether PRV uterine inoculation impairs blastocyst implantation. In the present study, a PRV infection mouse model was developed. Pregnant mice were inoculated with either 104 or 105 50% tissue culture infectious dose (TCID50) units of PRV on gestation day 2 (GD2). Viral DNA was detected in tissues by PCR and/or in situ hybridization. Histopathological change and expression of proinflammatory cytokines in uterus were analyzed by H.E. staining and qPCR, respectively. Apoptosis was also investigated by TUNEL assay, and the expression of apoptosis-related proteins including Bax and Bcl-2 was detected by Western blot. The results showed that intrauterine exposure of PRV on GD2 reduced the number of embryo implantation site. Abundant viral DNA was detected in spinal marrow and brain, and small amounts of PRV genomes were detected in embryo implantation site, ovary as well as thymus. Considerable inflammatory cells infiltrating in the endometrium, with high levels of pro-inflammatory cytokines of interleukin (IL)-6, IL-1β and tumor necrosis factor-α mRNA after infection. In addition, PRV infection promoted apoptosis in stroma and endothelium of the mouse endometrium. Collectively, intrauterine inoculation of PRV during early pregnancy causes cytokine release syndrome and apoptosis in endometrium, which impairs mouse embryo implantation.

Canine bufavirus (Carnivore protoparvovirus-3) infection in dogs with respiratory disease

Canine bufavirus (CBuV) or Carnivore protoparvovirus-3, a nonenveloped DNA virus belonging to the genus Protoparvovirus, family Parvoviridae, has been identified in dogs with respiratory and enteric diseases. Although CBuV detection has been reported in multiple countries, descriptions of pathologic findings associated with infection have not yet been provided. In this study, the authors necropsied 14 dogs (12 puppies and 2 adult dogs) from a breeding colony that died during multiple outbreaks of respiratory diseases. Postmortem investigations revealed extensive bronchointerstitial pneumonia with segmental type II pneumocyte hyperplasia in all necropsied puppies but less severe lesions in adults. With negative results of common pathogen detection by ancillary testing, CBuV DNA was identified in all investigated dogs using a polymerase chain reaction (PCR). Quantitative PCR demonstrated CBuV DNA in several tissues, and in situ hybridization (ISH) indicated CBuV tissue localization in the lung, tracheobronchial lymph node, and spinal cord, suggesting hematogenous spread. Dual CBuV ISH and cellular-specific immunohistochemistry were used to determine the cellular tropism of the virus in the lung and tracheobronchial lymph node, demonstrating viral localization in various cell types, including B-cells, macrophages, and type II pneumocytes, but not T-cells. Three complete CBuV sequences were successfully characterized and revealed that they clustered with the CBuV sequences obtained from dogs with respiratory disease in Hungary. No additional cases were identified in small numbers of healthy dogs. Although association of the bufavirus with enteric disease remains to be determined, a contributory role of CBuV in canine respiratory disease is possible.

Virome characterization of diarrheic red-crowned crane (G. japonensis)

BACKGROUND

The red-crowned crane is one of the vulnerable bird species. Although the captive population has markedly increased over the last decade, infectious diseases can lead to the death of young red-crowned cranes while few virological studies have been conducted.

METHODS

Using a viral metagenomics approach, we analyzed the virome of tissues of the dead captive red-crowned crane with diarrhea symptoms in Dongying Biosphere Reserve, Shandong Province, China and feces of individual birds breeding at the corresponding captive breeding center, which were pooled separately.

RESULTS

There is much more DNA and RNA viruses in the feces than that of the tissues. RNA virus belonging to the families Picornaviridae, and DNA viruses belonging to the families Parvoviridae, associated with enteric diseases were detected in the tissues and feces. Genomes of the picornavirus, genomovirus, and parvovirus identified in the study were fully characterized, which further suggested that infectious viruses of these families were possibly presented in the diseased red-crowned crane.

CONCLUSION

RNA virus belonging to the families Picornaviridae, and DNA viruses belonging to the families Genomoviridae and Parvoviridae were possibly the causative agent for diarrhea of red-crowned crane. This study has expanded our understanding of the virome of red-crowned crane and provides a baseline for elucidating the etiology for diarrhea of the birds.

Reply to Piewbang et al. Domestic Cat Hepadnavirus Antigens in Lymphoma Tissues. Comment on "Beatty et al. Domestic Cat Hepadnavirus and Lymphoma. Viruses 2023, 15, 2294"

We are grateful to the authors for providing additional data to demonstrate the presence of domestic cat hepadnavirus in lymphoma tissues [...].

Domestic Cat Hepadnavirus Antigens in Lymphoma Tissues. Comment on Beatty et al. Domestic Cat Hepadnavirus and Lymphoma. Viruses 2023, 15, 2294

We are addressing the comments made by Beatty et al [...].

Domestic Cat Hepadnavirus and Lymphoma

We write to comment on Piewbang C et al [...].