Inflammatory bowel disease.

This review focuses on the prominent etiological and pathogenetic aspects of inflammatory bowel disease (IBD), with particular attention being paid to the mucosal immune response to commensal micro-organisms in health and disease. Pathogenetic implications for target therapy will also be discussed. The clinical presentation, diagnostic aspects, and currently recommended therapeutic options for the two main types of IBD are also taken into consideration, including manifestations of these conditions in the oral cavity.

Oral therapeutic administration of a probiotic mixture suppresses established Th2 responses and systemic anaphylaxis in a murine model of food allergy.

BACKGROUND: No effective treatment is available for food allergy and its primary management still consists of avoiding relevant allergens. Probiotics are claimed to beneficially affect the immune system. We sought to investigate the therapeutic potential of VSL#3 probiotic mixture on specific immune responses and anaphylactic reaction induced in mice by the major food allergen shrimp tropomyosin (ST). METHODS: The cytokine production by spleen cell from ST-sensitized mice upon allergen re-stimulation in the presence of VSL#3 was analysed. Next, the effects of oral administration of VSL#3 on allergen-induced anaphylaxis and Th2 response in the murine model of food allergy to ST was investigated by evaluating symptom score and histamine content in the faeces after allergen challenge, antibody response in serum and faeces, and cytokine and transcription factor expression in the jejunum. RESULTS: The in vitro studies on mouse spleen cells indicates that the VSL#3 preparation has the capacity to shift a polarized Th2 response to a Th1/T regulatory-type profile. Oral therapeutic administration of VSL#3 to ST-sensitized mice significantly reduces symptom score and histamine release in the faeces following allergen challenge, as well as specific IgE response. In the jejunum, IL-4, IL-5 and IL-13 tissue content was significantly reduced, whereas FOXP3 and IL-27 mRNA expression, IL-10, TGF-ß and IFN-γ tissue content were up-regulated. CONCLUSIONS: Oral therapeutic treatment with the probiotic mixture VSL#3 is effective in redirecting allergen-specific Th2-polarized immune responses towards Th1-T regulatory responses and in the protection against anaphylactic reactions induced by the allergen in a murine model of food allergy.

Oxazolone colitis: A murine model of T helper cell type 2 colitis treatable with antibodies to interleukin 4.

In this study we describe oxazolone colitis, a new form of experimental colitis. This model is induced in SJL/J mice by the rectal instillation of the haptenating agent, oxazolone, and is characterized by a rapidly developing colitis confined to the distal half of the colon; it consists of a mixed neutrophil/lymphocyte infiltration limited to the superficial layer of the mucosa which is associated with ulceration. Oxazolone colitis is a T helper cell type 2 (Th2)-mediated process since stimulated T cells from lesional tissue produce markedly increased amounts of interleukin (IL)-4 and IL-5; in addition, anti-IL-4 administration leads to a striking amelioration of disease, whereas anti-IL-12 administration either has no effect or exacerbates disease. Finally, this proinflammatory Th2 cytokine response is counterbalanced by a massive transforming growth factor-beta (TGF-beta) response which limits both the extent and duration of disease: lesional (distal) T cells manifest a 20-30-fold increase in TGF-beta production, whereas nonlesional (proximal) T cells manifest an even greater 40-50-fold increase. In addition, anti-TGF-beta administration leads to more severe inflammation which now involves the entire colon. The histologic features and distribution of oxazolone colitis have characteristics that resemble ulcerative colitis (UC) and thus sharply distinguish this model from most other models, which usually resemble Crohn's disease. This feature of oxazolone colitis as well as its cytokine profile have important implications to the pathogenesis and treatment of UC.

Serum transforming growth factor ß1 during diabetes development in non-obese diabetic mice and humans.

Recent data show that regulatory cells with transforming growth factor (TGF)-ß1-dependent activity are able to restore self-tolerance in overtly diabetic non-obese diabetic (NOD) mice. Thus, TGF-ß1 seems to have a relevant role in protection from autoimmune diabetes. Our aim was to investigate the possible significance of serum TGF-ß1 measurement in the natural history of diabetes in NOD mice, as well as in children positive for at least one islet-related antibody. Serum TGF-ß1 (both total and active) was measured by enzyme-linked immunosorbent assay at monthly intervals in 26 NOD mice during the spontaneous development of diabetes and, on a yearly basis, in nine siblings of patients with type 1 diabetes (T1D) with a follow-up of 4 years. Diabetes appeared between the 12th week of age and the end of the study period (36 weeks) in 17 mice. TGF-ß1 serum level variations occurred in the prediabetic period in both NOD mice and humans and diabetes diagnosis followed a continuing reduction of active TGF-ß1 (aTGF-ß1) serum levels. In mice, aTGF-ß1 serum levels measured at 4 weeks of age correlated positively with severity of insulitis, and negatively with percentage of insulin-positive cells. Our findings suggest that in NOD mice serum TGF-ß1 levels during the natural history of the diabetes reflect the course of islet inflammation. The measurement of aTGF-ß1 in islet-related antibody-positive subjects may provide insights into the natural history of prediabetic phase of T1D.

