Introduction/purpose: Recovery from muscle damage involves a type of programmed cell death known as apoptosis. Damage Associated Molecular Patterns (DAMPs) are released after muscle damage and may cause premature apoptosis in monocytes infiltrating the damaged site. This may alter the time course of events towards recovery. Therefore, the purpose of this study was to investigate if downhill running causes a change in the susceptibility of monocytes to apoptosis. Methods: Participants (5 male, 6 female) completed a downhill running protocol consisting of 6-5 minute bouts at a speed of 6-9mph on a -15% grade treadmill. Venous blood samples were collected immediately pre-exercise (PRE), in addition to 4 -h, 24 -h and 48 -h post-exercise. Creatine kinase (CK) was measured to give an indication of muscle damage. Monocytes were analyzed by flow cytometry for expression of multicaspase and annexin v reagent was used to detect changes in the plasma membrane. A MILLIPLEX MAP human early apoptosis magnetic bead 7-plex kit (EMD Millipore, Billerica, MA) was used to assess the relative concentration of phosphorylated protein kinase B (Akt), Bcl-2 associated death promoter (BAD), B cell lymphoma-2 (Bcl-2), active caspase-8, active caspase-9, c jun N terminal kinase (JNK) and tumor protein p53 by Luminex multiplex assay. Results: CK peaked at 24- h. Monocytes showed greater expression of multicaspase at 24 –h and 48 -h than at PRE. Bcl-2, p53 and caspase-8 were all significantly greater at 24 –h than at PRE. Conclusion: Downhill running did alter the apoptotic response of monocytes and therefore may be important in the recovery process from muscle damage.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Monocytes and macrophages are important components of the innate immune response. These mononuclear phagocytes form a heterogeneous cell population, of which phenotype and functions can be modified under the influence of different signals coming from the surrounding microenvironment. The aim of this work was to modulate the phenotype of these cells by a variety of stimulants and to compare the changes induced on the model of THP-1 monocytic cell line and on the human peripheral blood monocytes. Surface marker expression was analyzed by flow cytometry. Further on, IL-8 production was evaluated by Luminex assay and the concentration of soluble calprotectin was assessed by ELISA. The most significant changes in surface marker expression were induced by exposure to IFNγ. This cytokine increased the expression of CD54, CD14 and HLA-DR on the surface of THP-1 cell line. Higher concentrations of IFNγ promoted higher apoptotic rate and augmented calprotectin expression and production in THP-1 cell line. On the surface of monocytes, IFNγ stimulation resulted only in the upregulation of CD54 expression. IL-4 increased the expression of CD36 by THP-1 cell line and inhibited the expression of CD163 by human monocytes. LPS stimulation caused the suppression of HLA-DR activation in monocytes and enhanced IL-8...

Sarcoidosis is a multisystem inflammatory disorder of unknown aetiology. The immune pathology is characterised by dysregulated T cell (T_H1) activity, macrophage activation and granuloma formation, resulting in systemic inflammation, and organ dysfunction. I hypothesised that, as the systemic precursor to the macrophage, altered monocyte activity in sarcoidosis may contribute to the early immune pathology of the disease. In this thesis, I examined their phenotype, four key monocytic functions: cytokine production, suppression of T cell proliferation, phagocytosis and fusion (as a precursor to granulomagenesis); and their gene expression profile compared to monocytes from healthy controls. My data show that the expanded monocyte compartment comprise a greater proportion of the inflammatory (CD14⁺⁺CD16⁺) and patrolling (CD14⁺CD16⁺⁺) subsets, increased TNFα and IL-12 and decreased IL-10 and IL-4 production in sarcoidosis compared with healthy controls. The IL-10 deficit renders the monocytes less able to regulate T cell proliferation or their own fusion to multinucleate giant cells, potentially contributing to T cell expansion and granuloma formation respectively. Additionally, sarcoidosis monocytes are less able to phagocytose inert material. I also showed that previously reported deficiency in invariant NKT cells and low serum vitamin D levels in sarcoidosis may be linked to reduced IL-10 production by monocytes. Vitamin D treatment in vitro restored most of these deficiencies and provides a potential therapeutic method for manipulating monocyte function and disease genesis in sarcoidosis.

