Investigation of the poultry idiotypic network using Pasteurella multocida

The idiotypic network in leghorn laying hens was investigated by inoculating hens with a 35.5 kD outer membrane protein of Pasteurella multocida (Pm35.5), idiotype (Id), or Pm35.5 anti-Id. Egg yolks were analyzed for the presence of Id, anti-Id, or anti-anti-Id. Anti-Pm35.5 antibodies (Id) were not titered to an end-point but were present in high concentrations. The presence of anti-Id antibody in yolk was demonstrated by the inhibition of Pm35.5 binding to Id by anti-Id using a flow microsphere inhibition immunoassay. Inhibition of Pm35.5 binding to Id caused by different anti-Id preparations ranges from 51.5 to 56.1%. Not all of the anti-Id bound to a paratope-associated Id, since 8.3-12.8% of the fluoresceinated anti-Id bound to Id-coated beads in the presence of excess Pm35.5. We confirmed that a portion of the anti-Id antibodies was an internal image of the Pm35.5 Id and could mimic antigen by demonstrating that anti-Id inoculated in naive hens caused the synthesis of anti-anti-Id antibodies that bound to Pm35.5 in enzyme linked immunosorbent assay. Monoclonal anti-Id antibodies were also capable of inhibiting Pm35.5 binding to Pm35.5 Id coated microspheres and inducing anti-anti-Id antibodies in BALB/cJ mice that reacted with the original antigen, Pm35.5. Our investigation has also shown that idiotypic antibodies to P. multocida were transferred from chicken to egg.