Eosinophilic gastroenteritis in a patient with Bruton's tyrosine kinase deficiency.

Eosinophilic gastrointestinal diseases (EGID) are relatively rare diseases characterized by eosinophilic infiltration of the gastrointestinal tract resulting in various gastrointestinal symptoms. EGID are often caused by allergic reactions or systemic eosinophilic disorders, but their comorbidity with Bruton's tyrosine kinase (BTK) deficiency has not been previously documented. Here, we report a case of eosinophilic gastroenteritis (EG) in a patient with BTK deficiency. Despite adequate replacement immunoglobulin (Ig) therapy, trough serum IgG was not maintained. To identify the underlying cause of the low trough level and chronic diarrhea, the intestine was investigated on endoscopy. We also screened for the variable number of tandem repeat polymorphism in FCGRT. Genetic analysis could not explain the low trough IgG, but endoscopy indicated eosinophilic enterocolitis. EG may be an important differential diagnosis when primary immunodeficiency patients have chronic diarrhea or continued low serum IgG.

Phenotypic differences of patients with fibrodysplasia ossificans progressive due to p.Arg258Ser variants of ACVR1.

Fibrodysplasia ossificans progressiva (FOP) is a rare, congenital disorder caused by heterozygous mutation of the bone morphogenetic protein type I receptor ACVR1. Various forms of atypical FOP have recently been identified, and a recurrent mutation, ACVR1 (p.Arg258Ser) was reported. We encountered a 17-year-old Japanese female patient with sporadic occurrence of FOP. At the age of 7 years, radiological examination revealed progressive heterotopic ossification and cervical spine malformations. Although great toe malformation was not observed, we diagnosed her as having FOP. Then, ACVR1 was analyzed and a recurrent mutation of p.Arg258Ser was identified. We noticed that there may be phenotypic differences between c.774G>T and c.774G>C, which lead to the same amino-acid change, p.Arg258Ser. Genotype-phenotype correlation was discussed with the review of the previous reports.

Outcome of infants presenting rectal bleeding: a retrospective study in a single institution.

BACKGROUND: Although rectal bleeding in infancy (RBI) is not a rare phenomenon, the clinical course of RBI is not fully understood. METHODS: To investigate the outcome and pathogenesis of RBI, especially when concomitant with food-protein-induced proctocolitis (FPIP) and neonatal transient eosinophilic colitis (NTEC), 22 neonates with rectal bleeding with FPIP and NTEC from January 2008 to June 2012 were enrolled and their clinical course and mechanisms of inflammation were examined. RESULTS: Thirteen infants showed rectal bleeding after feeding and were diagnosed with FPIP, and nine infants showed rectal bleeding before feeding and were diagnosed with NTEC. Elevated peripheral white blood cell (12,685 ± 3754/µl and 30,978 ± 16,166/µl) and eosinophil (1084 ± 816/µl and 4456 ± 3341/µl) were confirmed in FPIP and NTEC, respectively. Colonoscopy revealed nodular lymphoid hyperplasia, a pale mucosal surface and oozing with diffuse infiltration of neutrophils, lymphocytes, and eosinophils in both groups. Reverse transcription polymerase chain reaction analysis revealed enhanced expression of the interleukin-6, CCL11, and CXCL13 genes, where CXCL13 expression was more prominent in FPIP. Mucosal infiltration by CD3- and immunoglobulin-A- but not immunoglobulin-E-positive cells was confirmed. Among them, only one infant with FPIP developed milk allergy, whereas none with NTEC had developed milk allergy at the age of 1 year. CONCLUSIONS: FPIP in infancy and NTEC are similar diseases and interleukin-6, CCL11, and CXCL13 may play a major role in the pathogenesis of rectal bleeding. Although the involvement of allergic reaction is possible, milk allergy was not a common outcome after 1 year of follow up.

Critical Roles for PU.1, GATA1, and GATA2 in the expression of human FcεRI on mast cells: PU.1 and GATA1 transactivate FCER1A, and GATA2 transactivates FCER1A and MS4A2.

