# OUTER MEMBRANE PROTEINS OF HAEMOPHILUS INFLUENZAE TYPE B

> **NIH NIH R01** · WASHINGTON UNIVERSITY · 1988 · $235,757

## Abstract

The purified capsule of H. influenzae type b (Hib) is a poor immunogen in
human infants, the age group a greatest risk of developing Hib disease.
Outer membrane proteins (OMP) are immunogenic in infant animals and human
infants recovered from Hib disease.  Antisera directed against OMPs are
protective against experimental Hib bacteremia in infant rats.  We have
purified and partially characterized the major OMPs of Hib.  The most
abundant OMP, P2, binds lipopolysaccharide and has porin activity.
Antibody directed against OMP P2 protects against experimental bacteremia
in infant rats challenged with the strain from which we prepared the
immunogen.  This protection is unaffected by absorption of anti-LPS
antibody.  OMP P2 is present in all Hib strains examined.  Preliminary
peptide analysis indicates that these proteins are conserved proteins
although immunofluorescence and rat protection data indicate heterogeneity
of the surface exposed epitopes.  We propose to map the surface exposed
epitopes of this protein by a combination of chemical, immunologic and
genetic approaches.  Antisera will be prepared against purified proteolytic
and CNBr peptides and tested for protection in the rat model.  Monclonal
antibodies will be prepared and used to map surface epitopes and to
determine their presence in different disease producing isolates.  The
primary structure of the protein will be determined by DNA sequencing the
cloned P2 gene.  Through these approaches we will obtain data to construct
an antigenic model of the protein.  Peptides representative of the surface
exposed epitopes will then be synthesized.  These peptides will be tested
for reactivity with polyclonal and monoclonal antibodies reactive against
the native protein.  We also will conjugate the synthetic peptides to
carrier proteins, immunize animals and assay the antisera for reactivity
with the native protein; and determine the protective activity in the
infant rat model.  In other systems, cross reactive but normally
immunorecessive epitopes have been identified by exploiting these
methodologies.  Conceivably, we can identify broadly crossreactive
antigenic determinants that can be synthesized and incorporated into
nontoxic vaccines.  However, even if immunity is strain-specific, it should
be possible to incorporate peptides from representative strains into future
vaccines as a limited number of strains produce greater than 90% of Hib
disease in this country.  The experiments proposed will provide molecular
characterization of a major OMP from an important pathogen, and increase
our understanding of the use of defined peptides in vaccines.

## Key facts

- **NIH application ID:** 3127286
- **Project number:** 5R01AI017572-08
- **Recipient organization:** WASHINGTON UNIVERSITY
- **SAM.gov UEI:** L6NFUM28LQM5
- **Principal Investigator:** ROBERT S. MUNSON
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1988
- **Award amount:** $235,757
- **Award type:** 5
- **Project period:** 1980-07-01 → 1990-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3127286

## Citation

> US National Institutes of Health, RePORTER application 3127286, OUTER MEMBRANE PROTEINS OF HAEMOPHILUS INFLUENZAE TYPE B (5R01AI017572-08). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3127286. Licensed CC0.

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