Interference by human and bovine serum and serum protein fractions with the absorption of antibodies by suckling rats and mice

Abstract

Suckling rats and mice derive passive immunity from the mother, mainly by way of the milk. Antibodies pass into the circulation also from immune serum administered by mouth. The sera of certain species, including rabbit, man and ox, when mixed with the immune serum administered by mouth, have been shown to reduce the entry of antibodies, relative to similar admixture with homologous non-immune serum. This effect was called interference. It is shown that the $\gamma $-$\text{globulin}$ fraction of either human or bovine serum, at concentrations in buffered saline approximately equivalent to those in serum, is as effective as whole serum in interfering with the transmission of antibodies, whether homologous or heterologous. The albumin fraction of either human or bovine serum does not interfere, nor does buffered saline. The $\gamma $-$\text{globulin}$ must be present in considerable quantity relative to the immune globulin to be effective. It is most effective if administered at the same time as the immune serum and is ineffective if administered more than four hours previously. The theoretical implications of the results are discussed and a hypothesis is suggested.