# MOLECULAR ANALYSIS OF T PALLIDUM MEMBRANE IMMUNOGENS

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 1992 · $333,850

## Abstract

Recently it was discovered that several of the major integral membrane
immunogens of Treponema pallidum are lipoproteins. Further analyses
indicate that the 47-kDa antigen, the most immunogenic and abundant among
the membrane lipoproteins, possesses an as yet unclarified novel structure.
In addition to the profound immunogenicities of the lipoproteins,
preliminary studies suggest that they also are stimulatory for human T
cells and B cells, and perhaps endothelial cells. The working hypothesis
for this study is that the lipoprotein structure of these immunogens,
particularly the 47-kDa novel lipoprotein structure, is responsible for
some of these important biological activities. To relate structure with
function, the N-terminus and site(s) of lipid attachment in the 47-kDa
lipoprotein will be determined by using both genetic and biochemical
strategies. Biological activities of the 47-kDa, 34-kDa, and 15-kDa
lipoproteins and their relevant lipopeptides will be examined in three key
areas: 1) polyclonal activation of human B cells; 2) stimulation of
specific subsets of human T cells; and, 3) activation of human vascular
endothelial cells. Investigations into polyclonal B cell activation may
clarify many unexplained aspects of the non-treponemal (VDRL) and specific
antibody responses during syphilis. Identification of responsive human T
cell subpopulations will help to explain a critical area of cell-mediated
immunity in syphilis that is poorly understood. A long term goal of
isolating human T cells clones will help to evaluate both stimulatory as
well as possibly suppressive cellular activities operative during the
progression of syphilis. Endothelial cell activation to promote T cell
binding and migration will be examined to understand how T. pallidum, its
lipoproteins, or other constituents induce any of the characteristic
inflammatory responses of syphilis. Finally, our discovery that the major
immunogens of T. pallidum are lipoproteins allows us to exploit in vaccine
experiments their affinity for liposome (Iscom) incorporation.

Knowledge obtained in this study will clarify the roles of the lipoproteins
in several of the major events in the immunopathogenesis of syphilis, and
will provide a foundation for a better understanding of cell-mediated
immune mechanisms operative during syphilis. The information ultimately
will be useful in conceptualizing potentially novel immunologic
intervention strategies for treponemal infections.

## Key facts

- **NIH application ID:** 3126780
- **Project number:** 5R01AI016692-12
- **Recipient organization:** UT SOUTHWESTERN MEDICAL CENTER
- **SAM.gov UEI:** YZJ6DKPM4W63
- **Principal Investigator:** MICHAEL V. NORGARD
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1992
- **Award amount:** $333,850
- **Award type:** 5
- **Project period:** 1980-05-01 → 1995-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126780

## Citation

> US National Institutes of Health, RePORTER application 3126780, MOLECULAR ANALYSIS OF T PALLIDUM MEMBRANE IMMUNOGENS (5R01AI016692-12). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126780. Licensed CC0.

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