IL-7 and IL-15 Levels Reflect the Degree of T Cell Depletion during Lymphopenia and Are Associated with an Expansion of Effector Memory T Cells after Pediatric Hematopoietic Stem Cell Transplantation.

Differentially and functionally distinct T cell subsets are involved in the development of complications after allogeneic hematopoietic stem cell transplantation (HSCT), but little is known about factors regulating their recovery after HSCT. In this study, we investigated associations between immune-regulating cytokines, T cell differentiation, and clinical outcomes. We included 80 children undergoing allogeneic HSCT for acute leukemia using bone marrow or peripheral blood stem cells grafted from a matched sibling or unrelated donor. Cytokines (IL-7, IL-15, IL-18, SCF, IL-6, IL-2, and TNF-α) and active anti-thymocyte globulin (ATG) levels were longitudinally measured along with extended T cell phenotyping. The cytokine profiles showed a temporary rise in IL-7 and IL-15 during lymphopenia, which was strongly dependent on exposure to active ATG. High levels of IL-7 and IL-15 from graft infusion to day +30 were predictive of slower T cell recovery during the first 2 mo post-HSCT; however, because of a major expansion of memory T cell stages, only naive T cells remained decreased after 3 mo (p < 0.05). No differential effect was seen on polarization of CD4+ T cells into Th1, Th2, or Th17 cells or regulatory T cells. Low levels of IL-7 and IL-15 at day +14 were associated with acute graft-versus-host disease grades II-IV in ATG-treated patients (p = 0.0004 and p = 0.0002, respectively). Children with IL-7 levels comparable to healthy controls at day +14 post-HSCT were less likely to develop EBV reactivation posttransplant. These findings suggest that quantification of IL-7 and IL-15 may be useful as biomarkers in assessing the overall T cell depletion and suggest a potential for predicting complications after HSCT.

Clinical and immunologic impact of CCR5 blockade in graft-versus-host disease prophylaxis.

Graft-versus-host disease (GVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Lymphocyte trafficking via chemokine receptors such as CCR5 plays a critical role in alloreactive responses, and previous data suggest that CCR5 blockade with maraviroc results in a low incidence of visceral GVHD. However, the full scope of clinical and immunologic effects of CCR5 blockade in HSCT has not been described. We compared a cohort of patients enrolled on a trial of reduced-intensity allo-HSCT with standard GVHD prophylaxis plus maraviroc to a contemporary control cohort receiving standard GVHD prophylaxis alone. Maraviroc treatment was associated with a lower incidence of acute GVHD without increased risk of disease relapse, as well as reduced levels of gut-specific markers. At day 30, maraviroc treatment increased CCR5 expression on T cells and dampened T-cell activation in peripheral blood without impairing early immune reconstitution or increasing risk for infections. Patients who developed acute GVHD despite maraviroc prophylaxis showed increased T-cell activation, naive T-cell skewing, and elevated serum CXCL9 and CXCL10 levels. Collectively, these data suggest that maraviroc effectively protects against GVHD by modulating alloreactive donor T-cell responses, and that CXCR3 signaling may be an important resistance mechanism to CCR5 blockade in GVHD.

IL-15 concentrations in skeletal muscle and subcutaneous adipose tissue in lean and obese humans: local effects of IL-15 on adipose tissue lipolysis.

