Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 7 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

by Tsang Chi Man. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2005. / Includes bibliographical references (leaves 137-155). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abbreviations --- p.iii / Abstract --- p.vi / 撮要 --- p.ix / Publications --- p.xi / Table of contents --- p.xii / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Human mast cells and their pathological roles in inflammation --- p.1 / Chapter 1.1.1 --- Morphology of mast cells --- p.1 / Chapter 1.1.2 --- Mediators of mast cells --- p.1 / Chapter 1.1.3 --- Migration and activation --- p.3 / Chapter 1.1.4 --- Pathological roles of mast cells --- p.3 / Chapter 1.1.5 --- Human mast cell-1 (HMC-1) --- p.5 / Chapter 1.2 --- Cytokines as stimulator of mast cells in inflammation --- p.7 / Chapter 1.2.1 --- SCF --- p.7 / Chapter 1.2.2 --- TNF-α --- p.8 / Chapter 1.2.3 --- IL-13 --- p.8 / Chapter 1.2.4 --- IL-18 --- p.9 / Chapter 1.2.5 --- IL-25 --- p.9 / Chapter 1.3 --- Interaction of mast cells with inflammatory cells through adhesion molecules and chemokines --- p.11 / Chapter 1.3.1 --- Adhesion molecules on mast cells --- p.11 / Chapter 1.3.2 --- Chemokines released by mast cells --- p.12 / Chapter 1.4 --- Intracellular signaling pathways in mast cells --- p.16 / Chapter 1.4.1 --- p38-MAPK pathway --- p.16 / Chapter 1.4.2 --- ERK pathway --- p.17 / Chapter 1.4.3 --- NF-kB Pathway --- p.18 / Chapter 1.4.3 --- Cross-talking of pathways --- p.18 / Chapter 1.5 --- Signal transduction pathways and pharmacological intervention --- p.23 / Chapter 1.6 --- Traditional Chinese Medicine and pharmacological intervention --- p.25 / Chapter 1.6.1 --- Anti-allergic effects of traditional Chinese Medicine --- p.25 / Chapter 1.6.2 --- Anti-asthmatic effects of a newly developed Wheeze-Relief Formula --- p.26 / Chapter 1.7 --- Aims and scope of the study --- p.30 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Materials --- p.32 / Chapter 2.1.1 --- HMC-1 cell Line --- p.32 / Chapter 2.1.2 --- Media and reagents for cell culture --- p.32 / Chapter 2.1.3 --- Recombinant human cytokines --- p.33 / Chapter 2.1.4 --- "Signal transduction pathway inhibitors: PD98035, SB203580 and BAY 117082" --- p.34 / Chapter 2.1.5 --- Monoclonal antibodies and reagents for immunofluorescent staining --- p.34 / Chapter 2.1.6 --- Reagents and buffers for chemokine detection --- p.35 / Chapter 2.1.7 --- Reagents and buffers for total RNA extraction --- p.36 / Chapter 2.1.8 --- Reagents and buffers for reverse transcription 一 polymerase chain reaction (RT-PCR) --- p.37 / Chapter 2.1.9 --- Reagents and buffers for protein extraction --- p.40 / Chapter 2.1.10 --- Reagents and buffers for detection of activated signaling pathways --- p.41 / Chapter 2.1.11 --- Reagents and buffers for agarose gel electrophoresis --- p.42 / Chapter 2.1.12 --- Reagents and buffers for SDS-polyacrylamide gel electrophoresis (PAGE) --- p.43 / Chapter 2.1.13 --- Reagents and buffers for Western blot analysis --- p.45 / Chapter 2.1.14 --- Reagents and buffers for cDNA expression array analysis --- p.47 / Chapter 2.1.15 --- Reagents and buffers for cell viability and proliferation assay --- p.48 / Chapter 2.1.16 --- Reagent kit for endotoxin level assay --- p.49 / Chapter 2.2 --- Methods --- p.49 / Chapter 2.2.1 --- HMC-1 cell cultures --- p.49 / Chapter 2.2.2 --- Flow cytometry of cell surface expression of ICAM-1 and ICAM-3 --- p.50 / Chapter 2.2.3 --- Total cellular RNA extraction --- p.50 / Chapter 2.2.4 --- Reverse Transcription - Polymerase Chain Reaction (RT-PCR) --- p.51 / Chapter 2.2.5 --- Agarose gel electrophoresis --- p.51 / Chapter 2.2.6 --- "Quantitative analysis of IL-8, IP-10,MCP-1 and RANTES" --- p.52 / Chapter 2.2.7 --- Quantitative analysis of 1-309 and MIP-1β --- p.52 / Chapter 2.2.8 --- Detection of phosphorylated-ERX and phosphorylated-p38 MAPK --- p.53 / Chapter 2.2.9 --- Detection of NF-kB activity --- p.53 / Chapter 2.2.10 --- Detection of phosphorylated-ATF-2 --- p.53 / Chapter 