The high-affinity IgE receptor, FcεRI, which is composed of α-, ß-, and γ-chains, plays an important role in IgE-mediated allergic responses. In the current study, involvement of the transcription factors, PU.1, GATA1, and GATA2, in the expression of FcεRI on human mast cells was investigated. Transfection of small interfering RNAs (siRNAs) against PU.1, GATA1, and GATA2 into the human mast cell line, LAD2, caused significant downregulation of cell surface expression of FcεRI. Quantification of the mRNA levels revealed that PU.1, GATA1, and GATA2 siRNAs suppressed the α transcript, whereas the amount of ß mRNA was reduced in only GATA2 siRNA transfectants. In contrast, γ mRNA levels were not affected by any of the knockdowns. Chromatin immunoprecipitation assay showed that significant amounts of PU.1, GATA1, and GATA2 bind to the promoter region of FCER1A (encoding FcεRIα) and that GATA2 binds to the promoter of MS4A2 (encoding FcεRIß). Luciferase assay and EMSA showed that GATA2 transactivates the MS4A2 promoter via direct binding. These knockdowns of transcription factors also suppressed the IgE-mediated degranulation activity of LAD2. Similarly, all three knockdowns suppressed FcεRI expression in primary mast cells, especially PU.1 siRNA and GATA2 siRNA, which target FcεRIα and FcεRIß, respectively. From these results, we conclude that PU.1 and GATA1 are involved in FcεRIα transcription through recruitment to its promoter, whereas GATA2 positively regulates FcεRIß transcription. Suppression of these transcription factors leads to downregulation of FcεRI expression and IgE-mediated degranulation activity. Our findings will contribute to the development of new therapeutic approaches for FcεRI-mediated allergic diseases.

Lissencephaly with marked ventricular dilation, agenesis of corpus callosum, and cerebellar hypoplasia caused by TUBA1A mutation.

We described the clinical course and pathological findings in a child with TUBA1A mutation. MRI revealed marked ventricular dilation with thin cortex, poorly differentiated basal ganglia, agenesis of corpus callosum, cerebellar hypoplasia with preserved vermis at 2 months of age. No gain of developmental milestones was observed until she died with respiratory failure at 23 months of age. A de novo missense mutation of c.1096G>A (G366R) was identified in TUBA1A gene. Pathological findings included a lack in lamination in the cerebral cortex, absent corpus callosum without Probst bundle, blurred demarcation among the striatum, internal capsule and globus pallidus in association with irregular running of myelinated fibers, cerebellar hypoplasia with irregular undulation in the dentate nucleus and inferior olivary nucleus, absent olfactory bulbs and tracts, and pyramidal tract hypoplasia. These findings are consistent with previous reports and will be a clue to diagnosis of TUBA1A mutation.

GATA2 is a critical transactivator for the human IL1RL1/ST2 promoter in mast cells/basophils: opposing roles for GATA2 and GATA1 in human IL1RL1/ST2 gene expression.

The IL1RL1/ST2 gene encodes a receptor for IL-33. Signaling from IL1RL1/ST2 induced by IL-33 binding was recently identified as a modulator of the Th2 response. The target cells for IL-33 are restricted in some hematopoietic lineages, including mast cells, basophils, eosinophils, Th2 cells, natural killer cells, and dendritic cells. To clarify the molecular mechanisms of cell type-specific IL1RL1/ST2 expression in mast cells and basophils, transcriptional regulation of the human IL1RL1/ST2 promoter was investigated using the mast cell line LAD2 and the basophilic cell line KU812. Reporter assays suggested that two GATA motifs just upstream of the transcription start site in the ST2 promoter are critical for transcriptional activity. These two GATA motifs possess the capacity to bind GATA1 and GATA2 in EMSA. ChIP assay showed that GATA2, but not GATA1, bound to the ST2 promoter in LAD2 cells and that histone H3 at the ST2 promoter was acetylated in LAD2 cells, whereas binding of GATA1 and GATA2 to the ST2 promoter was detected in KU812 cells. Knockdown of GATA2 mRNA by siRNA reduced ST2 mRNA levels in KU812 and LAD2 cells and ST2 protein levels in LAD2 cells; in contrast, GATA1 siRNA transfection up-regulated ST2 mRNA levels in KU812 cells. The ST2 promoter was transactivated by GATA2 and repressed by GATA1 in coexpression analysis. When these siRNAs were introduced into human peripheral blood basophils, GATA2 siRNA reduced ST2 mRNA, whereas GATA1 siRNA up-regulated ST2 mRNA. These results indicate that GATA2 and GATA1 positively and negatively control human ST2 gene transcription, respectively.

