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Isolation and Flow Cytometric Characterization of Murine Small Intestinal Lymphocytes
Published on: May 8, 2016
Intraepithelial lymphocytes in normal human intestine do not express proteins associated with cytolytic function
1Cancer Biology Program, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
The American Journal of Pathology
|August 1, 1997
Summary
Human intestinal T cells (IELs) in the small intestine are mostly resting cytolytic cells. They do not express key molecules for cell killing in their normal state, suggesting they don't cause epithelial cell death.
Area of Science:
- Immunology
- Gastroenterology
- Cell Biology
Background:
- Intraepithelial T lymphocytes (IELs) are abundant in the human small intestine.
- IELs are suspected to be cytolytic and involved in intestinal epithelial cell turnover.
- The precise cytolytic function of IELs in normal conditions remains unclear.
Purpose of the Study:
- To investigate the cytolytic potential of human small intestine IELs in situ.
- To determine the expression of key cytotoxic molecules by IELs in the normal small intestine.
- To understand the role of IELs in intestinal epithelial cell apoptosis.
Main Methods:
- Immunohistochemical analysis of small and large intestine tissues.
- Detection of granzyme A, granzyme B, perforin, Fas ligand, TNF-alpha, and IFN-gamma.
- Isolation and in vitro activation of IELs for protein expression analysis.
Main Results:
- In situ, small intestinal IELs did not express granzyme B, perforin, Fas ligand, or TNF-alpha.
- Granzyme A was expressed by a significant proportion of IELs in situ.
- In vitro activated IELs expressed granzyme B, Fas ligand, TNF-alpha, and IFN-gamma.
Conclusions:
- The majority of IELs in the normal human small intestine are resting cytolytic T cells.
- These resting IELs do not appear to mediate apoptotic cell death in normal intestinal epithelium.
- IELs may require activation to exert their full cytolytic effector functions.
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