2.2.11 --- Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis (PAGE) --- p.54 / Chapter 2.2.12 --- Western blot analysis --- p.54 / Chapter 2.2.13 --- MTT assay --- p.55 / Chapter 2.2.14 --- Cell proliferation assay --- p.55 / Chapter 2.2.15 --- Hot water extraction of TCM --- p.56 / Chapter 2.2.16 --- Endotoxin level assay --- p.56 / Chapter 2.2.17 --- cDNA expression array analysis --- p.57 / Chapter 2.2.18 --- Statistical analysis --- p.57 / Chapter Chapter 3 --- Results / Chapter 3.1 --- The effects of cytokines on the expression of ICAM-1 and ICAM-3 on HMC-1 --- p.59 / Chapter 3.1.1. --- "SCF, TNF-α and IL-13 up-regulated ICAM-1 but not ICAM-3 expression on HMC-1 cells" --- p.59 / Chapter 3.1.2. --- "SCF, TNF-α and IL-13 up-regulated the mRNA expression of ICAM-1" --- p.59 / Chapter 3.1.3 --- "The combined treatment of SCF and TNF-α, and SCF and IL-13 showed synergistic and additive effect on ICAM-1 expression respectively" --- p.60 / Chapter 3.1.4 --- Synergistic up-regulation of ICAM-1 expression in combined treatment of SCF and TNF-α was dose-dependently enhanced by SCF --- p.60 / Chapter 3.2 --- "The effects of cytokines on the release of IL-8, IP-10, MCP-1, RANTES, 1-309 and MIP-1β from HMC-1 cells" --- p.66 / Chapter 3.2.1 --- "SCF induced the release of IL-8, MCP-1, RANTES, 1-309 and MIP-1β" --- p.66 / Chapter 3.2.2 --- "TNF-a induced the release of IL-8, IP-10, MCP-1, RANTES and 1-309" --- p.66 / Chapter 3.2.3 --- SCF and TNF-α did not enhance the proliferation rate of HMC-1 --- p.66 / Chapter 3.3 --- "The effect of SCF and TNF-α on the activation of ERK, p38 MAPK and NK-kB" --- p.71 / Chapter 3.3.1 --- SCF activated ERK but not p38 MAPK and NF-kB --- p.71 / Chapter 3.3.2 --- TNF-α activated p38 MAPK and NF-kB but not ERK --- p.71 / Chapter 3.4 --- The effect of inhibitors on the SCF and TNF-a-induced release of chemokines --- p.76 / Chapter 3.4.1 --- "The optimal dose of PD98059, SB203580 and BAY117082" --- p.76 / Chapter 3.4.2 --- "PD98059 suppressed the SCF induced IL-8, MCP-1, RANTES, 1-309 and MIP-1β release from HMC-1 cells" --- p.76 / Chapter 3.4.3 --- SB203580 and BAY117082 differentially suppressed the TNF-α induced chemokine release from HMC-1 cells --- p.77 / Chapter 3.5 --- The effect of inhibitors on the SCF and TNF-a-induced upregulation of ICAM-1 --- p.83 / Chapter 3.5.1 --- BAY117082 but not SB203580 suppressed the TNF-α-induced ICAM-1 expression --- p.83 / Chapter 3.5.2 --- PD98059 and BAY 117082 suppressed the combined treatment of SCF and TNF-α induced ICAM-1 expression --- p.83 / Chapter 3.6 --- "Effect of inhibitors on TNF-α and SCF-induced ERK, p38 MAPK and NF-kB activities in HMC-1 cells." --- p.85 / Chapter 3.6.1 --- PD98059 suppressed the SCF-induced activity of ERK --- p.85 / Chapter 3.6.2 --- SB203580 and BAY117082 suppressed the TNF-α induced p38 MAPKand NF-kB activity respectively --- p.85 / Chapter 3.6.3 --- PD98059 suppressed the enhanced NF-kB activity after the combined treatment of SCF and TNF-α for 18 hours --- p.86 / Chapter 3.7 --- Effect of TNF-α and SCF on the gene expression profile of inflammatory cytokines and receptors of HMC-1 cells. --- p.90 / Chapter 3.8 --- The effects of TCM on the SCF-induced 1-309 and MCP-1 from HMC-1 cells --- p.95 / Chapter 3.8.1 --- "Endotoxin level of Radix astragali, Radix Scutellariae, Radix stemonae, Bulbus Fritillariae cirrhosae and Cordyceps sinensis" --- p.95 / Chapter 3.8.2 --- The effects of TCM on the proliferation rate of HMC-1 cells --- p.95 / Chapter 3.9.3 --- The effects of TCM on the SCF-induced release of 1-309 from HMC-1 cells --- p.96 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Involvement of adhesion molecules and chemokines in mast cell-mediated immunological events --- p.107 / Chapter 4.2 --- HMC-1 as the in vitro mast cell model adapted in my project --- p.108 / Chapter 4.3 --- The effect of cytokines on the expression of ICAM-1 and ICAM-3 in HMC-1 cells --- p.109 / Chapter 4.4 --- The effect of cytokines on the release of chemokines in HMC-1 cells --- p.111 / Chapter 4.5 --- "The regulation of ICAM-1, IL-8, IP-10, MCP-1, RANTES, 1-309 and MIP-1β through p-38 MAPK, ERK and NF-kB signaling pathways in HMC-1 cells" --- p.115 / Chapter 4.6 --- Further characterization of HMC-1 cells using cDNA array --- p.119 / Chapter 4.7 --- Investigating the in vitro anti-allergic activities of a newly developed Wheeze-relief formula using cytokine-activated HMC-1 cells --- p.128 / Chapter 4.8 --- Concluding remarks and future prospective --- p.132 / References --- p.137 / Appendix --- p.156

