MECHANISM OF PATHOGENIC ACTIVITY OF PEPTIDOGLYCAN

Project: Research project

Description

Bacterial infections are still a major cause of morbidity and
mortality, especially in immunocompromised individuals.
Peptidoglycan and lipopolysaccharide can reproduce most major signs
and symptoms of infections with Gram-positive and Gram-negative
bacteria, yet their molecular mechanism of action on host cells is
virtually unknown. This laboratory has recently discovered one
dominant peptidoglycan-binding protein on mouse lymphocytes and
macrophages, and demonstrated that this protein is identical with
the recently discovered lipopolysaccharide receptor. The overall
goals of these studies are to unravel the molecular mechanisms of
action of these bacterial constituents on host cells and to develop
new treatments to prevent pathologic effects of bacterial
infections. As a first step towards these goals, this project will
test the hypothesis that peptidoglycan and lipopolysaccharide act
on host cells through one specific cell surface receptor. This
project has six specific aims: (i) To isolate this
peptidoglycan-lipopolysaccharide receptor protein from mouse, sheep,
and cow lymphocytes and macrophages; (ii) To obtain hamster
monoclonal antibodies to this receptor protein; (iii) To prove that
these monoclonal antibodies indeed bind to one
peptidoglycan-lipopolysaccharide receptor, by demonstrating binding
of these antibodies to this receptor on cells and in an isolated
form, and by showing inhibition of ligand binding by monoclonal
antibodies and inhibition of monoclonal antibody binding by the
receptor ligands; (iv) To obtain further evidence for the function
of the peptidoglycan-lipopolysaccharide receptor protein as a cell
activating receptor by demonstrating agonistic or antagonistic
nature of anti-receptor monoclonal antibodies for activation of
macrophages and B cells, and modulation of cell surface expression
and function of this receptor by these antibodies; (v) To
characterize the fine specificity of this receptor by determining
the structural requirements of peptidoglycan and lipopolysaccharide
for the binding to this receptor, by studying competitive inhibition
of ligand binding by a series of natural and synthetic peptidoglycan
and lipopolysaccharide partial structures and analogs; (vi) To
obtain highly purified peptidoglycan-lipopolysaccharide receptor
protein by affinity chromatography with immobilized anti-receptor
monoclonal antibodies. These studies will: (i) verify the
hypothesis of receptor-mediated activation of lymphocytes and
macrophages by two most important bacterial cell wall constituents;
(ii) provide new tools to study novel mechanisms of signal
transduction in leukocyte activation by bacterial cell wall
components; (iii) enable future development of reagents that can
prevent or reverse septic shock and other pathologic effects of
bacterial products; and (iv) result in a discovery of a potentially
clinically useful marker for various leukocyte subpopulations and
hematologic neoplasms.
StatusFinished
Effective start/end date7/1/9211/30/14

Funding

  • National Institutes of Health: $330,668.00
  • National Institutes of Health: $377,500.00
  • National Institutes of Health: $205,704.00
  • National Institutes of Health: $369,988.00
  • National Institutes of Health: $245,241.00
  • National Institutes of Health
  • National Institutes of Health: $338,625.00
  • National Institutes of Health: $252,600.00
  • National Institutes of Health: $165,870.00
  • National Institutes of Health
  • National Institutes of Health: $338,625.00
  • National Institutes of Health: $369,988.00
  • National Institutes of Health
  • National Institutes of Health: $231,164.00
  • National Institutes of Health: $373,725.00
  • National Institutes of Health: $260,178.00
  • National Institutes of Health: $378,229.00
  • National Institutes of Health: $338,625.00
  • National Institutes of Health: $321,078.00

Fingerprint

Peptidoglycan
CD14 Antigens
Infection
Innate Immunity
Bacterial Infections
Lipopolysaccharides
Proteins
Cytokines
Ligands
Monoclonal Antibodies
Cell Wall
Bacteria
Antibodies
Morbidity
Leukocytes
Lymphocytes
Antibody Formation
Arthritis
Immobilized Antibodies
Septic Shock

ASJC

  • Medicine(all)
  • Immunology and Microbiology(all)