THE LIPOPEPTIDE, PAM(3)CYS-SER-(LYS)(4) - AN ALTERNATIVE ADJUVANT TO FREUND ADJUVANT FOR THE IMMUNIZATION OF CHICKEN TO PRODUCE EGG-YOLK ANTIBODIES

This study describes an alternative adjuvant for the immunisation of c hicken. The lipopeptide, Pam(3)Cys-Ser-(Lys), (PCSL), has been demonst rated to be a very potent adjuvant, by immunisation with the hapten me thyl phosphonic acid paraaminophenyl 1,2,2-trimethylpropyl diester, wi th coronavirus, with rotavirus and with the Escherichia coli K99 pilus antigen. The antibody titres in chickens that received PCSL were comp ared with those in animals that received Freund's complete adjuvant/Fr eund's incomplete adjuvant (FCA/FIA). Antigen-dependent differences in antibody titres could be shown. The optimal dosage for PCSL was 250 m u g per injection. Whereas injection of FCA/FIA resulted in chronic in flammatory alterations, mostly accompanied with granulomatous reaction s, no long-term tissue damage could be found with PCSL. When PCSL was used as the adjuvant, the total immunoglobulin Y (IgY) levels in chick en sera were constant during the immunisation period (20.2mg/ml, SD +/ - 1.3), and were significantly different (p < 0.0001) from those in ch ickens given FCA as adjuvant (26.6mg/ml, SD +/- 4.9). IgY concentratio ns in the egg yolks showed no significant differences in both groups ( PCSL - 13.7mg/ml, SD +/- 3.7; FCA - 13.5mg/ml, SD +/- 4.2), and were s ignificantly lower (p < 0.0001) than the IgY serum levels.