All eukaryotic organisms have an innate immune system characterized by germ-line encoded receptors and effector molecules, which mediate detection and clearance of microbes such as bacteria, fungi, and parasites. VertebrateDrosophila as a genetically tractable organism with a This thesis concerns the peptidoglycan recognition protein (PGRP) gene family in the fruit fly. The family consists of thirteen genes, of which a few have been reported to be part of the signaling pathways that regulates immune Data presented show that the putative receptors have affinity for peptidoglycan, but not for lipopolysaccharide, or the fungal cell wall polymer beta-glucan. PGRP-SA, receptor of the Toll pathway, has a preference for In a search for novel PGRP receptors I found two PGRP proteins that instead displayed enzymatic activity towards peptidoglycan. They are of the N-actylmuramoyl L-alanine amidase type, which degrades peptidoglycan by splittingStaphylococcus aureus peptidoglycan looses its immune elicitor capacity. This is in contrast to lysozyme-degraded peptidoglycan, which isDrosophila PGRPs to be potential enzymes. PGRP-SB1 is the other enzymatic PGRP described within this thesis. It has a moreBacillus megaterium. In conclusion, receptor PGRP proteins binds bacterial peptidoglycan and triggers immune gene pathways and enzymatic PGRPs have the capacity to reduce the elicitor property of peptidoglycan.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 243 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 213-240).

<p>The Immunity-Related GTPases (IRGs) are a family of dynamin-like proteins found in vertebrates that play critical roles in cell-autonomous resistance to bacteria and protozoa. The IRGs are divided into two subfamilies, with the GMS IRGs exerting a regulatory function over the GKS IRGs, affecting GKS IRG expression, localization, and ultimately function. The profound loss of host resistance seen in mice lacking the GMS protein Irgm1 suggests that GMS IRGs may additionally have broader functions beyond the regulation of GKS IRGs, though the nature of these functions remains poorly understood. In this dissertation, we address the regulatory functions of GMS IRGs in mouse cells.</p><p>We first addressed regulation of GKS IRGs (Irga6 and Irgb6) by GMS IRGs (Irgm1 and Irgm3). We found that in both fibroblasts and macrophages lacking these GMS IRGs, that the GKS IRGs relocalized to form punctate structures that were ubiquitin-, p62-, and LC3-positive. A biochemical analysis indicated that the GKS IRGs were directly ubiquitinated through K63 linkages. Collectively, these results suggested that GMS IRGs regulate aggregation of GKS IRGs and their transfer to autophagosomes through one of at least two possible mechanisms -- by the direct association of GMS IRGs with GKS IRGs to block their aggregation that subsequently leads to autophagic removal, and/or by directly promoting autophagic removal of spontaneously forming GKS aggregates. The latter hypothesis was addressed using a series of complementary assays, which ultimately showed that absence of Irgm1 has no effect on the maturation of autophagosomes in fibroblasts, and only a very small and statistically insignificant effect in macrophages. Thus, we conclude that the major mechanism through which GMS IRGs regulate GKS IRGs is by directly inhibiting their aggregation, rather than through general effects on autophagic initiation or maturation of GKS IRG-containing autophagosomes.