The mucosal system, which forms a barrier between internal organ systems and the external environment, is frequently exposed to pathogenic microorganisms. Immunoglobulin A (IgA) antibody secreting cells (ASCs) localize in the lamina propria, and produce IgA antibodies which help protect mucosal tissues. The concept of a common mucosal immune system in which IgA ASCs have the ability to populate any mucosal site has been proposed (1, 2). However, recent research has suggested that IgA ASCs primed in different mucosal sites might possess different sets of chemokine receptors, and therefore migrate specifically to particular mucosal locations (3). In this study, the specific compartmentalization of IgA ASCs in two mouse salivary glands: sublingual gland (SLG), and submandibular gland (SMG) was studied. It was observed that SLG had 12 times more IgA ASCs per gram of gland than that of SMG (p<0.01). This suggested that IgA ASCs migrated to the two salivary glands with different efficiencies. Since the migration of lymphocytes is mediated by interactions between tissue specific chemokines and chemokine receptors, I hypothesized that the specific compartmentalization of IgA ASCs in the SLG and SMG was mediated by the differential expression of IgA ASC attracting chemokines. Quantitative PCR was used and showed that SLG expressed high levels of CCL28 and its receptor CCR10, which correlated to the distribution of IgA ASCs in the two salivary glands. In agreement with QPCR data, reduced levels of IgA ASCs were found in the SLG of CCR10 deficient mice when compared to wild type (WT) mice. Adoptive transfer of CCR10 deficient mice with WT spleen cells reconstituted the WT phenotype. It was therefore concluded that the interaction between CCL28 and CCR10 play an important role in mediating the migration of IgA ASCs into SLG. These results suggested that the accumulation of IgA ASC to distinct salivary glands is a highly selective process. These data also suggested that homing within mucosal sites is not common but rather a highly regulated process with specific subsets of cells homing to different tissues within the mucosal immune system.

Celiac Disease (CD) is an autoimmune disorder that emerges due to the ingestion of gluten, a protein found in a variety of common grains such as wheat, rye, and barley. Approximately 1 in 100 individuals in the US suffer from CD, making it the most commonly diagnosed gastrointestinal disorder (Ciclitira et. al., 2005). These proline-rich gluten peptides are resistant to proteolysis and accumulate in the duodenum of the small intestine. Once in the duodenum, these peptides illicit an autoimmune response resulting in villous atrophy. Current treatment for CD requires a rigorous adherence to a gluten-free diet. Nevertheless, gluten-containing grains are ubiquitous in the western diet, so accidental exposure to gluten remains as a persistent threat. The approach of this project centers on genetically engineering a strain Lactobacillus reuteri to secrete a Myxococcus xanthus prolyl endopeptidase (PEP), an enzyme that hydrolyzes a peptide bond adjacent to an internal proline residue. The data from this study revealed that recombinant M. xanthus PEP purified from E. coli was effective in degrading Suc-Ala-Pro-pNA, a chromogenic substrate containing an internal proline residue. When introduced into a L. reuteri expression vector, mutations accumulated in the vector over the course of 5 days. These data suggested that toxicity was possibly associated with M. xanthus PEP and the amyl signal peptide.

Background: A hallmark of Notch signaling is its variable role in tumor biology, ranging from tumor-suppressive to oncogenic effects. Until now, the mechanisms and functions of Notch pathways in bladder cancer (BCa) are still unclear. Methods: We used publicly available data from the GTEx and TCGA-BLCA databases to explore the role of the canonical Notch pathways in BCa on the basis of the RNA expression levels of Notch receptors, ligands, and downstream genes. For statistical analyses of cancer and non-cancerous samples, we used R software packages and public databases/webservers. Results: We found differential expression between control and BCa samples for all Notch receptors (NOTCH1, 2, 3, 4), the delta-like Notch ligands (DLL1, 3, 4), and the typical downstream gene hairy and enhancer of split 1 (HES1). NOTCH2/3 and DLL4 can significantly differentiate non-cancerous samples from cancers and were broadly altered in subgroups. High expression levels of NOTCH2/3 receptors correlated with worse overall survival (OS) and shorter disease-free survival (DFS). However, at long-term (>8 years) follow-up, NOTCH2 expression was associated with a better OS and DFS. Furthermore, the cases with the high levels of DLL4 were associated with worse OS but improved DFS. Pathway network analysis revealed that NOTCH2/3 in particular correlated with cell cycle, epithelial–mesenchymal transition (EMT), numbers of lymphocyte subtypes, and modulation of the immune system. Conclusions: NOTCH2/3 and DLL4 are potential drivers of Notch signaling in BCa, indicating that Notch and associated pathways play an essential role in the progression and prognosis of BCa through directly modulating immune cells or through interaction with cell cycle and EMT.

