Of Mice and Men: Studying Innate and Adaptive Immunity Against the Epstein-Barr Virus

The Epstein-Barr virus (EBV) is a lymphotropic -herpes virus infecting over 90% of the human adult population. A striking feature that the virus shares with other -herpes viruses is its oncogenic potential. This transforming property can be observed as B cell transformation in vitro and lymphomas as well as epithelial cancers in vivo, but most immunocompetent individuals control EBV infection successfully without the occurrence of disease. Cells of the innate immune system act in synergy to provide a first line of defense against pathogens. Here we describe that dendritic cells (DCs), matured with viral products or mimics thereof, activated natural killer (NK) cells more efficiently than other mature DC preparations. CD56brightCD16- NK cells, which are enriched in human secondary lymphoid tissues, responded primarily to this DC activation. In fact, 100-fold less tonsilar than peripheral blood NK cells were required to achieve the same protection against EBV-mediated B cell transformation in vitro, indicating that innate immune control of EBV by NK cells is most efficient at this primary site of EBV infection. The lack of an animal model of EBV infection prevents assignment of a protective value to immune subsets in vivo. We generated a small animal model that can be infected with EBV by reconstituting NOD-scid c -/- mice with CD34+ hematopoietic stem cells. We demonstrated that primary T cell responses in these humanized mice control infection with EBV. These T cell responses were HLA restricted and partially specific for EBV derived peptides. In HLA-A2 transgenic animals T cell responses against lytic EBV antigens dominated over recognition of latent EBV antigens during early phases of infection similarly to human EBV carriers. This mouse model recapitulates features of symptomatic primary EBV infection, and generates T cell mediated immune control that resists oncogenic transformation. We were also able to demonstrate that humanized mice develop functional human NK cells, this will allow us now to study the contributions of NK cells to innate immune control of EBV in vivo in the future

The DNA-sensing AIM2 inflammasome controls radiation-induced cell death and tissue injury

Acute exposure to ionizing radiation induces massive cell death and severe damage to tissues containing actively proliferating cells, including bone marrow and the gastrointestinal tract. However, the cellular and molecular mechanisms underlying this pathology remain controversial. Here, we show that mice deficient in the double-stranded DNA sensor AIM2 are protected from both subtotal body irradiation-induced gastrointestinal syndrome and total body irradiation-induced hematopoietic failure. AIM2 mediates the caspase-1-dependent death of intestinal epithelial cells and bone marrow cells in response to double-strand DNA breaks caused by ionizing radiation and chemotherapeutic agents. Mechanistically, we found that AIM2 senses radiation-induced DNA damage in the nucleus to mediate inflammasome activation and cell death. Our results suggest that AIM2 may be a new therapeutic target for ionizing radiation exposure

Comparison of a Novel Insulin Bolus-Patch with Pen/Syringe Injection to Deliver Mealtime Insulin for Efficacy, Preference, and Quality of Life in Adults with Diabetes: A Randomized, Crossover, Multicenter Study

Objective: This study compared the efficacy, safety, device satisfaction, and quality of life (QOL) in people with diabetes using an insulin bolus-patch versus current devices (pen/syringe) to deliver mealtime insulin. Research Design and Methods: Thirty-eight subjects with diabetes (26 with type 1 and 12 with type 2) were randomized to bolus-patch or current injection device (55% pen and 45% syringe) to deliver mealtime insulin in a multicenter, 6-week crossover study. Efficacy was assessed by equivalence in mean daily seven-point blood glucose (MDBG). Safety assessments included severe hypoglycemia episodes, adverse device effects (ADEs), and adverse events (AEs). Device satisfaction was determined by the validated Insulin Delivery System Rating Questionnaire (IDSRQ) and QOL by the validated Diabetes Specific QOL Scale (DSQOLS). Results: Using bolus-patch, MDBG (mean•SE) was equivalent to that using pen/syringe (8.61+/-0.28 vs. 9.02+/-0.26-mmol/L; P=0.098). SD of the seven-point blood glucose measurements was lower using bolus-patch (3.18+/-0.18 vs. 3.63+/-0.17 mmol/L; P=0.004), as was the coefficient of variation (CV) (37.2+/-1.7 vs. 40.3+/-1.7%; P=0.046). Hemoglobin A1c, 1,5-anhydroglucitol, fructosamine, and insulin use were similar between groups. There were no severe hypoglycemia episodes or serious ADEs. Between-device AEs were comparable. Subjects scored better on six of seven subscales on the DSQOLS and five of six subscales on the IDSRQ while using bolus-patch versus pen/syringe. At study completion, 76% of subjects would choose to switch to bolus-patch (P=0.001). Conclusions: Delivery of mealtime insulin with bolus-patch compared with pen/syringe resulted in equivalent MDBG, lower SD and CV of seven-point blood glucose measurements, good safety, significant device satisfaction, and improved QOL.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90477/1/dia-2E2011-2E0047.pd

