Differential appearance of T cell subsets in the large and small intestine of neonatal mice.

We examined the appearance of intestinal intraepithelial lymphocytes (IEL) during the first 12 wk of life to gain insight into postnatal factors that contribute to the differences found between IEL in the large and small intestines of adult mice. Intestinal T cells were very infrequent at birth, but increased in number in the large and small intestine during the first 4 wk of life and then stabilized. The small intestinal epithelium at 2 wk of age contained mostly T cell receptor (TCR) alphabeta+, CD2+ T cells, unlike IEL in adult mice, which were composed of nearly equal proportions of CD2-, TCR alphabeta+ and TCR gammadelta+ cells.

A novel model of inflammatory bowel disease: mice deficient for the multiple drug resistance gene, mdr1a, spontaneously develop colitis.

The murine multiple drug resistance (mdr) gene, mdr1a, encodes a 170-kDa transmembrane protein that is expressed in many tissues including intestinal epithelial cells, a subset of lymphoid cells and hematopoietic cells. We report that mdr1a knockout (mdr1a-/-) mice are susceptible to developing a severe, spontaneous intestinal inflammation when maintained under specific pathogen-free animal facility conditions. The intestinal inflammation seen in mdr1a-/- mice has a pathology similar to that of human inflammatory bowel disease (IBD) and is defined by dysregulated epithelial cell growth and leukocytic infiltration into the lamina propria of the large intestine.

Adhesion molecule expression and adhesion properties of murine intestinal intraepithelial lymphocyte hybridomas.

We used mouse intraepithelial lymphocyte hybridomas (IELH) to study the role of adhesion molecules, especially beta 7 integrins, in the adherence of IELH to intestinal epithelial cells. Unstimulated 9.1 gamma delta IELH cells expressed high levels of CD11a, CD11a/CD18, CD44, and CD45; medium levels of CD45RB and integrin alpha 4; low levels of alpha M290, beta 7, and 33D1; and very low levels of ICAM-1 and VCAM-1.

Structure and function of H-2 T (Tla) region class I MHC molecules.

The T region of the mouse major histocompatibility complex (MHC) encodes a relatively large number of nonclassical or nonpolymorphic class I genes. In BALB/c mice, at least five of these genes are likely to encode a functional class I gene product. Some of these T region products are ubiquitously expressed, while others are expressed by just a few tissues.

Regional specialization of the mucosal immune system. Intraepithelial lymphocytes of the large intestine have a different phenotype and function than those of the small intestine.

Intraepithelial lymphocytes (IEL) are found in both the small and the large intestine. We demonstrate that there are a number of striking phenotypic and functional differences between the two populations of IEL isolated from mice. In the large intestine, the majority of IEL express the alpha beta TCR, and among these TCR-alpha beta+ lymphocytes, CD4+ cells are as prevalent as CD8+ cells.