Native/citrullinated LL37-specific T-cells help autoantibody production in Systemic Lupus Erythematosus.

LL37 exerts a dual pathogenic role in psoriasis. Bound to self-DNA/RNA, LL37 licenses autoreactivity by stimulating plasmacytoid dendritic cells-(pDCs)-Type I interferon (IFN-I) and acts as autoantigen for pathogenic Th17-cells. In systemic lupus erythematosus (SLE), LL37 also triggers IFN-I in pDCs and is target of pathogenic autoantibodies. However, whether LL37 activates T-cells in SLE and how the latter differ from psoriasis LL37-specific T-cells is unknown. Here we found that 45% SLE patients had circulating T-cells strongly responding to LL37, which correlate with anti-LL37 antibodies/disease activity. In contrast to psoriatic Th17-cells, these LL37-specific SLE T-cells displayed a T-follicular helper-(TFH)-like phenotype, with CXCR5/Bcl-6 and IL-21 expression, implicating a role in stimulation of pathogenic autoantibodies. Accordingly, SLE LL37-specific T-cells promoted B-cell secretion of pathogenic anti-LL37 antibodies in vitro. Importantly, we identified abundant citrullinated LL37 (cit-LL37) in SLE tissues (skin and kidney) and observed very pronounced reactivity of LL37-specific SLE T-cells to cit-LL37, compared to native-LL37, which was much more occasional in psoriasis. Thus, in SLE, we identified LL37-specific T-cells with a distinct functional specialization and antigenic specificity. This suggests that autoantigenic specificity is independent from the nature of the autoantigen, but rather relies on the disease-specific milieu driving T-cell subset polarization and autoantigen modifications.

Nod2 Deficiency in mice is Associated with Microbiota Variation Favouring the Expansion of mucosal CD4+ LAP+ Regulatory Cells.

Nucleotide-binding Oligomerization Domain-2 (NOD2) mutations are associated with an increased risk to develop Crohn's Disease. In previous studies, we have shown that Nod2-/- mice manifest increased proportion of Lamina Propria (LP) CD4+ LAP+ Foxp3- regulatory cells, when compared with Nod2+/+ mice, while CD4+ Foxp3 + regulatory cells were not affected. Here, we investigated the Nod2 gut microbiota, by 16S rRNA pyrosequencing, at steady state and after TNBS-colitis induction in mice reared separately or in cohousing, correlating the microbial profiles with LP regulatory T cells proportion and tissue cytokines content. We found that enrichment of Rikenella and Alistipes (Rikenellaceae) in Nod2-/- mice at 8 weeks of age reared separately was associated with increased proportion of CD4+ LAP+ Foxp3- cells and less severe TNBS-colitis. In co-housed mice the acquisition of Rickenellaceae by Nod2+/+ mice was associated with increased CD4+ LAP+ Foxp3- proportion and less severe colitis. Severe colitis was associated with enrichment of gram-negative pathobionts (Escherichia and Enterococcus), while less severe colitis with protective bacteria (Barnesiella, Odoribacter and Clostridium IV). Environmental factors acting on genetic background with different outcomes according to their impact on microbiota, predispose in different ways to inflammation. These results open a new scenario for therapeutic attempt to re-establish eubiosis in Inflammatory Bowel Disease patients with NOD2 polymorphisms.

Stimulated human lamina propria T cells manifest enhanced Fas-mediated apoptosis.

