Enoyl-acyl carrier protein (ACP) reductase from chloroplast nonaggregated fatty acid synthetase (FAS) of Euglena gracilis variety bacillaris was purified to a single band on a denaturing polyacrylamide gel. The enzyme was partially characterized with respect to substrate specificity, reduced nucleotide requirement, and the effect of ACP and Ca$\sp{++}$ on enzyme activity. Antibodies against the purified protein were raised in hens and isolated from eggs. ACP was purified from Euglena in yields of about 1mg/100g (wet weight) of cells. Antibodies were raised against the purified protein. ACP antibodies inhibited the Euglena chloroplast FAS using Euglena or E. coli ACP as a substrate. Comparisons with other ACPs included the following items: biological activity, pI, behavior in size exclusion media, and amino acid sequence of the N-terminal portion of the molecule. ACPs from E. coli and Euglena have been shown to interact with melittin, a cationic peptide from bee venom. E. coli ACP is a small (Mr, 8847), acidic, Ca$\sp{++}$-binding protein which possesses some characteristics resembling those of regulatory Ca$\sp{++}$-binding proteins including interaction with melittin. Melittin inhibited activity of the nonaggregated FAS from Euglena using either E. coli or Euglena ACP as a substrate. The peptide also inhibited activity of the aggregated FAS from Euglena. Antibodies against melittin were raised. Anti-melittin inhibited activity of both the nonaggregated and aggregated FAS enzyme systems from Euglena relative to nonimmune antibody. Investigation of inhibition of the nonaggregated FAS enzyme system demonstrated that acetyl-CoA-ACP transacylase, malonyl-CoA-ACP transacylase, and keto-acyl-ACP synthetase activities were inhibited to different degrees by anti-melittin antibodies, while keto-acyl-ACP reductase and enoyl-ACP reductase enzyme activities were not inhibited.

Tumor necrosis factor α (TNFα) is a pleiotropic cytokine that is predominantly produced by activated macrophages. The effects of TNFα are as diverse as the cells with which it interacts, e.g., stimulating fibroblast growth, exerting cytotoxic/cytostatic; activity against various human and murine cell lines, promoting inflammation through upregulation of endothelial adhesion molecules and IL-8 production. Yet TNFα is best known, and in fact was originally described, for its role in the bacterial-induced hemorrhagic necrosis of tumors and exacerbation of septic shock in which aberrant TNFα production leads to vascular collapse, cachexia, multiple organ failure, and ultimately death in as many as 100,000 people each year in the United States alone. LPS, a component of the outer cell wall of gram-negative bacteria, is the principal inducer of macrophage TNFα production. TNFα production can be enhanced by IFNγ which also induces upregulation of TNFα receptors allowing for the establishment of a TNFα autocrine loop. It has been hypothesized that autocrine TNFα stimulation plays a critical role in the induction of macrophage effector function, e.g., nitric oxide production. This dissertation represents efforts to evaluate the respective roles of the TNFα receptors in the induction of macrophage effector function, in addition to examining the mechanism by which autocrine TNFα exerts its effects on macrophages. Exploiting the species specificity of the murine TNFα receptor type 2 (TNF-R2), splenic macrophages were stimulated with human TNFα (which binds to TNF-R1 but not TNF-R2), in the presence of IFNγ. Human TNFα was effective in the induction of nitric oxide production, albeit at concentrations 12.5-fold greater than those required by murine TNFα to achieve the same result. Addition of anti-TNF-R1 completely inhibited the murine TNFα mediated induction of macrophage effector function. However, treatment with anti-TNF-R2 resulted in partial inhibition of macrophage activation. Taken together this data suggests that the primary TNFα mediated signals involved in macrophage activation are transduced through TNF-R1, although TNF-R2 appears to contribute to the intensity of the macrophage response. To evaluate the role of autocrine TNFα signaling in the induction of macrophage effector function, immortalized macrophages from normal C57Bl/6J mice (B6/J2) and C57Bl/6J mice containing gene targeted disruptions of the TNF-R1 and TNF-R2 genes (TRN) were stimulated under CD14-dependent and CD14-independent conditions. Although the B6/J2 and TRN clones mounted similar NO responses to LPS in the presence of serum, the TRN macrophages generated a weak nitric oxide response as compared to B6/J2 when stimulated with LPS under serum-free conditions. The involvement of TNFα autocrine stimulation in the CD14-independent activation was corroborated by the ability of soluble TNF-R1 to inhibit the response of B6/J2 macrophages to LPS in serum-free medium. CD14-independent LPS stimulation of TRN and B6/J2 resulted in equivalent levels of IL-1β, TNFα, and NOS gene expression, as determined by RT-PCR, and in release of equivalent amounts of biologically active TNFα. However, western blot analysis revealed that NOS protein production by TRN was as much as 50% less than that produced by B6/J2. These results indicate that autocrine TNFα stimulation contributes to the signaling pathways initiated by ligation of CD14-independent LPS receptors and may be involved in NOS post-transcriptional regulation.