Animal/cell investigations indicate that there is a decreased adipose tissue mass resulting from skeletal muscle (SkM) IL-15 secretion (e.g., SkM-blood-adipose tissue axis). IL-15 could regulate fat mass accumulation in obesity via lipolysis, although this has not been investigated in humans. Therefore, the purpose was to examine whether SkM and/or subcutaneous adipose tissue (SCAT) IL-15 concentrations were correlated with SCAT lipolysis in lean and obese humans and determine whether IL-15 perfusion could induce lipolysis in human SCAT. Local SkM and abdominal SCAT IL-15 (microdialysis) and circulating IL-15 (blood) were sampled in lean (BMI: 23.1 ± 1.9 kg/m(2); n = 10) and obese (BMI: 34.7 ± 3.5 kg/m(2); n = 10) subjects at rest/during 1-h cycling exercise. Lipolysis (SCAT interstitial glycerol concentration) was compared against local/systemic IL-15. An additional probe in SCAT was perfused with IL-15 to assess direct lipolytic responses. SkM IL-15 was not different between lean and obese subjects (P = 0.45), whereas SCAT IL-15 was higher in obese vs. lean subjects (P = 0.02) and was correlated with SCAT lipolysis (r = 0.45, P = 0.05). Exercise increased SCAT lipolysis in lean and obese (P < 0.01), but exercise-induced SCAT lipolysis changes were not correlated with exercise-induced SCAT IL-15 changes. Microdialysis perfusion resulting in physiological IL-15 concentrations in the adipose tissue interstitium increased lipolysis in lean (P = 0.04) but suppressed lipolysis in obese (P < 0.01). Although we found no support for a human IL-15 SkM-blood-adipose tissue axis, IL-15 may be produced in/act on the abdominal SCAT depot. The extent to which this autocrine/paracrine IL-15 action regulates human body composition remains unknown.

Differential expression of pro-inflammatory cytokines IL-15Ralpha, IL-15, IL-6 and TNFalpha in synovial fluid from rheumatoid arthritis patients.

BACKGROUND: Pro-inflammatory cytokines are directly implicated in the pathogenesis of Rheumatoid arthritis (RA). Variable clinical response to cytokine targeted therapies as TNFalpha and IL-6, strongly highlights the heterogeneity of inflammatory process in RA. Another cytokine, IL-15 has also been related to the inflammatory process in RA. Recently we described for the first time, the presence of its specific receptor, IL-15Ralpha, in synovial fluid (SF). The aim of this work was to compare the expression profile of IL-15Ralpha, its ligand IL-15, TNFalpha and IL-6 and how these cytokines are correlated in SF from RA patients taking as a reference Osteoarthritis (OA), an articular but not autoimmune disease. METHODS: Synovial fluids were obtained from the knee joints of 60 patients, 30 with confirmed diagnosis of RA and 30 with OA diagnosis. The levels of TNFalpha, IL-6, IL-15 and IL-15Ralpha were measured by ELISA. A statistical analysis was performed with GraphPad Prism v5.0 using the Mann-Whitney U test and Spearman's rank correlation. A cluster analysis was run in MeV software v4.9.0 and differences across clusters were evaluated by an ANOVA including post-test analysis. RESULTS: We found higher and significant levels of TNFalpha, IL-6 and IL-15Ralpha but not of IL-15 in RA compared with the OA group. Additionally, a high inter-individual variability in the levels of these 4 cytokines was observed in RA, although we identified 4 patients' subgroups by cluster analysis of cytokines concentration in SF. We also found a positive correlation between IL-15Ralpha-IL-6 and IL-15Ralpha-IL-15, but not for other pairs of cytokines in RA. In addition we found correlation between the value of IL-15Ralpha in SF and disease activity score, DAS28. CONCLUSIONS: In our current work we found a high inter-individual variability in the levels of TNFalpha, IL-6, IL-15 and IL-15Ralpha in SF of RA patients and were identified four principal clusters of cytokines concentration in SF, suggesting the importance of identifying disease subset of patients for personalized treatment. Finally, we found a correlation between IL-15Ralpha-IL-6, IL-15Ralpha-IL-15, but we did not find any correlation between other pairs of studied cytokines in SF.

Does cytokine profiling of aspirate from jaw cysts and tumors have a role in diagnosis?