Sepse é uma síndrome, na qual, o paciente apresenta lesões de órgãos com risco a vida, em decorrência de uma inflamação exagerada desencadeada por uma infecção. Estima-se uma ocorrência anual de 31,5 milhões de casos de sepse e 19,4 milhões de casos de choque séptico no mundo, causando potencialmente 5,3 milhões de mortes. Esses índices alarmantes fizeram com que em 2017, a Organização Mundial da Saúde (OMS) adotasse uma resolução com o objetivo de aperfeiçoar a prevenção, diagnóstico e tratamento dessa condição clínica que vem sendo negligenciada. A iniciação da sepse, ocorre quando há um descontrole da infecção, acarretando excessiva ativação de células do sistema imune inato. Isso resulta em uma inflamação sistêmica danosa que é responsável pela maioria das alterações fisiopatológicas da sepse. Nesse contexto do sistema imune inato, o papel de neutrófilos já é bem compreendido da patogênese da sepse. Contudo, a função dos monócitos inflamatórios ainda não é bem estabelecida. Ao mesmo tempo que essas células podem participar do controle de infecções, elas também podem contribuir com a inflamação sistêmica e a lesão de órgãos. Deste modo, a compreensão do papel dessas células se faz importante para determinação de novos alvos terapêuticos para essa condição clínica. Nossos resultados demonstraram, em modelo experimental de sepse, que o aumento da emigração de monócitos inflamatórios da medula óssea está relacionado com maior taxa de mortalidade dos animais e exacerbação da inflamação sistêmica. A migração dessas células para órgãos, como rim e pulmão, está relacionado com inflamação e aumento de lesões, nesses locais. Deste modo, conclui-se que monócitos inflamatórios possuem um papel deletério na patogênese da sepse / Sepsis is a syndrome in which the patient has life-threatening organ damage due to an exaggerated inflammation triggered by an infection. The annual occurrence is 31.5 million cases of sepsis and 19.4 million cases of septic shock in the world, which potentially cause 5.3 million deaths. In concern of these alarming reports in 2017, the World Health Organization (WHO) adopted a resolution aimed at improving the prevention, diagnosis and treatment of this neglected clinical condition. The initiation of sepsis occurs when the infection was not controlled, causing excessive activation of the innate immune cells. This excessive activation causes a systemic inflammation that is responsible for most pathophysiological phenomena in sepsis. In this context of the innate immune system, the role of neutrophils is already well understood in the pathogenesis of sepsis. However, the role of inflammatory monocytes is not yet well established. These cells can participate in the control of infections, or can also contribute to systemic inflammation and organs damage. Thus, the understanding of the roles of these cells become important for the development of new therapeutic targets for this clinical condition. Our results demonstrated that the systemic increase of the inflammatory monocytes frequency is related to higher mortality rate, exacerbation of systemic inflammation, increased migration to organs (lung and kidney), and in these sites, are related to inflammation and lesions. Thus, we concluded that these cells have a deleterious role in the pathogenesis of sepsis

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg for the Degree of Master of Science / The antiinflammatory effects of lnterleukin-4 (IL-4) and the synthetic glucocorticoid dexamethasone were studied in adhered monocytes and the leukaemic cells HL-60 and THP-1, with respect to the expression of interleukin-lB (IL-lLB), the (signalling) IL-1 receptor type I (IL..1RtI), and the (inhibitory) IL-1 receptor type I (IL-lRtI). (Abbreviation abstract) / AC2018

Introduction Chikungunya virus (CHIKV) is an alphavirus in the family Togaviridae. Since 2005 the virus has caused a major epidemic of disease in humans, ranging from Central Africa, South-East Asia, Caribbean and more recently the Americas. The virus is spread by mosquitoes, most notably Aedes aegypti and Ae. albopictus. CHIKV causes an acute disease in humans, which is characterised by a rapid onset of high fever, rash, myalgia and arthralgia. The symptoms typically resolve within a week. Remarkably, up to a third of patients who recover from acute chikungunya develop chronic arthritis/arthralgia, which may last for months or years and has a large negative impact on the quality of life. The mechanism by which this occurs is not yet fully understood. CHIKV can infect human monocytes, and macrophages positive for CHIKV antigen have been observed in joint tissue from patients recovered from acute CHIKV infection but with chronic arthritis. Furthermore, it has been demonstrated that macrophages can be infected with CHIKV in vitro by a mechanism involving apoptotic debris from CHIKV-infected cells. Hypothesis and aims Infection of monocytes and macrophages with