The pathophysiology of chronic morphine on the immune system, especially on the cells of the innate immune system that leads to an immune compromise state has not been fully elucidated. The cells of the innate immune system are the first line of defense in mounting an immune response needed in infections, inflammation, cancer development, etc. One of the ways by which these innate immune cells act is by the production of cytokines with direct effects and to also recruit other immune cells, as required. A balance of pro- and anti-inflammatory cytokines is necessary for immune competence. I hypothesized that chronic morphine would act via a classical opioid receptor to stimulate the PI3K/Akt/Gsk3β pathway to produce predominantly anti-inflammatory cytokines. Cytokine gene expression levels were assessed via RT-PCR; Akt and Gsk3β protein levels measured using indirect ELISA. The data suggests that chronic morphine causes a significant reduction in IL-6 production, but does not act via the Akt/Gsk3β pathway or the classical opioid receptor to cause this effect in microglia cells.

Sepsis is the body’s response to an overwhelming infection and is a serious consequence of critical illness. It can cause tissue damage, organ failure, and death. Sepsis continues to have an unacceptably high mortality rate, due to the lack of effective treatments. Specific therapeutic targets for sepsis remain elusive since the complex functional changes that result in a septic state remain poorly understood. Macrophage Scavenger Receptor A (SRA, CD204) is a surface receptor that binds negatively charged, endogenous and exogenous ligands. We have discovered that SRA plays a significant role in the pathophysiology of sepsis. We have shown that mice with SRA have increased inflammation, decreased survival, and increased bacterial burden compared to SRA deficient mice. We have also found an increase in the expression of SRA on monocytes and macrophages in septic wild type mice. To determine the mechanism responsible for increased SRA expression in sepsis we treated a mouse macrophage cell line, (J774a.1), with mediators that stimulate toll like receptors (TLRs), innate immune receptors which are activated in sepsis. The cells were cultured with ultra pure LPS (a TLR 4 ligand), PAM3CSK4 (a TLR 2 ligand), glucan (a Dectin-1 ligand), ultra pure LPS and PAM3CSK4, or ultra pure LPS and glucan for 24 hours. The cells were stained with an SRA antibody, and flow cytometry was used to measure the SRA expression for each treatment group. LPS treatment alone resulted in a significant increase in SRA expression when compared to control cells. Specifically, LPS increased SRA expression by 53.4% compared to media alone (p

Sympathetic nerves are important for renal physiology and sepsis pathophysiology. A recent study showed sprouting of sympathetic nerves in spleen of septic mice. This study was done to test if renal sprouting of sympathetic nerves also happens and to investigate renal morphology in septic mice. Cecal ligation and puncture (CLP) was used to induce sepsis and kidneys were removed for evaluation. Bowman’s space was diminished with cortical bubble cells present suggestive of acute renal pathology, however, renal function was unchanged. Acute sepsis did not affect either renal sympathetic innervation or non-neuronal cholinergic cells. Mouse kidneys had more epinephrine (EPI) than norepinephrine (NE) in both groups. This is most likely due to uptake of epinephrine by renal sympathetic nerves and may have no correlation with sepsis. In conclusion, septic mice showed minor renal pathology and no evidence of acute sympathetic nerve sprouting. Further studies are needed to understand the mechanism and consequences of elevated EPI in mice kidney.

abstract: Understanding the consequences of changes in social networks is an important an- thropological research goal. This dissertation looks at the role of data-driven social networks on infectious disease transmission and evolution. The dissertation has two projects. The first project is an examination of the effects of the superspreading phenomenon, wherein a relatively few individuals are responsible for a dispropor- tionate number of secondary cases, on the patterns of an infectious disease. The second project examines the timing of the initial introduction of tuberculosis (TB) to the human population. The results suggest that TB has a long evolutionary history with hunter-gatherers. Both of these projects demonstrate the consequences of social networks for infectious disease transmission and evolution. The introductory chapter provides a review of social network-based studies in an- thropology and epidemiology. Particular emphasis is paid to the concept and models of superspreading and why to consider it, as this is central to the discussion in chapter 2. The introductory chapter also reviews relevant epidemic mathematical modeling studies. In chapter 2, social networks are connected with superspreading events, followed by an investigation of how social networks can provide greater understanding of in- fectious disease transmission through mathematical models. Using the example of SARS, the research shows how heterogeneity in transmission rate impacts super- spreading which, in turn, can change epidemiological inference on model parameters for an epidemic. Chapter 3 uses a different mathematical model to investigate the evolution of TB in hunter-gatherers. The underlying question is the timing of the introduction of TB to the human population. Chapter 3 finds that TB’s long latent period is consistent with the evolutionary pressure which would be exerted by transmission on a hunter- igatherer social network. Evidence of a long coevolution with humans indicates an early introduction of TB to the human population. Both of the projects in this dissertation are demonstrations of the impact of var- ious characteristics and types of social networks on infectious disease transmission dynamics. The projects together force epidemiologists to think about networks and their context in nontraditional ways. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2019