Celiac disease (CD), an autoimmune disorder affecting millions of Americans, poses significant obstacles leading to a normal life. With no known cure, adherence to a strict glutenfree diet (GFD) is essential. However, the cost and limited availability of gluten-free alternatives can burden individuals with CD. Additionally, factors such as socioeconomic status, nutrient deficiencies, and the nature of the disease may contribute to mental health issues. This study aimed to investigate the influence of adherence to a GFD on depression in CD patients. The prevalence of depression among individuals with CD from diverse backgrounds was examined, along with the analysis of macro- and micronutrient distribution and the impact of the GFD. Data from the National Health and Nutrition Examination Survey spanning three cycles (2009-2014) were extracted, including 70 CD patients and 271 participants reporting general gluten issues. The dataset was analyzed using SAS v9.4 (SAS Institute, Inc., Cary, NC) with the three cycles merged using a unique identifier sequential number. Sample weights were applied to mitigate bias in national estimates due to unequal probability of selection, while oversampling was utilized to enhance the study’s reliability when examining subgroups or minorities. Survey weight and sampling design considerations were incorporated into the SAS syntax to safeguard participants’ privacy, as managed by the National Center for Health Statistics. Multiple linear regression analysis revealed no significant association between depression and adherence to the GFD or CD; however, ethnicity showed significance. Celiac disease exhibited a prevalence of 0.12% among White individuals, 3-6 times higher than other ethnic groups, and was twice as prevalent in females compared to males. Notably, deficiencies in macro- and micronutrients among CD and GFD cases were observed. Carbohydrate intake exhibited a negative association with GFD consumers and those with CD, while individuals adhering to a GFD showed an association with decreased polyunsaturated fat consumption, yet within adequate intakes. Deficiencies in micronutrients such as thiamin, vitamins B12, D, and E, and calcium were also observed within GFD group, while a low sodium intake was observed among CD group. This study provides insights into the complex interplay between diet, mental health, and CD management.

P2X7 receptors are ion-gated channels activated by ATP. Under pathological conditions, the extensive release of ATP induces sustained P2X7 receptor activation, culminating in induction of proinflammatory pathways with inflammasome assembly and cytokine release. These inflammatory conditions, whether occurring peripherally or in the central nervous system (CNS), increase blood-brain-barrier (BBB) permeability. Besides its well-known involvement in neurodegeneration and neuroinflammation, the P2X7 receptor may induce BBB disruption and chemotaxis of peripheral immune cells to the CNS, resulting in brain parenchyma infiltration. For instance, despite common effects on cytokine release, P2X7 receptor signaling is also associated with metalloproteinase secretion and activation, as well as migration and differentiation of T lymphocytes, monocytes and dendritic cells. Here we highlight that peripheral immune cells mediate the pathogenesis of Multiple Sclerosis and Parkinson’s and Alzheimer’s disease, mainly through T lymphocyte, neutrophil and monocyte infiltration. We propose that P2X7 receptor activation contributes to neurodegenerative disease progression beyond its known effects on the CNS. This review discusses how P2X7 receptor activation mediates responses of peripheral immune cells within the inflamed CNS, as occurring in the aforementioned diseases.