</p><p>We also addressed the possibility of broad regulatory functions of GMS IRGs beyond the regulation of GKS IRGs by examining whether GMS IRGs can affect another family of dynamin-like GTPases, the guanylate-binding proteins (GBPs). Despite no previous evidence of interactions between these two protein families, we found that the absence of GMS IRGs had striking effects on the localization of the murine Gbp2, leading it to colocalize with GKS IRG aggregates formed as a consequence of GMS IRG deficiency. We further demonstrated that unlike the GKS IRGs, Gbp2 was not tagged with K63-linked ubiquitin chains, which might have targeted it for specific macroautophagy, implying that Gbp2 is not aggregating in the absence of Irgm1. We then showed both that Gbp2 forms puncta in the presence of generic protein aggregates, and that guanylate-binding proteins including Gbp2 promote the degradation of GKS IRG protein aggregates. These findings suggest that GMS IRGs do not exert direct control over GBPs, but rather that GBPs are involved in the macroautophagic degradation of protein aggregates as a primary function, and are thus influenced indirectly by GMS IRGs.</p><p>In total, our experiments contribute to the understanding of regulatory interactions among GMS IRGs, GKS IRGs, and GBPs. These results will be important in establishing the mechanisms through which these important families of proteins influence eradication of bacterial and protozoan pathogens through key innate immune mechanisms.</p> / Dissertation

The use of metals like titanium (Ti) and vanadium (V) are common in many medical implants for orthopaedic and orthodontic purposes. The most frequent cause of implant failure is aseptic loosening, resulting from an inflammatory reaction and increased osteolysis at the bone-metal interface. Currently, the pathophysiological mechanism of aseptic loosening remains poorly understood. One hypothesis suggests the reactivity of immune cells (metal hypersensitivity) towards metal ions released through the biocorrosion of metal implants. This thesis examines the effects of titanium and vanadium ions on various immune cells like monocytes, dendritic cells (DCs) and T-lymphocytes. Thereby investigating the role and mechanism which titanium and vanadium plays in aseptic loosening. Through energy filtered transmission electron microscopy, the accumulation of titanium ions was visualized in human monocyte-derived DCs and T-lymphocytes after 24 hours exposure. Titanium was seen to co-localise with phosphorous-rich regions, like the cell membrane, organelles and nucleus of these cells. Flow cytometry measured changes in the cell surface marker expression of monocytes, osteoclasts, DCs and T-lymphocytes treated with the metals. Monocytes exposed to titanium (IV) showed an increase of Tartate-Resistant Acid Phosphatase (TRAP), important for osteolysis and indicative of differentiation towards an osteoclast-like phenotype. DCs treated with Ti(IV) and vanadium (III) had reduced antigen presenting MHC class II expression, but not a reduced capacity to proliferate non-adherent peripheral blood monocytic cells (naPBMCs). Under the influence of Ti(IV), T-lymphocytes, DCs and monocytes expressed elevated levels of the chemokine receptor, CCR4. This would allow for the migration of CCR4+ cells towards the bone and skin regions. Functional changes were measured with BrdU incorporation proliferation assays, cytokine assays (CBA Kits) and the successful generation of titanium-specific T-lymphocytes from Ti(IV) treated DCs. Ti(IV) specific T-lymphocytes conceptually shows the possible formation of an antigenic titanium-protein complex, which can be recognized by the immune system. DCs treated with Ti(IV) and V(III) were able to cause the proliferation of naPBMCs, even with a reduced antigen presenting capability. However, there was no additional influence of V(III) on the immune response through DCs. Cytokines released by DCs and T-lymphocytes after Ti(IV) treatments showed a skew towards an inflammatory Th1-type response through the release of TGF-! and IL-12p70. Activated T-lymphocytes exposed to Ti(IV) also released RANK-L, which drives osteoclastogenesis and subsequently increased osteolysis. The research supports and suggests an interaction between immune and bone cells where titanium-induced inflammation drives an osteolytic cycle that prevents the integration of metal implants into the bone. Hence, suggesting a mechanism for implant failure through aseptic loosening in patients with titanium-vanadium implants.