A prevalência de doenças respiratórias alérgicas tem aumentado, embora de origem multifatorial, a atividade física parece representar um importante contribuinte. Objetivo: Nós hipotetizamos que o condicionamento aeróbio (AC) prévio à sensibilização com OVA, poderia reduzir a inflamação das vias aéreas, através de um desbalanço via Th1/Th2 ou da citocina regulatória (IL-10). Métodos: camundongos BALB/c foram divididos em 4 grupos (n=8): não treinados e não-sensibilizados (controle), treinados e não-sensibilizados (AC), não treinados e sensibilizados-OVA (OVA) e o grupo treinado e sensibilizado (OV+AC). O condicionamento aeróbio foi realizado em esteira ergométrica adaptada para camundongos por 8 semanas, seguidos de sensibilização por OVA ou soro fisiológico. Foram avaliadas a inflamação celular das vias aéreas e peribrônquica, títulos IgE e IgG1, expressão de Th1 (IL-2 e IFN-), Th2 (IL-4, IL-5, IL-13), citocina regulatória (IL -10), PGE2 e remodelamento das vias aéreas. No peribrônquico a expressão de eotaxina, RANTES, ICAM-1, VCAM-1, TGF- e VEGF. Resultados: Os grupos controle e AC tiveram resultados semelhantes nas avaliacões (p> 0,05). O grupo OVA apresentou células inflamatórias nas vias aéreas e região peribrônquica, remodelamento e um aumento da IgG1 e títulos IgE (p <0,05). Apresentou um aumento na expressão de citocinas Th2, mas não Th1, assim como, aumento na expressão de IL-10, ICAM-1, VCAM-1, RANTES, TGF- e VEGF também foram observadas. O grupo OVA+AC apresentou uma menor migração de eosinófilos e linfócitos para as vias aéreas inferiores e titulação de IgG1 e IgE (p<0,05) e menor expressão de citocinas Th2, porém, os níveis Th1 não foram alterados. A inibição da expressão de IL-10, ICAM-1, VCAM-1, RANTES, TGF- e VEGF, assim como, o remodelamento das vias aéreas, também foi observado no grupo OVA+AC (p<0,05). Conclusão: Nossos resultados sugerem que a melhora do condicionamento aeróbio inibi a sensibilização e a inflamação alérgica / Prevalence of allergic respiratory diseases has increased and although its origin likely multifactorial, reduced physical activity seems to represent an important contributor. Objective: We hypothesize that an improvement in aerobic conditioning (AC) previous to OVA sensitization would reduce airway inflammation via either an imbalance Th1/Th2 pathway or regulatory cytokine (IL-10). Methods: BALB/c mice were divided in 4 groups (n=8): non-trained and non-sensitized (Control), AC and non-sensitized (AC), non-trained and OVA-sensitized (OVA), and AC and OVA (OVA+AC). AC was performed in a treadmill (8 weeks) followed by either OVA or saline sensitization. It was evaluated airway and peribronchial cell inflammation, specific OVA-IgE and -IgG1 titers, expression of Th1 (IL-2 and IFN-), Th2 (IL-4, IL-5, IL-13) or regulatory (IL-10) cytokines, PGE2 and airway remodeling. Peribronchial expression of eotaxin, RANTES, ICAM-1, VCAM-1, TGF- and VEGF was also evaluated. Results: AC and control groups had similar results in all evaluated outcome (p>0,05) OVA sensitization induced airway and peribronchial cell inflammation and remodeling and an increase in the IgG1 and IgE titers (p<0,05). An increase in the expression of Th2 but not Th1 cytokines was well as an increase in the expression of IL-10, ICAM-1, VCAM-1, RANTES, TGF- and VEGF was also observed. OVA+AC group presented a lower migration of eosinophils and lymphocytes to the airways and lower titer of IgG1 and IgE (p<0,05). OVA+AC group also presented lower expression of Th2 cytokines however Th1 levels were unchanged. A lower expression of IL-10, ICAM-1, VCAM-1, RANTES, TGF- and VEGF as well as airway remodeling was also observed in OVA+AC group (p<0,05). Conclusion: Our results suggest that improvement in aerobic conditioning inhibit allergic sensitization and inflammation

