Molecular characterization of common treponemal antigens

Abstract

A molecular characterization of cross-reactive antigens of Treponema pallidum Nichols and Treponema phagedenis biotype Reiter that are reactive with normal and syphilitic human sera is described. At least 8 common polypeptides, 14 T. pallidum-specific antigens, and 2 T. phagedenis biotype Reiter-specific antigens were identified.Antigenic characterization of Treponema pallidum has been hampered by the inability to obtain large quantities of pure, motile, and virulent organisms (1,9,10,21,22,(28)(29)(30). Nonpathogenic treponemes, however, can be grown in vitro in pure culture. Thus, in an attempt to obtain information about treponemal antigenic interrelationships, investigators have concentrated their efforts toward the examination of cross-reactive antigens obtained from the nonpathogens. Most of the studies have identified antigens common to both T. pallidum Nichols and the host-indigenous, nonpathogenic Treponema phagedenis biotype Reiter (referred to here as Reiter). Complement fixation (3-5, 7, 8, 12, 18, 20), gel diffusion (12,18,20), fluorescentantibody (6,13,17,27), crossed immunoelectrophoresis (20,(23)(24)(25)(26) and Western blot (15) techniques have revealed the presence of shared protein, polysaccharide, and/or protein-lipopolysaccharide complex antigens. Furthermore, absorption studies have shown that the presence of treponemicidal activity in normal human serum against T. pallidum and Reiter is stimulated by common T. pallidum and Reiter immunogens (P. A. Hanif and J. N. Miller, submitted for publication). However, with the exception of axial filament proteins (12, 21), the common treponemal antigens have not been well characterized in terms of their cellular location or molecular weight. As a prelude to isolation and purification of these particular cell components, we have characterized the common polypeptide antigens of T. pallidum and Reiter with normal and syphilitic human sera by using sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis followed by electrophoretic transfer of the t Present address:

Molecular analysis of immunoglobulins M and G immune response to protein antigens of Treponema pallidum in human syphilis

“…Utilizing sera from syphilitic patients and the Western blotting technique, Hanff et al (5) recently characterized eight protein antigens with MW of 30,000, 33,000, 35,500, 40,000, 45,000, 47,000, 73,000, and 82,000 that are common to both T. pallidum and T. phagedenis biotype Reiter. Using a crossed immunoelectrophoresis technique, Pedersen et al (10) have identified six cross-reacting protein antigens.…”

“…Lukehart et al (7), using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) followed by Western blotting (11), have identified at least eight antigens of T. pallidum which react with a serum pool from infected rabbits. By the same technique, Hanff et al (4,5) have studied the humoral immune response to protein antigens of T. pallidum in human syphilis.…”

“…Methods hitherto used for antigen analysis (crossed electrophoresis and SDS-PAGE followed by Western blotting) have different sensitivities (5). Theoretical considerations led to the idea that internal radiolabeling of treponemes by [35S]methionine and subsequent separation of protein antigens by SDS-PAGE followed by autoradiography should result in highly sensitive and specific findings as far as protein antigens are concerned.…”

Antigenic interrelationship between endoflagella of Treponema phagedenis biotype Reiter and Treponema pallidum (Nichols): molecular characterization of endoflagellar proteins

“…The nonpathogenic, cultivatable treponemes provide an alternative means for the study of analagous T. pallidum constituents at the molecular level. It has been demonstrated by Western blotting (13,20) and crossed immunoelectrophoresis (27)(28)(29) that nonpathogenic treponemes, specifically Treponema phagedenis biotype Reiter, possess a number of polypeptides that are cross-reactive with proteins of T. pallidum. Antisera raised to these purified, cross-reactive proteins can be used as probes for characterization and ultrastructural localization of the corresponding molecules in T. pallidum.…”

Purification and characterization of a cloned protease-resistant Treponema pallidum-specific antigen

“…Basic questions about the composition of the Treponema pallidum cell surface and the biological functions of its component molecules have been difficult to answer because in vitro multiplication of the organism is limited (6) and growth in rabbit testicles creates the inherent problem of interpreting whether molecules copurified with T. pallidum are rabbit or treponemal in origin. Recent approaches to define T. pallidum antigens have utilized immunoprecipitation of T. pallidum polypeptides radiolabeled in vitro (2, 12a, 14, 17) or immunoblotting of T. pallidum polypeptides with syphilitic sera (7,8,10,17). More than 20 antigens have been identified in human and experimental syphilis.…”