Foi avaliado o desempenho de vacina de subunidade e bactéria completa antileptospirose em matrizes suínas analisando-se os níveis de anticorpos aglutinantes e neutralizantes. A intensidade e duração da imunidade passiva nos leitões, e ativa nas matrizes suínas foi investigada pela soroaglutinação microscópica (SAM) e teste de inibição de crescimento de leptospiras (ICL) em grupos de animais tratados com vacina experimental de subunidade e leptospira completa produzida com a mesma estirpe e com duas bacterinas comerciais. O experimento foi realizado em duas fases, na primeira, sendo utilizadas 33 matrizes. Os animais foram divididos em três grupos: grupo 1 (n=11):controle; grupo 2 (n=11): recebeu duas doses, em intervalo de 30 dias, de vacina anti-leptospirose constituída da subunidade de lipopolissacarídeo (LPS) de leptospira sorovar Canicola. Grupo 3 (n=11): recebeu duas doses, em intervalo de 30 dias, de uma bacterina de bactérias completas antileptospirose. Na segunda fase foram utilizadas 24 matrizes. Os animais foram divididos em três grupos: Grupo A (n=08): recebeu duas doses, em intervalo de 30 dias, de bacterina comercial anti-leptospirose A. Grupo B (n=08): recebeu duas doses, em intervalo de 30 dias, de bacterina comercial antileptospirose B e Grupo C (n=08): controle. Tanto na primeira fase como na segunda, foram realizados exames de SAM e de ICL nas matrizes e nos seus leitões, a fim de se avaliar títulos de aglutininas e de anticorpos neutralizantes obtidos respectivamente com a imunidade ativa e passiva. Os resultados das comparações dos títulos de anticorpos aglutinantes dos grupos tratados, 2 e 3, na primeira fase, apresentaram diferença aos 32 e 68 dias pós-vacinação. Não houve diferença para os anticorpos neutralizantes. No 30&ordm; dia de vida não foram detectados anticorpos aglutinantes nos leitões das matrizes vacinadas com LPS, e para anticorpos neutralizantes, os títulos médios foram de 0,832 no grupo 2 e 0,930 no grupo 3. Os títulos de anticorpos aglutinantes dos grupos A e B, na segunda fase, apresentaram diferença entre os sorovares das bacterinas comerciais, aos 60, 90 e 120 dias pós-vacinação. Aos 60 dias, houve diferença para o sorovares Copenhageni e Icterohaemorrhagiae. Em relação aos níveis de anticorpos neutralizantes das matrizes para o sorovar Hardjo, houve persistência de títulos de anticorpos neutralizantes nas sete avaliações realizadas nas duas bacterinas comerciais empregadas, e, em títulos baixos. Nos leitões foi constatada a transferência da imunidade colostral, somente com a bacterina comercial B confirmada pela presença de anticorpos aglutinantes, aos três e oito dias de vida. A vacina de LPS de bactéria completa apresentou perspectivas para emprego na prevenção da leptospirose suína. Houve diferença e baixa resposta imunológica nas bacterinas comerciais A e B anti-leptospirose, principalmente, para os sorovares Canicola, Grippotyphosa, Icterohaemorrhagiae e Pomona, Copenhageni para a bacterina comercial B. A imunidade passiva, medida por anticorpos aglutinantes conferida pelas bacterinas comerciais A e B, foi de curta duração. / It was evaluated the performance of a subunit and whole culture bacterin vaccines against leptospirosis in sows by the analysis of agglutinating and neutralizing antibodies level. The intensity and duration of passive immunity in the offspring and active immunity in sows were investigated with microscopic agglutination test (MAT) and leptospira growth inhibition (LGI) in groups of animals treated with experimental subunit vaccine and whole bacterin produced with the same serotype and with two commercial bacterin vaccines. The experiment was performed in two phases. First, 33 sows were divided into three groups of eleven animals each: group 1 was the control and group 2 received two doses with 30 days interval of anti-leptospirosis lipopolysaccharid (LPS) subunit vaccine serovar Canicola and group 3 received two doses with 30 days interval of whole leptospira bacterin. On a second phase 24 sows were divided into three groups of eight animals each: group A received two doses with 30 days interval of the commercial leptospira bacterin A. Group B received two doses with 30 days interval of a commercial leptospira bacterin B and group C was the control. Either in the first phase as in the second one, MAT and LGI were performed in the sows and its piglets in order to evaluate titers of agglutinins and neutralizing antibodies obtained with active and passive immunities respectively. The comparison of agglutinating titers of groups 2 and 3 at the first phase showed differences on days 32 and 68 post vaccination. There was no difference in relation to neutralizing antibodies. Agglutinating antibodies were not detected on thirty days old piglets, born from sows vaccinated with LPS, and for neutralizing antibodies, mean titers were 0.832 on group 2 and 0.930 on group 3. Agglutinating antibodies titers of groups A and B, on the second phase, presented differences between the commercial vaccines serovars at 60, 90 and 120 post vaccination days. At 60 days, there were differences for serovars Copenhageni and Icterohaemorrhagiae. There was persistency of low titers of neutralizing antibodies to serovar Hardjo in the sows, for the seven measurements performed with the two commercial bacterins. It was observed colostral immunity transfer to piglets with three and eight days old only for commercial vaccine B, with detectable agglutinating antibodies. LPS bacteria vaccine presented perspectives to prevent swine leptospirosis. There was difference and low immunological response for commercial vaccines A and B, especially for serovars Canicola, Grippotyphosa, Icterohaemorrhagiae and Pomona; and for serovar Copenhageni only for commercial vaccine B. The passive immunity conferred by commercial vaccines A and B and measured by agglutinating antibodies had low duration.