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2009. / Härtill 3 uppsatser.

The persistent increase of bovine tuberculosis (bTB) over the past twenty years has put a substantial strain on both the British economy and the welfare of livestock. However, the development of an effective bTB vaccine has been continually hindered by the lack of knowledge on the immune response following Mycobacterium bovis (M. bovis) infection. In collaboration with the TB Research Group at the Veterinary Laboratories Agency (VLA, Surrey), this thesis is part of a much wider strategy managed by the Department of Environment, Food and Rural Agency (DEFRA) aimed at elucidating the immunopathogenesis of M. bovis and to develop more effective infection control measures. The specific focus of this thesis was to enable a stronger understanding of the bovine immune response over different periods of M. bovis infection and to apply this new knowledge in evaluating the efficacy of a novel BCG vaccination. Time Course Study: Knowledge of time dependent cytokine expression following M. bovis infection would aid vaccine development by revealing potential correlates of protection. Interferon gamma (IFN-γ), tumour necrosis factor alpha (TNF-α), interleukin (IL) 4 and 10 expression were analysed using quantitative (q) PCR in formalin fixed bovine lymph nodes following five, twelve and nineteen weeks of M. bovis infection. A strong pro-inflammatory/ T helper 1 (TH1) lymphocyte response was evident at five weeks post M. bovis infection, represented by IFN-γ and TNF-α expression (log2 copies of 6.5 and 2.15, respectively) in the absence of IL4. Between five and twelve weeks of infection, a significant increase was observed in IL10 (log2 copies from 5.97 to 8.27, p<0.01, Mann Whitney test), accompanied by an increase in both IFN-γ (log2 7.53) and TNF-α (log2 3.94). This data conformed to a recently described aspect of TH1 lymphocytes, a ‘self-limiting’ nature in which cells produced both IFN-γ and IL10 with the aim of controlling the heightened pro-inflammatory response. The role of IL10 as an immunosuppressive became evident when comparing cytokine expression between four different types of thoracic lymph node; the left bronchial (LB), cranial mediastinal (CRM), caudal mediastinal (CM) and cranial tracheobronchial (CRT) nodes. The LB and CRM lymph nodes produced significantly higher levels of IFN-γ expression (log2 copies between 8.2 and 10) as compared to the CM and CRT (log2 copies between 2.6 and 5.5, p<0.001, Mann Whitney test). Further analysis of the data as a profile of cytokine expression for each lymph node type revealed that IFN-γ was dominantly expressed within the LB and CRM nodes, whereas within the CM and CRT nodes, IL10 was the dominant cytokine. The former nodes also displayed a higher level of pathological damage (represented by mean percentage area coverage of granuloma, 33.6 and 20%, respectively) as compared to the CM (13%) and the CRT lymph node types (10.8 %). This suggests conflicting roles for IFN-γ and IL10 in the development of immune-associated pathology. Following nineteen weeks of infection, the expression levels of IFN-γ, TNF-α and IL10 reduced (log2 6.22, 3.02 and 7.03, respectively) implying a loss of the cellular response. The later stages of bovine tuberculosis have been shown within the literature to display characteristics of a humoral rather than cell mediated response. However, within this study at nineteen weeks post infection IL4 (an important cytokine in the development of the humoral response) remained undetectable. The results from this study therefore confirm the importance of the cell mediated immune profile in response to M. bovis infection as well as the integral role of IFN-γ in both protection and pathology. It also further demonstrates the involvement of IL10 in controlling the IFN-γ response and highlights this cytokine