Skip to main content

Your Impact Will Go Twice as Far for a Pup

Do you notice all those folds of skin? They tell a heartbreaking story of a pup far too thin. 

Right now, there’s a $5,000 gift match waiting for the pups, and your support is needed to unlock it. 

Yes, your $5 = $10 today, meaning you can provide double the fish meals for a pup like Horseshoe. 

Get your gift matched
elephant seal pup Horseshoe
California sea lion

Use of a Lymph-Node Explant Culture System from California Sea Lions to Study Phocine Distemper Virus

California sea lion (Zalophus californianus) lymph-node explant reveals involvement and possible transcriptional regulation of SLAM and nectin-4 during phocine distemper virus infection
  • Infectious disease

Abstract

Phocine distemper virus (PDV) is a significant cause of mortality for phocid seals; however, the susceptibility of otariids to this virus is poorly understood. The authors used a lymph-node explant culture system from California sea lions (Zalophus californianus, CSL) to investigate: (1) the role of signaling lymphocyte activation molecule (SLAM) and nectin-4 in PDV infection and their cellular expression patterns, (2) if PDV induces transcriptional regulation of cell-entry receptors, and (3) the involvement of apoptosis in PDV infection. PDV replicated in the lymph-node explants with peak replication 3 days post-infection (dpi), but the replication was not sustained 4 to 5 dpi. The PDV+ cells co-localized SLAM and nectin-4. These cells expressed IBA1, indicating a histiocytic lineage. Comparison of receptor expression between infected and mock-infected lymph nodes suggested transcriptional downregulation of both receptors during the initial stage of infection and upregulation during the late stage of infection, but the values lack of statistical significance. Cleaved caspase-3+ cells were slightly increased in the infected lymph nodes compared with the mock-infected lymph node from 1 to 4 dpi, but without statistical significance, and a few apoptotic cells co-expressed PDV. The results suggest that lymph-node explants might be an important model to study PDV pathogenesis. CSLs have the potential to be infected with PDV, as they express both cell-entry receptors in histiocytes. The lack of statistical significance in the PDV replication, transcriptional regulation of viral receptors, and changes in apoptosis suggest that although CSL might be infected by PDV, they might be less susceptible than phocid species.


Gonzales-Viera, O., Goldstein, T., Duignan, P., Eiamcharoen, P., Keel, M.K., 2023. California sea lion (Zalophus californianus) lymph-node explant reveals involvement and possible transcriptional regulation of SLAM and nectin-4 during phocine distemper virus infection. Veterinary Pathology 2023;0(0).

infectious disease
Pádraig Duignan
phocine distemper virus, PDV, California sea lion, lymph-node explant

Meet The Experts

Related Publications

Recent News