Dendritic cells (DCs), as professional antigen-presenting cells, are members of the innate immune system and function as key players during the induction phase of adaptive immune responses. Uptake, processing, and presentation of antigens direct the outcome toward either tolerance or immunity. The cells of the immune system are among the most highly radiosensitive cells in the body. For high doses of ionizing radiation (HD-IR) both immune-suppressive effects after whole body irradiation and possible immune activation during tumor therapy were observed. On the other hand, the effects of low doses of ionizing radiation (LD-IR) on the immune system are controversial and seem to show high variability among different individuals and species. There are reports revealing that protracted LD-IR can result in radioresistance. But immune-suppressive effects of chronic LD-IR are also reported, including the killing or sensitizing of certain cell types. This article shall review the current knowledge of radiation-induced effects on the immune system, paying special attention to the interaction of DCs and T cells.

The immune system plays critical roles in the human heart in health, injury, and disease. Of the major immune cell types that reside in the cellular landscape of the myocardium, macrophages are particularly prevalent. Macrophages are responsible for a wide range of biological processes, including immunosurveillance, maintaining cardiomyocyte homeostasis, and regulating electrical conduction of cardiomyocytes. Within certain pathophysiological contexts such as Myocardial Infarction, they also facilitate the initiation and resolution of inflammation, and regulate cardiac repair and remodeling, significantly affecting injury trajectory and outcome. In addition to these already intricate interactions, both the immune system and the cardiovascular system are known to display sex-specific disparities, particularly under pathophysiological conditions, which may have important ramifications for patient health. The complex interplay within the human cardiac immune system has become increasingly evident, and therefore, understanding the interactions along the immune-cardiac axis and how they may vary among patient populations is of great interest to the clinical and research communities. An opportunity to study these interactions is presented by leveraging recent advances in induced pluripotent stem cell technology to engineer iPSC-derived models, which enable patient-specific studies of immune-cardiac interactions in a highly controllable environment. In this dissertation, we engineer patient-specific iPSC-derived models for studying immune-cardiac interactions. In Chapters 1 and 2, we introduce the importance of engineered models for studying the functions of the human heart, review the current state of the field, and identify key ways in which these models can be advanced. In Chapter 3, we create an iPSC-derived engineered cardiac tissue model with a resident macrophage population and investigate its impact on the function of the model under healthy conditions. In Chapter 4, we illustrate the capacity of iPSC-derived models to be patient-specific by showing how iPSC-derived macrophages demonstrate sex-specific dimorphism that emerges in response to an inflammatory stimulus. Finally, in Chapter 5, we present the optimization of an engineered model of myocardial ischemia reperfusion injury, which can be applied in future studies to study immune-cardiac interactions in the context of injury. Collectively, this dissertation provides a set of engineered tools that can be leveraged for improved understanding of the relationship between the heart and the immune system.