Identification of mutations in the PYRIN-containing NLR genes (NLRP) in head and neck squamous cell carcinoma

Head and Neck Squamous Cell Carcinoma (HNSCC) encompasses malignancies that arise in the mucosa of the upper aerodigestive tract. Recent high throughput DNA sequencing revealed HNSCC genes mutations that contribute to several cancer cell characteristics, including dysregulation of cell proliferation and death, intracellular proinflammatory signaling, and autophagy. The PYRIN-domain containing NLR (Nucleotide-binding domain, Leucine rich Repeats - containing) proteins have recently emerged as pivotal modulators of cell death, autophagy, inflammation, and metabolism. Their close physiologic association with cancer development prompted us to determine whether mutations within the NLRP (PYRIN-containing NLR ) gene family were associated with HNSCC genome instability and their clinicopathologic correlations. Catastrophic mutational events underlie cancer cell genome instability and mark a point-of-no-return in cancer cell development and generation of heterogeneity. The mutation profiles of 62 patients with primary conventional type HNSCC excluding other histologic variants were analyzed. Associations were tested using Fisher's Exact test or Mann-Whitney U test. Mutations in NLRP were associated with elevated genome instability as characterized by higher mutation rates. Clinically, NLRP mutations were more frequently found in HNSCC arising in the floor of mouth (50.0%) in comparison with HNSCC at other head and neck locations (14.8%). These mutations were clustered at the leucine rich repeats region of NLRP proteins, and affected NLRP genes were mostly localized at chromosomes 11p15.4 and 19q13.42-19q13.43. Twenty novel NLRP mutations were identified in HNSCC, and mutations in this group of genes were correlated with increased cancer cell genome mutation rates, and such features could be a potential molecular biomarker of HNSCC genome instability. © 2014 Lei et al

Association between virulence factors of helicobacter pylori and gastric mucosal interleukin-18 mRNA expression in dyspeptic patients

Background: Helicobacter pylori (Hp) infection is associated with gastritis and marked infiltration of the gastric mucosa by several cytokines secreting inflammatory cells that contribute to sustain and expand the local inflammation. Different clinical expressions of the infection may reflect distinctive patterns of cytokine expression. IL-1 beta, TNF-alpha, IL-17 and IL-23 have been reported to be involved in Hp-induced gastric mucosal inflammation, but the details and association to different patterns of inflammation and virulence factors remain unclear. Methods: Total RNA was extracted from gastric biopsies of 51 Hp-infected patients and 44 Hp-negative patients. Mucosal IL-18 mRNA expression in gastric biopsies was determined by Real-Time PCR. Presence of virulence factors was evaluated using PCR. Results: IL-18 mRNA expression was significantly increased in biopsies of Hp-infected patients compared to Hp-uninfected individuals. There was no association between virulence factors and IL-18 mRNA expression. Also severity of mononuclear infiltration was significantly higher in gastritis patients with vacA (m1)-positive compare patients with vacA (m2)-positive. Conclusions: IL-18 may play an important role in the inflammatory response and promote the chronic and persistent inflammatory changes in the stomach. This may ultimately influence the outcome of Hp-associated diseases that arise within the context of gastritis. (C) 2013 Elsevier Ltd. All rights reserved

Genetic basis for variation in plasma IL-18 levels in persons with chronic hepatitis C virus and human immunodeficiency virus-1 infections

Inflammasomes are multi-protein complexes integrating pathogen-triggered signaling leading to the generation of pro-inflammatory cytokines including interleukin-18 (IL-18). Hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infections are associated with elevated IL-18, suggesting inflammasome activation. However, there is marked person-to-person variation in the inflammasome response to HCV and HIV. We hypothesized that host genetics may explain this variation. To test this, we analyzed the associations of plasma IL-18 levels and polymorphisms in 10 genes in the inflammasome cascade. About 1538 participants with active HIV and/or HCV infection in three ancestry groups are included. Samples were genotyped using the Illumina Omni 1-quad and Omni 2.5 arrays. Linear regression analyses were performed to test the association of variants with log IL-18 including HCV and HIV infection status, and HIV RNA in each ancestry group and then meta-analyzed. Eleven highly correlated single-nucleotide polymorphisms (r²=0.98–1) in the IL-18-BCO2 region were significantly associated with log IL-18; each T allele of rs80011693 confers a decrease of 0.06 log pg ml⁻¹ of IL-18 after adjusting for covariates (rs80011693; rs111311302 β=−0.06, P-value=2.7 × 10⁻⁴). In conclusion, genetic variation in IL-18 is associated with IL-18 production in response to HIV and HCV infection, and may explain variability in the inflammatory outcomes of chronic viral infections