CHIKV contributes to clinical disease and virus persistence in vivo. The aim of this project was to investigate the mechanism by which alphaviruses infect macrophages in vitro, and to generate a CHIKV which is unable to replicate in monocytes and macrophages in vitro, and to study its pathogenicity in vivo. Materials and methods HeLa cells were infected with Semliki Forest virus (SFV), an alphavirus closely related to CHIKV, or SFV replicon particles (SFV VRP). Following cell death, whole cell supernatant or clarified cell supernatant from SFV- and SFV VRP-infected cells was passaged onto human monocyte-derived macrophages (MDMs). These cells were observed microscopically for expression of the fluorescent marker encoded by the SFV. Virus and VRP-infected apoptotic debris were inspected for the presence of alphavirus replication complexes by electron microscopy. Subsequently, a recognition element (RE) for a haematopoietic-specific miRNA (miR-142-3P) was incorporated into the genome of SFV (proof-of-concept) and CHIKV to investigate if blocking virus replication in cells of the mononuclear phagocyte system altered virus kinetics in vitro. The replication of the modified viruses was investigated in macrophage/monocyte cell lines Thp-1 and IC-21, and in HEK 293 cells modified to express miR-142-3P under the control of an inducible tetracycline promoter. Modified viruses were tested in animal models of disease (mouse for SFV and non-human primate for CHIKV) to investigate the pathogenicity of these viruses in vivo. Results The presence of apoptotic debris from SFV-infected cells was required to infect MDMs with SFV. The presence or absence of infectious virus particles in the apoptotic debris did not affect the infection rate. Intact alphavirus replication complexes were found within the apoptotic debris. MiR-142-3P RE was successfully incorporated into the genome of both SFV and CHIKV. RE-virus replication in all cells expressing miR-142-3P was reduced by 90-99% when compared to control viruses. RE-virus replication was not affected in cells which did not express miR- 142-3P. In interferon-α/β receptor knockout mice, RE-SFV generated viraemia comparable to the control virus, but could not infect efficiently the population of macrophages resident in the marginal zone of the spleen. RE-CHIKV was found to be genetically stable in vitro following multiple passages on BHK-21 cells in the absence of a selective pressure from miR-142-3P. RE-CHIKV was inoculated into two cynomolgus macaques. The data from this experiment are not yet available. Conclusion SFV was shown to infect MDM via apoptotic debris containing intact alphavirus replication complexes, which were the most likely infectious agent. SFV and CHIKV unable to replicate in haematopoietic cells in vitro were successfully engineered. The pathogenicity of modified SFV and CHIKV was investigated in vivo.

Orientador: James Venturini / Resumo: A paracoccidioidomicose (PCM) é micose sistêmica causada por fungos do gênero Paracoccidioides. As principais formas clínicas da doença são aguda/subaguda e crônica (FC), sendo que nessa última, a maioria dos pacientes desenvolvem fibrose pulmonar e enfisema. Estudos prévios demonstraram que pacientes FC, na forma ativa da doença, apresentam elevada produção de mediadores inflamatórios, incluindo a IL-1β. Essa citocina, diferente das demais, é produzidas por uma plataforma protéica intracelular denominada inflamassoma que pode ser ativadas por patógenos e sinais de dano do hospedeiro. Considerando-se que os mecanismos de ativação do inflamassoma em pacientes com PCM não são conhecidos, o presente estudo teve por objetivo determinar a expressão de genes envolvidos na ativação do inflamassoma e a produção de citocinas por monócitos e macrófagos alveolares de pacientes com PCM em diferentes momentos do tratamento antifúngico.Nossos resultados demonstram a ativação do NLRP3-inflamassoma, caracterizada pela elevada expressão de NLRP3, CASP1 e IL1B por monócitos. Esses achados corroboram a contribuição do NLRP3-inflamassoma na patogênese da PCM também em pacientes. / Abstract: Paracoccidioidomycosis (PCM) is a systemic mycosis caused by species of the genus Paracoccidioides . The main clinical forms of the disease are acute/subacute (AF) and chronic (CF), and in the latter, most patients develop pulmonary fibrosis and emphysema. Previous studies showed that CF patients in active disease, exhibit elevated production of inflammatory mediators, including IL-1β. This cytokine, different from the others, are produced by an intracellular multiprotein platform called inflammasome that can be activated by pathogens and host signs of damage. Considering that the activation mechanisms of the inflammasome in patients with PCM are not know, this study aimed to determine the expression of genes involved in inflammasome activation and cytokine production by monocytes and alveolar macrophages from PCM patients at different times of antifungal treatment. Our results demonstrate the activation of the NLRP3 inflammasome-characterized by high expression of NLRP3, CASP1 and IL1B by monocytes. These findings corroborate the contribution of NRLP3-inflamassome in pathogenesis of PCM also in patients. / Mestre