Involvement of PU.1 in mast cell/basophil-specific function of the human IL1RL1/ST2 promoter.

BACKGROUND: The human IL1RL1/ST2 gene encodes IL33 receptor. Recently, IL33 has been recognized as a key molecule for the development of Th2 response. Although mast cells and basophils are major targets of IL33 and play important roles in IL33-mediated Th2-type immune responses, the expression mechanism of ST2 in mast cells and basophils is largely unknown. In the present study, we analyzed regulation mechanism of the human ST2 promoter in the human mast cell line LAD2 and basophilic cell line KU812. METHODS: Promoter activity was determined by reporter assay with plasmids carrying the wild-type ST2 promoter obtained from human genomic DNA and its mutant. The transcription factor binding to the identified cis-element was identified by an electrophoretic mobility shift assay (EMSA). The effect of candidate transcription factor on ST2 expression was confirmed by analyzing ST2 mRNA level in siRNA-introduced cells. RESULTS: Reporter assay demonstrated that a cis-element of typical Ets-family binding sequence was critical for promoter activity in LAD2 and KU812. An Ets-family transcription factor PU.1 bound to this element in an EMSA. When PU.1 expression was suppressed by siRNA, ST2 mRNA level was significantly reduced in KU812. CONCLUSIONS: These observations indicated that PU.1 positively regulates the ST2 promoter as a transcription factor that directly transactivates the ST2 promoter via Ets-family-related cis-element in mast cells and basophils.

Effects of Bifidobacterium breve on inflammatory gene expression in neonatal and weaning rat intestine.

INTRODUCTION: To examine the immune-modulatory effects of probiotics during early infancy, Bifidobacterium breve M-16V (B. breve) was administered to rat pups during the newborn or weaning period, and the expression of inflammatory genes was investigated using a cDNA microarray and real-time PCR. RESULTS: After B. breve administration, significant increases in the numbers of Bifidobacterium in both the cecum and colon were confirmed during the newborn period. The numbers of upregulated and downregulated genes were greater during the weaning period than in the newborn period and were greatest in the colon, with fewer genes altered in the small intestine and the fewest in the spleen. The expression of inflammation-related genes, including lipoprotein lipase (Lpl), glutathione peroxidase 2 (Gpx2), and lipopolysaccharide-binding protein (Lbp), was significantly reduced in the colon during the newborn period. In weaning rat pups, the expression of CD3d, a cell surface receptor-linked signaling molecule, was significantly enhanced in the colon; however, the expression of co-stimulatory molecules was not enhanced. DISCUSSION: Our findings support a possible role for B. breve in mediating anti-inflammatory and antiallergic reactions by modulating the expression of inflammatory molecules during the newborn period and by regulating the expression of co-stimulatory molecules during the weaning period. METHODS: Gene expression in the intestine was investigated after feeding 5 × 10(8) cfu of B. breve every day to the F344/Du rat from days 1 to 14 (newborn group) and from days 21 to 34 (weaning group). mRNA was extracted from intestine, and the expression of inflammatory gene was analyzed by microarray and real-time PCR.

B-transferase with a Pro234Ser substitution acquires AB-transferase activity.

A/B-Transferase is a glycosyltransferase that transfers a sugar substrate onto H-antigen, which is responsible for the synthesis of glycoprotein- and glycolipid-conjugates termed A/B-antigens. One polymorphism that causes the Pro234Ser substitution in B-transferase was recently found in a genotyping study, and might be cis-AB. In the present study, we analyzed the phenotypes arising from the enzymatic specificity of B-transferase with the Pro234Ser mutation. To evaluate the effect of the P234S mutation on enzymatic specificity, we generated an expression plasmid for B-transferase with Pro234Ser as well as A-transferase with Leu266Met, which is frequently found in cis-ABs. Transfection of B-transferase/P234S or A-transferase/L266M cDNA into HeLa cells, an O-blood group cell line, resulted in an AB-phenotype by absorption-elution testing and immunostaining, whereas A- and B-transferase-expressing HeLa cells exhibited only their own activity. Molecular simulation indicated that the P234S mutation causes a conformational change in the substrate pocket making it suitable for N-acetylgalactosamine.

Circadian clock gene Period2 regulates a time-of-day-dependent variation in cutaneous anaphylactic reaction.

