Previous Article | Next Article ![]()
Infection and Immunity, September 1999, p. 4352-4359, Vol. 67, No. 9
Departments of
Microbiology1 and Oral
Biology,2 School of Dentistry, The University
of Alabama at Birmingham, Birmingham, Alabama 35294
Received 22 February 1999/Returned for modification 26 April
1999/Accepted 5 June 1999
Porphyromonas gingivalis, a gram-negative,
black-pigmented anaerobe, is among the microorganisms implicated in
the etiology of adult periodontal disease. This bacterium possesses a
number of factors, including hemagglutinins, of potential
importance in virulence. Several hemagglutinin genes have been
identified, cloned, and expressed in Escherichia coli. The
purpose of this study was to characterize host responses to purified
recombinant hemagglutinin B (rHag B), using the conventional Fischer
rat as the experimental animal model. The effectiveness of immunization with rHag B on protection against experimental periodontal bone loss
following infection with P. gingivalis was also evaluated. Groups of rats were immunized by the subcutaneous route with rHag B in
complete Freund's adjuvant, immunized with rHag B and orally infected
with P. gingivalis, nonimmunized and noninfected, or orally
infected with P. gingivalis only. Serum and saliva samples were collected throughout the experiment and evaluated for serum immunoglobulin G (IgG) and IgM and salivary IgA antibody activity by
enzyme-linked immunosorbent assay. No salivary IgA anti-Hag B activity
was detected in the various groups of rats. A slight serum IgM response
similar to that seen in preimmune samples was observed. Serum IgG
antibody activity to Hag B was detected only in samples from rats
immunized with rHag B. This response was primarily of the IgG1 and
IgG2a subclasses, followed by IgG2b and low levels of IgG2c.
Supernatants from rHag B-stimulated splenic lymphoid cell cultures from
immunized rats contained high levels of gamma interferon, followed by
interleukin-2 (IL-2), IL-10, and then IL-4. These results are
consistent with the induction of T helper type 1 (Th1)- and Th2-like
responses. Western blot analysis of sera derived from rHag B-immunized
rats reacted with trichloroacetic acid (TCA) precipitates of P. gingivalis 33277, 381, A7A1-28, and W50, revealing a
50-kDa band reflective of Hag B. However, sera derived from rats
immunized with P. gingivalis whole cells or from rats
infected with P. gingivalis only did not react with rHag B
but did react with TCA precipitates of P. gingivalis
strains. Finally, radiographic measurements of periodontal bone loss
indicated that rats immunized with rHag B had less bone loss than
those infected with P. gingivalis only. These results demonstrate the effectiveness of purified rHag B in inducing a protective immune response and support the potential usefulness of
this component of P. gingivalis in the development of a
vaccine against adult periodontitis.
0019-9567/99/$04.00+0
Copyright © 1999, American Society for Microbiology. All rights reserved.
Host Responses to Recombinant Hemagglutinin B of
Porphyromonas gingivalis in an Experimental Rat
Model
*
Corresponding author. Mailing address: Department of
Oral Biology, The University of Alabama at Birmingham, 845 South 19th St., BBRB 713/5, Birmingham, AL 35294-2170. Phone: (205) 934-2878. Fax:
(205) 934-1426. E-mail:
jenny_katz{at}micro.microbio.uab.edu.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|