# GENETICS OF T PALLIDUM PATHOGENESIS

> **NIH NIH R01** · UT SOUTHWESTERN MEDICAL CENTER · 1988 · $144,788

## Abstract

The overall objective of this proposal is to utilize recombinant DNA
technology to isolate the major immunogens of Treponema pallidum for
examination of their roles in the immunopathogenesis of syphilis.  We
recently described the identification of a major immunodominant 47,000
(47K) mol wt surface immunogen of T. pallidum.  E. coli recombinant DNA
clones expressing the major 47K immunogen of T. pallidum also have been
isolated.  A 1.75 kb DNA fragment encoding the 47K immunogen will be
sequenced to derive the first amino acid sequence for a major immunogen of
T. pallidum.  Simultaneously, "native" and "recombinant DNA-derived" 47K
immunogens will be characterized using radioimmunoprecipitation, Western
blotting, peptide mapping, N-terminal amino acid sequencing, and
hydrophilicity analysis.  Genes encoding a 44,000 mol wt immunogen and
other immunogens of T. pallidum also will be analyzed by these techniques.
Respective "recombinant" immunogens will be analyzed by E. coli cell-free
in vitro coupled transcription/translation, or by expression in minicells
or maxicells.  High level expression (production) of cloned immunogens will
be achieved by subcloning genes into the expression vector pKC30, followed
by isolation of the product(s) using polyclonal or monoclonal antibody
immunoaffinity chromatography.  Pre-established (pBR322) or newly-generated
(pKC30; controlled expression) T. pallidum genomic clone banks in E. coli
will continue to be screened by solid-phase radioimmuno-colony blot (RICB)
assay employing immune rabbit serum, human syphilitic serum, and selected
anti-T. pallidum monoclonal antibodies, to detect additional E. coli clones
expressing relevant T. pallidum immunogens that may not have been recovered
by previous strategies.

The biological relevance of recombinant immunogens will be tested through
immunogenicity studies in animals to determine 1) if antibodies raised
against recombinant immunogens are reactive in the T. pallidum
immobilization test; 2) if they can block the attachment of T. pallidum to
host cells; and 3) their activity in the in vitro-in vivo neutralization
test.  Long term studies include vaccine trials in animals.

Selected genetic studies will determine the genomic complexity of T.
pallidum by DNA-DNA hybridization (Cot) analysis using "total clones insert
DNA."  The activity of T. pallidum gene promoters in E. coli will be
examined through the expression of various cloned immunogen genes.

## Key facts

- **NIH application ID:** 3126777
- **Project number:** 5R01AI016692-08
- **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:** 1988
- **Award amount:** $144,788
- **Award type:** 5
- **Project period:** 1980-05-01 → 1989-11-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126777

## Citation

> US National Institutes of Health, RePORTER application 3126777, GENETICS OF T PALLIDUM PATHOGENESIS (5R01AI016692-08). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126777. Licensed CC0.

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