Dendritic cells in plasmodium infection

Infection with Plasmodium parasites (malaria) contributes greatly to morbidity and mortality in affected areas. Interaction of the protozoan with the immune system has a critical role in the pathogenesis of the disease, but may also hold a key to containing parasite numbers through specific immune responses, which vaccine development aims to harness. A central player in the generation of such immune responses is the dendritic cell. However, Plasmodium parasites appear to have profound activating and suppressing effects on dendritic cell function, which may enhance immunopathology or facilitate the parasite’s survival by depressing beneficial immunity. Furthermore, immune responses to other infections and vaccines may be impaired. A greater understanding of the effects of the parasite on dendritic cells will contribute to insight and potential defeat of this infectious disease

Role of antibodies and T cells in pigeon fanciers' lung

Introduction: Pigeon fanciers’ lung (PFL) is one of the most common forms of hypersensitivity pneumonitis (HP) in the UK. Generally it is considered that PFL is caused by immune complexes, however, this does not explain why some fanciers are asymptomatic despite the presence of high levels of anti-avian antigen antibodies in their serum. Pigeon intestinal mucin (PIM) is considered to be an important antigen in PFL. Thus this study was designed in order to understand the role of specific antibodies and T cells in the pathogenesis of PFL. Methods: Anti-avian IgG and IgG subclass responses among 50 symptomatic and 50 asymptomatic pigeon fanciers were determined by ELISA and the functional affinity of IgG1 and IgG2 against a range of pigeon antigens was determined by inhibition ELISA and microcalimetry. Mucin-specific T cell clones were also generated from pigeon fanciers and T cell phenotypes and cytokine profile of these cells were identified. Results: The median titres of IgG1 and IgG2 against all the pigeon antigens tested was always higher in asymptomatic than symptomatic fanciers and these differences were significant for anti-PS IgG1 (P=0.04), anti-PDF IgG2 (P=0.028), anti-PDO IgG2 (P=0.04) and anti-PIS IgG2 (P=0.03). The functional affinity of IgG1 and IgG2 against PDO was higher in symptomatic individuals as compared to asymptomatic fanciers (P=0.006 and P=0.002, respectively) whilst the functional affinity of anti-PDF IgG2 was also significantly higher in these patients (P≤0.001). Symptomatic fanciers were also significantly more likely to have high ΔH and thus had higher avidity antibodies against PDO (P=0.044). 12 T cell clones specific for t mucin also were generated from an asymptomatic fancier and 90-96% of clone 04, 22, 23 were CD4-CD8- double negative (DN). Conclusion: The data suggests that the magnitude of the serum antibody response cannot determine the development of the disease and as symptomatic fanciers had higher IgG antibody avidities and therefore immune complexes in individuals with PFL may have a stronger composition and bonds. In addition, this is the first demonstration of the use of ITC to measure antibody avidity in a clinical situation. This is a rapid and simple method of measuring antibody avidity and has a diagnostic potential in PFL. Finally t mucin-specific T cell clones with double negative phenotype may have a crucial role in immune regulation in asymptomatic fanciers and can be one of the reasons why these individuals do not have any symptoms in spite of having high antibody responses.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Exercise-Conditioned Plasma and DNMT3B Concentration in PBMCs

DNA methylation is modifiable by acute and chronic exercise. DNA methyltransferases (DNMT) catalyze this process; however, there is a lack of literature concerning the specific mechanisms by which exercise‐induced modifications occur. Interleukin 6 (IL‐6) stimulation of various cell lines has been shown to augment DNMT expression and nuclear translocation, which suggests a possible pathway by which exercise is able to elicit changes in epigenetic enzymes. The present study sought to elucidate the response of thede novomethyltransferases DNMT3A and DNMT3B to circulatory factors found in plasma isolated from whole blood before and after 120‐min of treadmill running at an intensity of 60% of individual velocity at(v) interspersed with 30‐sec sprints at 90% of vevery 10‐min. Peripheral blood mononuclear cells (PBMCs) isolated from a resting participant were incubated with plasma isolated from exercising participants (n=10) or recombinant IL‐6 (rIL‐6), followed by nuclear protein extraction and quantification of DNMT3A and DNMT3B concentrations. Nuclear concentrations of DNMT3B significantly decreased following the experimental protocol (P=0.03), with no change observed in DNMT3A (P=0.514).Various concentrations of rIL‐6 caused an elevation in both DNMT3A and DNMT3B nuclear concentration compared with the blank control. The conflicting results between exercising and rIL‐6 conditions suggests that IL‐6 does regulate DNMT nuclear transport, however, other plasma mediators may also exert significant influence on the nuclear concentrations of these enzymes

Tracking Circulating HLA-Specific IgG-Producing Memory B Cells with the B-Cell ImmunoSpot Assay

Donor-specific antibodies (DSA) against human leukocyte antigen (HLA) molecules are a major risk factor for rejection of transplanted organs (in antibody-mediated rejection [ABMR]), particularly in patients who have prior sensitization or receive insufficient immunosuppression through minimization or noncompliance. These DSA are measured routinely in the serum of patients prior to transplantation mainly using bead-based technologies or cell-based assays. However, the absence of detectable serum DSA does not always reflect the absence of sensitization or histologically defined ABMR, and so it has been proposed that the detection and measurement of memory B cells capable of secreting antibodies against donor HLA antigens could be carried out using B-cell ImmunoSpot, to better inform the degree of immune sensitization of transplant patients prior to as well as after transplantation. Such an assay is described here.</p

