Characteristics of γ-Globulin, lacking Antibody Properties, in New-born Pigs

Abstract

IN solving the problem whether γ-globulin lacking antibody properties exists and whether γ-globulin can be formed without an antigenic stimulus, our attention was focused on γ-globulin in piglets which had not been fed with colostrum¹. The serum of piglets bred by a special technique without colostrum² is very suitable material for these experiments, because the placenta of these animals does not permit the penetration of γ-globulin³, and the newborn animals lack this protein completely^4–8. In our previous experiments¹, however, the presence of a detectable amount of γ-globulin has been demonstrated after 100 times concentration of the γ-globulin fraction of the serum taken from the piglets bred under sterile conditions without colostrum for the first 14 days after birth ; at that time piglets are not yet able to produce antibodies, not even against an artificially injected antigen (Brucella suis) nor against antigens naturally present (E. coli strains). This γ-globulin cannot combine with any of the tested antigens and it could therefore be described as ‘normal’ γ-globulin. By injecting methionine labelled with sulphur-35 to piglets bred without colostrum it was found that this small amount of γ-globulin was not transmitted passively from the mother by the intra-uterine route, but that the γ-globulin of the young animals was synthesized de novo during the period when the piglets were not yet producing antibodies.