Indiana University-Purdue University Indianapolis (IUPUI) / Vaccinia virus (VV) is the prototypical member of the orthopoxvirus genus of the Poxviridae family, and is currently being evaluated as a vector for vaccine development and cancer cell-targeting therapy. Despite the importance of studying poxvirus effects on the human immune system, reports of the direct interactions between poxviruses and primary human leukocytes (PHLs) are limited. We studied the specific molecular events that determine the VV tropism for major PHL subsets including monocytes, B cells, neutrophils, NK cells, and T cells. We found that VV exhibited an extremely strong bias towards binding and infecting monocytes among PHLs. VV binding strongly co-localized with lipid rafts on the surface of these cell types, even when lipid rafts were relocated to the cell uropods upon cell polarization. In humans, monocytic and professional antigen-presenting cells (APCs) have so far only been reported to exhibit abortive infections with VV. We found that monocyte-derived macrophages (MDMs), including granulocyte macrophage colony-stimulating factor (GM-CSF)-polarized M1 and macrophage colony-stimulating factor (M-CSF)-polarized M2, were permissive to VV replication. The majority of virions produced in MDMs were extracellular enveloped virions (EEV). Visualization of infected MDMs revealed the formation of VV factories, actin tails, virion-associated branching structures and cell linkages, indicating that infected MDMs are able to initiate de novo synthesis of viral DNA and promote virus release. Classical activation of MDMs by LPS plus IFN-γ stimulation caused no effect on VV replication, whereas alternative activation of MDMs by IL-10 or LPS plus IL-1β treatment significantly decreased VV production. The IL-10-mediated suppression of VV replication was largely due to STAT3 activation, as a STAT3 inhibitor restored virus production to levels observed without IL-10 stimulation. In conclusion, our data indicate that PHL subsets express and share VV protein receptors enriched in lipid rafts. We also demonstrate that primary human macrophages are permissive to VV replication. After infection, MDMs produced EEV for long-range dissemination and also form structures associated with virions which may contribute to cell-cell spread.

