Critical role of caspases in the regulation of apoptosis and proliferation of mucosal T cells

Gastroenterology. 2002 May;122(5):1334-45. doi: 10.1053/gast.2002.32996.


Background & aims: Caspases are critical mediators of apoptosis and proliferation of peripheral blood T cells (PBT), but their role in lamina propria T cells (LPT), a cell population highly susceptible to apoptosis, has not been explored.

Methods: RA(+), RO(+) PBT, and LPT were activated with CD3, CD2, and CD28 antibodies, and caspase activity, apoptosis, and proliferation were measured by a fluorometric assay, DNA content, and thymidine incorporation, respectively. Levels of FLIP, an endogenous inhibitor of caspase 8, were measured by immunoblotting.

Results: In RA(+) and RO(+) PBT, activation leads to significant increase of caspase activity but not cell death, whereas in LPT a lower elevation of caspase activity was followed by a marked degree of apoptosis. Based on the results of its inhibition, caspase 8 seemed to be essential for LPT apoptosis but, in contrast to RA(+) PBT, had no effect on proliferation. In addition, compatible with their differential susceptibility to apoptosis, levels of FLIP were lower in LPT than PBT.

Conclusions: The high susceptibility of LPT to apoptosis is associated with a distinct regulation of caspase 8 activity, which seems to reflect their mucosal origin rather than simply their memory status. This unique behavior may allow proper control of mucosal T-cell proliferation while still permitting elimination by apoptosis in the face of excessive antigenic pressure.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Apoptosis*
  • Caspases / physiology*
  • Humans
  • Intestinal Mucosa / immunology*
  • Lymphocyte Activation*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / physiology


  • Caspases