Novilhas Holandesas (n=35) foram vacinadas e distribuídas em grupos de acordo com os adjuvantes presentes nas vacinas comerciais contra BVDV e BoHV-1: Halum (hidróxido de alumínio, n=9), Oleosa (emulsão oleosa, n=10), Prezent A (composto saponina, n=10) e Salina (controle, n=6). As reações locais e sistêmicas foram avaliadas às zero horas (h), seis, 24, 48, 72 e 168h pós-vacinal. A produção de anticorpos (ACs) foi mensurada nos dias da vacinação (D0), D21 e D42. Capítulo 1 O objetivo deste estudo foi avaliar a resposta inflamatória sistêmica em novilhas vacinadas contendo diferentes tipos de adjuvantes. O número de hemácias (P=0,009) e hemoglobina (P=0,028) foram maiores no grupo Prezent A após a 2a dose. Os teores de ferro foram maiores no grupo controle após 1ª e 2ª dose (P=0,000; 0,000). Em geral, no leucograma os grupos vacinados apresentaram decréscimo nos números de leucócitos (P=0,001) em 2ª dose, neutrófilos (%) (P=0,000; 0,000) em ambas aplicações e monócitos (%) (P=0,010) após 1ª dose. Os linfócitos (%) apresentaram aumento gradual após as duas doses (P=0,031; 0,000), observando-se menores proporções nos grupos Prezent A e Oleosa. Basófilos (%) após 2ª dose (P=0,012) e eosinófilos (%) (P=0,000; 0,000) foram mais reativos nos grupos Prezent A e Halum entre 24 e 72h. As novilhas Prezent A apresentaram maiores valores (P=0,000; 0,000) haptoglobina às 24 e 48h em relação aos demais grupos após a 1ª e 2ª dose. Em geral, a produção de EROs foi suprimida nas novilhas vacinadas em relação ao controle após 1a dose (P=0,018) e entre 24 à 168h após a 2a dose (P=0,002). Capítulo 2 O objetivo desta pesquisa foi avaliar os efeitos adversos associados às reações locais e sistêmicas, assim como verificar a reposta imune humoral induzida pelas vacinas. A reatividade local foi mais intensa no grupo Oleosa após a 1a dose (P=0,000), em contrapartida o grupo Prezent A após a 2a dose foi mais reativo (P=0,000). A temperatura retal foi elevada em Prezent A entre 0 a 24h em 1a dose (P=0,000). O escore de Doença Respiratória Bovina foi mais intensa no grupo Prezent A e Oleosa às 48 horas (P=0,0024). Os ACs contra BVDV foram detectados apenas em D42, observando-se médias semelhantes entre Prezent A (log2=5) e Halum (log2=5). A soroconversão foi maior em Halum (78%) em comparação ao Prezent A (40%) e oleosa (10%). Em relação ao BoHV-1, observou-se títulos e soroconversão em D21 nos grupos Halum (log2=3; 67%) e Prezent A (log2=1; 80%). No D42 verificou-se uma maior intensidade de resposta para Prezent A (log2= 6; 100%), seguido de Halum (log2=4; 100%) e Oleosa (log2=3,0; 60%). Os dados permitem concluir que a vacina contendo o adjuvante oleoso e Prezent A ocasionaram maior reatividade local, porém a Prezent A induziu maior resposta inflamatória sistêmica. A produção de ACs contra o BVDV e BoHV-1 foi mais intensa na vacina com hidróxido de alumínio e Prezent A. Estudos futuros são necessários para demonstrar os efeitos benéficos da resposta inflamatória sistêmica do Prezent A sobre a resposta imune adquirida mediada por células do tipo Th1. / Dairy heifers (n=35) were vaccinated and distributed according to adjuvants present in commercial vaccines against BVDV and BoHV-1: Halum (n=9), Oil (n=10), Prezent A (n=10) and Saline (n=6). The local and systemic reactions were evaluated at zero hours (h), 6, 24, 48, 72 and 168h post-vaccination. The production of antibodies (ABs) was measured at vaccination days (D0), D21 and D42. Chapter 1 The objective of this study was to evaluate the inflammatory systemic