Background. Islet amyloid polypeptide (IAPP, also known as amylin) is a 37-amino acid peptide principally co-secreted with insulin from the beta-cells of the pancreatic islets. Some of the physiological actions of human amylin (hIAPP) include glucose regulation, suppression of appetite and stimulation of renal sodium and water reabsorption. Amylin deficiency and diminished post-prandial amylin response have been reported in advanced stages of type 1 and type 2 diabetes. In autopsy specimens of type 2 diabetes, amyloid is found in 40--90% of cases. During the characterization of islet morphology of aged hIAPP transgenic mice, I observed pathological features suggestive of immune dysregulation. Review of literature also suggested possible immuno-modulating functions of human amylin in in vitro experiments. Since autoimmunity and innate immunity are implicated in aging and diabetes, I explored the immunological role of amylin with particular focus on CD4+CD25+ T regulatory cells and toll-like receptors (TLR) which are known mediators of autoimmunity and innate immunity respectively. / Conclusions. Human amylin may play an important role in modulating immunity mainly through stimulating CD4+CD25+ Treg cells, decreasing PLN and altering expression of TLR-4 and cytokines. If these findings are confirmed in in vivo model, human amylin has the potential to become a novel and promising therapy to prevent and reverse autoimmune disease such as autoimmune type 1 diabetes. / Hypothesis. Human amylin may have immunomodulating effects which may have implications on pathogenesis of autoimmune type 1 diabetes. / Materials and methods. Male hemizygous hIAPP transgenic mice (n=32) and their nontransgenic littermates (n=20) were fed with normal chow and studied longitudinally up to 18 months of age with measurement of plasma insulin, glucose and amylin at regular intervals. Detailed oral glucose tolerance test, intra-peritoneal insulin tolerance test, insulin and amylin protein expression were examined at 3, 7, 12 and 18 months of age. Histological changes of pancreas and spleen including changes in CD4+CD25+ T regulatory cells and cytokines were examined at 12 and 18 months. / Objectives. (1) I systemically characterized the morphological, functional and immune regulatory role of human amylin in aged hIAPP transgenic mice which include metabolic profiles, plasma levels of amylin and insulin as well as morphological changes of pancreatic lymph nodes (PLN). (2) I then examined splenic expression of TLR-4 associated changes in cytokines (TNF-alpha, TGF-beta, and IL-6). (3) I also examined the expression level of receptor activity modifying proteins (RAMPs) in pancreas and spleen. (4) I finished by investigating the role of human amylin on stimulating CD4+CD25+ T regulatory (Treg) cells in hIAPP transgenic mice and peripheral blood monocytes (PBMC) from healthy subjects. / Results. (1) With aging, the hIAPP transgenic mice demonstrated increased plasma amylin, decreased plasma insulin, reduced insulin to amylin ratio and improved insulin sensitivity (p<0.05). (2) The aged hIAPP transgenic mice showed changes in immune function as indicated by: (a) Reduced number and size of PLN (p<0.05). (b) Decreased expression level of TLR-4 in splenocytes (p<0.05). (c) Increased expression of transforming growth factor-beta (TGF-beta) and tumor necrosis factor-alpha (TNF-alpha) protein but decreased level of IL-6 in splenocytes (p<0.05). (3) The changes in the levels of immune cytokines such as IL-1, IL-2, IL-4, IL-10, IL-17, interferon-gamma and GM-CSF were similar between hIAPP transgenic and nontransgenic mice (p>0.05). (4) The levels of RAMP1, RAMP2, and RAMP3 were higher in the spleen of hIAPP transgenic mice than nontransgenic mice (p<0.05). (5) The hIAPP transgenic mice showed higher percentage of CD4+CD25+ Treg cells compared with nontransgenic littermates. Treatment with human amylin, but not rat amylin, increased the percentage of FoxP3+CD4+CD25+ Treg cells in both splenic T lymphocytes of hIAPP transgenic mice and PBMCs of healthy subjects ex vivo (p<0.05). / He, Lan / Adviser: Juliana C.N. Chan. / Source: Dissertation Abstracts International, Volume: 73-01, Section: B, page: . / Thesis (Ph.D.)--Chinese University of Hong Kong, 2010. / Includes bibliographical references (leaves 176-199). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [201-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

Cellular defense and metabolism are important biological processes in living cells. In this study, these two biological processes were investigated in two selected disease models: diabetes mellitus (DM) and severe acute respiratory syndrome associated coronavirus (SARS-CoV) infection by two-dimensional gel electrophoresis (2DE) coupled with Matrix-Assisted Laser Desorption Ionisation Time-Of-Flight Mass Spectrometry (MALDI-TOF MS)-based proteomic approaches. The major findings are summarized as follows: / Our results on DM investigation can help to better understand the pathophysiological changes in patients with DM and the pathogenesis of hyperglycemia-caused complications. Data obtained from SARS-CoV studies provided novel insights into the molecular basis of the host cell response upon viral infection. / Protein profile of streptozotocin (STZ)-induced diabetic animal tissues, including mice liver, kidney and eye, and rats sera, indicated that DM has an impaired cellular defense system. These include the impairment in reactive oxygen species scavenging and the impairment in activation of complement system and innate immunity, and the enhancement in blood coagulation reaction. Our results also demonstrated that glycolysis and gluconeogenesis did not alter significantly in the liver of STZ-diabetic mice, while fatty acid oxidation and TCA cycle were attenuated under the same conditions. Moreover, we also detected other abnormal metabolism in aldehyde and amino acid, especially glutamate metabolism and the urea cycle. Abnormalities were also detected in lipid transport and metabolism. Besides, protein profile of mouse liver c37 cells indicated that high glucose may induce apoptosis in these cells, and this apoptotic effect may be mediated via the mitochondrial pathway. Furthermore, the proteomic results from the in vivo and in vitro diabetic models have prompted us to look for glucose responsive element on the promoters of these up-regulated hepatic genes. We found that the mouse aldolase 2 gene has glucose responsiveness in c37 cells treated with high glucose by semi-quantitative RT-PCR and promoter transfection assay. Finally, protein profile of Vero E6 cells strongly implicated that SARS-CoV can induce anti-apoptosis. This effect may be mediated via the mitochondrial pathway. Our data also suggested that the anti-apoptotic activity may be required for viral replication at the early stage of infection. While under the condition of long-term infection, this may be needed for viral survival. / Zhong Mingqi. / "October 2005." / Advisers: Sai Ming Ngai; Hon Ki Cheng. / Source: Dissertation Abstracts International, Volume: 67-11, Section: B, page: 6217. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (p. 223-248). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in English and Chinese. / School code: 1307.

