|Kehrli Jr, Marcus|
Submitted to: Research Workers in Animal Diseases Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 2004
Publication Date: November 14, 2004
Citation: Wesley, R.D., Lager, K.M., Kehrli Jr., M.E. 2004. PRRSV infection stimulates an early serum IFN-gamma response in pigs [abstract]. Conference of Research Workers in Animal Diseases. Paper No. P89. p. 103. Technical Abstract: Porcine reproductive and respiratory syndrome (PRRS) is present worldwide, and economically, is the most important infectious disease for swine production. Prophylactic control of PRRS has been difficult because the pigs' immune response to PRRSV is unconventional. Gamma interferon (IFN-gamma) is a central cytokine mediator for the induction of cellular or Th1 immunity which is important for PRRSV clearance. To better understand innate and adaptive immune responses to PRRSV, serum IFN-gamma concentrations and the duration of viremia were investigated. For 2 strains of atypical PRRSV, IFN-gamma was detectible in swine serum soon after experimental infection and lasted for approximately 3 weeks. Serum levels of IFN-gamma peaked at about 10 days post inoculation and returned to approximate baseline levels by day 22 post infection. However, individual pigs manifested short sporadic increases of IFN-gamma from 18 to 50 days post-infection. Prior vaccination blocked the serum IFN-gamma response with homologous virus challenge and altered the kinetics of the response following heterologous challenge. Other respiratory viruses of pigs do not appear to induce serum IFN-gamma at the same level. The role of IFN-gamma in innate and adaptive immunity to PRRSV will be considered.