# GONOCOCCAL POR, OPA, AND NEUTROPHIL ACTIVATION

> **NIH NIH R01** · HOSPITAL FOR JOINT DISEASES ORTHO INST · 1993 · $175,546

## Abstract

Neisseria gonorrhoeae has a single reservoir--Homo sapiens; mankind,
in turn, possesses multiple mechanisms with which to fight infection.
Despite this, untreated gonorrhea can persist for weeks. We have shown
that Por protein of N. gonorrhoeae (Por) inhibits granule enzyme
release (LER), but not O2 generation after chemoattractants (CTX).  Por
has no effect on LER triggered by immune complexes (IC).  We have
proposed that Por prevents phagosome-lysosome fusion in neutrophils
(PMN) prolonging gonococcal survival early in the course of infection.
We will examine this as follows: As Por- mutants are unavailable, we
will determine the effect of Por added to bactericidal assays of E.
Coli transfected with opa, the gonococcal opacity-associated and
attachment protein.  We will determine whether Por inhibits LER, O2
release or phagocytosis triggered by opa +E. coli or opa+ liposomes.
We have demonstrated that Por inhibits production of diacylglycerol
(DAG) and metabolism of phosphatidylcholine (PC) in PMN treated with
CTX but does not affect generation of phosphatidate (PA).  LER is
tightly correlated with production of DAG, most likely via a
PC-specific phospholipase C (PC-PLC) which is inhibited by Por.  In
parallel to its functional effects, Por does not inhibit DAG generation
triggered by IC.  We will then focus on the role of Por and opa of the
gonococcus in affecting signal transduction in PMN and how this may
favor neisserial infection.  We will determine where Por is located
after it binds to PMN (plasmalemma cytoskeleton, granules) using light
and electronmicroscopic techniques (fluorescent antibody
immunogold-labelling-125I-labelling and cell fractionation).  We will
determine whether this inhibition is secondary to porin activity by
determining whether, in fact, Por acts as an ion channel in vitro (ion
fluxes [22Na, 36Cl-, 42K+ ,35SO-2-4] or fluorescent probes (SBFI, PBFI,
or SPQ).  We will determine whether CTX provoke metabolism of both the
diacyl- and alkyl,acyl (EA) fractions of phosphatidylcholine
(radiolabel, phospholipid mass after CTX) and whether EAG generation
is inhibited by Por.  We will perform similar experiments in PMN
triggered by opa+ E. coli and opa+ liposomes.  We will determine
whether PC-PLC activity in purified plasma membranes can be augmented
by treatment with the above CTX.  We will attempt to parallel the
effects of Por by using other disruptors of ion movements (amiloride,
SITS, DIDS) and determine PL turnover (HPLC,TLC).  We will determine
whether other organelles are required for activation and inhibition of
PC-PLC by examining PL metabolism in cytoplasts.  We will determine the
effect of Por on phospholipid domains of the cell membrane (freeze
fracture). We will examine whether activation of the PC-PLC universally
triggers exocytosis after CTX in PMN and monocytes.  We will determine
the source of DG after IC by examining diradyl-PL metabolism.  In
learning how the gonococcus can escape immediate killing, we wil...

## Key facts

- **NIH application ID:** 3150148
- **Project number:** 1R01AI035694-01
- **Recipient organization:** HOSPITAL FOR JOINT DISEASES ORTHO INST
- **Principal Investigator:** Kathleen ANN Haines
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1993
- **Award amount:** $175,546
- **Award type:** 1
- **Project period:** 1993-08-01 → 1998-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3150148

## Citation

> US National Institutes of Health, RePORTER application 3150148, GONOCOCCAL POR, OPA, AND NEUTROPHIL ACTIVATION (1R01AI035694-01). Retrieved via MORVS 2026-10-24 from https://api.morvs.ai/grant/nih/3150148. Licensed CC0.

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