The regulation of systemic immune responses is dependent on individual cell responses that will concur to induce a coherent response against a stimulus. In turn, cell response is dependent on the processing of intracellular signals generated at the cell membrane and transmitted through successive protein modifications to the nucleus in order to activate gene transcription. This is referred to as intracellular signalling. Tight control of these mechanisms is required to generate an appropriate cell response to environmental stimulations and globally to establish an appropriate immune response. Among protein modifications used to transmit a signal to the nucleus, protein tyrosine phosphorylation represents a pivotal method used by immune cells to rapidly induce signalling. While protein tyrosine kinases (PTKs) phosphorylate proteins, protein tyrosine phosphatases (PTPs) regulate the signalling by removing the phosphate group. The goal of this study was to better characterize intracellular signalling events involved in allergic asthma, a chronic inflammatory disease involving a Th2 immune response. In a first time, we investigated the role of PTPs in the development of asthma. We show that inhibition of global PTP activity in mice, during either the allergen sensitization or the allergen challenge phase, reduces asthma development and is linked to an increased Th1 response in the spleen and lung. Secondly, we revealed that TC-PTP inhibition reduces asthma development, while PTP-1B inhibition exacerbates inflammatory cells recruitment to the lung. Inhibition of either SHP-1 or PTP-PEST activity did not significantly modulate asthma development in our model. In a third set of experiments, we got interested in the signalling pathways triggered by the pro-inflammatory molecules myeloid-related proteins (MRPs) 8 and 14. MRPs are small cytosolic proteins recently described to have extracellular functions. MRP8 expression is resistant to corticosteroid treatment, and potentially promotes inflammation in corticosteroid-treated patients. We identified that MRPs induce signal through the action of TLR-4 and trigger the activation of MEK/ERK and JNK pathways that lead to NF-kappaB translocation. Collectively, our data provide a new characterization of signalling pathways engaged in allergic asthma. This should be helpful in the elaboration of new therapeutic approaches targeting precise pathways to inhibit mechanisms of inflammation.

Cytomegaloviruses (CMVs) are ubiquitous in nature, having evolved over many millenia with their hosts. While in healthy hosts most infections with CMV are asymptomatic, the virus can cause severe disease in immunocompromised hosts. Thus, the increase in organ transplantation and the HIV/AIDS pandemic have established human CMV (HCMV) as a clinically important pathogen. Indeed, HCMV infections are now the major cause of morbidity and mortality among immunocompromised patients, which has led to more research targeting CMV for effective anti-viral treatment. The discovery that cytomegaloviruses encode several genes which are involved in immune escape has prompted a new area of research, aimed at understanding immune escape mechanisms for exploitation as potential anti-viral therapeutics. By targeting the viral proteins directly, or their receptors in the host, it may be possible to treat CMV disease by agonistic/antagonistic therapy. The first part of this thesis describes the first demonstration of anti-NK1.1 staining in situ to identify NK cells using a modified in vivo perfusion/fixation method. Using this method, we have compared the acute NK1.1+ cellular response to wild-type MCMV infection in the visceral organs of genetically susceptible intra-NK complex recombinant BALB.B6-CT6 (Cmv1s, NK1.1+) mice with resistant C57B⁄J (Cmv1r, NK1.1+) and BALB.B6-Cmv1r mice (Cmv1r, NK1.1+). Expression of viral antigens and the consequences of infection on other cellular subsets, were also analyzed in this study. The data show that in susceptible mice (Cmv1s) MCMV infection is predominent in the marginal zone of splenic white pulp, resulting in local changes in various cellular constituents, including macrophages, NK cells and DC. In the liver, distinct foci of infection were comprised of large numbers of macrophages and NK1.1+ cells surrounding infected cytomegalic cells. In resistant mice (Cmv1r), 6 MCMV infection predominantly affected the red-pulp of the spleen and was associated with increased accumulation of NK1.1+ cells and macrophages at sites of viral infection

