ARE INTRAEPITHELIAL LYMPHOCYTES IN CELIAC MUCOSA RESPONSIBLE FOR INDUCING PROGRAMMED CELL-DEATH (APOPTOSIS) IN ENTEROCYTES - HISTOCHEMICAL-DEMONSTRATION OF PERFORINS IN CYTOPLASMIC GRANULES OF INTRAEPITHELIAL LYMPHOCYTES
M. Shiner et al., ARE INTRAEPITHELIAL LYMPHOCYTES IN CELIAC MUCOSA RESPONSIBLE FOR INDUCING PROGRAMMED CELL-DEATH (APOPTOSIS) IN ENTEROCYTES - HISTOCHEMICAL-DEMONSTRATION OF PERFORINS IN CYTOPLASMIC GRANULES OF INTRAEPITHELIAL LYMPHOCYTES, Journal of pediatric gastroenterology and nutrition, 27(4), 1998, pp. 393-396
Background: Programmed cell death refers to the genetically determined
processes by which cells die in response to physiologic extracellular
and intracellular signals, morphologically described as apoptosis. In
physiologic and pathologic circumstances this process may involve eff
ector acid target cells. Methods: To identify serine esterase granules
in intraepithelial lymphocytes, fresh-frozen human small intestine mu
cosal sections from normal and celiac-affected mucosa were incubated w
ith substrate-specific N-alpha-benzyloxy-carbonyl-L-lysine thiobenzyl
(BLT) and a chromogen (4 Benzoylamino-2,5-diethoxybenzene-dazonium chl
oride hemi [zinc chloride] salt as capture agent and were examined by
light microscopy. Results: Normal mucosa showed an occasional intraepi
thelial lymphocyte with BLT-positive intracytoplasmic granules. Some l
arge mononuclear cells of the lamina propria were similarly stained. M
any more intraepithelial lymphocytes were BLT-positive among the surfa
ce enterocytes of untreated celiac mucosa. Lamina propria mononuclear
cells close to the basal layer of crypt cells also appeared to be incr
eased. Conclusions: The histochemical identification of BLT-positive e
aters within intraepithelial lymphocytes suggests their involvement in
enterocyte death under physiologic conditions. The increased BLT-posi
tive intraepithelial lymphocytes found in the celiac mucosa may be rel
ated to the known increase in cytotoxic intraepithelial lymphocytes in
untreated celiac disease.