Distinct Microbial Taxa Are Associated with LDL-Cholesterol Reduction after 12 Weeks of Lactobacillus plantarum Intake in Mild Hypercholesterolemia: Results of a Randomized Controlled Study

Probiotic microbes such as Lactobacillus may reduce serum total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol. The objective of this study was to assess the effect of Lactobacillus plantarum strains CECT7527, CECT7528, and CECT7529 (LP) on the serum lipids, cardiovascular parameters, and fecal gut microbiota composition in patients with mild hypercholesterolemia. A randomized, double-blinded, placebo-controlled clinical trial with 86 healthy adult participants with untreated elevated LDL cholesterol ≥ 160 mg/dl was conducted. Participants were randomly allocated to either placebo or LP (1.2 × 109 CFU/d) for 12 weeks. LDL, HDL, TC, and triglycerides (TG), cardiovascular parameters (blood pressure, arterial stiffness), and fecal gut microbiota composition (16S rRNA gene sequencing) were assessed at baseline and after 12 weeks. Both groups were comparable regarding age, sex, and LDL-C at baseline. LDL-C decreased (mean decrease − 6.6 mg/dl ± − 14.0 mg/dl, P time*group = 0.006) in the LP group but not in the placebo group. No effects were observed on HDL, TG, or cardiovascular parameters or overall gut microbiota composition. Responders to LP intervention (> 5% LDL-C reduction) were characterized by higher BMI, pronounced TC reduction, higher abundance of fecal Roseburia, and lower abundance of Oscillibacter. In conclusion, 12 weeks of L. plantarum intake moderately reduced LDL-C and TC as compared to placebo. LDL-C-lowering efficacy of L. plantarum strains may potentially be dependent on individual difference in the gut microbiota. Trial registration: DRKS00020384, dated 07/01/2020

Short-term mucosal disruption enables colibactin-producing <i>E. coli</i> to cause long-term perturbation of colonic homeostasis

Colibactin, a bacterial genotoxin produced by E. coli strains harboring the pks genomic island, induces cytopathic effects, such as DNA breaks, cell cycle arrest, and apoptosis. Patients with inflammatory bowel diseases, such as ulcerative colitis, display changes in their microbiota with the expansion of E. coli. Whether and how colibactin affects the integrity of the colonic mucosa and whether pks+ E. coli contributes to the pathogenesis of colitis is not clear. Using a gnotobiotic mouse model, we show that under homeostatic conditions, pks+ E. coli do not directly interact with the epithelium or affect colonic integrity. However, upon short-term chemical disruption of mucosal integrity, pks+ E. coli gain direct access to the epithelium, causing epithelial injury and chronic colitis, while mice colonized with an isogenic & UDelta;clbR mutant incapable of producing colibactin show a rapid recovery. pks+ E. coli colonized mice are unable to reestablish a functional barrier. In turn, pks+ E. coli remains in direct contact with the epithelium, perpetuating the process and triggering chronic mucosal inflammation that morphologically and transcriptionally resembles human ulcerative colitis. This state is characterized by impaired epithelial differentiation and high proliferative activity, which is associated with high levels of stromal R-spondin 3. Genetic overexpression of R-spondin 3 in colon myofibroblasts is sufficient to mimic barrier disruption and expansion of E. coli. Together, our data reveal that pks+ E. coli are pathobionts that promote severe injury and initiate a proinflammatory trajectory upon contact with the colonic epithelium, resulting in a chronic impairment of tissue integrity

Pharmacological Treatment of the Pathogenetic Defects in Type 2 Diabetes: The randomized multicenter South Danish Diabetes Study

AbstractObjective: To determine the effect of treatment with insulin Aspart as compared to NPH insulin, together with metformin/placebo and rosiglitazone/placebo. The hypothesis was that combined correction of major pathogenetic defects in type 2 diabetes would result in optimal glycemic control. Research Design and Methods: A 2-year investigator driven, randomized, partly placebo controlled, multicenter trial in 371 patients with type 2 diabetes on at least oral antiglycemic treatment. Patients were assigned to one of eight treatment groups in a factorial design with insulin aspart at mealtimes vs. NPH insulin once daily at bedtime, metformin twice daily vs. placebo, and rosiglitazone twice daily vs placebo. Main outcome measurement: change in HbA1c. Results: HbA1c decreased more in patients treated with insulin aspart compared to NPH (-0.41 ± 0.10%,