Made available in DSpace on 2014-07-29T15:26:24Z (GMT). No. of bitstreams: 1 LEDICE TESE.pdf: 4130760 bytes, checksum: 417837b74b4f56201f6555cdb552d8b2 (MD5) Previous issue date: 2012-08-31 / American Tegumentary Leishmaniasis (ATL) is caused by Leishmania protozoan that infects mononuclear phagocytic cells leading to cutaneous or mucosal lesions. The mechanisms responsible for parasite control or persistence are not completely known. Human monocytes are blood cells subdivided into three subsets (classical, nonclassical and intermediate) according to the CD14 and CD16 expression that is associated with different phenotypical and functional characteristics. The aim of this study was to evaluate the profile of monocytes in ATL. First, it was analyzed the nonclassical monocytes (CD14loCD16+) and CD56+CD16+ NK cell frequencies in peripheral blood (by using flow cytometry) of a patient with diffuse cutaneous leishmaniasis (DCL) before, during and after immunochemotherapy (chemotherapy treatment together with L. (L.) amazonensis and L. (V.) braziliensis monovalent vaccines plus BCG). Then, in localized cutaneous leishmaniasis (LCL) patients (n = 32) and healthy donors, the three monocyte subsets (CD14hiCD16-, CD14hiCD16+, CD14loCD16+) were evaluated by flow cytometry; in the whole blood cultures we evaluated the expression of cytokines in CD14+ monocytes activated with lipopolysaccharide (LPS, by flow cytometry), and the secretion of proinflammatory (tumor necrosis factor, TNF) and antiinflammatory (interleukin 10, IL-10) after activation with Toll-like receptor agonists (TLR2 (Pam3Cys), TLR4 (LPS)) or L. (V.) braziliensis antigen (Ag; ELISA was used). In DCL patient it was detected an increase in non classical monocytes and NK cell frequencies probably associated to BCG stimulation, contributing to the clinical cure of several lesions caused by L. (L.) amazonensis. In LCL patients, the CD16+ monocyte subsets were increased before treatment. A similar TNF and IL-10 expression in CD14+ monocytes activated with LPS was found in patients and controls. It was not possible to identify which monocyte subpopulation was the responsible for the TNF or IL-10 production due to alterations of the percentages of each subset after LPS stimulation. Activation through TLR2, TLR4 or with Ag leads to a higher production of TNF but not IL-10 in whole blood cultures of patients than of controls. Whereas in healthy controls there was a positive correlation between TNF and IL-10 production after different stimulations (LPS, Pam3Cys and Ag), this was not observed in LCL patients, except for TLR2 stimulation. A positive correlation was detected between amount of TNF in serum or in activated-whole blood cultures and the number of cutaneous lesions. These results suggested that nonclassical monocytes can contribute to the control of infection in DCL patient, a clinical form in which patients do not present acquired cellular immune response. In this case, activation of innate cells as monocytes can cause lesion regression decreasing costs with medicines and improving the life quality of the patients. On the other hand, in LCL patients monocyte subsets and cytokine imbalance, especially with increase of nonclassical and intermediate monocytes (CD14loCD16+, CD14hiCD16+) and TNF, can contribute to leishmaniasis immunopathogenesis. To understand the role of monocyte subsets in ATL can open new avenues to the identification of biological markers of disease severity as well as new therapeutic targets to ATL treatment. / A Leishmaniose Tegumentar Americana (LTA) é causada por protozoários do gênero Leishmania que infectam células do sistema fagocíticomononuclear, causando lesões na pele ou nas mucosas oral e nasofaríngea. Apesar dos vários estudos sobre a imunologia da LTA, o conhecimento ainda é insuficiente para a compreensão dos mecanismos que levam ao controle ou à persistência dos parasitos. Os monócitos são células do sangue que se subdividem em clássicos, não clássicos e intermediários, de acordo com a expressão de moléculas CD14 e CD16, apresentando diferenças fenotípicas e funcionais. O objetivo deste trabalho foi avaliar a participação dos monócitos na LTA. Para tanto, foram avaliadas as alterações nas frequências dos monócitos CD14loCD16+ (não clássicos) e de células NK CD56+CD16+ (por citometria de fluxo) do sangue periférico de um paciente com leishmaniose cutâneo difusa (LCD), antes e após imunoquimioterapia (tratamento quimioterápico mais vacinas monovalentes de L. (L.) amazonensis e de L. (V.) braziliensis com BCG). Em seguida, em pacientes com leishmaniose cutânea localizada (LCL), foram avaliadas as subpopulações