Lamina propria (LP) T cells respond poorly to a proliferative stimulus delivered via TCR/CD3 pathway, but retain considerable ability to respond to a stimulus delivered via CD2 costimulatory or accessory pathway. In the present study, we showed first that unstimulated LP T cells, as compared to unstimulated peripheral blood (PB) T cells, exhibit an increased level of apoptosis which is further increased following CD2 pathway stimulation, but not following via TCR/CD3 pathway stimulation. We next showed that IL-2 had a sparing effect on apoptosis of unstimulated LP T cells in that IL-2 decreased and anti-IL-2 increased apoptosis of these cells; in contrast, IL-2 had no effect on apoptosis of CD2-pathway stimulated cells. Finally, we showed that increased apoptosis of LP T cells induced by CD2-pathway stimulation is inhibited when Fas antigen is blocked by a nonstimulatory anti-Fas antibody. These studies suggest that LP T cells are characterized by increased susceptibility to Fas-mediated apoptosis most due to a downstream change in the Fas signaling pathway. Given that IFN-gamma secretion is significantly increased in LP T cells in which apoptosis is inhibited, this feature of LP T cells may represent a mechanism of regulating detrimental immune responses in the mucosal environment.

Functional expression of Fas and Fas ligand on human gut lamina propria T lymphocytes. A potential role for the acidic sphingomyelinase pathway in normal immunoregulation.

The expression and function of Fas (CD95/APO-1), a cell surface receptor directly responsible for triggering cell death by apoptosis, was investigated on human T lymphocytes resident within the intestinal lamina propria, a major site of antigen challenge and persistent lymphocyte activation. Three color immunofluorescence and FACS analysis indicated that virtually all freshly isolated human gut lamina propria T lymphocytes (T-LPL) express Fas, together with the marker of progress activation CD45R0. A discrete fraction of freshly isolated T-LPL also constitutively expressed Fas ligand (FasL), perhaps as a result of recent in vivo activation. Importantly, whereas Fas cross-linking did not result in apoptosis induction in peripheral blood T lymphocytes (T-PBL), Fas was found to be fully effective in generating the apoptotic signal in T-LPL. This was associated with the activation of an acidic sphingomyelinase and with ceramide generation, early events known to be involved in Fas-mediated apoptotic signaling. By contrast, acidic sphingomyelinase activation and ceramide production were not detectable in T-PBL after Fas cross-linking. However C2-ceramide, a cell permeant synthetic analog of ceramide, could efficiently induce apoptosis in T-LPL and T-PBL when added exogenously. These data indicate that T-LPL constitutively express both Fas and FasL and that Fas cross-linking generates signals resulting in sphingomyelin hydrolysis and apoptosis, outlining a potential mechanism involved in intestinal tolerance. Moreover, they provide the first evidence of a role for ceramide-mediated pathways in normal immunoregulation.

Postpartum thyroiditis is associated with fluctuations in transforming growth factor-beta1 serum levels.

Postpartum thyroiditis (PPT) is characterized by a rapid evolution and recovery of euthyroidism. Therefore, it can represent a good model to study early cytokine fluctuations in autoimmune thyroid diseases. TGFbeta1 is an immunosuppressive cytokine, as it inhibits T and B cell proliferation, natural killer cell cytotoxic activity, and the generation of T cell cytotoxicity. The aim of this study was to assess serum concentrations of TGFbeta1 during pregnancy and to study possible serum fluctuations of this cytokine during the different phases of PPT. Thyroid biochemical pattern, antithyroid autoantibodies (ATA), and total and active TGFbeta1 (aTGFbeta1) serum concentrations were evaluated in 63 pregnant women. Thirty-four of them were ATA(+), and 29 were ATA(-). Twenty of the 34 ATA(+) women were followed in the postpartum year. Nine of these 20 women developed PPT; 11 remained euthyroid. All of the PPT women became euthyroid during the follow-up. Our results showed 1) detectable serum levels of aTGFbeta1 in 50% of ATA(+) pregnant women, suggesting that the presence of autoantibodies may characterize a favorable condition for TGFbeta1 activation; and 2) decreased total TGFbeta1 and increased aTGFbeta1 serum levels during the active phase of PPT in ATA(+) women. This seems to suggest that inflammation may be responsible for TGFbeta1 activation and autoantibody increase because of antigen release. Although further studies of women with persistent hypothyroidism after the postpartum year are needed, the possibility that the enhanced activation of TGFbeta1 may contribute to resolution of thyroid inflammation postpartum cannot be excluded.

Effects of somatostatin on human intestinal lamina propria lymphocytes. Modulation of lymphocyte activation.