response in vaccinated heifers with products that contained different types of adjuvants. The numbers of red blood cells (P=0.009) and hemoglobin (P=0,028) were higher in Prezent A after the 2nd dose. The iron were higher in saline group after 1st and 2nd dose (P=0.000; 0.000). In leukogram, vaccinated groups showed a decrease in total leukocytes (P = 0.001) at 2nd dose, neutrophils (%) (P = 0.000; 0.000) in both applications and monocytes (%) (P = 0.010) . Lymphocytes (%) presented gradual increase after received two doses (P = 0.031; 0.000), showing smaller proportions in Prezent A and Oil groups. Basophils (%) after 2nd dose (P = 0.012) and eosinophils (%) (P = 0.000; 0.000) were more reactive in Prezent A and Halum groups between 24 and 72h. Prezent A group presented higher values (P = 0.000; 0.000) of haptoglobin at 24 and 48h compared to the other groups after the 1st and 2nd doses. In general, ROS production was suppressed in vaccinated heifers relative to control after the 1st dose (P = 0.018) and 24 to 168h after the 2nd dose (P = 0.002). Chapter 2 The objective of this research was to evaluate the adverse effects associated with local and systemic reactions as well measure humoral immune response induced by reproductive vaccines containing different adjuvants. Local reactivity was more intense in Oil group after the 1st dose (P = 0.000), in contrast, Prezent A group presented higher reactivity after the 2nd dose. Rectal temperature was higher in Prezent A between 0 and 48 hours in the 1st dose. Bovine Respiratory Disease score was higher in Prezent A and Oil groups at 48h (P=0.002). ABs against BVDV were detected only at D42, observing the similar averages between Prezent A (log2=5) and Halum (log2=5). The seroconversion was higher in Halum (78%) compared to Prezent A (40%) and oil (10%). The titers and seroconversion against BoHV-1 at D21 were observed in Halum (log2 = 3; 67%) and Prezent A (log2 = 1; 80%) groups. At D42 a higher response was observed for Prezent A (log2 = 6, 100%), followed by Halum (log2 = 4, 100%) and Oil (log2 = 3.0, 60%). The data allow to conclude that the vaccine containing oil adjuvant and Prezent A caused greater local reactivity, but Prezent A induced a greater systemic inflammatory response. The production of ABs against BVDV and BoHV-1 was more intense in Halum vaccine and Prezent A. Future studies are needed to demonstrate the beneficial effects of the systemic inflammatory response of Prezent A on the acquired Th1 cell-mediated immune response.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-06-28T14:37:59Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_FABIANA_LETICIA_DIGITAL.pdf: 2539644 bytes, checksum: ffb2ea48912cab654c0a8e8bdc397ac2 (MD5) / Made available in DSpace on 2016-06-28T14:37:59Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) TESE_FABIANA_LETICIA_DIGITAL.pdf: 2539644 bytes, checksum: ffb2ea48912cab654c0a8e8bdc397ac2 (MD5) Previous issue date: 2014-08-27 / FACEPE / O contato prévio com o leite de mães esquistossomóticas induziu, em camundongos adultos, potencialização da produção de anticorpos e aumento da capacidade de apresentação de antígeno pelos linfócitos B, em resposta ao antígeno heterólogo ovalbumina (OVA). Considerando a imunização com OVA um modelo vacinal, as reações inflamatórias e a produção de anticorpos em resposta a esse antígeno são importantes para o desenvolvimento de uma imunidade satisfatória do hospedeiro. Nesse sentido, as células Th1 e Th17 são importantes fatores para o desenvolvimento