PURPOSE: The objective of the present study was twofold: first, to assess aspirates for use in cytokine profiling and second, to initiate pilot analyses to determine whether the cytokine profiling can serve as an aid in the diagnosis of jaw lesions. MATERIALS AND METHODS: The aspirates from 12 benign odontogenic cysts and tumors of the jaw were collected and randomized, and a formal incisional biopsy was performed to establish the tissue diagnosis. The biopsies revealed keratocystic odontogenic tumor, ameloblastoma, and dentigerous cyst. The cystic aspirate was analyzed using the Q-Plex Human Cytokine Screen to detect cytokine expression and determine the level of expression for each pathologic entity. An array of 16 cytokines was investigated, including interleukin (IL)-1α, IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IL-23, interferon-γ, tumor necrosis factor (TNF)-α, and TNF-ß. Tables were developed to determine the ratio of expression for the candidate cytokine pairs that were differentially expressed among the 3 pathologic entities encountered. One-way analysis of variance was used to search for significant differences in the ratio of expression of the candidate pairs among the 3 entities. RESULTS: Cytokines expressed by the 3 distinct jaw lesions were detected in the aspirate without the need for tissue biopsy. Cytokine profiling of these entities is possible owing to differential expression of the various cytokines studied. The ratio of expression was significant (P < .05) for 15 pairs of cytokines: IL-5/IL-1α, IL-4/IL-2, IL-8/IL-4, TNF-ß/IL-6, IL-23/IL-6, TNF-α/IL-23, TNF-α/TNF-ß, TNF-α/IL-8, TNF-ß/IL-5, TNF-ß/TNF-α, TNF-ß/IL-13, IL-12/IL-23, IL-13/IL-15, IL-15/IL-2, and IL-6/IL-2. A comparison of the mean values indicated a "high/low" expression value for each lesion type for the 15 cytokine pairs. CONCLUSIONS: Cytokines, expressed by the 3 groups of jaw lesions, can be detected in the cystic aspirate, and a comparison of the ratio of the expression of the aspirates demonstrated a differential expression pattern of cytokines among the 3 groups. These ratios could assist in establishing a prompt and accurate diagnosis of lesions that might be difficult to discern clinically and radiographically. The use of a simple, minimally invasive aspiration procedure can help to establish an accurate diagnosis.

Interleukin-15 expression is increased in human eosinophilic esophagitis and mediates pathogenesis in mice.

BACKGROUND & AIMS: Quantitative microarray analyses have shown increased expression of interleukin-15 (IL-15) messenger RNA in the esophagus of patients with eosinophilic esophagitis (EoE), a recently recognized allergic disorder with poorly understood pathogenesis. METHODS: Quantitative polymerase chain reaction and enzyme-linked immunosorbent assay analyses were performed to examine protein and transcript levels in tissue samples from patients with EoE. Tissues from IL-15Ra-deficient and wild-type (control) mice were also examined. Tissue eosinophilia was determined by immunostaining for major basic protein and flow cytometry for cell-surface receptors. RESULTS: Quantitative polymerase chain reaction analyses showed that levels of IL-15 and its receptor IL-15Ra were increased approximately 6- and approximately 10-fold, respectively, in tissues from patients with EoE and approximately 3- and approximately 4-fold, respectively, in mice with allergen-induced EoE. A >2-fold increase in serum IL-15 protein levels was also detected in human EoE samples compared with those from healthy individuals. Human IL-15 messenger RNA levels correlated with esophageal eosinophilia (P < .001). IL-15Ra-deficient mice were protected from allergen-induced esophageal eosinophilia compared with controls (P < .001), even though similar levels of airway eosinophilia were observed in all mice. IL-15 activated STAT5 and CD4(+) T cells to produce cytokines that act on eosinophils. Incubation of primary esophageal epithelial cells from mice and humans with IL-15 caused a dose-dependent increase in the mRNA expression and protein levels of eotaxin-1, -2, and -3. CONCLUSIONS: IL-15 mediates in the pathogenesis of EoE. IL-15 activates CD4(+) T cells to produce cytokines that act on eosinophils.

Elevated number of recently activated T cells in bone marrow of patients with rheumatoid arthritis: a role for interleukin 15?