Infectious diseases caused by bacteria, fungi, viruses and parasites have affected humans historically. Infectious diseases remain a major cause of premature death and a public health concern globally with increased mortality and significant economic burden. Unvaccinated individuals, people with suppressed and compromised immune systems are at higher risk of suffering from infectious diseases. In spite of significant advancements in infectious diseases research, the control or treatment process faces challenges. The mucosal immune system plays a crucial role in safeguarding the body from harmful pathogens, while being constantly exposed to the environment. To develop treatment options for infectious diseases, it is vital to understand the immune responses that occur during infection. The two infectious diseases presented here are: i) Helicobacter pylori infection and ii) human immunodeficiency (HIV) and human papillomavirus (HPV) co-infection. H pylori, is a bacterium that colonizes the stomach and causes gastric cancer in 1-2% but is beneficial for protection against allergies and gastroesophageal diseases. An estimated 85% of H pylori colonized individuals show no detrimental effects. HIV is a virus that causes AIDS, one of the deadliest and most persistent epidemics. HIV-infected patients are at an increased risk of co-infection with HPV, and report an increased incidence of oral cancer. The goal of this thesis is to elucidate the host immune responses in infectious diseases via the use of computational and mathematical models. First, the thesis reviews the need for computational and mathematical models to study the immune responses in the course of infectious diseases. Second, it presents a novel sensitivity analysis method that identifies important parameters in a hybrid (agent-based/equation-based) model of H. pylori infection. Third, it introduces a novel model representing the HIV/HPV coinfection and compares the simulation results with a clinical study. Fourth, it discusses the need of advanced modeling technologies to achieve a personalized systems wide approach and the challenges that can be encountered in the process. Taken together, the work in this dissertation presents modeling approaches that could lead to the identification of host immune factors in infectious diseases in a predictive and more resource-efficient manner. / Doctor of Philosophy / Infectious diseases caused by bacteria, fungi, viruses and parasites have affected humans historically. Infectious diseases remain a major cause of premature death and a public health concern globally with increased mortality and significant economic burden. These infections can occur either via air, travel to at-risk places, direct person-to-person contact with an infected individual or through water or fecal route. Unvaccinated individuals, individuals with suppressed and compromised immune system such as that in HIV carriers are at higher risk of getting infectious diseases. In spite of significant advancements in infectious diseases research, the control and treatment of these diseases faces numerous challenges. The mucosal immune system plays a crucial role in safeguarding the body from harmful pathogens, while being exposed to the environment, mainly food antigens. To develop treatment options for infectious diseases, it is vital to understand the immune responses that occur during infection. In this work, we focus on gut immune system that acts like an ecosystem comprising of trillions of interacting cells and molecules, including membars of the microbiome. The goal of this dissertation is to develop computational models that can simulate host immune responses in two infectious diseases- i) Helicobacter pylori infection and ii) human immunodeficiency virus (HIV)-human papilloma virus (HPV) co-infection. Firstly, it reviews the various mathematical techniques and systems biology based methods. Second, it introduces a "hybrid" model that combines different mathematical and statistical approaches to study H. pylori infection. Third, it highlights the development of a novel HIV/HPV coinfection model and compares the results from a clinical trial study. Fourth, it discusses the challenges that can be encountered in adapting machine learning based computational technologies. Taken together, the work in this dissertation presents modeling approaches that could lead to the identification of host immune factors in infectious diseases in a predictive and more resourceful way.

Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / Electromagnetic fields are present wherever electricity is created. The frequency range of these electromagnetic fields is from extremely low to extremely high. The fields present in domestic areas fall within the extremely low frequency range. These fields are created by domestic electrical appliances and telecommunication. There has been much debate on the effect of exposure to these fields on human health. Research has not yet been able to prove adverse effect of these fields on human health. In fact, the benefits of magneto therapy has been recognized and used for several decades. Recently a specific electromagnetic signal has been under investigation for its ability to stimulate the immune response. This signal is produced by a patented generator, called Immunent Activator. Studies performed with the Immunent Activator signal on farm animals revealed increased feed conversion and decreased intestinal lesions of animals with intestinal infections. Most of the research was performed on fish and fowls and evidence of similar findings in mammals is lacking. In the current study, mice were exposed to the Immunent BV signal for seven days, after which immune cell counts were performed and compared to the immune cell counts of a control group of mice which received no electromagnetic exposure. It was found that the T-lymphocyte population of immune cells in the exposed group of mice was statistically significantly higher than that of the control group. The neutrophil count was statistically significantly lower in the exposed group compared to the control group. These findings revealed evidence of immune stimulation in the mice which were exposed to the Immunent Activator signal. Suggestions for further research could be made with regard to specific mechanisms of immune stimulation. The findings of this and other related studies hold benefits for the farming and health industry.

The study sought to analyse the perception of HIV/AIDs by clients attending a community clinic in Mutale area in Limpopo province by interviewing them as they are attending the clinic. The study sought to determine ideas, beliefs or images clients have as a result of how they see or understand HIV/AIDS. The major inferences drawn from this study are that clients still need information on the rights of HIV/AIDS client and the immune system. Feedback from the study is indicative of culture and beliefs playing a major role in diseases epidemic. / Health Studies / MA (HEALTH STUDIES)