Antigenic analysis of Chlamydiae by two-dimensional immunoelectrophoresis. II. A trachoma-LGV-specific antigen.

Two-dimensional immunoelectrophoresis was utilized to study precipitins in hyperimmune rabbit serum made against chlamydiae and from patients with chlamydial infections. An antigen of Triton X-100-solubilized L2/434/Bu organisms with an electrophoretic mobility of 0.65 relative to bovine serum albumin at pH 8.6 was excised from the agarose gel of electrophorograms as antigen-antibody complexes and used to immunize rabbits. A monospecific antiserum to antigen 0.65 was obtained that reacted with Trachoma-LGV strains L2/434/Bu, B/TW-5/OT, and K/UW-31/Cx, but not with the mouse pneumonitis (Nigg) strain or the psittacosis strain meningopneumonitis (Cal-10). The Trachoma-LGV specificity of antigen 0.65 was further shown by indirect immunofluorescence straining with the monospecific antiserum of chlamydial inclusions in infected HeLa cells. Precipitins with a specificity for antigen 0.65 were indentified in 15 of 18 sera from patients with diagnosed Chlamydia trachomatis infections LGV, trachoma, nongonococcal urethritis, and nongonococcal cervicitis by using monospecific antiserum to antigen 0.65 in the peak suppression test. Thus, antigen 0.65 appears to be a Trachoma-LGV-specific antigen that has considerable promise for serodiagnosis.