as being potentially important in future immunologybased vaccination studies. BCG Vaccination Study: The current vaccine used against human tuberculosis, BCG, has provided variable results on protection against infection in experimental bovine studies. The BCG bacterium has lost a comparatively large quantity of genomic DNA through attenuation since its primary production in 1921, of which the majority represented genes encoding antigenic proteins. MPB70 and MPB83 are differentially expressed between BCG sub-strains due to a single nucleotide polymorphism in the alternative sigma factor K (SigK). BCG Pasteur has been shown to produce low levels of these antigenic proteins; however complementation of BCG Pasteur with a copy of sigK from BCG Russia resulted in up-regulating expression. It was therefore hypothesised that the recombinant BCG (sigK) Pasteur would prove more efficient in controlling M. bovis infection by inducing a stronger protective immune response post vaccination. IFN-γ, TNF-α, IL 4 and 10 expression were analysed using qPCR within the freshly dissected lymph nodes of five experimental cattle groups; BCG Pasteur vaccinated M. bovis challenged, BCG (sigK) Pasteur vaccinated challenged, non-vaccinated infected, non-vaccinated noninfected and BCG Pasteur vaccinated non-infected. Five weeks following infection, a strong IFN-γ mRNA response was detected in both the non-vaccinated and vaccinated cattle (mean log2 copies between 9.6 and 10.5 as compared to between 7.84 and 8.58 in the non-infected cattle). M. bovis infection also induced a significant reduction in IL10 mRNA levels in both vaccinated and non-vaccinated cattle (mean log2 14.4 in the infected groups compared to 15.5 in the non-infected cattle, p<0.005, Mann Whitney test) although there was little difference in TNF-α expression (mean log2 copies between 11.06 and 11.8 in all five groups). Interestingly, IL4 mRNA was detectable only within the two non-infected control groups (mean log2 12.4), further supporting the concept of a strong cell mediated response after five weeks of infection. Vaccination prior to challenge had an effect on IFN-γ mRNA levels only, as both the BCG Pasteur and BCG (sigK) Pasteur vaccinated groups displayed a smaller increase in IFN-γ mRNA following challenge (mean log2 10.3 and 9.6, respectively) as compared to the nonvaccinated group (mean log2 10.5). This reflected the role of vaccination in priming the immune response to enable more rapid elimination of the bacteria and subsequently inducing a lesser pro-inflammatory response. Interestingly, the BCG Pasteur vaccinated group appeared to control the immune response to a greater extent, as IFN-γ mRNA was significantly similar to that observed in the non-vaccinated non-infected group (mean log2 8.58, p>0.05, Mann Whitney test). In addition to the qPCR data, levels of IFN-γ and TNF-α protein (represented by the number of cells producing these proteins) were also analysed by immunohistochemistry. IFN-γ protein in the five experimental groups displayed the same pattern as that observed for IFN-γ mRNA expression (p<0.001, Spearmans correlation coefficient). However, analysis of TNF-α protein revealed significant differences between the five groups (p<0.005, Kruskal Wallis test) in contrast to that observed for the mRNA levels (p>0.05, Spearmans correlation coefficient) suggesting that posttranscriptional controls may play an important role in TNF-α translation. The difference in IFN-γ mRNA and protein expression between the two vaccination groups was also reflected within the pathological data. Although both BCGs reduced levels to below that of the non-vaccinated group (represented by mean percentage area coverage of granuloma, 59%), the BCG Pasteur group displayed less pathology (mean 6%) compared to the BCG (sigK) Pasteur cattle (mean 35%). It was suggested that the increased antigenic repertoire of the recombinant BCG (sigK) Pasteur did result in a stronger stimulation of the immune response post vaccination but that, as a consequence the bacterial threat was eliminated more rapidly.

