No abstract

Gestating Holstein cows were vaccinated with Clostridium difficile toxoid prepared from the culture filtrate of a strain that produces high levels of toxins A and B and other antigens. A bovine immunoglobulin G (IgG) concentrate was prepared from colostrum collected at parturition. The results of our studies showed that hamsters treated prophylactically with the hyperimmune bovine IgG concentrate were protected against C. difficile disease. These results suggest that orally administered hyperimmune bovine IgG specific for C. difficile culture ifitrate may be useful in prophylaxis against C. difficile disease.

Recycling isoelectric focusing (RIEF) was used to from an electrophoretically heterogeneous rabbit antibody population. Milligram quantities of antibodies were processed to single band purity in 4 h. The ease of operation, extremely short run times, and high resolution of the RIEF apparatus give this system great flexibility. The demonstrated capacity of the RIEF system to Division Of University'' Manhattan' KS' and Biophysics Technology Laboratory, University of Arizona', Tucson, AZ Kansas State single band purity isolate monoclonal antibodies process laige quantities of protein suggests that the system is applicable to the largescale purification of antibodies.

Naturally induced auto-anti-idiotypic (AAI) antibody responses specific for antimicrococcal antibody idiotypes were detected in 42% of the rabbits in a family immunized with Micrococcus lysodeikticus. The natural AAI response of each rabbit recognized only a portion (11-41%) of that individual's total antimicrococcal antibody population. Cross-reactions of idiotypes were observed within the group of rabbits exhibiting natural AAI responses. Examination of the basis for the cross-reactions showed that the natural AAI antisera recognized identical idiotopes on the antimicrococcal F(ab')2 fragments from each rabbit that made an AAI response. The cross-reactive idiotopes were shown to be of paternal origin and were found in the antimicrococcal antibodies of each offspring. The data strongly support the idiotypic network concept that naturally induced AAI responses may occur routinely in outbred normal individuals as a result of antigenic stimulation. Further, the data suggest that the induction of regulatory AAI antibody responses in outbred rabbits may depend on the expression of particular germ line idiotopes.

Immunization of pregnant cows with bacteria leads to the presence of high concentrations of specific antibodies in colostrum and milk. A total of 14 cows was immunized with single strains of heat-killed oral bacteria or pools of strains of Actinomyces, Porphyromonas, Prevotella, and Fusobacterium. Two cows were treated with adjuvant alone. The mean percentages of IgG1, IgG2, IgM, and IgA in all of the milks were 83.8, 3.8, 9.3, and 3.1, respectively. ELISA and whole cell agglutination assays demonstrated high titers in the milks from the cows immunized with either individual strains or the bacterial pools. The highest titers determined by ELISA belonged to the IgG1 isotype and in several milks were 64-fold greater than titers in milk from cows treated with adjuvant alone. The concentrations of all antibodies and the titers determined by ELISA and whole cell agglutination assays markedly decreased from the first to the sixth milkings. The functional specificity of the antibodies was demonstrated by agglutination tests against a wide range of bacteria including members of Actinomyces, Fusobacterium, Porphyromonas, Prevotella, Streptococcus, Eubacterium, Propionibacterium, Peptostreptococcus, Bacteroides, Actinobacillus, Haemophilus, Capnocytophaga, and Wolinella. Minimal cross-reactions with bacteria in other genera were observed with all of the milks. High-titer milk preparations have been obtained from immunized cows, and the capacity of the bovine antibodies to agglutinate target bacteria indicates their potential usefulness in oral passive immunization studies.