We have investigated the effect of somatostatin (SOM) on the mitogen-induced activation of lamina propria mononuclear cells isolated from the human intestinal mucosa (LPMNC) and of the autologous peripheral blood lymphocytes (PBMNC). The occurrence of specific SOM receptors and their biological characteristics were also investigated. The counts of interleukin-2 receptor (IL-2R)-positive cells after mitogen stimulation were significantly lower in the presence of SOM. This effect of SOM appeared to be dose dependent, with SOM concentrations ranging between 1 pM and 1 microM. The amount of SOM required for the 50% inhibition of this expression was 1000 times lower in the LPMNC population than in the PBMNC. Binding studies showed that human LPMNC bear specific receptors for SOM and demonstrated that the affinity of these receptors was 1000 times higher than that of the SOM receptors present on the PBMNC (Kd 2.1 +/- 0.34 nM vs. 910 +/- 46 nM, respectively). The inhibitory effect of SOM on the proliferative response appeared to be restricted to PBMNC, with a maximal inhibition at 1 nM SOM, while LPMNC proliferative response was poorly affected. SOM inhibited the in vitro immunoglobulin production of both PBMNC and LPMNC over a wide range of concentrations, with a maximal inhibition at 1 nM. At this concentration the effect of SOM on IgA was more pronounced in the PBMNC than in the LPMNC. Our results lend support to the concept that in humans SOM plays a role in the modulation of the immune response at the level of the intestinal mucosa where cell-to-cell interactions between SOM releasing nerve fibers and cells and the immune system occur.

Apoptosis induction by human immunodeficiency virus type 1 (HIV-1) gp120 peptides.

We investigated the role of some gp120 peptides on the apoptosis induction in malignant T cell lines. We took advantage of recent findings reporting that three major regions of gp120 are important for CD4 binding. They consist of residues 256-262 in the C2 domain, residues 368-389 in the C3 domain, and residues 421-457 in C4 domain. We used a peptide from C2 domain (aa 250-263) the homologous major histocompatibility complex (MHC) class II peptide (aa 135-155) and three peptides from domain C4 (aa 414-434; 419-430; 428-445). We selected for this study the following human cell lines: CEM and Jurkat, two lymphoblastoid CD4-positive T cell line and U937, a myelomonocytic CD4 positive cell line. We demonstrated that the CD4-positive T cell lines, in the presence of gp120 250-263 peptide and DR 135-155 peptide, can be induced to accelerate apoptosis, while no effect in apoptosis induction was observed in the presence of 414-424 gp120 peptide. Interestingly, we have shown by fluorescence study, that the small sequence 414-419 must be responsible for the inhibition of binding of gp120 to the CD4 molecule. Indeed while 414-424 gp120 peptide is very efficient in CD4-gp120 binding inhibition, no effect is observed in the presence of either 419-430 or 428-445 peptide.

Phenotypes and spontaneous immunoglobulin production in mononuclear cells suspensions isolated from colonic biopsies of patients with mild active and quiescent ulcerative colitis.

Lamina propria mononuclear cells can be isolated from mucosal specimens of human colon. In the present study, we have explored whether both the phenotypes and functional properties can be studied in lamina propria mononuclear cell suspensions isolated from the same set of endoscopic biopsies in patients with ulcerative colitis. The counts of CD11b+ lamina propria mononuclear cells in mild active ulcerative colitis were significantly higher than those of both quiescent ulcerative colitis and controls. Similarly, the CD16+ and the CD19+ lamina propria mononuclear cells were significantly increased in mild ulcerative colitis patients in comparison to both quiescent ulcerative colitis and control lamina propria mononuclear cells. Lamina propria mononuclear cells from all the biopsy samples appeared to produce detectable amounts of immunoglobulins of the three classes. The production of IgG in mild ulcerative colitis cultures was significantly higher than that observed in quiescent ulcerative colitis and controls. In contrast, the production of IgA in active ulcerative colitis lamina propria mononuclear cell cultures appeared to be significantly lower than that of both quiescent ulcerative colitis and controls. This study shows that morphology, phenotypes, and functional properties can be assessed in lamina propria mononuclear cell suspensions obtained from the same set of endoscopic biopsy samples. We have also shown that changes in phenotypes and functional status of lamina propria mononuclear cells occurred in mild active ulcerative colitis while no significant abnormality of these parameters was found in quiescent ulcerative colitis. This indicates that a normalization of mucosal immune functions occurs in ulcerative colitis patients when complete clinical and histological remission is achieved.

[Functional status of intestinal t lymphocytes, regulatory mechanisms, and their variations in the course of Crohn disease and ulcerative colitis]. / Stato funzionale dei linfociti T intestinali, meccanismi di regolazione e loro variazioni nel corso di morbo di Crohn e colite ulcerosa.

