# HOST-FREE ACTIVITIES OF CHLAMYDIAE

> **NIH NIH R01** · UNIVERSITY OF TENNESSEE HEALTH SCI CTR · 1993 · $192,171

## Abstract

Chlamydia trachomatis and C. psittaci are important pathogens of humans and
animals.  The most fundamental chlamydial virulence property is the ability
to grow within and destroy host cells by means of an obligate intracellular
developmental cycle.  Very little is known about how chlamydiae grow and
survive within cells, and essentially nothing is known about how chlamydiae
regulate gene expression within the unusual environment of a eukaryotic
host cell.  Not a single chlamydial promotor has been defined by functional
studies, nor have repressors, activators and enhancers of gene activity
been identified.  The signals that trigger intracellular developmental
events are also unknown.  The goal of the proposed research is to
understand how gene expression is regulated by chlamydiae as they progress
through the developmental cycle.  Towards this end, the expression of
selected developmental stage-specific and other key G. trachomatisand C.
psittaci genes will be examined in an in vitro transcription system.  Genes
requiring the major chlamydial sigma factor for expression will be
identified by determining the effects of antisigma monoclonal antibodies on
transcription and by reconstitution experiments with recombinant chlamydial
major sigma factor and E. coli core RNA polymerase.  The effects of in
vitro-generated mutations on transcription will be studied in the system in
order to identify the regulatory DNA elements of selected chlamydial genes,
and attempts will be made to identify the proteins that bind to these
regions and to clone the genes that encode these proteins.  In vitro
transcription of the extracellular elementary body form of chlamydiae will
also be studied in an attempt to define genes which may be active
immediately upon entry of chlamydiae into host cells.  An understanding of
promotor structure and the mechanism of gene regulation should be
invaluable if and when a chlamydial genetic system is developed.  These
studies should also contribute towards the achievement of the long-term
objective of this research: understanding how chlamydiae grow within host
cells--a necessary and fundamental step in the process by which chlamydiae
cause disease.

## Key facts

- **NIH application ID:** 3128899
- **Project number:** 5R01AI019570-10
- **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:** 1993
- **Award amount:** $192,171
- **Award type:** 5
- **Project period:** 1983-09-01 → 1996-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3128899

## Citation

> US National Institutes of Health, RePORTER application 3128899, HOST-FREE ACTIVITIES OF CHLAMYDIAE (5R01AI019570-10). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3128899. Licensed CC0.

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