OBJECTIVES: (1) To compare the absolute T-cell numbers in bone marrow (BM) isolated from patients with rheumatoid arthritis (RA) and osteoarthritis (OA); (2) to measure the levels of soluble interleukin 15 (IL-15) and IL-7; (3) to analyse the expression of activation markers on T cells; (4) to analyse influence of IL-15 stimulation on T-cell proliferation. METHODS: BM samples were obtained from patients undergoing joint replacement surgery. Concentrations of IL-15 and IL-7 were measured using specific ELISAs. The absolute number of T lymphocytes, their activation status and proliferation were evaluated by flow cytometry. RESULTS: BM from patients with RA contained double the number of CD3 T cells in comparison with OA (6.1 vs 2.7 × 10(6) cells/ml, p<0.008). Ratio CD3CD4:CD3CD8 was increased in RA BM, clearly indicating accumulation of CD3CD4 cells. T cells obtained from patients with RA expressed higher level of early activation markers than from OA. Elevated levels of IL-15 were found in BM plasma from patients with RA in comparison with patients with OA (1304.5±956.3 pg/ml and 760±238.7 pg/ml respectively, p<0.01). These data were confirmed by immunohistochemistry of RA BM from regions proximal and distal to the joint. Although both CD3CD4 and CD3CD8 cells proliferated after IL-15 stimulation in vitro, CD3CD4 cells from patients with RA proliferated more vigorously than those from patients with OA, reflecting the composition of T-cell subsets in BM. CONCLUSION: These results suggest that locally overproduced IL-15 may be responsible for the activation and proliferation of T cells in situ, reflected by significantly increased number of activated T cells in RA BM, possibly contributing to the pathogenesis of RA.

Influence of smoking on gingival crevicular fluid cytokines in severe chronic periodontitis.

AIM: The aim of this study was to compare the expression of 22 chemokines and cytokines in gingival crevicular fluid (GCF) from smokers and non-smokers with periodontitis and periodontally healthy control subjects. MATERIALS AND METHODS: Forty subjects with generalized severe chronic periodontitis (20 smokers and 20 non-smokers) and 12 periodontally healthy control subjects participated in this study. Four diseased and two healthy sites were selected from each of the periodontitis subjects. GCF samples were collected and cytokines analysed utilizing a multiplexed immunoassay (Luminex(®) ). Statistical analyses employed non-parametric tests including the Mann-Whitney and Wilcoxon matched-pairs signed-rank tests. RESULTS: Compared with healthy control subjects, GCF in subjects with chronic periodontitis contained significantly higher amounts of interleukin (IL)-1α, IL-1ß, IL-6, IL-12(p40) (pro-inflammatory cytokines); IL-8, macrophage chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, regulated on activation normal T-cell expressed and secreted (RANTES) (chemokines); IL-2, IFN-γ, IL-3, IL-4 (Th1/Th2 cytokines); IL-15 [regulator of T-cells and natural killer (NK) cells]. Smokers displayed decreased amounts of pro-inflammatory cytokines [IL-1α, IL-6, IL-12(p40)], chemokines (IL-8, MCP-1, MIP-1, RANTES), and regulators of T-cells and NK cells (IL-7, IL-15). CONCLUSIONS: Periodontitis subjects had significantly elevated cytokine and chemokine profiles. Smokers exhibited a decrease in several pro-inflammatory cytokines and chemokines and certain regulators of T-cells and NK-cells. This reflects the immunosuppressant effects of smoking which may contribute to an enhanced susceptibility to periodontitis.

High concentrations of interleukin 15 in breast milk are associated with protection against postnatal HIV transmission.

Given the central role that interleukin 15 (IL-15) plays in human immunodeficiency virus (HIV) immunity, we hypothesized that IL-15 in breast milk may protect against postnatal HIV transmission. In a nested case-control study, we compared breast milk IL-15 levels in 22 HIV-infected women who transmitted HIV to their infants to those in 72 nontransmitters. Samples were collected in the first month of life, prior to HIV infection. IL-15 concentrations were associated with a decreased risk of HIV transmission in unadjusted analysis and after adjusting for milk viral load, CD4 cell count, and other cytokines in breast milk. IL-15-mediated immunity may protect against HIV transmission during breast-feeding.

Poor Oral Hygiene and High Levels of Inflammatory Cytokines in Saliva Predict the Risk of Overweight and Obesity.

