On Cross Reactions of Immune Sera to Azoproteins

Abstract

The overlapping reactions commonly observed in serological tests are ascribed by most authors to multiple antibodies formed as a result of the presence of several substances or distinct specific groups in the immunizing antigen. Yet studies on azoprotein immune sera have shown that antibodies corresponding to a particular compound regularly react with other substances which are sufficiently related in chemical structure (1, 2). Thus cross reactions in general can be understood on this principle alone without postulating a multiplicity of antibodies. However, this explanation does not cover the observations made when immune sera are partially exhausted by heterologous antigens.It is unnecessary to cite examples of the well known and widely used fact that immune sera for bacteria and blood cells after treatment with a heterologous antigen (sensitive to its action) still react with the homologous antigen but no longer with that used for exhaustion. This method does not succeed as readily and regularly with precipitin sera for proteins (3). Yet in a number of experiments such sera could be made highly specific by fractional precipitation with heterologous antigen which reveals the presence of several antibodies. For instance, Hooker and Boyd (4) found that a precipitin for chicken serum acting also on duck serum, after removal of the precipitate formed on addition of the latter, still precipitated chicken serum intensely, but no longer duck serum. The assumption made here and in similar instances that the sera contain several antibodies directed toward different determinant groups in the protein has not been proved by chemical evidence. In order to investigate this question experiments were carried out with precipitins for artificially conjugated antigens 325 on

The specificity of antisera against crystalline serum albumin

“…Table V gives the results of ring tests carried out after the antisera which reacted with both homologous and heterologous antigens had been absorbed with human serum and with horse-serum albumin. The findings are similar to those of previous authors (Landsteiner & van der Scheer, 1936;Marrack & Carpenter, 1938;Cole, 1938;Kabat & Heidelberger, 1937) in that absorption with homologous antigen at the optimal point removed all reactivity with heterologous antigen. It has been asserted by Kabat & Heidelberger (1937) that the persistence of the reaction with homologous antigen after homologous absorption at the optimal point is due to contamination with globulin of the albumin used for immunization, so that antibody to this protein is also produced and gives a residual reaction due to globulin-antiglobulin.…”

Immunological Studies of the Immobilization Antigens of Paramecium aurelia variety 2

“…A mechanism such as this was suggested by Landsteiner & van der Scheer (1936) as the most reasonable explanation for some of their results from using artificial conjugated azoproteins. The basis for cross-reactivity according to this view would reside in the lack of uniform reactivity of the antibody molecules formed against the homologous antigen, for the heterologous and homologous antigens would not be expected to show the same affinities for the different antibody molecules.…”

Further Studies of Specificity of Antibodies Contained in Antiserum against Poliovirus

“…11 T. URASAWA AND M. KANAMITSU against Mahoney strain was prepared in rabbits by multiple intravenous injections with the virus grown in HeLa cells [17]. Neutralizing titers of the antiserum and its components were measured using Mahoney strain (wild type virus).…”