Replication and immunosuppressive effects of Pseudorabies virus on swine peripheral blood mononuclear cells

Area of Science:

• Veterinary Virology
• Immunology
• Swine Health

Background:

• Pseudorabies virus (PRV) is a significant pathogen in swine.
• Understanding PRV's interaction with the host immune system is crucial for disease management.
• Peripheral blood mononuclear cells (PBMC) are key components of the immune system.

Purpose of the Study:

• To investigate the infectivity of PRV in swine PBMC.
• To evaluate the immunosuppressive effects of PRV on PBMC functions.
• To explore the potential role of PBMC in PRV systemic spread.

Main Methods:

• In vitro culture of swine PBMC.
• Inoculation with PRV and assessment of viral replication (progeny titers, DNA synthesis).
• Evaluation of PBMC viability, lymphocyte proliferation, IL-2 synthesis, and NK cell activity.

Main Results:

• PRV replicated in both monocytes and lymphocytes, with restricted replication in lymphocytes.
• PRV caused monocyte damage and death but did not affect lymphocyte viability.
• PRV suppressed lymphocyte proliferation and IL-2 synthesis in a multiplicity-of-infection-dependent manner; UV-inactivated PRV had no effect.
• Natural killer cell activity remained unaffected.

Conclusions:

• PRV infects swine PBMC and induces immunosuppression, particularly affecting lymphocyte function.
• These immunosuppressive effects could predispose pigs to secondary infections.
• The study supports the hypothesis that PRV can spread systemically through infected PBMC.