[Truncated abstract] The dramatic increase in the expression of allergic diseases such as asthma and allergy over the last 20-30 years has highlighted the urgent need to identify causative factors. It was hypothesised that direct immune interactions between mother and fetus contribute to the cytokine milieu of pregnancy, thus influencing immune maturation after birth. Further it was speculated that the cytokine responses produced as a result of maternalfetal interactions are Th-2 skewed in women allergic disease, which programmes their offspring towards developing an allergic phenotype after birth. To test this hypothesis a cohort of 169 pregnant women were recruited at 20 weeks gestation and defined as allergic or non-allergic based on both clinical history and skin prick test sensitisation. These women and their infants were followed up throughout pregnancy (20 weeks, 30 weeks, 36 weeks gestation and 6 weeks post-partum) and up to 2.5 years of age. Mixed lymphocyte reactions (MLR) were used to measure maternal cytokine (IL-6, IL-10, IL-13 and IFN-) and lymphoproliferative responses to fetal alloantigens at each pregnancy time-point. Human leukocyte antigen (HLA) typing of mothers and infants were performed to assess the effect of HLA mismatch on maternal MLR responses to their fetus. After delivery, mononuclear cells (MNC) were isolated from cord blood (CB) and stimulated with allergens, mitogen and toll-like receptor (TLR) ligands. .... As IL-6 also participates in adaptive immunity by promoting Th-2 differentiation it is proposed that the production of IL-6 as a results of maternal encounters with paternal antigens during pregnancy, contribute to the Th-2 skewed responses observed universally in most infants at birth. Associations between maternal-fetal interaction and clinical outcomes in infancy: Although clinical signs of allergy in infancy were not the main outcome measure of this thesis, there were interesting, yet complex relationships between the production of these maternal cytokines towards the fetus and allergic disease at infant follow-ups. Increased maternal IFN-¿ to fetal alloantigen was associated with asthma at 2.5 years and a trend towards recurrent wheeze at 12 months. In contrast decreased maternal IL-13 production was associated with IgE mediated food allergy at 12 months. Adjusting for maternal allergy and other potential confounders including infant gender, method of delivery, HLA mismatch, and paternal allergy did not account for these relationships. Further follow-ups of these infants are required to determine if these relationship last in to early childhood. In conclusion, the findings of this thesis provides further support for the hypothesis that immune responses at birth are programmed prenatally, and that this programming has implications later in life. Importantly, the placenta is the immunologically active interface between mother and fetus during pregnancy. Therefore it is emphasised that there is a crucial need for future research to focus on early immune programming at the placental level before the aetiological pathways of immune mediated diseases can be fully elucidated.

A prevalência de doenças respiratórias alérgicas tem aumentado, embora de origem multifatorial, a atividade física parece representar um importante contribuinte. Objetivo: Nós hipotetizamos que o condicionamento aeróbio (AC) prévio à sensibilização com OVA, poderia reduzir a inflamação das vias aéreas, através de um desbalanço via Th1/Th2 ou da citocina regulatória (IL-10). Métodos: camundongos BALB/c foram divididos em 4 grupos (n=8): não treinados e não-sensibilizados (controle), treinados e não-sensibilizados (AC), não treinados e sensibilizados-OVA (OVA) e o grupo treinado e sensibilizado (OV+AC). O condicionamento aeróbio foi realizado em esteira ergométrica adaptada para camundongos por 8 semanas, seguidos de sensibilização por OVA ou soro fisiológico. Foram avaliadas a inflamação celular das vias aéreas e peribrônquica, títulos IgE e IgG1, expressão de Th1 (IL-2 e IFN-), Th2 (IL-4, IL-5, IL-13), citocina regulatória (IL -10), PGE2 e remodelamento das vias aéreas. No peribrônquico a expressão de eotaxina, RANTES, ICAM-1, VCAM-1, TGF- e VEGF. Resultados: Os grupos controle e AC tiveram resultados semelhantes nas avaliacões (p> 0,05). O grupo OVA apresentou células inflamatórias nas vias aéreas e região peribrônquica, remodelamento e um aumento da IgG1 e títulos IgE (p <0,05). Apresentou um aumento na expressão de citocinas Th2, mas não Th1, assim como, aumento na expressão de IL-10, ICAM-1, VCAM-1, RANTES, TGF- e VEGF também foram observadas. O grupo OVA+AC apresentou uma menor migração de eosinófilos e linfócitos para as vias aéreas inferiores e titulação de IgG1 e IgE (p<0,05) e menor