The study aimed to determine if oral hygiene influences not only oral health but also potentially metabolic disorders such as overweight or obesity. Participants were 94 patients: 40 with increased body mass and 54 with normal body mass. The methods included dental examination, a questionnaire concerning hygienic habits and an assessment of selected salivary inflammatory markers. The new parameter named "cleaning index" (describing the interaction between average time of tooth brushing in minutes and its frequency per day) significantly correlated with Body Mass Index (RSpearman = 0.300). The multivariate regression model incorporating cleaning index, approximal plaque index, receptor 1 for tumor necrosis factor-alpha (TNFα-R1) and interleukin-15 (IL-15) had a high power to predict overweight or obesity (AUC = 0.894). Patients with poor oral hygiene (approximal plaque index >40%) were more than eight times more likely to suffer from obesity than patients with good oral hygiene. Cleaning index higher than 4 decreased the odds by about 85%. Oral hygiene habits, adjusted by salivary concentrations of selected inflammatory markers may allow predicting effectively overweight or obesity risk. Early proper dental prophylaxis and treatment could lead to the better prevention of metabolic disorders.

The influence of processing factors and non-atopy-related maternal and neonate characteristics on yield and cytokine responses of cord blood mononuclear cells.

RATIONALE: Several studies have evaluated the associations between cord blood cellular responses and atopic diseases in children, but the results of these studies are inconsistent. Variations in blood processing factors and maternal and infant characteristics are typically not accounted for and may contribute to these inconsistencies. METHODS: Cord blood samples were obtained from 287 subjects participating in the Childhood Origins of ASThma project, a prospective study of children at high risk for the development of asthma/allergies. Mononuclear cells were stimulated with phytohaemagglutinin (PHA), phorbal myristate acetate/ionomycin or a suspension of killed staphylococcus, and IFN-gamma, IL-10 and IL-13 were quantitated by ELISA. Cell yields and cytokine production were related to processing factors and maternal and infant characteristics. RESULTS: The strongest relationships between independent variables and cell yield or cytokine responses occurred with the season of birth. The highest median cell yields were seen in fall, and the lowest in summer (difference of 47%, P=0.0027). Furthermore, PHA-induced IL-5 and IL-13 responses were approximately 50% higher in spring and summer than in fall or winter (P<0.0001). Clots in the cord blood samples were associated with a reduced median cell yield (42% reduction, P<0.0001), and an increased PHA-induced IL-10 secretion (27% increase, P=0.004). CONCLUSIONS: These data suggest that season of collection, and to a lesser extent clotting in samples, affect cord blood mononuclear cell yield and cytokine responses. Careful documentation and analysis of processing and environmental variables are important in understanding biological relationships with cytokine responses, and also lead to greater comparability among studies using these techniques.

Impact of preformed T-cell alloreactivity by means of donor-specific and panel of reactive T cells (PRT) ELISPOT in kidney transplantation.

Donor-specific (d-sp) interferon gamma enzyme-linked immunosorbent spot (d-sp ELISPOT) and Panel of reactive T-cell (PRT) ELISPOT assays have been developed to detect alloreactive memory T (Tmem) cells in order to estimate the risk of acute rejection after kidney transplantation. Adding IL15 to the PRT assay (PRT+IL15) may uncover the presence of pathogenic alloreactive CD28-Tmem. Face-to-face comparisons of these assays have not been done yet. We performed pre-transplant d-sp ELISPOT and PRT assays (±IL15, against six B-cell lines) in 168 consecutive kidney transplant recipients and evaluated the multivariable-adjusted associations with biopsy-proven acute rejection (BPAR), de novo donor-specific antibodies (DSA), and eGFR decline over a 48-month follow-up period. D-sp ELISPOT was positive in 81 (48%) subjects, while 71 (42%) and 81 (48%) subjects displayed positive PRT and PRT+IL15, respectively. Their median [interquartile range] numerical test result was 23 [6-65], 18 [8-37], and 26 [10-45] spots/3x105 PBMCs, respectively. The number of PRT spots were weakly correlated with those of d-sp ELISPOT, but highly correlated with PRT+IL15 (rho = 0.96, P<0.001). d-sp ELISPOT, but not PRT (±IL15) was independently associated with BPAR (adjusted Odds Ratio of BPAR associated with d-sp ELISPOT positivity: 4.20 [95%CI: 1.06 to 21.73; P = 0.041]). Unlike d-sp ELISPOT, median PRT and PRT+IL15 were independently associated with higher Δ3-48month eGFR decline post-transplantation (for both assays, about -3mL/min/1.73m2 per one standard deviation unit increase in the spot number). Pre-transplant T-cell immune-monitoring using d-sp ELISPOT and PRT assays identifies kidney transplant candidates at high risk of BPAR and worse kidney allograft progression.

