Antigenic competition

As to the first point, it has been shown by Adler (1964), Radovich and Talmage (1967), Eidinger et al. (1968) and Moller and Sjoberg (1971) that this is not the case on the contrary, a time interval of several days between the two injections is more effective. 

The second prediction was tested by Radovich and Talmage (1967). Lethally irradiated mice received transfers of 10 or 5 X 10 normal spleen cells on the same day as transfer, horse red cells were also injected and sheep red cells were given four days later. The results of the experiment showed, that contrary to what would be expected if the cells were uncommitted, the competition was more pronounced at the higher cell concentration. 

The third point was tested by several groups. Waterston (1970) reported that prior in vivo exposure to pig red cells caused an increase rather than a decrease in the in vitro response to SRC. Furthermore, Moller and Sjoberg (1971) have shown that when HRC-primed mice (which would have shown a decreased response in vivo to SRC) are sacrificed and their spleens injected 

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The microplate ELISA testis conducted in standard 96-well microplates. A microplate consists of a 12 X 8 grid of wells for test solutions. The three most widely used ELISA formats are immobilized antigen competitive immunoassay, immobilized antibody competitive immunoassay and sandwich immunoassay. " ... 

FIGURE 16.9 Principle of reagentless amperometric immunosensor based on immobilized antigen, competitive immunological reaction, and direct electrochemistry of HRP label (adapted from [138]). 

The specificity of fluorescence localization is dependent on the specificity of the primary antibody, a property that must be tested and controlled by other methods, such as immunoprecipitation or immunoblotting. Controls for the labeling procedure described include deletion of the primary antibody step, which controls for the second-step reagent, or inclnsion of a similar, but nonreactive antibody as a first step. In the case of the availability of purified primary antigen, competition controls can be used, but they only control for the reactivity of the antibody with one antigen, and do not mle ont the possibility of a crossreactive, but unrelated antigen. 

Chemiluminescent labels may also be used in labeled-antigen (competitive) assays. The antigen (analyte) competes with the labeled analyte for immobilized antibody, and, following a rinse step, reagents are added to generate chemiluminescence from the labels. 

Help overcome antigen competition in combination vaccines... 

Eidinger, D., Khan, S. A., Millar, K. G. The effect of antigenic competition on various manifestations of humoral antibody formation and cellular immunity. J. exp. Med. 128, 1183-1200 (1968). 

Moller, G., Sjoberg, O. Studies on the mechanism of antigenic competition. In Cell interactions and receptor antibodies in immune responses (O. Makela, A. Cross, T. U. Kosunen, Eds.), p. 419-432. London and New York Academic Press 1971. 

Radovich, J., Talmage, D. W. Antigenic competition Cellular or humoral. Science 158, 512-514 (1967). 

Taussig, M. Antigenic competition. Current Top. Microbiol. Immunol. 60, 125-174 (1973). 

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