expressão de citocinas Th2, porém, os níveis Th1 não foram alterados. A inibição da expressão de IL-10, ICAM-1, VCAM-1, RANTES, TGF- e VEGF, assim como, o remodelamento das vias aéreas, também foi observado no grupo OVA+AC (p<0,05). Conclusão: Nossos resultados sugerem que a melhora do condicionamento aeróbio inibi a sensibilização e a inflamação alérgica / Prevalence of allergic respiratory diseases has increased and although its origin likely multifactorial, reduced physical activity seems to represent an important contributor. Objective: We hypothesize that an improvement in aerobic conditioning (AC) previous to OVA sensitization would reduce airway inflammation via either an imbalance Th1/Th2 pathway or regulatory cytokine (IL-10). Methods: BALB/c mice were divided in 4 groups (n=8): non-trained and non-sensitized (Control), AC and non-sensitized (AC), non-trained and OVA-sensitized (OVA), and AC and OVA (OVA+AC). AC was performed in a treadmill (8 weeks) followed by either OVA or saline sensitization. It was evaluated airway and peribronchial cell inflammation, specific OVA-IgE and -IgG1 titers, expression of Th1 (IL-2 and IFN-), Th2 (IL-4, IL-5, IL-13) or regulatory (IL-10) cytokines, PGE2 and airway remodeling. Peribronchial expression of eotaxin, RANTES, ICAM-1, VCAM-1, TGF- and VEGF was also evaluated. Results: AC and control groups had similar results in all evaluated outcome (p>0,05) OVA sensitization induced airway and peribronchial cell inflammation and remodeling and an increase in the IgG1 and IgE titers (p<0,05). An increase in the expression of Th2 but not Th1 cytokines was well as an increase in the expression of IL-10, ICAM-1, VCAM-1, RANTES, TGF- and VEGF was also observed. OVA+AC group presented a lower migration of eosinophils and lymphocytes to the airways and lower titer of IgG1 and IgE (p<0,05). OVA+AC group also presented lower expression of Th2 cytokines however Th1 levels were unchanged. A lower expression of IL-10, ICAM-1, VCAM-1, RANTES, TGF- and VEGF as well as airway remodeling was also observed in OVA+AC group (p<0,05). Conclusion: Our results suggest that improvement in aerobic conditioning inhibit allergic sensitization and inflammation

Bioengineered probiotics enable new opportunities to improve colorectal cancer (CRC) prevention, screening, and treatment strategies. With CRC incidence on the rise in younger populations, there is an increased need to engineer technologies that enhance patient access to diagnostic exams and disease management. This dissertation presents the development of an orally-delivered probiotic to screen for and treat early CRC lesions with a particular emphasis on translatability factors including: safety of probiotic use, exploration of oral delivery, and testing in clinically relevant models. At the interface of immunology, synthetic biology, and the microbiome fields is the overarching concept that microbes play a critical role in the tumor microenvironment (TME). The innate ability of bacteria to seek out tumor-specific signatures and proliferate within their necrotic cores due to reduced immune surveillance enables the precise immunoengineering of the local TME. Here, we will design, characterize, and test a probiotic encoded with a lysis mechanism to aid in biocontainment and maximize the release of recombinantly-produced diagnostic and immunotherapeutic cargo. In this lysis circuit, bacteria grow to a critical density within tumors and synchronously lyse, locally releasing their payload. A small fraction of bacteria remains to reseed the population and the cycle continues, resulting in repeated and sustained drug delivery. Drawing from advancements in immunology, we engineered bacteria to produce immune checkpoint inhibitors. Monoclonal antibodies targeting immune checkpoints have revolutionized cancer therapy, but only work in a subset of patients and can lead to a multitude of toxicities, suggesting the need for more targeted delivery systems. Due to their preferential colonization of tumors, bacteria are a natural chassis for the localized delivery of such therapeutics. Therefore, we engineered a commercially available probiotic, E.coli Nissle 1917 (EcN), for the controlled production and intratumoral release of nanobodies targeting programmed cell death protein – ligand 1 (PD-L1) and cytotoxic T- lymphocyte-associated protein-4 (CTLA-4) using the described lysing release mechanism. We demonstrate that a single injection of this engineered probiotic enhanced therapeutic response compared to analogous clinically-relevant antibodies, resulting in tumor regression in syngeneic mouse models. In an effort to create a more effective therapeutic for poorly immunogenic cancers, we utilized the modularity of our platform to slow tumor growth