Complement-Fixation Reaction in Rinderpest

Abstract

In the first report, (1) it was shown that a marked complement-fixation occurs between a boiled extract of calf lymphatic gland, obtained from laboratory cases of rinderpest and an antirinderpest serum, obtained from cattle which have been hyperimmunized by several injections of large quantities of fresh pest lymphatic gland. In this reaction, an unheated serum must be used, as it loses its activity completely when it is heated in a water-bath at 55°C for 30 minutes. The question then arises: May such thermolabile antibody exist? To elucidate this problem, some experiments were made, results of which are reported in this communication and are summarized as follows:(1) Activity of heated immune serum is reproducible by addition of an unheated normal cattle serum, which can not demonstrate any slight reaction by itself. Such reactivating effect of normal serum is also completely destroyed when it is heated at the temperature, which inactivates the immune serum.These facts suggest that the immune serum contains 2 different components, thermostable and thermolabile, which cause a positive reaction with the antigen under their co-operation.The thermolabile component is found not only in the immune serum, but also in normal serum and so it is obvious that this component is not a product of the immunisation process. On the other hand, the thermostable component is demonstrable only in the immune serum and can be probably said to be a specific antibody. The immune serum loses its activity when it is heated at 55°C., because its thermolabile component is inactivated at that temperature, though the antibody remains still unchanged, and the heated serum recovers its activity, when the lack of the thermolabile component is supplied with the new one in normal serum.(2) Is such mechanism of complement-fixation only to the rinderpest reaction? Some 20 years ago, Takano reported about a special complement-fixation with cattle serum, which occurs under the mechanism quitely similar to that described above about the rinderpest reaction. He found that the hyperimmunized cattle sera against Bac. typhosus, Bac. dysenteriae or Vibrio cholerae fix complements with the homologous antigen, when the serum is used without heating, while the reaction failed completely when the serum was previously heated at 55°C. He experienced further that the heated immune serum recovers its activity when an unheated normal cattle serum is added.It is well known that certain complement fixations-with cattle serum, such as those in contagious pleuropneumonia, Bang infection, etc., belong to the ordinary reaction and occur with heated serum. So 2 kinds of complement-fixation, which occur under different mechanism, may be distinguished when cattle serum is used as the antibody.(3) Further experiments show that the normal serum of some animals, such as sheep, goat, horse and rabbit, has also an effect similar to that of cattle serum on heated anti-rinderpest serum to reproduce its lost activity, while the normal serum of another group of animal, such as guinea-pig, swine, goose and fowl, fails to do so.(4) Through CO2 gas, the thermplabile component is precipitated from the immune and normal serum, while the thermostable component (antibody) in the immune serum remains in the supernatant fraction. By this method, 2 components in the immune serum can be easily separated.When the serum is fractionated by high concentration of ammonium sulphate, the whole of the thermolabile component and a large part of the thermostable component are precipitated in the euglobulin fraction, though a small part of the latter component is often still demonstrable in the pseudoglobulin fraction.When the globulin fraction is separated into water-soluble and water-insoluble parts by means of dialysis through collodion membrane, 2 above-mentioned components are also clearly separated,