We analyzed the phenotype, proliferative responsiveness, cytokine production and apoptosis susceptibility of lamina propria lymphocytes to different activation pathways. Lamina propria lymphocytes is a population enriched of activated lymphocytes showing a "memory" phenotype. As opposite to peripheral blood lymphocytes, lamina propria lymphocytes show proliferative hyporesponsiveness when stimulated via TCR/CD3 pathway while proliferative response to the CD2 activation pathway is relatively preserved. Under the latter activation pathway, cytokine production, especially IL-4 and IFN-gamma, is higher than that observed in peripheral lymphocytes. When compared to controls, lamina propria lymphocytes isolated from inflammatory bowel disease (Crohn's disease and ulcerative colitis) show distinctive variation in the cytokine production. In particular, Crohn's disease is characterized by an increased production of IFN-gamma, while in ulcerative colitis an increased production of IL-5 is observable. Among the different regulatory mechanisms contributing to maintain immunological homeostasis we analyzed the susceptibility to apoptosis of lamina propria lymphocytes. We found that CD2-activation pathway is regulated by Fas-mediated apoptosis, which regulates proliferation and cytokine production. In inflammatory bowel disease this apoptosis is defective thus contributing to the chronic inflammation and cytokine dysregulation.

Nod2 deficiency is associated with an increased mucosal immunoregulatory response to commensal microorganisms.

On the basis of previous studies demonstrating that a breach of the colonic epithelial barrier is associated with a microbiota-dependent increase in lamina propria (LP) regulatory cells, we investigated if the lack of spontaneous intestinal inflammation observed in nucleotide-binding oligomerization domain 2 (Nod2)-/- mice was due to enhanced intestinal regulatory function. We found that the LP CD4+ T-cell population of Nod2-/- mice contains an increased percentage of CD4+ regulatory T cells bearing transforming growth factor -ß/latency peptide (LP CD4+LAP (latency-associated peptide) + T cells) both under baseline conditions and following an intentional breach of the colonic barrier induced by ethanol administration. In addition, we found that Nod2-/- mice manifest decreased severity of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-colitis and that TNBS-colitis in Nod2-/- or Nod2+/+ mice is ameliorated by adoptive transfer of LP cells from ethanol-treated mice before, but not after, depletion of LAP+ T cells. This increased regulatory T-cell response in Nod2-/- mice could explain why NOD2 polymorphisms in humans are not in themselves sufficient to establish inflammatory lesions.

Intestinal microflora and immunoregulation.

Immune homeostasis at mucosal level results from controlled response to intestinal luminal antigens. Recent insights into the nature of inflammatory bowel diseases, derived mainly from studies of experimental models of colonic inflammation, strongly suggest that they can result from a loss of immune tolerance to antigens in the bacterial microflora. Investigations of the regulatory mechanisms operating at the mucosal level suggest that regulatory cells reactive to the intestinal microflora might play a role in cross-reactive protection toward different antigens. Expansion of microflora-reactive regulatory cells by probiotic administration is able to protect from experimental colitis. Characterization of regulatory cells in response to normal commensal flora, the basis of their development and the role of innate immunity in this process might contribute to the understanding of the development of inflammatory bowel diseases.

TGF-beta1 and Smad7 in the regulation of IBD.

Inflammatory bowel diseases (IBDs) are caused by an aberrant and excessive local immune response to components of the bacterial microflora that are: poorly controlled by endogenous counter regulatory mechanisms such as the immunosuppressive cytokine transforming growth factor-beta1 (TGF-beta1). Studies in human IBD tissues have documented a disruption of TGF-beta1 signaling marked by a block in the phosphorylation of the activated TGF-beta receptor-associated signaling molecule, Smad3, caused by the upregulation of the intracellular inhibitor of Smad signaling, Smad7. Inhibition of Smad7 with a specific antisense oligonucleotide restores TGF-beta1/Smad3 signaling, resulting in a marked suppression of inflammatory cytokine production. The functional relevance of Smad7 in gut inflammation was confirmed by studies in murine models of IBD. In inflamed tissues of mice with colitis induced by either the trinitrobenzene sulfonic acid or oxazolone, p-Smad3 was low despite active TGF-beta1 being produced in excess. In vivo administration of Smad7 antisense oligonucleotides to mice with colitis restored TGF-beta1 signaling and decreased the synthesis of inflammatory molecules and the extent of gut damage. These data support a role for Smad7 in maintaining intestinal inflammation, and suggest that blocking Smad7 could be a promising way to dampen the ongoing inflammation in IBD.