BACKGROUND: IgE-mediated immediate-type skin reaction shows a diurnal rhythm, although the precise mechanisms remain uncertain. Period2 (Per2) is a key circadian gene that is essential for endogenous clockworks in mammals. OBJECTIVE: This study investigated whether Per2 regulates a time-of-day-dependent variation in IgE-mediated immediate-type skin reaction. METHODS: The kinetics of a passive cutaneous anaphylactic reaction were compared between wild-type mice and mice with a loss-of-function mutation of Per2 (mPer2(m/m) mice). The effects of adrenalectomy, aging, and dexamethasone on the kinetics of a passive cutaneous anaphylactic reaction were also examined. In addition, the extent of IgE-mediated degranulation in bone marrow-derived mast cells (BMMCs) was compared between wild-type and mPer2(m/m) mice. RESULTS: A time-of-day-dependent variation in a passive cutaneous anaphylactic reaction observed in wild-type mice was absent in mPer2(m/m) mice and in adrenalectomized and aged mice associated with the loss of rhythmic secretion of corticosterone. In addition, mPer2(m/m) mice showed decreased sensitivity to the inhibitory effects of dexamethasone on the passive cutaneous anaphylactic reactions. IgE-mediated degranulation in BMMCs was comparable between wild-type and mPer2(m/m) mice, but Per2 mutation decreased sensitivity to the inhibitory effects of dexamethasone on IgE-mediated degranulation in BMMCs. CONCLUSION: A circadian oscillator, Per2, regulates a time-of-day-dependent variation in a passive cutaneous anaphylactic reaction in mice. Per2 may do so by controlling the rhythmic secretion of glucocorticoid from adrenal glands and/or by gating the glucocorticoid responses of mast cells to certain times of the day (possibly when Per2 levels are high in mast cells).

Critical role of transcription factor PU.1 in the expression of CD80 and CD86 on dendritic cells.

In this study, we investigated the role of a transcription factor, PU.1, in the regulation of CD80 and CD86 expression in dendritic cells (DCs). A chromatin immunoprecipitation assay revealed that PU.1 is constitutively bound to the CD80 and CD86 promoters in bone marrow-derived DCs. In addition, co-expression of PU.1 resulted in the transactivation of the CD80 and CD86 promoters in a reporter assay. The binding of PU.1 to cis-enhancing regions was confirmed by electromobility gel-shift assay. As expected, inhibition of PU.1 expression by short interfering RNA (siRNA) in bone marrow-derived DCs resulted in marked down-regulation of CD80 and CD86 expression. Moreover, overexpression of PU.1 in murine bone marrow-derived lineage-negative cells induced the expression of CD80 and CD86 in the absence of monocyte/DC-related growth factors and/or cytokines. Based on these results, we conclude that PU.1 is a critical factor for the expression of CD80 and CD86. We also found that subcutaneous injection of PU.1 siRNA or topical application of a cream-emulsified PU.1 siRNA efficiently inhibited murine contact hypersensitivity. Our results suggest that PU.1 is a potential target for the treatment of immune-related diseases.

Monitoring 6-thioguanine nucleotide concentrations in Japanese children and adolescents with inflammatory bowel disease.

BACKGROUND AND AIM: 6-Mercaptopurine (6-MP) and azathioprine (AZA) are widely used as maintenance therapy in children with inflammatory bowel disease (IBD). However, proper 6-thioguanine nucleotide (6-TGN) concentrations in Japanese children with IBD have not been reported. METHODS: This retrospective review examines 32 ulcerative colitis (UC) patients and 19 Crohn's disease (CD) patients (12.87 ± 3.56 years) who required 6-MP or AZA to maintain disease remission. All patients were treated with 6-MP or AZA for at least 3 weeks prior to this study in addition to previous treatment. 6-MP dose, 6-TGN levels, assayed by high-performance liquid chromatography, as well as laboratory data were evaluated. RESULTS: Thirty-five children were successfully kept in remission with 6-MP and AZA therapy after weaning off corticosteroids. Overall, 123 measurements (59 active disease, 64 in remission) were analyzed. The mean 6-TGN concentration of the entire study population was 499.61 ± 249.35 pmol/8 × 10(8) red blood cell. The mean 6-MP dose in patients with active disease (0.910 ± 0.326 mg/kg per day) was significantly higher than for patients in remission (0.749 ± 0.225) (P = 0.0016). A significant inverse correlation was found between white blood cell counts and 6-TGN concentrations (r = 0.275, P < 0.002). Two patients experienced leukopenia with alopecia, and four transiently experienced increased serum levels of pancreatic enzymes, although no thiopurine S-methyl transferase mutations were confirmed. CONCLUSION: The doses of 6-MP or AZA needed to maintain remission in Japanese children with IBD are lower than those reported in Western countries. However, 6-TGN concentrations in this population are higher than previously reported.