Protection from influenza A virus (IAV) challenge requires switched, high affinity Abs derived from long-lived memory B cells and plasma cells. These subsets are generated in germinal centers (GCs), hallmark structures of T helper cell-driven B cell immunity. A full understanding of the acute and persistent GC B cell reaction following respiratory IAV infection is lacking, as is the characterization of IAV-induced T follicular helper (TFH) cells that support GCs. Additionally, it remains unclear as to whether IAV-induced GC B cells are subject to control by regulatory T cells (Tregs). To address this, GC B cell and TFH cell responses were analyzed in mice following pulmonary challenge with IAV. Studies demonstrated that marked GC reactions were induced in lung-draining lymph nodes (dLNs), lung, spleen and nasal-associated lymphoid tissue (NALT), although the magnitude, kinetics, and isotype switching patterns of the response was site-specific, and largely depended on the magnitude of IAV-induced TFH cell populations. TFH cell magnitude peaked prior to that of GC B cells in all tissues, and TFH cells purified from dLNs generated IL-21 and IFN-gamma upon activation, although CD4+CXCR5- T effector cells produced higher levels of all cytokines. IgA+ GC B cells were infrequent in most sites, but composed a significant subset of the switched GC population in NALT. Further, splenectomized mice withstood a lethal recall challenge, suggesting the spleen to be unnecessary for long-term protection. Additionally, GC B cell populations were analyzed at distal time points to assess the understudied, persistent GC B cell response after IAV infection. Our analysis demonstrated that persistent GC B cell populations in mouse lungs directly correlated with infectious dose, pathogenicity of the virus, as well as the presence of long-term CD4+ T cell help. Finally, experiments showed that Tregs contribute to the control of GCs induced in the spleen by IAV challenge. This was demonstrated by a marked increase in the number of total and switched GC B cell numbers when Tregs were either depleted or disrupted in vivo proximal to IAV exposure.

Human γδ T cells expressing Vγ2Vδ2 TCRs monitor foreign- and self-prenyl pyrophosphate metabolites in isoprenoid biosynthesis to mediate immunity to microbes and tumors. Vγ2Vδ2 cells have been used for adoptive cancer immunotherapy with some partial and complete remissions. Most trials have used continuous zoledronate exposure to expand Vγ2Vδ2 cells. Zoledronate inhibits farnesyl pyrophosphate synthase causing isopentenyl pyrophosphate to accumulate that then stimulates Vγ2Vδ2 cells. Because zoledronate exposure is toxic, we hypothesized that a short period of exposure would reduce T cell toxicity but still be sufficient for monocytes uptake. Supporting this hypothesis, pulse zoledronate exposure with IL-2 resulted in more uniform expansion of Vγ2Vδ2 cells with higher purity and cell numbers as compared with continuous exposure. These Vγ2Vδ2 cells also had higher levels of CD107a and perforin and slightly increased tumor cytotoxicity. Importantly, adoptive immunotherapy with Vγ2Vδ2 cells derived by pulse stimulation controlled human PC-3 prostate cancer cells in immunodeficient NSG mice significantly better than those derived by continuous stimulation. Pulse zoledronate stimulation of Vγ2Vδ2 cells with IL-15 also resulted in higher purity and cell numbers. Like with CD8 αβ T cells, IL-15 preserved early memory Vγ2Vδ2 T cell subsets better than IL-2. However, despite this fact, adoptive immunotherapy with Vγ2Vδ2 cells derived with IL-15 showed similar inhibition of PC-3 tumor growth as those derived with IL-2. Thus, pulse zoledronate stimulation maximizes the purity, quantity, and quality of expanded Vγ2Vδ2 cells. This simple modification to existing protocols would likely enhance the effectiveness of adoptively transferred Vγ2Vδ2 T cells.