Indiana University-Purdue University Indianapolis (IUPUI) / Platelet-activating Factor (PAF) stimulates various cell types by the activation of the G-protein coupled PAF-receptor (PAFR). Systemic PAFR activation induces an acute pro-inflammatory response, as well as delayed systemic immunosuppressive effects in vivo. De novo enzymatic PAF synthesis and degradation are closely regulated, but oxidative stressors, such as UVB, and cigarette smoke, can generate PAF-like species via the oxidation of membrane lipids in an unregulated process. Mast cells (MCs) and the PAFR have been shown to be necessary to mediate the resulting systemic immune suppression from oxidative stressors. The work herein implicates pro-oxidative chemotherapeutics, such as melphalan and etoposide, in mediating augmentation in tumor growth by inducing the generation of PAFR agonists via the oxidation of membrane lipids. This work also demonstrates the role of MCs and MC-released mediators in PAFR systemic immunosuppression. Through a contact hypersensitivity (CHS) model, the MC PAFR was found to be necessary and sufficient for PAF to mediate systemic immunosuppression. Additionally, activation of the MC PAFR seems to induce MC histamine and prostaglandin E2 release. Furthermore, by transplanting histamine- or COX-2-deficient MCs into MC-deficient mice, MC-derived histamine and prostaglandin release were found to be necessary for PAF to induce systemic immunosuppression. Lastly, we have evidence to suggest that prostaglandin release modulates MC migration to draining lymph nodes, a process necessary to promote immunosuppression. These studies fit with the hypothesis that MC PAFR activation mediates PAFR systemic immunosuppression in part by histamine and prostaglandin release.

No description available.

This review presents several aspects of the innovative concept of sebaceous immunobiology, which summarizes the numerous activities of the sebaceous gland including its classical physiological and pathophysiological tasks, namely sebum production and the development of seborrhea and acne. Sebaceous lipids, which represent 90% of the skin surface lipids in adolescents and adults, are markedly involved in the skin barrier function and perifollicular and dermal innate immune processes, leading to inflammatory skin diseases. Innovative experimental techniques using stem cell and sebocyte models have clarified the roles of distinct stem cells in sebaceous gland physiology and sebocyte function control mechanisms. The sebaceous gland represents an integral part of the pilosebaceous unit and its status is connected to hair follicle morphogenesis. Interestingly, professional inflammatory cells contribute to sebocyte differentiation and homeostasis, whereas the regulation of sebaceous gland function by immune cells is antigen-independent. Inflammation is involved in the very earliest differentiation changes of the pilosebaceous unit in acne. Sebocytes behave as potent immune regulators, integrating into the innate immune responses of the skin. Expressing inflammatory mediators, sebocytes also contribute to the polarization of cutaneous T cells towards the Th17 phenotype. In addition, the immune response of the perifollicular infiltrate depends on factors produced by the sebaceous glands, mostly sebaceous lipids. Human sebocytes in vitro express functional pattern recognition receptors, which are likely to interact with bacteria in acne pathogenesis. Sex steroids, peroxisome proliferator-activated receptor ligands, neuropeptides, endocannabinoids and a selective apoptotic process contribute to a complex regulation of sebocyte-induced immunological reaction in numerous acquired and congenital skin diseases, including hair diseases and atopic dermatitis.

