Interaction of PCV2 and the immune system
Porcine circovirus type 2 (PCV2) alone appears to be inoffensive, but its immunomodulating activity, together with co-infections and other husbandry factors, contribute to the devastating effects of PCVD.
Read more about the immunosuppressive characteristics of PCV2 infections as discussed by Artur Summerfield, DVM, Ph.D., Institute of Virology and Immunoprophylaxis, Mittelhäusern, Switzerland.
Schematic overview of different phases of immune responses influenced by PCV2 infection.
In Phase I cells of the innate immune system are activated to produc antiviral factors such IRN-α/β, proinflammatory cytokines and chemokines. This limits early pathogen replication and provides important "danger signals" required to trigger the adaptive response. The anti-inflammatory Phase II prevents extensive tissue damage caused by uncontrolled innate immune responses. In Phase III adaptive immune responses are induced following expansion and activation of lymphocytes. After pathogen elimination, in Phase IV the adaptive immune response is settled down to steady state levels.
PCV2 can interfere by acting inhibitory during the activation phases I and III and promoting the regulatory phases II and IV.×