Suppressive effects of transcription factor GATA-1 on cell type-specific gene expression in dendritic cells.

To evaluate the effects of the transcription factor GATA-1 on determining cell fate between dendritic cell (DC) and mast cell (MC) lineages, GATA-1 was exogenously expressed in bone marrow-derived (BM) DCs. Exogenous expression of GATA-1 by a retrovirus in BMDCs inhibited expression of CD11c, CD80, CD86, and major histocompatibility complex class II with suppression of antigen-presenting ability and morphological changes toward granulocyte-like cells. Transcription of MC proteases and c-kit was markedly upregulated by GATA-1. Expression of IRF-4 and -8 was markedly suppressed, whereas PU.1 mRNA level was not affected by GATA-1. Chromatin immunoprecipitation assay showed that recruitment of PU.1 on the IRF-8 promoter was reduced in GATA-1-expressing DCs. These results indicate that GATA-1 suppresses PU.1 function but not PU.1 transcription. Thus, GATA-1 appears to determine cell fate by regulating several cell-specific transcription factors.

Estimation of postoperative fat absorption using the 13C mixed-triglyceride breath test in children with choledochal cyst.

No previous studies have focused on postoperative fat malabsorption in children with choledochal cyst (CC) who undergo cyst excision and Roux-en-Y (RY) hepatico-jejunostomy (HJ), a combination of procedures that can lead to the non-physiological mixture of food and bile juice. To examine the effect of RYHJ with cholecystectomy on the fat absorption ability of children with CC, we estimated postoperative fat-absorption ability using the carbon 13-labeled mixed triglyceride (13C-MTG) breath test. Twelve postoperative children with CC and 12 normal control children were administered 13C-MTG orally and asked to give breath samples at six time points: once before the 13C-MTG ingestion and at five 60-min intervals postingestion. Fecal chymotrypsin activity and fecal fat excretion were also measured. The delta value of breath 13CO2 at 3, 4, and 5 h after administration and the 5-h cumulative breath 13CO2 were significantly lower in the CC children than in the controls. There were no significant differences in the fecal chymotrypsin activity or fecal fat excretion of the two groups. Conclusion. Occult fat malabsorption occurs in patients with CC after RYHJ, even in the absence of clinical symptoms or abnormal laboratory data.

Usefulness of nonbreath-hold 1-shot magnetic resonance cholangiopancreatography for the evaluation of choledochal cyst in children.

OBJECTIVE: The aim of this study was to clarify the usefulness of magnetic resonance cholangiopancreatography (MRCP) for the evaluation of choledochal cyst in children. SUBJECTS AND METHODS: MRCP was performed preoperatively in 33 patients. The MRCP findings were compared with those of endoscopic retrograde cholangiopancreatography or intraoperative cholangiopancreatography. RESULTS: In all 33 patients, MRCP could detect choledochal cyst. The detection rate of a cyst in the main pancreatic duct was 62.2%, of abnormal union of the pancreaticobiliary junction (AUPBJ) was 53.3%, of dilatation or abnormalities of the main pancreatic duct was 75.0% and of a protein plug or stone was 76.9%. In patients under 2 years of age (group A), these findings were significantly lower than those of patients above 2 years of age (group B) [main pancreatic duct: 16.6% (1/6) vs 73.1% (19/26), P < 0.01; AUPBJ: 0.0% (0/6) vs 66.7% (16/24), P < 0.05; and protein plug or stone: 0.0% (0/2) vs 90.9% (10/11), P < 0.05]. The detection rate of AUPBJ in the patients with fusiform dilatation was superior to that of those with cystic dilatation [70% (14/20) vs 20% (2/10), P < 0.05]. In the patients with fusiform dilatation, the detection rate in group A was significantly lower than that in group B [0.0% (0/3) vs 82.4% (14/17), P < 0.01]; however, there was no significant difference between the 2 groups in the detection of cystic dilatation. CONCLUSION: In patients older than 2 years, MRCP should be the first-choice method for confirming the diagnosis and for ensuring accurate visualization of the pancreaticobiliary system.

