The non-insecticidal control strategies currently being implemented in South African orchards for the control of codling moth, Cydia pomonella (L.) may be hampered by wooden fruit bins being infested ...with diapausing codling moth larvae, acting as a potential source of re-infestation. Key factors contributing to the success or failure of an entomopathogenic nematode application were investigated using the SF 41 isolate of Heterorhabditis zealandica in laboratory bioassays with wooden minibins. Under operational conditions, an application rate of 100 IJs/mL (LD90=102 IJs/mL) effectively controlled codling moth larvae in these bins, and for further laboratory bioassays, the LD50 value of 18 IJs/mL (approximately equal to 25 IJs/mL) was identified as the discriminating dosage. Maximum mortality was attained when bins were pre-wet for at least 1 min (>90% RH) and maintained at maximum humidity (>95% RH) post-treatment for at least 3 days (LT90=73 h), to ensure nematode survival and subsequent satisfactory infection of diapausing codling moth larvae. Tarping bins achieved the desired high level of humidity required. Furthermore, adjuvants (specifically Reverseal 10) also improved an application. The study conclusively illustrated that if all the above-mentioned conditions are met, H. zealandica has the potential to successfully disinfest wooden fruit bins of codling moth.
Thesis (M.A.)--Florida State University, 2006.
Advisor: John Kelsay, Florida State University, College of Social Sciences, Dept. of International Affairs. Title and description from dissertation home ...page (viewed June 6, 2006). Document formatted into pages; contains iv, 41 pages. Includes bibliographical references.
Background Celiac disease is a chronic immune-mediated inflammatory disorder of the gut triggered by dietary gluten. Although the effector T-cell response in patients with celiac disease has been ...well characterized, the role of regulatory T (Treg) cells in the loss of tolerance to gluten remains poorly understood. Objective We sought to define whether patients with celiac disease have a dysfunction or lack of gluten-specific forkhead box protein 3 (FOXP3)+ Treg cells. Methods Treated patients with celiac disease underwent oral wheat challenge to stimulate recirculation of gluten-specific T cells. Peripheral blood was collected before and after challenge. To comprehensively measure the gluten-specific CD4+ T-cell response, we paired traditional IFN-γ ELISpot with an assay to detect antigen-specific CD4+ T cells that does not rely on tetramers, antigen-stimulated cytokine production, or proliferation but rather on antigen-induced coexpression of CD25 and OX40 (CD134). Results Numbers of circulating gluten-specific Treg cells and effector T cells both increased significantly after oral wheat challenge, peaking at day 6. Surprisingly, we found that approximately 80% of the ex vivo circulating gluten-specific CD4+ T cells were FOXP3+ CD39+ Treg cells, which reside within the pool of memory CD4+ CD25+ CD127low CD45RO+ Treg cells. Although we observed normal suppressive function in peripheral polyclonal Treg cells from patients with celiac disease, after a short in vitro expansion, the gluten-specific FOXP3+ CD39+ Treg cells exhibited significantly reduced suppressive function compared with polyclonal Treg cells. Conclusion This study provides the first estimation of FOXP3+ CD39+ Treg cell frequency within circulating gluten-specific CD4+ T cells after oral gluten challenge of patients with celiac disease. FOXP3+ CD39+ Treg cells comprised a major proportion of all circulating gluten-specific CD4+ T cells but had impaired suppressive function, indicating that Treg cell dysfunction might be a key contributor to disease pathogenesis.
Abstract
Background
Crohn’s disease (CD) can affect any segment of the digestive tract but is most often localized in the ileal, ileocolonic, and colorectal regions of the intestines. It is believed ...that the chronic inflammation in CD is a result of an imbalance between the epithelial barrier, the immune system, and the intestinal microbiota. The aim of the study was to identify circulating markers associated with CD and/or disease location in CD patients.
Methods
We tested 49 cytokines, chemokines, and growth factors in serum samples from 300 patients with CD and 300 controls. After quality control, analyte levels were tested for association with CD and disease location.
Results
We identified 13 analytes that were higher in CD patients relative to healthy controls and that remained significant after conservative Bonferroni correction (P < 0.0015). In particular, CXCL9, CXCL1, and interleukin IL-6 had the greatest effect and were highly significant (P < 5 × 10–7). We also identified 9 analytes that were associated with disease location, with VEGF, IL-12p70, and IL-6 being elevated in patients with colorectal disease (P < 3 × 10–4).
Conclusions
Multiple serum analytes are elevated in CD. These implicate the involvement of multiple cell types from the immune, epithelial, and endothelial systems, suggesting that circulating analytes reflect the inflammatory processes that are ongoing within the gut. Moreover, the identification of distinct profiles according to disease location supports the existence of a biological difference between ileal and colonic CD, consistent with previous genetic and clinical observations.
