De: Maria Inês Reinert Azambuja [mailto:miazambuja@terra.com.br]
Enviada em: terça-feira, 22 de março de 2005 13:11
Para: aloyzio.achutti@terra.com.br
Assunto: trypanosoma invasion
http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=174296&blobtype=pdf
Gastric Invasion by Trypanosoma cruzi and Induction of
Protective Mucosal Immune Responses
DANIEL F. HOFT,1* PATRICIA L. FARRAR,2 KATHERINE KRATZ-OWENS,1 AND DAWN SHAFFER2
Departments of Internal Medicine1 and Comparative Medicine,2 Saint Louis University Health Sciences Center,
St. Louis, Missouri 63110
Received 6 February 1996/Returned for modification 27 March 1996/Accepted 13 May 1996
Trypanosoma cruzi is an intracellular parasite transmitted from a reduviid insect vector to humans by exposure of mucosal surfaces to infected insect excreta. We have used an oral challenge murine model that mimics vector-borne transmission to study T. cruzi mucosal infection. Although gastric secretions have microbicidal activity against most infectious pathogens, we demonstrate that T. cruzi can invade and replicate in the gastric mucosal epithelium. In addition, gastric mucosal invasion appears to be the unique portal of entry for systemic T. cruzi infection after oral challenge. The mucosal immune responses stimulated by T. cruzi gastric infection are protective against a secondary mucosal parasite challenge. This protective mucosal
immunity is associated with increased numbers of lymphocytes that secrete parasite-specific immunoglobulin A. Our results document the first example of systemic microbial invasion through gastric mucosa and suggest the feasibility of a mucosal vaccine designed to prevent infection with this important human pathogen
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