Despite Human Leukocyte Antigen (HLA) matching and use of immunosuppressive drugs, graft-versus-host disease (GVHD) following hematopoietic stem cell transplant (HSCT) is prevalent and often fatal. Additionally, older HSCT recipients experience increased morbidity and mortality. Prophylactic treatment with age-matched syngeneic (recipient strain-derived) cultured regulatory DC (DCreg) has been shown to decrease GVHD-associated mortality in young bone marrow transplanted (BMT) mice. The purpose of this study was to investigate: 1) the potential to generate DCreg from older mice and their subsequent ability to ameliorate GVHD in older BMT mice, 2) the mechanism(s) by which DCreg mitigate GVHD in vivo, 3) the ability of DCreg-treated BMT mice to respond to infectious pathogens, and 4) whether DCreg can be generated under clinically relevant conditions from healthy donor and HSCT recipient PBMCs. To evaluate the efficacy of DCreg treatment in older mice, complete MHC-mismatched BMT mice were treated with DCreg (hereafter referred to as DCreg-treated BMT mice). Although DCreg treatment ameliorated GVHD in older BMT mice, these mice had increased morbidity and decreased survival compared to their young counterparts. Following transfer into BMT mice, older DCreg failed to increase inhibitory molecule (PD-L1 and PIR B) expression while significantly upregulating co-stimulatory molecule (CD40 and CD80) expression, conversely young DCreg upregulated inhibitory molecules as well as co-stimulatory molecules. These phenotypic differences between young and older DCreg in vivo provide a potential mechanism for modestly increased morbidity and mortality in older DCreg-treated BMT mice relative to their young counterparts. Indeed, BMT mice treated with DCreg deficient in PD-L1 or PIR B had significantly reduced overall survival, thus both molecules are required for optimal GVHD mitigation. A murine H1N1 influenza (IAV) infection model was used to assess the donor immune system's capacity to respond to relevant antigens other than those responsible for GVHD. Surprisingly, sub-lethally IAV-infected DCreg-treated BMT mice began to die after d. +21 and all were deceased by d. +25. Virus-specific CD8+ T cell and antibody (Ab) responses were undetectable following primary infection. Interestingly, following a prime-boost infection strategy, DCreg-treated BMT mice survived lethal IAV challenge with no signs of morbidity and had demonstrable IAV-specific Ab and CD8+ T cell responses. Thus a prime-boost IAV infection strategy establishes a protective immune response in the DCreg-treated BMT mice and underscores the potential role vaccination may play in establishing immune competence in DCreg-treated BMT mice. We investigated whether human DCreg can be generated under clinically relevant conditions: 1) following peripheral blood mononuclear cell (PBMC) cryopreservation, 2) in bovine serum-free media, and 3) from older individuals and HSCT recipients. DCreg were generated from healthy donor and HSCT patient PBMCs isolated from young (old) and older (> 50 years old) individuals by culturing cells in X-vivo serum-free. Human DCreg generated from both young and older healthy donor PBMCs had comparable numbers, surface molecule phenotype, cytokine production, and able to induce Treg. Cryopreserved and fresh PBMCs generated DCreg with similar phenotypes and cytokine production. DCreg generated from HSCT recipients maintained low co-stimulatory molecule and high inhibitory molecule expression as well as immunosuppressive cytokine production. These studies confirm DCreg can be generated under clinically relevant conditions.

Activation of the cysteine protease caspase-1 and the subsequent processing and secretion of the pro-inflammatory cytokines IL-1Β and IL-18 is central to the inflammatory response as well as the induction of adaptive immune responses. Caspase-1 is activated as a part of a high-molecular weight multi-protein complex termed the inflammasome. The NLRP3 inflammasome is by far the best studied of these complexes, and it is the most promiscuous in terms of activating signals. The diversity of NLRP3 activating signals makes it likely that NLRP3 does not recognize each agonist directly, rather it detects a molecule that is generated, revealed, or altered by cellular stress. Recent studies have indicated that mitochondrial dysfunction is crucial for NLRP3 inflammasome activation, yet the activating ligand has not yet been identified. Appropriate and timely activation of this inflammatory pathway is required for host immunity to a variety of pathogens, however dysregulated activation leads to autoinflammation and potentially autoimmunity. Hence it is important to identify mechanisms for inflammasome activation and regulation. Therefore, this dissertation has focused on investigating the mechanisms for activation and regulation of the NLRP3 inflammasome, and the biological consequences of these changes. We show that the mitochondrial lipid cardiolipin is required for NLRP3 inflammasome activation. We have also identifying a novel mechanism by which inflammasome activation is regulated. Data presented in this dissertation shows that IgG immune complexes effectively suppress inflammasome activation and the subsequent processing and secretion of IL-1Α and IL-1Β. Furthermore we show that immunization with IgG immune complexes suppresses both Th2 and Th17 immune responses. Together these data provide novel insights into the activating and regulatory pathways of both the innate and adaptive immune systems.