Intelligent Leukaemia Diagnosis with Bare-Bones PSO based Feature Optimization

In this research, we propose an intelligent decision support system for acute lymphoblastic leukaemia (ALL) diagnosis using microscopic images. Two Bare-bones Particle Swarm Optimization (BBPSO) algorithms are proposed to identify the most significant discriminative characteristics of healthy and blast cells to enable efficient ALL classification. The first BBPSO variant incorporates accelerated chaotic search mechanisms of food chasing and enemy avoidance to diversify the search and mitigate the premature convergence of the original BBPSO algorithm. The second BBPSO variant exhibits both of the abovementioned new search mechanisms in a subswarm-based search. Evaluated with the ALL-IDB2 database, both proposed algorithms achieve superior geometric mean performances of 94.94% and 96.25%, respectively, and outperform other metaheuristic search and related methods significantly for ALL classification

Efficient delivery of small interfering RNA for inhibition of IL-12p40 expression in vivo

Background: RNA interference is an evolutionary conserved immune response mechanism that can be used as a tool to provide novel insights into gene function and structure. The ability to efficiently deliver small interfering RNA to modulate gene expression in vivo may provide new therapeutic approaches to currently intractable diseases. Methods: In vitro, siRNA targeting IL-12p40 was delivered to the murine macrophage cell line (J774A.1) encapsulated in a liposome with an IL-12 inducing agent (LPS/IFN-γ) over a number of time points. Controls included a variety of non-target specific siRNA reagents. Supernatants were analyzed for cytokine production while the cells were removed for mRNA profiling. In vivo, siRNA-targeting IL-12p40 was delivered to the murine peritoneal cavity in a therapeutic fashion, after endotoxin (LPS) challenge. Cells from the peritoneal cavity were removed by lavage and analyzed by flow cytometry. Levels of IL-12 present in lavage and in serum were also examined by ELISA. Results: In this report, we show that IL-12p40 siRNA can specifically silence macrophage expression of IL-12p40 mRNA and IL-12p70 protein in vitro. We extend this finding to demonstrate that delivery of liposome encapsulated siRNA targeting IL-12p40 to the murine peritoneal cavity can modulate an inflammatory stimulus in vivo. Furthermore, specific siRNA can be used therapeutically after endotoxin challenge to reduce both the local and systemic inflammatory response. Thus, the delivery of siRNA can be used to elicit specific non-permanent inhibition of endogenous protein expression. Conclusion: In vitro silencing of IL-12p40 using siRNA at selected doses leads to specific knockdown of IL-12p70 protein production without inducing type I interferons. Furthermore, siRNA targeting murine IL-12p40 can be used therapeutically to counter an inflammatory response in vivo

Revisiting the Elusive Hepatitis C Vaccine

The impactful discovery and subsequent characterisation of hepatitis C virus (HCV), an RNA virus of the flavivirus family, led to the awarding of the 2020 Nobel Prize in Physiology or Medicine to Harvey J. Alter, Michael Houghton and Charles M. Rice [...

Efficient delivery of small interfering RNA for inhibition of IL-12p40 expression in vivo

Background: RNA interference is an evolutionary conserved immune response mechanism that can be used as a tool to provide novel insights into gene function and structure. The ability to efficiently deliver small interfering RNA to modulate gene expression in vivo may provide new therapeutic approaches to currently intractable diseases. Methods: In vitro, siRNA targeting IL-12p40 was delivered to the murine macrophage cell line (J774A.1) encapsulated in a liposome with an IL-12 inducing agent (LPS/IFN-γ) over a number of time points. Controls included a variety of non-target specific siRNA reagents. Supernatants were analyzed for cytokine production while the cells were removed for mRNA profiling. In vivo, siRNA-targeting IL-12p40 was delivered to the murine peritoneal cavity in a therapeutic fashion, after endotoxin (LPS) challenge. Cells from the peritoneal cavity were removed by lavage and analyzed by flow cytometry. Levels of IL-12 present in lavage and in serum were also examined by ELISA. Results: In this report, we show that IL-12p40 siRNA can specifically silence macrophage expression of IL-12p40 mRNA and IL-12p70 protein in vitro. We extend this finding to demonstrate that delivery of liposome encapsulated siRNA targeting IL-12p40 to the murine peritoneal cavity can modulate an inflammatory stimulus in vivo. Furthermore, specific siRNA can be used therapeutically after endotoxin challenge to reduce both the local and systemic inflammatory response. Thus, the delivery of siRNA can be used to elicit specific non-permanent inhibition of endogenous protein expression. Conclusion: In vitro silencing of IL-12p40 using siRNA at selected doses leads to specific knockdown of IL-12p70 protein production without inducing type I interferons. Furthermore, siRNA targeting murine IL-12p40 can be used therapeutically to counter an inflammatory response in vivo