Antigenic analysis of Treponema pallidum: cross-reactions between individual antigens of T. pallidum and T. Reiter.

Seven antigens were demonstrated in the Nichols pathogenic strain of Treponema pallidum when tested by cross immunoelectrophoresis against rabbit antibodies raised by immunization with T. pallidum sonicate. Indirect evidence was obtained for the presence of two more T. pallidum antigens. Of the nine antigens six reacted with antibodies in a human syphilitic serum pool. Cross-reactions between individual T. Reiter antigens and the seven directly demonstrated T. pallidum antigens were studied by different immunoelectrophoretic techniques, using rabbit anti-T. Reiter Ig, rabbit anti-T. pallidum Ig, and human syphilitic serum pool. Of the seven T. pallidum antigens three were found in T. Reiter, three had epitopes identical to corresponding antigens in T. Reiter, and one had both cross-reacting and T. pallidum-specific epitopes. Human syphilitic serum had antibodies against two of the T. pallidum-specific antigens and against four T. pallidum antigens cross-reacting with antigens of T. Reiter.