de monócitos (CD14hiCD16-, CD14hiCD16+, CD14loCD16+, usando citometria de fluxo); a expressão de citocinas em monócitos CD14+ em hemoculturas ativadas com lipopolissacarídeo (LPS; usando citometria de fluxo); a produção de citocinas pro- (fator de necrose tumoral, TNF) e antiinflamatória (interleucina 10, IL-10) secretadas em hemoculturas ativadas com agonistas de receptores similares a Toll [TLR2 (Pam3Cys) e TLR4 (LPS)] ou antígenos de L. (V.) braziliensis (Ag; dosados por ELISA) e associação com dados clínicos. No paciente com LCD, houve um aumento da frequência de monócitos CD14loCD16+ e de células NK, provavelmente associado ao uso do BCG, que contribuiu para a cura clínica das lesões causadas por L. (L.) amazonensis. Nos pacientes com LCL, as subpopulações de monócitos CD16+ estavam aumentadas no sangue periférico, antes do tratamento. Foi detectada uma expressão similar das citocinas TNF e IL-10 intracelularmente nos monócitos CD14+, após cultura com LPS, de pacientes com LCL e indivíduos controles. Não foi possível avaliar quais subpopulações de monócitos estavam produzindo as citocinas, porque após ativação dos monócitos com LPS houve alterações nas porcentagens das subpopulações de monócitos. Após a ativação de hemoculturas com agonistas de TLR2 e TLR4 ou Ag, hemoculturas de pacientes com LCL produziram mais TNF e similares concentrações de IL-10 em relação às hemoculturas de indivíduos sadios. Enquanto em indivíduos sadios foi detectada uma correlação positiva entre as concentrações de TNF e IL-10 produzidas após diferentes estímulos (LPS, Pam3Cys e Ag), esta correlação não foi detectada nas hemoculturas de pacientes com LCL, exceto quando usado Pam3Cys. Houve uma correlação positiva entre as concentrações de TNF, presentes no soro e produzidos antes e após diferentes estímulos nas hemoculturas, e o número de lesões dos pacientes com LCL. Os dados sugerem que ativar os monócitos pode levar ao controle da infecção em paciente com LCD, uma forma clínica em que não há uma eficiente resposta imune celular adquirida, sendo, portanto, importante ativar células da imunidade natural que possam causar regressão das lesões, diminuindo os custos com medicamentos e melhorando a qualidade de vida do paciente. Por outro lado, na LCL, alterações nas subpopulações de monócitos e um desequilíbrio na produção de citocinas pro- e antiinflamatórias podem contribuir para a imunopatogenia da doença. Nos casos estudados houve aumento de monócitos não clássicos e intermediários (CD14loCD16+, CD14hiCD16+) e associação entre o número de lesões e a produção de TNF pelos monócitos. Uma compreensão sobre o papel das subpopulações de monócitos na LTA pode abrir novas perspectivas para a identificação de marcadores de gravidade da doença, bem como de futuros alvos terapêuticos na LTA.

A análise da expressão da enzima indoleamina 2,3-dioxigenase (IDO), envolvida na regulação da resposta imune, em vacinas de células dendríticas (DCs) como imunoterapia para tratamento de indivíduos HIV+, pode fornecer informações sobre o perfil dessas células e auxiliar o aperfeiçoamento das técnicas atualmente utilizadas. A avaliação da expressão de IDO, por citometria de fluxo, foi realizada em monócitos e DCs de indivíduos sadios e HIV+. A expressão do RNAm de IDO foi analisada por PCR e a capacidade das DCs em estimular linfoproliferação e apresentar antígenos de HIV a linfócitos autólogos foi avaliada por ensaio de cocultivo. DCs ativadas de indivíduos HIV+ demonstraram expressão mais elevada de IDO tanto em relação às DCs imaturas quanto em relação às DCs dos indivíduos sadios. DCs foram capazes de induzir resposta proliferativa e polifuncional de linfócitos autólogos. Nossos resultados sugerem uma expressão diferencial de IDO entre indivíduos sadios e HIV+, indicando um importante papel da enzima no controle da resposta imune e na patogênese da AIDS. / The evaluation of indoleamine 2,3-dioxygenase (IDO) levels, a regulatory enzyme, in the context of DCs vaccines as a therapeutic alternative for the HIV+ patients, can bring information about DCs profiles that can improve current techniques of vaccine production. IDO expression was evaluated by flow cytometry in monocytes and DCs from healthy subjects and HIV+ patients. Expression of IDO mRNA was performed by real-time PCR and the ability in stimulate lymphoproliferation and presenting HIV antigens to autologous lymphocytes was evaluated in coculture assays. Comparison between immature and activated DCs showed an increased IDO expression in activated DCs in patients group. DCs derived from HIV+ patients showed an increased IDO expression when compared to healthy donors. DCs were able to induce lymphofoproliferation and polyfunctional response in autologous lymphocytes. Our results suggest a differential expression of IDO between health subjects and HIV+ patients, indicating an important role of IDO in the control of the immune response and in the HIV pathogenesis.