Polarized production of T-helper cell type 1 cells in Peyer's patches in Crohn's disease.

BACKGROUND/AIMS: Although Peyer's patches (PPs) serve as important antigen-sampling sites for the immune system, surprisingly little attention has been paid to their associations with the onset of Crohn's disease (CD) as antigen entry sites. To examine the immunological events in PPs, we performed functional and phenotypical studies on PP cells, the lamina propria cells in the colonic mucosa and peripheral blood mononuclear cells (PBMC) in inflammatory bowel disease. PATIENTS: The subjects were 9 children and adolescents with active CD, 9 with inactive CD, 11 with active ulcerative colitis (UC), and 22 normal controls. METHODS: The cytokine profile in PPs and lamina propria was performed through Elispot assay and RT-PCR. PP mononuclear cells and PBMC from the subjects were analyzed by flow cytometry using monoclonal antibodies to interferon-gamma and interleukin-4, and CC chemokine receptors (CCR) 4 and 5. RESULTS: Th1 together with Tc1 cells were dominant in PPs in the active phase of CD, but not in inactive CD, UC, or normal controls. They did not actually produce interferon-gamma, however they have abundant mRNA of the cytokine. Substantial levels of CCR5 ligands, MIP-1alpha and RANTES mRNA were found in the inflamed intestinal mucosa in CD. CONCLUSIONS: It is conceivable that PPs in the terminal ileum in CD may initially sample luminal antigens where Th1-type memory cells are activated which migrate to the peripheral intestinal mucosa. Those immunological changes may not be related to the etiology of UC.

Effects of highly purified eicosapentaenoic acid on erythrocyte fatty acid composition and leukocyte and colonic mucosa leukotriene B4 production in children with ulcerative colitis.

BACKGROUND: n-3 Polyunsaturated fatty acids (PUFAs) have been suggested as a treatment for ulcerative colitis (UC). However, the efficacy of n-3 PUFAs against UC has not been examined in children. Therefore, the authors investigated the effects of eicosapentaenoic acid (EPA) on fatty acid composition and leukotriene (LT) production in children with UC. METHODS: For 2 months the authors administered highly purified EPA ethyl ester (EPA-E) (1.8 g/d) to children with UC in remission. Colonic mucosal histology, fatty acid composition of erythrocyte membrane phospholipids, and LTB4 production by leukocytes and colonic mucosa were measured before and 2 months after the initiation of EPA-E treatment. RESULTS: No patients relapsed during the study period, and no significant differences were detected in laboratory findings obtained before and 2 months after the initiation of EPA-E ingestion. There were no significant differences in mucosal histologic scores before and 2 months after EPA-E treatment. The EPA levels in erythrocyte membranes 2 months after the initiation of EPA-E treatment were significantly higher than before treatment, but the other fatty acids showed no significant changes. LTB4 production by leukocytes and rectal mucosa after 2 months of EPA-E treatment was significantly lower than before treatment. CONCLUSION: EPA-E treatment increased the levels of EPA in erythrocytes and decreased LTB4 levels produced by leukocytes and colonic mucosa. To assess the concomitant clinical changes, we should examine the long-term effects of EPA-E ingestion on the maintenance of remission in children with UC.

Localization of intestinal intraepithelial T lymphocytes involves regulation of alphaEbeta7 expression by transforming growth factor-beta.

Induction of alphaEbeta7 expression on T cells by transforming growth factor (TGF)-beta is thought to be important for intestinal intraepithelial T lymphocyte (IEL) entry into the epithelial compartment. However, there has been no in vivo evidence that up-regulation of alphaEbeta7 expression on T cells by TGF-beta is critical for the selective localization of intestinal IEL in the epithelial area. We have recently established transgenic mice expressing Smad7 under the control of a distal lck promoter where TGF-beta/Smad signaling is specifically blocked in mature T cells. Here we showed that TGF-beta-mediated up-regulation of alphaEbeta7 was impaired on T cells isolated from the Smad7 transgenic mice associated with reduced numbers of intestinal IEL when compared with that in wild-type littermates. These results indicated that failure to induce alphaEbeta7 on T cells by TGF-beta resulted in reduced numbers of intestinal IEL, suggesting the importance of alphaEbeta7 expression by TGF-beta in selective localization of intestinal IEL.