Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1992-6-25
pubmed:abstractText
Trypanosoma cruzi proteinases are very likely involved in host-cell invasion. Physiological plasma-proteinase inhibitors from the macroglobulin (MG) family, among them alpha-2-macroglobulin (A2M), are found in tissues and in the plasma of mammals. By complexing to all classes of proteinases, MGs inhibit their action on high-molecular-weight substrates. In vitro studies have shown that A2M impairs T. cruzi proteases and, consequently, the parasite's ability to invade host cells and enhances the phagocytic and microbicidal actions of resident macrophages against T. cruzi. To test the hypothesis of a putative "protective" effect for MG, we quantified it in BALB/cj mice during the course of an experimental T. cruzi infection, comparing a posteriori the levels in mice that died with those in animals that survived, which were considered as being susceptible and resistant to the infection, respectively. The results showed that surviving mice showed an increase in plasma concentrations of MG during the first few weeks after the infection, whereas the levels in mice that died during the acute phase did not differ significantly from those in non-infected mice. These findings and the previous in vitro data indicate a role for physiological proteinase inhibitors, particularly alpha-macroglobulins, in resistance to T. cruzi infection, whereby a balance between parasite proteases and host protease inhibitors may be crucial. MG may thus participate in the complex network of reactions involved in the early acute phase of the disease and contribute by conferring to the host an ability to survive the infection.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0932-0113
pubmed:author
pubmed:issnType
Print
pubmed:volume
78
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
215-21
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Trypanosoma cruzi: enhanced alpha-macroglobulin levels correlate with the resistance of BALB/cj mice to acute infection.
pubmed:affiliation
Dept. Ultraestrutura e Biologia Celular, Fundação Oswoldo Cruz, Rio de Janeiro, Brasil.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't