Elevation of interleukin-15 protein expression in bronchoalveolar fluid in acute lung allograft rejection.

BACKGROUND: Acute rejection remains a major source of morbidity in lung transplantation. Although interleukin (IL)-2 has been the principal T-cell growth factor implicated in acute rejection, IL-2 blockade does not prevent acute rejection completely. Recently, IL-15, a stromal cell-derived cytokine, has been found to share a similar biological function with IL-2. We hypothesized that IL-15 levels may be elevated in acute lung rejection in the presence of IL-2 blockade. METHODS: Acute allograft rejection developed in 21 of 42 lung transplant recipients. BAL fluid (BALF) was analyzed for IL-2 and IL-15 protein expression by standard enzyme-linked immunosorbent assay. RESULTS: The average (+/- SD) BALF IL-15 level was higher in lung transplant recipients with acute rejection compared to those without rejection (25 +/- 25 pg/mL vs 4.5 +/- 1.5 pg/mL, respectively; p < 0.0001). In addition, there appeared to be a bimodal distribution of BALF IL-15 levels in lung transplant recipients with acute rejection. BALF IL-2 levels were not associated with acute rejection. BALF IL-15 levels were not associated with bacterial, fungal, or cytomegalovirus infection. CONCLUSION: These data show that BALF IL-15 levels are elevated in acute lung allograft rejection in the presence of IL-2 receptor blockade and may be an important mediator for acute rejection in lung transplantation.

The contribution of interleukin-13 and -15 to the cytokine network within normal and diseased gingiva.

BACKGROUND: There are no comparisons of concentrations of interleukin (IL)-13 and -15 and gingival sulcular depth within healthy or inflamed gingiva. Study of non-oral inflammations indicated that IL-15 has similar functions to IL-2, and IL-13 has similar functions to IL-4 and -10. Thus, IL-13 and -15 likely have a function in gingival inflammation. METHODS: We compared the concentrations of IL-13 and -15 within healthy or inflamed human gingiva to gingival sulcular depth and the concentration of various T-helper 1 and T-helper 2 cytokines in a group of Hispanic subjects. Gingival papillae were grouped by the depth of the adjacent gingival sulcus: 6 mm (diseased). The gingival concentrations of IL-2, -4, -6, -10, -13, and -15 and interferon (IFN)-gamma were assessed by enzyme-linked immunosorbent assay. RESULTS: IL-2, -4, -6, -10, and -13 and IFN-gamma concentrations were higher within gingiva adjacent to 3 to 6 mm diseased compared to normal; IL-15 concentrations were significantly greater within normal gingiva than within diseased gingiva (P <0.001). Within gingiva adjacent to >6 mm sulci, IL-6 concentrations were significantly higher than in normal gingiva, and the concentrations of the other cytokines were similar to those in normal gingiva. Gingival IL-6 concentration correlated significantly with the adjacent gingival sulcular depth, whereas the IL-15 concentration correlated inversely with the adjacent gingival sulcular depth (P <0.001). CONCLUSIONS: IL-13, -4, and -10 had a similar concentration pattern within normal and diseased tissue; however, the concentration pattern of IL-15 was not similar to IL-2. Relatively low IL-15 concentrations within diseased gingiva suggest that IL-15 might have anti-inflammatory properties.

TLR2 signals via NF-κB to drive IL-15 production in salivary gland epithelial cells derived from patients with primary Sjögren's syndrome.

