RESUMO
The Galß1,3GalNAcα1,O-Ser/Thr specific lectin from Amaranthus leucocarpus (ALL) binds a â¼70 kDa glycoprotein on murine T cell surface. We show that in the absence of antigen presenting cells, murine CD4(+) T cells activated by an anti-CD3 antibody plus ALL enhanced cell proliferation similar to those cells activated via CD3/CD28 at 48 h of culture. Moreover, ALL induced the production of IL-4, IL-10, TNF-alpha, and TGF-beta in CD3-activated cells. Proteomic assay using two-dimensional electrophoresis and far-Western blotting, ALL recognized two prominent proteins associated to the lipid raft microdomains in CD3/CD28-activated CD4(+) T cells. By mass spectrometry, the peptide fragments from ALL-recognized proteins showed sequences with 33% homology to matricin (gi|347839 NCBInr) and 41% identity to an unnamed protein related to moesin (gi|74186081 NCBInr). Confocal microscopy analysis of CD3/CD28-activated CD4(+) T cells confirmed that staining by ALL colocalized with anti-moesin FERM domain antibody along the plasma membrane and in the intercellular contact sites. Our findings suggest that a moesin-like O-glycoprotein is the ALL-recognized molecule in lipid rats, which induces costimulatory signals on CD4(+) T cells.
RESUMO
Pulmonary tuberculosis is currently considered a serious health problem worldwide. To understand tuberculosis infection we need to know the interaction between the host's immune response and the microorganism causing tuberculosis. Ample research has been carried out to identify new molecules and genes involved in the evasion mechanism of the host's immune response. This knowledge has generated the possibility that future therapeutic schemes will be designed to fight these particular molecules or genes. We reviewed recent experimental evidence on the mechanisms that will successfully fight against mycobacteria.
