Assessment of humoral immune responses of sheep immunized with affinity purified excretory / secretory antigen of 
Haemonchus contortus

ARUNKUMAR SELVARAYAR

Abstract
ABSTRACT
In the present investigation, live adult Haemonchus contortus worms were harvested from the abomasums of sheep. In vitro culture of adult worms were made in RPMI 1640 medium at a concentration of approximately 50 worms / ml in a culture flask at 370 C for 24 hours and the culture supernatant was used as antigen. The E/S antigen was purified by thiol – sepharose affinity chromatography. The protein content of thiol – purified antigen was 1.6 mg /ml. on western blot analysis, it was demonstrated that the affinity purified antigen showed a single reactive band at 66 kDa. In immunization trial, sheep were immunized with 500 µg of thiol – purified E/S antigen along with montanide as adjuvant on day 0,30 and 60 intramuscularly. Further, the assessment of serum antibody levels in immunized sheep was made at weekly intervals by enzyme linked immuno sorbent assay (ELISA). It was observed that the mean absorbance values were significantly (P≤0.01) higher up to 20 weeks post immunization in purified antigen immunized group compared to unimmunized control group.

Key words: Key words : Haemonchus contortus, Excretory /Secretory antigen, Thiol – sepharose affinity chromatography, antibody, ELISA, Sheep.