Toll-like receptors (TLRs) are pattern recognition receptors linking innate and adaptive immune responses, which resulted overexpressed in primary Sjögren's syndrome (pSS). Interleukin-15 (IL-15) is a pro-inflammatory cytokine which was recently demonstrated to be involved in pSS pathogenesis. The study was undertaken to clarify whether TLR2 is involved in the production of IL-15 in human salivary gland epithelial cells (SGEC) from pSS patients. SGEC primary cell cultures were established from pSS minor salivary gland tissues explanted from patients with a sure diagnosis of SS. After neutralization of TLR2 with a blocking monoclonal antibody, IL-15 production was assayed by immunoblotting and flow cytometry, IL-15 in the culture supernatants was measured by ELISA, and mRNA levels were assessed by RT-PCR and real-time PCR. The production of IL-15 by pSS SGEC decreased in culture supernatants and in protein lysates (p < 0.01) when TLR2 signaling was inhibited in pSS SGEC. In addition, a control at the transcriptional level was also detected; in fact, inhibition of nuclear factor (NF)-κB through the transfection of pSS SGEC with the dominant-negative inhibitory κBα proteins (IκBα) vector (IκBαDN) abrogated the stimulatory effect of TLR2 on IL-15 production. These data suggest that TLR2 activation is involved in the induction of IL-15 production by pSS SGEC and promotes inflammation through NF-κB activation. Therefore, therapeutic strategies that target TLR2/IL-15 pathway might be strong candidates for preventing or treating pSS.

The toxicity of high molecular weight glutenin subunits of wheat to patients with coeliac disease.

OBJECTIVES: The ability of the gliadin fraction of wheat gluten to exacerbate coeliac disease is well documented. We investigated the possible toxicity of high molecular weight glutenin subunits (HMW-GS) in coeliac disease in vitro using gluten-sensitive T cells, and in vivo with challenge studies in patient volunteers. METHODS: A mixture of four HMW-GS was chemically separated from wheat flour and checked for purity by HPLC, SDS-PAGE and ELISA. T-cell lines, grown up from small intestinal biopsies from coeliac patients (n=17), were tested for their reactivity to HMW-GS. Adults with coeliac disease and who were on a gluten-free diet (n=3) underwent in-vivo challenges with HMW-GS. Duodenal biopsies, taken prior to the challenge and at intervals up to 6 h afterwards, were assessed for morphology, intra-epithelial lymphocyte count, and interleukin 15 (IL-15) expression, by immunohistochemistry. RESULTS: T-cell lines from 11 of 17 patients were stimulated by HMW-GS. There was a significant change in small intestinal morphology 4 h after commencing infusions with HMW-GS in all three subjects. For example villus height to crypt depth ratios were reduced in the three patients from 3.0+/-0.5 to 1.29+/-0.2, 2.53+/-0.7 to 0.81+/-0.6 and 3.0+/-0.7 to 1.85+/-0.3, P<0.0001 in all cases. There was increased expression of IL-15 in the small intestine from 2 h after the HMW-GS challenges. CONCLUSION: Mixed HMW-GS stimulate T-cell lines from some coeliac patients and exacerbate coeliac disease in vivo, inducing expression, within 2 h, of IL-15. This suggests an innate immune response to these proteins.

Decreased peritoneal concentrations of interleukin-15 in women with advanced stage endometriosis.

OBJECTIVE: To assess the concentrations of interleukin-15 (IL-15) in peritoneal fluid from women with endometriosis and fertile disease-free controls. STUDY DESIGN: Peritoneal fluid samples were obtained from 50 women with endometriosis and 29 fertile women having tubal ligation. Concentrations of IL-15 were measured. RESULTS: The mean (S.D.s) concentration of IL-15 in peritoneal fluid was 11.17 pg/mL (3.89) for women with endometriosis, and 12.59 pg/mL (4.11) for fertile disease-free controls. The difference of peritoneal IL-15 concentrations between endometriosis and control women was not statistically significant. However, peritoneal IL-15 concentrations were significantly lower in women with moderate/severe endometriosis when compared with those in women with minimal/mild endometriosis, and in controls (P<0.05). In addition, peritoneal IL-15 concentrations did not correlate with the phase of menstrual cycle in endometriosis or control women. CONCLUSIONS: Our results suggest that the decreased peritoneal IL-15 concentrations in women with moderate/severe endometriosis imply a role of IL-15 in the pathogenesis of advanced endometriosis as compared to those with minimal/mild endometriosis and fertile disease-free controls.

A Refractory Celiac Patient Successfully Treated With Mesenchymal Stem Cell Infusions.