Cholera toxin subunit B inhibits IL-12 and IFN-{gamma} production and signaling in experimental colitis and Crohn's disease.

BACKGROUND AND AIMS: Cholera toxin B subunit (CT-B) is a powerful modulator of immune responses. The authors have previously demonstrated that oral administration of recombinant CT-B (rCT-B) is able to prevent and cure the Crohn's disease (CD)-like trinitrobenzene sulfonic acid (TNBS) mediated colitis. In this study they extended their observations and examined if rCT-B interferes with the molecular signaling underlying the Th1 type response both in TNBS colitis and in ex vivo human CD explants. METHODS: TNBS treated mice were fed with rCT-B, and IFN-gamma and IL-12 production by colonic lamina propria mononuclear cells (LPMC) was examined by ELISA. In vitro culture of mucosal explants from CD patients and non-inflammatory bowel disease controls, pre-incubated with rCT-B, were examined for IFN-gamma and IL-12 production by ELISA and semiquantitative reverse transcription polymerase chain reactions. STAT-1, -4, -6 activation and T-bet expression were examined following rCT-B treatment by western blotting both in TNBS treated mice and in human mucosal explants. RESULTS: rCT-B significantly reduced IL-12 and IFN-gamma secretion by LPMC from TNBS treated mice. Consistent with this, rCT-B inhibited both STAT-4 and STAT-1 activation and downregulated T-bet expression. Inhibition of Th1 signaling by CT-B associated with no change in IL-4 synthesis and expression of active STAT-6 indicating that rCT-B does not enhance Th2 cell responses. Moreover, in vitro treatment of CD mucosal explants with rCT-B resulted in reduced secretion of IL-12/IFN-gamma and inhibition of STAT-4/STAT-1 activation and T-bet expression. CONCLUSIONS: These studies indicate that CT-B inhibits mucosal Th1 cell signaling and suggest that rCT-B may be a promising candidate for CD therapy.

Oral probiotic administration induces interleukin-10 production and prevents spontaneous autoimmune diabetes in the non-obese diabetic mouse.

AIMS/HYPOTHESIS: Recent observations suggest the involvement of the gastrointestinal tract in the pathogenesis of islet autoimmunity. Thus, the modulation of gut-associated lymphoid tissue may represent a means to affect the natural history of the disease. Oral administration of probiotic bacteria can modulate local and systemic immune responses; consequently, we investigated the effects of oral administration of the probiotic compound VSL#3 on the occurrence of diabetes in non-obese diabetic (NOD) mice. METHODS: VSL#3 was administered to female NOD mice three times a week starting from 4 weeks of age. A control group received PBS. Whole blood glucose was measured twice a week. IFN-gamma and IL-10 production/expression was evaluated by ELISA in culture supernatants of mononuclear cells isolated from Peyer's patches and the spleen, and by real-time PCR in the pancreas. Insulitis was characterised by immunohistochemistry and histomorphometric studies. RESULTS: Early oral administration of VSL#3 prevented diabetes development in NOD mice. Protected mice showed reduced insulitis and a decreased rate of beta cell destruction. Prevention was associated with an increased production of IL-10 from Peyer's patches and the spleen and with increased IL-10 expression in the pancreas, where IL-10-positive islet-infiltrating mononuclear cells were detected. The protective effect of VSL#3 was transferable to irradiated mice receiving diabetogenic cells and splenocytes from VSL#3-treated mice. CONCLUSIONS/INTERPRETATION: Orally administered VSL#3 prevents autoimmune diabetes and induces immunomodulation by a reduction in insulitis severity. Our results provide a sound rationale for future clinical trials of the primary prevention of type 1 diabetes by oral VSL#3 administration.

Small bowel angiodysplasia in association with Crohn's ileitis. A case report.

A case of a female patient affected by Crohn's ileitis associated with small bowel angiodysplasia is reported. Despite a good clinical and laboratory response to steroid therapy the patient showed an unexplained hypochromic microcytic anemia. At laparotomy Crohn's ileitis as well as an angiodysplastic lesion were found. Both lesions were resected in continuity. During a 2-year follow-up the patient did not show anemia despite pregnancy. It is suggested that the angiodysplastic lesion was the possible cause of hypochromic anemia and that the patient should have been operated on before, based on her recurrent anemia.