JOURNAL ARTICLE
RESEARCH SUPPORT, U.S. GOV'T, P.H.S.
The outer membrane, not a coat of host proteins, limits antigenicity of virulent Treponema pallidum.
Infection and Immunity 1992 March
Virulent Treponema pallidum reacts poorly with the specific antibodies present in human and rabbit syphilitic sera, a phenomenon often attributed to an outer coat of host serum proteins. Here we present additional evidence that the limited antigenicity of virulent organisms actually is due to a paucity of proteins in the outer membrane. Initially, we used electron microscopy to demonstrate that the outer membrane is highly susceptible to damage from physical manipulation (i.e., centrifugation and resuspension) and nonionic detergents. Organisms with disrupted outer membranes were markedly more antigenic than intact treponemes as determined by immunoelectron microscopy (IEM) with rabbit syphilitic and antiendoflagellar antisera. Data obtained with a new radioimmunoassay, designated the T. pallidum surface-specific radioimmunoassay, corroborated these IEM findings by demonstrating that the major T. pallidum immunogens are not surface exposed; the assay also was unable to detect serum proteins, including fibronectin, on the surfaces of intact organisms. Furthermore, IEM of T. pallidum on ultrathin cryosections with monospecific anti-47-kDa-immunogen antiserum confirmed the intracellular location of the 47-kDa immunogen. On the basis of these and previous findings, we proposed a new model for T. pallidum ultrastructure in which the outer membrane contains a small number of transmembrane proteins and the major membrane immunogens are anchored by lipids to the periplasmic leaflet of the cytoplasmic membrane. This unique ultrastructure explains the remarkable ability of virulent organisms to evade the humoral immune response of the T. pallidum-infected host.
Full text links
Trending Papers
Fluid Resuscitation in Patients With Traumatic Brain Injury: A Comprehensive Review.Curēus 2023 August
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
Read by QxMD is copyright © 2021 QxMD Software Inc. All rights reserved. By using this service, you agree to our terms of use and privacy policy.
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app