Type II refractory celiac disease (RCD), as defined according to the amount of aberrant intraepithelial lymphocytes, is a condition characterized by severe malabsorption syndrome and poor prognosis, with no effective treatment. Based on the regenerative and immunomodulatory properties of mesenchymal stem cells (MSCs), we investigated the feasibility, safety, and efficacy of serial infusions of autologous bone marrow-derived MSCs in a 51-year-old woman with type II RCD. Mesenchymal stem cells were isolated, expanded, and characterized following standard protocols. Monitoring of the patient's malabsorption indexes, mucosal architecture, and percentage of aberrant intraepithelial lymphocytes was scheduled for the time of enrollment, at each infusion, and after 6 months. Determination of mucosal expression of interleukin (IL)-15 and its receptor was also performed. Expansion of MSCs was feasible, and the patient underwent 4 systemic infusions of 2 × 10(6) MSCs/kg body weight 4 months apart, without adverse effects. During the treatment period, she experienced gradual and durable amelioration of her general condition, with normalization of stool frequency, body mass index, laboratory test results, and mucosal architecture. Remarkably, the expression of IL-15 and its receptor almost completely disappeared. Thus, treatment of RCD with serial MSC infusions seems promising, leading to recovery from the life-threatening condition while blocking the IL-15 pathogenic pathway.

Bile acid aspiration and the development of bronchiolitis obliterans after lung transplantation.

BACKGROUND: Aspiration of gastroesophageal refluxate may contribute to lung transplant bronchiolitis obliterans syndrome (BOS). We investigated bile acids in bronchoalveolar lavage fluid (BALF) and studied its role in BOS. MATERIALS AND METHODS: Surveillance pulmonary function tests and BALF were evaluated in 120 lung recipients. BOS-(0p-3) was diagnosed after 6 months' survival. BOS was defined as "early" if diagnosed within 12 months after a transplant. BALF was assayed for differential cell count, bile acids, and interleukins 8 and 15. Bile acids were considered elevated if greater than normal serum levels ( or =8 micromol/L). RESULTS: Elevated BALF bile acids were measured in 20 (17%) of 120 patients. BOS was diagnosed in 36 (34%) of 107 patients and judged "early" in 21 (57%) of 36. Median BALF bile acid values were 1.6 micromol/L (range, 0-32 micromol/L) in BOS patients and 0.3 micromol/L (range, 0-16 micromol/L) in non-BOS patients ( P = .002); 2.6 micromol/L (range, 0-32 micromol/L) in early BOS patients and 0.8 micromol/L (range, 0-4.6 micromol/L) in late BOS patients, ( P = .02). Bile acids correlated with BALF IL-8 and alveolar neutrophilia (r = 0.3, P = .0004, and r = 0.3, P = .004, respectively), but not with IL-15. Freedom from BOS was significantly shortened in patients with elevated BALF bile acids (Cox-Mantel test, P = .0001). CONCLUSIONS: Aspiration of duodenogastroesophageal refluxate is prevalent after lung transplantation and is associated with the development of BOS. Elevated BALF bile acids may promote early BOS development via an inflammatory process, possibly mediated by IL-8 and alveolar neutrophilia.

CNS interleukin-3 (IL-3) expression and neurological syndrome in antisense-IL-3 transgenic mice.

Interleukin-3 (IL-3) is an important mediator of physiological and pathophysiological processes affecting the central nervous system (CNS). It stimulates the proliferation and activation of microglia and can enhance differentiation of cholinergic and sensory neurons. To examine the role of IL-3 in the CNS, we utilized transgenic mice expressing a murine antisense IL-3 (AS-IL-3) RNA under the control of the T cell B19 promoter so that expression is limited to hematopoietic cells. The AS-IL-3 transgenic mice develop either a progressive neurologic dysfunction, which includes ataxia, bradykinesia, and paralysis, or a lymphoproliferative syndrome. Histopathology demonstrated accumulations of reactive astrocytes in the cerebellum, brain stem, and spinal cord, accompanied by activated microglia. Partial loss of cerebellar nuclei neurons as well as neurons in the cranial nerve nuclei and spinal cord motor neurons is seen. Despite depletion of IL-3 peripherally, expression of IL-3 mRNA and protein is turned on in the CNS of the transgenic mice. Astrocytes cultured from the AS-IL-3 mice contain IL-3 mRNA and may thus be responsible for the activation of the microglia. This model should provide important insights into the role of cytokines in neurological disorders.