title: Accumulation of intestinal intraepithelial lymphocytes in association with lack of polymeric immunoglobulin receptor.
abstract: Immunoglobulin A (IgA) is transported by the polymeric immunoglobulin receptor (pIgR) through epithelial cells of the gut, the airways, the tear and salivary glands, and the lactating mammary gland, and IgA accumulates in serum and the intestinal lamina propria of pIgR-deficient (pIgR(-/-)) mice. Intraepithelial lymphocytes (IEL) increased in number and Thy-1(+)CD8alphabeta(+)TCRalphabeta(+) IEL preferentially expanded in the small intestine (SI) of pIgR(-/-) mice. Cytotoxic activity of SI-IEL was comparable in pIgR(+/+) and pIgR(-/-) mice. Accumulation and cytotoxic activity of SI-IEL was attenuated in germ-free pIgR(-/-) mice. Furthermore, Thy-1(+)CD8alphabeta(+) IEL did not expand in pIgR(-/-)TCRbetadelta(-/-) mice compared with TCRbetadelta(-/-) mice, and SI-IEL from pIgR(-/-)TCRbetadelta(-/-) mice as well as TCRbetadelta(-/-) mice expressed perforin and granzyme B mRNA and serine esterase. The proliferative status of SI-IEL from pIgR(+/+) and pIgR(-/-) mice was similar, but adoptive transfer experiment showed that SI-IEL from pIgR(-/-) mice might have a stronger tendency to migrate into the intestinal epithelia than those from pIgR(+/+) mice. These results demonstrate that the accumulation of Thy-1(+)CD8alphabeta(+)TCRalphabeta(+) IEL in pIgR(-/-) mice triggered by intestinal microorganisms needed the expression of functional TCR and might be caused by lymphocyte migration into the intestinal epithelia.
authors.affiliation: Tokyo University of Pharmacy and Life Science, Tokyo, Japan.
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yamazaki
authors.forename: Shin-ichiro
authors.initials: S
authors.lastname: Shimada
authors.forename: Noriko
authors.initials: N
authors.lastname: Kato-Nagaoka
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Soga
authors.forename: Tsunetoshi
authors.initials: T
authors.lastname: Itoh
authors.forename: Masanobu
authors.initials: M
authors.lastname: Nanno
mesh_terms: D000818:Animals; D015870:Gene Expression; D005856:Germ-Free Life / Q000276:immunology; D007413:Intestinal Mucosa / Q000166:cytology / Q000276:immunology*; D008214:Lymphocytes / Q000276:immunology*; D051379:Mice; D008822:Mice, Transgenic; D011948:Receptors, Antigen, T-Cell / Q000172:deficiency / Q000235:genetics / Q000276:immunology; D019056:Receptors, Polymeric Immunoglobulin / Q000235:genetics / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic
chemical_list: D011948:Receptors, Antigen, T-Cell; D019056:Receptors, Polymeric Immunoglobulin