Previous Article | Next Article ![]()
Infection and Immunity, September 2000, p. 5167-5175, Vol. 68, No. 9
Division of Geographic Medicine and
Infectious Diseases, Tupper Research Institute, New England Medical
Center, Tufts University School of Medicine, Boston, Massachusetts
02111,1 and Division of Infectious
Diseases, Tufts University School of Veterinary Medicine, North
Grafton, Massachusetts 015362
Received 22 March 2000/Returned for modification 18 May
2000/Accepted 7 June 2000
The protozoan parasite Cryptosporidium parvum is a
significant cause of diarrheal disease worldwide. Attachment to and
invasion of host intestinal epithelial cells by C. parvum
sporozoites are crucial steps in the pathogenesis of cryptosporidiosis.
The molecular basis of these initial interactions is unknown. In order
to identify putative C. parvum adhesion- and
invasion-specific proteins, we raised monoclonal antibodies (MAbs) to
sporozoites and evaluated them for inhibition of attachment and
invasion in vitro. Using this approach, we identified two glycoproteins
recognized by 4E9, a MAb which neutralized C. parvum
infection and inhibited sporozoite attachment to intestinal epithelial
cells in vitro. 4E9 recognized a 40-kDa glycoprotein named gp40 and a
second, >220-kDa protein which was identified as GP900, a previously
described mucin-like glycoprotein. Glycoproteins recognized by 4E9 are
localized to the surface and apical region of invasive stages and are
shed in trails from the parasite during gliding motility. The epitope recognized by 4E9 contains
0019-9567/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Mediation of Cryptosporidium parvum
Infection In Vitro by Mucin-Like Glycoproteins Defined by a
Neutralizing Monoclonal Antibody

-N-acetylgalactosamine
residues, which are present in a mucin-type O-glycosidic linkage.
Lectins specific for these glycans bind to the surface and apical
region of sporozoites and block attachment to host cells. The surface
and apical localization of these glycoproteins and the neutralizing
effect of the MAb and
-N-acetylgalactosamine-specific
lectins strongly implicate these proteins and their glycotopes as
playing a role in C. parvum-host cell interactions.
*
Corresponding author. Mailing address: Division of
Geographic Medicine and Infectious Diseases, New England Medical
Center, Box 041, 750 Washington St., Boston, MA 02111. Phone: (617)
636-7032. Fax: (617) 636-5292. E-mail: hward{at}lifespan.org.
Present address: Reanimation Medicale, Maladies Infectieses et
Tropicales, Centre Hospitalier Universitaire Cote-de-Nacre, Caen 14033, France.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|