IgE antibody during infection with the ovine abomasal nematode, Teladorsagia circumcincta: primary and secondary responses in serum and gastric lymphof sheep

A monoclonal antibody to ovine IgE was employed in an ELISA to investigate the IgE antibody responses in serum and gastric lymph to a primary infectio n of Teladorsagia circumcincta, and following challenge in previously infec ted sheep. During a primary response, IgE antibody to antigens derived from the infective third stage (L3) and adult (L5) worms were negligable, with low levels of IgE antibody detected in serum and lymph. In contrast, there was a pronounced IgE antibody response in 2/4 sheep to L3 antigens during 2 -8 days after challenge of previously infected animals but low levels of Ig E antibody to LS antigens. This response was confirmed in a second but simi lar experiment, where relatively high levels of IgE antibody was detected t o antigens from L3, Antibody levels were higher in lymph than in serum from the same animals, and Western blots of L3 antigen following SDS-PAGE under reducing conditions revealed several bands of MW26-96KD which reacted with the IgE antibody from gastric lymph. Immunohistochemical staining indicate d that these IgE antibodies may be reacting with allergens associated with the surface cuticle of the worms.