CD4(+)FOXP3(+) regulatory T cells are essential for immune tolerance, and murine studies suggest that their dysfunction can lead to type 1 diabetes (T1D). Human studies assessing regulatory T cell ...dysfunction in T1D have relied on analysis of FOXP3-expressing cells. Recently, distinct subsets of CD4(+)FOXP3(+) T cells with differing function were identified. Notably, CD45RA(-)CD25(int)FOXP3(low) T cells lack suppressive function and secrete the proinflammatory cytokine IL-17. Therefore, we evaluated whether the relative fractions of CD4(+)FOXP3(+) subsets are altered in new-onset T1D subjects. We report that children with new-onset T1D have an increased proportion of CD45RA(-)CD25(int)FOXP3(low) cells that are not suppressive and secrete significantly more IL-17 than other FOXP3(+) subsets. Moreover, these T1D subjects had a higher proportion of both CD4(+) and CD8(+) T cells that secrete IL-17. The bias toward IL-17-secreting T cells in T1D suggests a role for this proinflammatory cytokine in the pathogenesis of disease.
Genetic studies have been tremendously successful in identifying genomic regions associated with a wide variety of phenotypes, although the success of these studies in identifying causal genes, their ...variants, and their functional impacts has been more limited.
We identified 145 genes from IBD-associated genomic loci having endogenous expression within the intestinal epithelial cell compartment. We evaluated the impact of lentiviral transfer of the open reading frame (ORF) of these IBD genes into the HT-29 intestinal epithelial cell line via transcriptomic analyses. By comparing the genes in which expression was modulated by each ORF, as well as the functions enriched within these gene lists, we identified ORFs with shared impacts and their putative disease-relevant biological functions.
Analysis of the transcriptomic data for cell lines expressing the ORFs for known causal genes such as HNF4a, IFIH1, and SMAD3 identified functions consistent with what is already known for these genes. These analyses also identified two major clusters of genes: Cluster 1 contained the known IBD causal genes IFIH1, SBNO2, NFKB1, and NOD2, as well as genes from other IBD loci (ZFP36L1, IRF1, GIGYF1, OTUD3, AIRE and PITX1), whereas Cluster 2 contained the known causal gene KSR1 and implicated DUSP16 from another IBD locus. Our analyses highlight how multiple IBD gene candidates can impact on epithelial structure and function, including the protection of the mucosa from intestinal microbiota, and demonstrate that DUSP16 acts a regulator of MAPK activity and contributes to mucosal defense, in part via its regulation of the polymeric immunoglobulin receptor, involved in the protection of the intestinal mucosa from enteric microbiota.
This functional screen, based on expressing IBD genes within an appropriate cellular context, in this instance intestinal epithelial cells, resulted in changes to the cell's transcriptome that are relevant to their endogenous biological function(s). This not only helped in identifying likely causal genes within genetic loci but also provided insight into their biological functions. Furthermore, this work has highlighted the central role of intestinal epithelial cells in IBD pathophysiology, providing a scientific rationale for a drug development strategy that targets epithelial functions in addition to the current therapies targeting immune functions.
•Validated biomarkers for predicting therapy response in autoimmunity are lacking.•Lack of standardization and independent validation impedes biomarker development.•Immune biomarkers must integrate ...patient-specific genetic and environmental factors.•Optimal pairing of patients with therapies requires multi-platform strategies.
Autoimmunity results from an intersection of genetic and environmental factors that cause patient-specific perturbations in immune homeostasis. Defining autoimmunity-associated genetic factors has led to mechanistic insight into underlying etiologies, and the development of many biologic therapies that target the immune system. However, biomarker-informed pairing of patients with optimal biologic therapy is lacking. Here, we discuss platforms commonly used to find biomarkers that predict response to biologic therapy in autoimmunity and highlight recent biomarker discoveries. We also outline how the lack of assay standardization is a barrier to successful biomarker validation. Finally, we argue that the successful development of companion biomarkers for biologic therapy requires collaborative approaches that integrate multiple platforms and enable comprehensive measurement of multiple immune pathways.
Regulatory T cell (Treg) therapy is a potential curative approach for a variety of immune-mediated conditions, including autoimmunity and transplantation, in which there is pathological tissue ...damage. In mice, IL-33R (ST2)-expressing Tregs mediate tissue repair by producing the growth factor amphiregulin, but whether similar tissue-reparative Tregs exist in humans remains unclear. We show that human Tregs in blood and multiple tissue types produced amphiregulin, but this was neither a unique feature of Tregs nor selectively upregulated in tissues. Human Tregs in blood, tonsil, synovial fluid, colon, and lung tissues did not express ST2, so ST2
Tregs were engineered via lentiviral-mediated overexpression, and their therapeutic potential for cell therapy was examined. Engineered ST2
Tregs exhibited TCR-independent, IL-33-stimulated amphiregulin expression and a heightened ability to induce M2-like macrophages. The finding that amphiregulin-producing Tregs have a noneffector phenotype and are progressively lost upon TCR-induced proliferation and differentiation suggests that the tissue repair capacity of human Tregs may be an innate function that operates independently from their classical suppressive function.
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