#02-015

Complete

Date Full Report Received

05/13/2003

Date Abstract Report Received

07/24/2006

Investigation

Institution:
Primary Investigator:
Co-Investigators: Jeffrey T. Gray PhD, Scott Hurd

PRRS is the most costly disease U.S. swine producers confront and little progress has been made in recent years to improve the situation. Prevention and control of PRRS has been difficult, in part because our knowledge of the immunity against PRRSV is limited. We know that antibodies generated during the early phase of infection cannot neutralize the virus; neutralizing antibodies and cellular immune responses appear much later in the course of infection; and animals remain persistently infected despite an active immune response.

In studying swine antibody responses, we discovered the presence of serum auto-anti-idiotypic antibodies in pigs experimentally infected with PRRSV. More importantly, clearance of virus from these animals was associated with the earlier appearance of auto-anti-idiotypic antibodies post infection. Our goals were 1) to determine the relationship between the appearance of auto-anti-idiotypic antibodies and clearance of virus in pigs; 2) serologically characterize auto-anti-idiotypic antibodies purified from pigs; and 3) determine specific functions of auto-anti-idiotypic antibodies by examining their ability to bind the cell surface and/or block the PRRSV infection of cells in vitro. This proposal represents a new approach, which if successful, would represent a major advance both in terms of understanding the pigs’ immunological response to PRRSV infection and providing new tools to bring an alternative anti-idiotype vaccine to the field.
Unfortunately, the proposal was only funded for one year (proposed for 2 years). We were only able to identify and characterize the auto-anti-idiotypic antibodies.