Para identificar, quantificar e correlacionar os eosinófilos, mastócitos, miofibroblastos e células TGF-beta positivas nos pólipos nasais de pacientes com e sem asma foi realizado a imunoistoquímica. A quantidade de eosinófilos, miofibroblastos e células TGF-beta positivas esteve aumentada no pólipo nasal de indivíduos asmáticos. O número de mastócitos não mostrou diferença entre os grupos. O miofibroblasto foi o denominador comum na correlação entre eosinófilos, mastócitos, células TGF-beta positivas e presença de asma / Introduction: Nasal polyposis is a chronic inflammatory disease of the nasal mucosa or paranasal sinuses characterized by the formation of benign polyps. The pathogenesis is not known, although nasal polyps are associated with several systemic diseases, with asthma being the most frequent. The aim of the present study was to identify, quantify, compare and correlate eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells in nasal polyps of patients with and without asthma. Material and Methods: Seventy-eight subjects with nasal polyps undergoing endoscopic sinus surgery were selected. Control specimens were obtained from eight subjects with a normal sinus mucosa. One group consisted of polyps from 56 patients with asthma and the other of polyps from 22 patients without asthma. Immunohistochemistry was performed using monoclonal antibodies against eosinophil cationic protein to stain eosinophils, against tryptase to stain mast cells, against alpha-smooth muscle actin to stain myofibroblasts, and against TGF-ß to stain TGF-ß-positive cells. Results: The number of eosinophils, myofibroblasts and TGF-ß-positive cells was significantly higher in the asthma group than in the nonasthma group, whereas no significant difference in the number of mast cells was observed between the two groups. The number of eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells was significantly higher in nasal polyps than in the control group. Myofibroblasts showed a significant correlation with eosinophils, mast cells, TGF-ß-positive cells, and asthma. Conclusion: Eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells were identified in all nasal polyps, although the number of eosinophils, myofibroblasts and TGF-ß-positive cells was higher in the asthma group. The number of mast cells was similar regardless of the presence or absence of asthma. Myofibroblasts were a common denominator in the correlation between eosinophils, mast cells, TGF-ß-positive cells, and asthma

Para identificar, quantificar e correlacionar os eosinófilos, mastócitos, miofibroblastos e células TGF-beta positivas nos pólipos nasais de pacientes com e sem asma foi realizado a imunoistoquímica. A quantidade de eosinófilos, miofibroblastos e células TGF-beta positivas esteve aumentada no pólipo nasal de indivíduos asmáticos. O número de mastócitos não mostrou diferença entre os grupos. O miofibroblasto foi o denominador comum na correlação entre eosinófilos, mastócitos, células TGF-beta positivas e presença de asma / Introduction: Nasal polyposis is a chronic inflammatory disease of the nasal mucosa or paranasal sinuses characterized by the formation of benign polyps. The pathogenesis is not known, although nasal polyps are associated with several systemic diseases, with asthma being the most frequent. The aim of the present study was to identify, quantify, compare and correlate eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells in nasal polyps of patients with and without asthma. Material and Methods: Seventy-eight subjects with nasal polyps undergoing endoscopic sinus surgery were selected. Control specimens were obtained from eight subjects with a normal sinus mucosa. One group consisted of polyps from 56 patients with asthma and the other of polyps from 22 patients without asthma. Immunohistochemistry was performed using monoclonal antibodies against eosinophil cationic protein to stain eosinophils, against tryptase to stain mast cells, against alpha-smooth muscle actin to stain myofibroblasts, and against TGF-ß to stain TGF-ß-positive cells. Results: The number of eosinophils, myofibroblasts and TGF-ß-positive cells was significantly higher in the asthma group than in the nonasthma group, whereas no significant difference in the number of mast cells was observed between the two groups. The number of eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells was significantly higher in nasal polyps than in the control group. Myofibroblasts showed a significant correlation with eosinophils, mast cells, TGF-ß-positive cells, and asthma. Conclusion: Eosinophils, mast cells, myofibroblasts and TGF-ß-positive cells were identified in all nasal polyps, although the number of eosinophils, myofibroblasts and TGF-ß-positive cells was higher in the asthma group. The number of mast cells was similar regardless of the presence or absence of asthma. Myofibroblasts were a common denominator in the correlation between eosinophils, mast cells, TGF-ß-positive cells, and asthma