Transforming growth factor-beta decreases survival of XXXX -activated T cells.

@entity1 @entity2667 @entity1977 @entity2533 @entity2499 @entity378 @entity2497
BACKGROUND: A comprehensive understanding of the immune response induced by @entity2497 Bacille Calmette-Gu  rin in activation of protective T cells against @entity378 is important to develop effective therapies to combat this disease. In this study, our experiments were designed to determine effects of transforming growth factor (TGF)-beta on @entity2499 -induced T-cell activation and survival. METHODS: Fluorescence-activated cell sorter (FACS) analysis was used for detection of apo-ptotic cells by three different methods: 1). scattered light change during early phase of apoptosis; 2). detection of hypodiploid DNA, or 3). terminal deoxynucleotidyl transferase @entity1977 nick end-labeling (TUNEL) technique. Quantification of positively stained population was based on samples stained with isotype control antibodies analyzed on a FACScan. RESULTS: @entity2533 added at initiation of culture did not alter percentage of viable cells. By contrast, @entity2533 added 72 h post-activation decreased percentage of viable cells. This effect was statistically significant (p <0.05). Furthermore, addition of anti- @entity2533 MoAb together with @entity2533 abolished the ability of this cytokine to decrease survival in post-activated @entity1 T cells. Role of @entity2533 on post-activated @entity1 T cells was further confirmed by staining apoptotic nuclei with @entity2667 , which detects late events of apoptosis, and by DNA fragmentation determined using TUNEL assay. Interestingly, @entity2533 did not promote Fas-mediated killing. Finally, @entity2533 increased apoptosis of CD4(+) T cells after mycobacterial stimulation. CONCLUSIONS: This study indicated an important role for @entity2533 in suppression of protective immune response against @entity2499 by promoting elimination of post-activated T cells. Furthermore, results showed that @entity2533 had no direct effect on @entity2499 -induced up-regulation of Fas (CD95).
