Immunogenicity of cholecystokinin octapeptide-conjugated antigens in pigs.

Abstract

An improved antigen is required to raise antiserum titers against cholecystokinin higher than those observed in previous studies to demonstrate the effect of immunoneutralization of cholecystokinin on feed intake in swine. Four immunogenic carrier proteins were compared. Unsulfated cholecystokinin octapeptide (CCK8ns) was conjugated to each of human serum globulin (HSG), BSA, Keyhole limpet hemocyanin (KLH), and Tuberculin purified protein derivative (PPD). Forty crossbred swine (four from each of 10 litters, 78 d of age, 22 kg BW) were randomly assigned to the four conjugated antigens by litter. The primary and three booster doses of antigen were injected at 14-d intervals. A blood sample was drawn before the primary dose on d 1 to assess basal nonspecific binding of antigen. Additional blood samples were drawn on d 22, 29, 36, 43, 50, 57, 71, and 92 to follow the time course of antiserum titer expression (d 1 = day of primary dose). Titer is the serum dilution that binds 50% of 1 fmol of radiolabeled antigen. Titers, compared by ANOVA of log titer values, were different between antigens (P < .01) and between litters (P < .01). Mean titer (n = 40; 10 pigs, four samples/pig) during the period after the immune response (d 50, 57, 71, and 92) was 55, 115, 176, and 535 for BSA, HSG, KLH, and PPD, respectively. It is concluded that the carrier protein component has an important effect on immunogenicity of conjugated CCK antigens in pigs; BSA was inferior and KLH and PPD were superior to HSG.

Assessment of enzyme-linked immunosorbent assay for the determination of 2,4,5-TP in water and soil

“…Because of the large molecular size of KLH, it was difficult to calculate the hapten/protein ratio; it was, however, expected to be higher than those obtained by use of BSA [21]. Thus, for the purpose of calculation of hapten density, BSA conjugates were simultaneously prepared to verify conjugation and for estimation of hapten/protein ratio by measurement of UV absorbance.…”

Effects of active immunization against cholecystokinin 8 on performance, contents of serum hormones, and expressions of CCK gene and CCK receptor gene in pigs

“…Active immunization against CCK was shown to improve feed intake and growth performance of pigs [10,11,21,22]. In this study, we showed that pigs immunized with 250 lg of CCK 8 indeed increase the feed intake and average daily gain of pigs.…”

Evaluation of Enzyme-Linked Immunoassays for the Determination of Chloroacetanilides in Water and Soils

“…On the other hand, either BSA or OVA was used as proteins for coating conjugates preparation. Because of KLH's high molecular size, it was difficult to calculate the hapten/protein ratio; however, it was expected to be higher than those obtained using other proteins such as BSA and OVA, due to the higher number of free amine groups (34). Thus, for hapten density calculation purposes, BSA and OVA conjugates were simultaneously prepared to verify conjugation and to estimate hapten/protein ratio according to UV absorbance.…”