in mouse models of established CRC by combining it with a probiotically-produced cytokine, granulocyte-macrophage colony stimulating factor (GM-CSF). We sought to expand upon the relevance of this approach for early-stage CRC screening and treatment, by characterizing the platform in CRC precancerous lesions, or adenomas. When orally-delivered, EcN robustly colonized adenomas in genetically-engineered and orthotopic murine models of CRC, and human CRC patients. Leveraging adenoma-specific colonization, we probed for EcN presence in fecal matter, demonstrating its utility as a non-invasive screen for adenomas. For more accessible testing, we engineered EcN to produce salicylate and showed that it could be detected in the urine of tumor-bearing mice for days after oral delivery of the probiotic. Moreover, we demonstrated that the therapeutic effectiveness of our previously engineered therapeutic strain, producing PD-L1, CTLA-4 and GM-CSF, was maintained when delivered orally, ultimately resulting in significant adenoma reduction. Altogether, this dissertation aims to highlight the potential for engineered EcN to be used as a safe, orally-deliverable screening and therapeutic platform for early-stage CRC disease. While we have chosen to focus on CRC here, we will conclude by discussing efforts to adapt this platform to work in combination with other cellular therapies and therapeutic indications, ultimately engineering a platform to impact a broader patient population.

In my dissertation, I have worked on two distinct projects related to the immune system. The abstracts for the two projects that make up my dissertation work are below. In the first project (presented in Chapter 2), we study regulatory T (Treg) cells in chronic liver disease. Current dogma holds that Treg cells preserve tissue function in settings of inflammation and damage. Consistent with this, herein we observe that Treg cells – in particular those producing the epidermal growth factor receptor (EGFR)-ligand amphiregulin (Areg) – are enriched in the livers of mice and humans with non-alcoholic steatohepatitis (NASH). Mouse and human Treg cells undergo substantial transcriptional changes in chronic liver damage, reflecting their increased activation; however, rather than playing a protective role, we find that Treg cell–derived Areg promotes NASH-induced liver fibrosis, the key prognostic factor for patients – through the direct activation of EGFR on hepatic stellate cells. Clinically, NASH is closely linked to insulin resistance, but the mechanistic contributions of NASH-induced disease processes to insulin resistance has hitherto been unclear. We further observe that Treg cell–derived Areg promotes glucose intolerance in a NASH-dependent manner, also mediated through EGFR signaling on hepatic stellate cells. Mechanistically, in the setting of NASH, we find that Areg from Treg cells promotes hepatocyte gluconeogenesis – through hepatocyte detection of fibrosis development and soluble mediators, including IL-6, produced by activated hepatic stellate cells – offering new insight into the cellular interplay of how chronic liver disease promotes insulin resistance. Taken together, we provide the first evidence that Treg cells mediate a maladaptive role in tissue injury, finding that their production of a growth factor plays a central role in liver disease and promotes liver fibrosis and glucose intolerance in NASH. In the second project (presented in Chapter 3), we use engineered bacteria to produce chemokines in the tumor to promote anti-tumor immunity. Tumors employ multiple mechanisms to actively exclude immune cells involved in anti-tumor immunity. Strategies to overcome these exclusion signals remain limited due to an inability to target therapeutics specifically to the tumor. Synthetic biology enables engineering of cells and microbes for tumor-localized delivery of therapeutic candidates previously unavailable using conventional systemic administration techniques. Here, we engineer bacteria to intratumorally release chemokines to attract adaptive immune cells into the tumor environment. Bacteria expressing an activating mutant of the human chemokine CXCL16 (hCXCL16K42A) offer therapeutic benefit in multiple mouse tumor models – an effect mediated via recruitment of CD8+ T cells. Furthermore, we target the presentation of tumor-derived antigens by dendritic cells – using a second engineered bacterial strain expressing CCL20. This led to type 1 conventional dendritic cell recruitment and synergized with hCXCL16K42A-induced T cell recruitment to provide additional therapeutic benefit. In summary, we engineer bacteria to recruit and activate innate and adaptive anti-tumor immune responses, offering a new cancer immunotherapy strategy.