The effects of atorvastatin on gluten-induced intestinal T cell responses in coeliac disease

Rapid accumulation of CD14+CD11c+ dendritic cells in gut mucosa of celiac disease after in vivo gluten challenge

BACKGROUND

Of antigen-presenting cells (APCs) expressing HLA-DQ molecules in the celiac disease (CD) lesion, CD11c(+) dendritic cells (DCs) co-expressing the monocyte marker CD14 are increased, whereas other DC subsets (CD1c(+) or CD103(+)) and CD163(+)CD11c(-) macrophages are all decreased. It is unclear whether these changes result from chronic inflammation or whether they represent early events in the gluten response. We have addressed this in a model of in vivo gluten challenge.

METHODS

Treated HLA-DQ2(+) CD patients (n = 12) and HLA-DQ2(+) gluten-sensitive control subjects (n = 12) on a gluten-free diet (GFD) were orally challenged with gluten for three days. Duodenal biopsies obtained before and after gluten challenge were subjected to immunohistochemistry. Single cell digests of duodenal biopsies from healthy controls (n = 4), treated CD (n = 3) and untreated CD (n = 3) patients were analyzed by flow cytometry.

RESULTS

In treated CD patients, the gluten challenge increased the density of CD14(+)CD11c(+) DCs, whereas the density of CD103(+)CD11c(+) DCs and CD163(+)CD11c(-) macrophages decreased, and the density of CD1c(+)CD11c(+) DCs remained unchanged. Most CD14(+)CD11c(+) DCs co-expressed CCR2. The density of neutrophils also increased in the challenged mucosa, but in most patients no architectural changes or increase of CD3(+) intraepithelial lymphocytes (IELs) were found. In control tissue no significant changes were observed.

CONCLUSIONS

Rapid accumulation of CD14(+)CD11c(+) DCs is specific to CD and precedes changes in mucosal architecture, indicating that this DC subset may be directly involved in the immunopathology of the disease. The expression of CCR2 and CD14 on the accumulating CD11c(+) DCs indicates that these cells are newly recruited monocytes.

Strategies to enhance viral penetration of solid tumors

The efficient delivery of viral vectors to tumors is an active area of investigation. A number of barriers exist that must be overcome to achieve good penetration of vectors into tumors and distribution of their effects throughout the tumor mass. Replicating oncolytic viruses have the advantage of being able to amplify the initial dose, but progeny virus are prevented from spreading because of a dense mass of tightly packed cells with a dense extracellular matrix, admixed normal stromal cells, and high interstitial pressure. Although intratumoral injection may ensure initial delivery the distribution achieved by intravenous administration may be superior and come with beneficial bystander damage to the tumor vasculature. Strategies to enhance intravenous delivery and subsequent spread of these vectors within tumors are being developed by a number of groups. Achieving the goal of efficient penetration and spread of viruses within solid tumors is a necessary prerequisite to significant improvements in virus-vectored therapy of solid tumors.

Regulation of different inflammatory diseases by impacting the mevalonate pathway

The 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) interfere with the mevalonate pathway. While initially developed for their lipid-lowering properties, statins have been extensively investigated with respect to their impact on autoantigen and alloantigen driven immune responses. Mechanistically it was shown that statins modify immune responses on several levels, including effects on dendritic cells, endothelial cells, macrophages, B cells and T cells. Several lines of evidence suggest that statins act in a disease-specific manner and are not effective in each immune disorder. This review discusses possible modes of action of statins in modulating immunity towards autoantigens and alloantigens.

Advances in celiac disease

PURPOSE OF REVIEW

Increasing numbers of atypical or asymptomatic cases of celiac disease are being diagnosed. This review aims to summarize recent critical research in celiac disease.

RECENT FINDINGS

Alternative candidate genes outside of the human leukocyte antigen complex continue to be identified, whilst innate and adaptive immune responses to key gliadin epitopes are now both recognized to be important in celiac disease pathogenesis.

SUMMARY

Serological tests and small bowel biopsy remain the cornerstones of diagnosis. Treatment options other than the restrictive gluten-free diet remain limited.

Atorvastatin fails to prevent the development of autoimmune diabetes despite inhibition of pathogenic beta-cell-specific CD8 T-cells

Statins, the widely used inhibitors of cholesterol biosynthesis, also have immunomodulatory properties. Statins have recently been shown to have beneficial prophylactic and therapeutic effects in actively induced, short-term animal models of the autoimmune diseases multiple sclerosis and rheumatoid arthritis, leading to clinical trials. We therefore investigated whether statins' protective effects could be reproduced in the nonobese diabetic (NOD) mouse, a spontaneous, chronic model of autoimmune diabetes. Mice were treated with 0, 1, 10, or 50 mg x kg(-1) x day(-1) oral atorvastatin from 6 or 12 weeks of age, without effect on the rate or prevalence of diabetes development, islet infiltration, or islet major histocompatibility complex class II expression. However, there was clear evidence of a disease-relevant immunological effect of statins in vivo, since short-term (12-day) treatment significantly reduced the number of proinflammatory (gamma-interferon-producing) CD8 cells recognizing a dominant pathogenic epitope. This effect was absent in mice treated for longer periods, suggesting that atorvastatin loses efficiency in inhibiting autoantigen-specific T-cells over time. This observation may explain the discrepancy between the reported success of statins in acutely induced models and the lack of it in a chronic, spontaneous model of autoimmune disease and has implications for the adoption of such therapy in humans.