# HOST-FREE ACTIVITIES-OF CHLAMYDIAE

> **NIH NIH R01** · UNIVERSITY OF TENNESSEE HEALTH SCI CTR · 1987 · $159,144

## Abstract

Members of the genus Chlamydia are obligate intracellular parasitic
bacteria and the agents of various animal and human diseases.  Infections
caused by C. trachomatis are now recognized as the most prevalent - and
among the most damaging - of all sexually transmitted diseases seen in the
United States.  Chlamydiae possess a unique life cycle which may be thought
of as the orderly alternation between infectious extracellular elementary
bodies (EBs) and noninfectious intracellulary dividing reticulate bodies
(RBs).  Almost nothing is known about the factors which govern EB entry
into host cells, reorganization of EBs to RBs, multiplication of RBs, and
reorganization of RBs to EBs.  The overall objective of this proposal is to
better understand the molecular events which take place during the
developmental cycle of C. trachomatis.  The long term goal is to establish
conditions for host-free growth of chlamydiae, an achievement which will
greatly facilitate basic studies on these difficult-to-grow organisms.

We will identify genes expressed at specific phases of the developmental
cycle and establish a library of these differentially expressed genes.
Phase-specific protein synthesis and the DNA library will be used to
monitor gene expression in host-free chlamydiae incubating under a variety
of conditions in order to identify environmental signals which control
chlamydial reorganization and promote multiplication.  Surface proteins
synthesized at the time of RB to EB conversion will be identified and
purified, and their roles as adhesins will be examined.  A recombinant
drug-resistant plasmid will be constructed, and attempts will be made to
introduce this plasmid into C. trachomatis in order to develop a system for
studying the genetics of chlamydiae.

The identification of genes involved in the reorganization of chlamydial
life-cycle forms and the determination of environmental signals which
control their expression should ultimately improve our understanding of how
chlamydiae survive within the human host and cause persistent infections.
Identification of a chlamydial adhesin might provide the basis for the
development of a subunit vaccine.

## Key facts

- **NIH application ID:** 3128895
- **Project number:** 5R01AI019570-05
- **Recipient organization:** UNIVERSITY OF TENNESSEE HEALTH SCI CTR
- **SAM.gov UEI:** X1M1PN3KG3E7
- **Principal Investigator:** THOMAS P HATCH
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1987
- **Award amount:** $159,144
- **Award type:** 5
- **Project period:** 1983-09-01 → 1991-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3128895

## Citation

> US National Institutes of Health, RePORTER application 3128895, HOST-FREE ACTIVITIES-OF CHLAMYDIAE (5R01AI019570-05). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3128895. Licensed CC0.

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