# IMMUNOGENS OF T PALLIDUM:  IDENTIFICATION AND FUNCTION

> **NIH NIH R01** · UNIVERSITY OF WASHINGTON · 1991 · $223,556

## Abstract

Syphilis is a chronic bacterial infection which, after five centuries,
continues to plague individuals worldwide. Although effective therapy has
been available for fifty years, the United States is currently in the midst
of a syphilis epidemic, with a 50% increase in incidence in the past two
years. In addition to the serious late sequelae of syphilis, numerous
studies suggest that syphilis and other genital ulcer diseases may be risk
factors for acquisition and transmission of human immunodeficiency virus
(HIV) infection.

The immune response to syphilis infection has been under investigation for
a number of years, however a clear understanding of the specific mechanisms
of resistance has not yet been achieved. Antibody, which is produced in
high titer during infection, can neutralize, immobilize, and opsonize T.
pallidum, yet its importance in lesion resolution and resistance is
unknown. Based upon histological and laboratory studies, it is generally
accepted that the cellular arm of the immune system is central to the
clearance of syphilitic lesions and the development of resistance. Our
working hypothesis of syphilis immunity centers around the production of
lymphokines (macrophage activating factors [MAF], including
gamma-interferon) by specifically sensitized lymphocytes with the resultant
activation of effector macrophages which are primarily responsible for
bacterial clearance. Although a number of Treponema pallidum antigens have
been identified and characterized in terms of antibody reactivity, little
is known about the antigens which induce cellular immune responses. In
order to focus future vaccine studies on molecules which are known to
stimulate the specific cellular functions believed to be central to
syphilis immunity, this renewal  application proposes the examination of
individual antigens of T. pallidum in terms of their interaction with
macrophages and lymphocytes in the induction and development of these
cellular responses.  Specifically, we propose 1) the identification of
antigenic molecules and peptides of T. pallidum which stimulate production
of macrophage activating factors (MAF) by sensitized lymphocytes in vitro
and induce delayed hypersensitivity in vivo 2) the examination of the
nature of antigen processing and kinetics of presentation of individual
antigens by macrophages in order to characterize molecules and determinants
which readily induce appropriate T lymphocyte responses; 3) the development
of T cell clones with specificity for T. pallidum antigens for use in
antigen presentation assays and for examination of lymphokine production in
response to individual T cell epitopes; 4) the immunization of rabbits with
T. pallidum antigens incorporated into liposomes; and 5) the examination of
the parameters of phagocytosis of T pallidum and the effector function of
macrophages on T. pallidum. We anticipate that these studies will aid in
the understanding of the mechanisms of immunity to T. pallidum and will
identify s...

## Key facts

- **NIH application ID:** 3128409
- **Project number:** 5R01AI018988-08
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **SAM.gov UEI:** HD1WMN6945W6
- **Principal Investigator:** Sheila A. Lukehart
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1991
- **Award amount:** $223,556
- **Award type:** 5
- **Project period:** 1984-03-01 → 1993-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3128409

## Citation

> US National Institutes of Health, RePORTER application 3128409, IMMUNOGENS OF T PALLIDUM:  IDENTIFICATION AND FUNCTION (5R01AI018988-08). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3128409. Licensed CC0.

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