Production of polyclonal antibodies in rabbits and chickens immunised with human immunoglobulin G : A study of the utility of egg yolk antibody production as a substitute for rabbit serum antibody production

Abstract: The utility of chicken egg yolk antibodies as an alternative to rabbit antisera was studied by comparing antibody and avidity development in immunised animals (15 rabbits and 30 chickens) during a one-year immunisation scheme. Human IgG was used as the model antigen and the efficacy of three adjuvants, Freund's Complete Adjuvant, Freund's Incomplete Adjuvant and Hunter's TiterMax, was compared. Purification procedures for egg yolk antibodies were developed, rendering the harvest and processing time for yolk and serum antibodies comparable. A majoradvantage of producing egg yolk antibodies instead of rabbit antisera is an increased productivity.Although the antibody response was found to be higher in rabbit serum than in egg yolk of chickensimmunised using identical schemes, the volumes of obtainable antibody source were ten timeshigher with egg yolk than with rabbit sera. Depending on the immunisation scheme and, inparticular, the choice of adjuvant, approximately five times more antibody can be produced per yearby a chicken than by a rabbit. Considering the cost of purchase and maintenance, rabbit antibodiesare ten times more expensive to produce. Serum antibody response in young and old chickens werecompared and no significant difference was found. The avidity of the egg yolk antibodies was foundto be similar to rabbit serum antibodies, but the qualitative properties of the immunoglobulinsdiffer. Different immunochemical and immunoelectrophoretic assays (different ELISAs, liquidphase immunosorbent assay, rocket-immunoelectrophoresis, fused-rocket-immunoelectrophoresis,line-immunoelectrophoresis, crossed-immunoelectro-phoresis, crossed-tandem-immunoelectro-phoresis, crossed-affino-immunoelectrophoresis, charge-shift-crossed-immunoelectrophoresis) weredeveloped for measuring antibody response, and analysing specificity and binding properties. TheIgG levels in developing oozytes (6 - 37 mm) were similar, and there was a significant linearcorrelation between antibody response in serum and corresponding egg yolk. From an animalwelfare point of view there are improvements associated with producing egg yolk antibodies insteadof rabbit serum antibodies.