dessas respostas. Dessa forma, os camundongos deficientes na produção de IL-12/IL-23 (12p40 knockout-KO) são predispostos a desenvolverem uma resposta Th2 polarizada, tornando-se menos responsivos às vacinações. Diante disso, o presente trabalho investigou o efeito da amamentação em mães infectadas pelo Schistosoma mansoni sobre as imunidades humoral e celular de camundongos adultos C57BL/6 12p40 KO, em resposta ao modelo vacinal acima citado. Foram avaliados: a cinética das reações de hipersensibilidade in vivo; os níveis plasmáticos das imunoglobulinas IgG1 e IgG2a; a produção das citocinas IFN-γ, IL-17, IL-5, IL-6, IL-10 e TGF- pelas células esplênicas e a reação inflamatória provocada no coxim plantar. Para isso, camundongos machos, deficientes na produção de IL-12 e IL-23 (IL-12p40 KO) e camundongos selvagens (wild-type/WT) foram divididos nos seguintes grupos: camundongos IL-12p40 KO amamentados em mães infectadas (AI IL-12p40 KO); camundongos IL-12p40 KO amamentados em mães sem infecção (NANI IL-12p40 KO); camundongos selvagens amamentados em mães infectadas (AI WT) e camundongos selvagens amamentados em mães sem infecção (NANI WT). Cinquenta por cento dos animais de cada grupo foram imunizados com OVA em adjuvante. Os outros 50% porcento restantes permaneceram sem imunização. No grupo AI WT houve aumentado de produção de IgG2a, IL-5, TGF-β e IL-6, com baixos níveis de IL-17, em comparação ao NANI WT. Nos animais AI IL-12p40 KO, a produção de IgG2a, IL-5 e TGF-β foi mais alta do que o grupo NANI IL-12p40 KO e similar ao grupo AI WT, mas a produção de IL-6 foi mais baixa. O grupo AI WT mostrou intenso infiltrado inflamatório de eosinófilos na reação de hipersensibilidade tardia (RHT), com acentuado edema em comparação com o edema menos intenso e infiltrado inflamatório de neutrófilos do grupo NANI WT. Os animais NANI IL-12p40 KO e AI IL-12p40 KO não apresentam RHT, porém a reação inflamatória no AI IL-12p40 KO foi menos intensa que nos NANI IL-12p40 KO. Em conclusão, o contato com antígenos do parasito, através da amamentação, induziu, no descendente adulto, uma melhor resposta de anticorpo neutralizante, mesmo diante da deficiência na produção de IL-12e IL-23. Nesta condição, embora tenha havido uma notável produção de IL-5, a lactação em mães infectadas atenuou a reação inflamatória, provavelmente através da regulação cruzada entre TGF-β e IL-6, modulando, desta forma, o status de hiperativação desses animais. / The previous contact with mothers milk schistosomiasis induced in adult mice enhancement of antibody production and increased antigen presentation capacity by B lymphocytes in response to the heterologous antigen ovalbumin (OA). Considering immunization with OA one vaccine model, inflammatory reactions and antibody production in response to antigen are important for the development of a suitable host immunity. In this sense, the Th1 and Th17 cells are important factors for the development of these responses. Thus, mice deficient in IL-12/IL-23 (12p40 knockout-KO) are likely to develop a polarized Th2 response, making it less responsive to vaccination. Therefore, the present study investigated the effect of breastfeeding in mothers infected with Schistosoma mansoni on the humoral and cellular adult C57BL/6 12p40 KO in response to vaccination model mentioned above. Were evaluated: the kinetics of in vivo hypersensitivity reactions; plasma levels of IgG1 and IgG2a immunoglobulins; the production of the cytokines IFN-γ, IL-17, IL-5, IL-6, IL-10 and TGF-β by spleen cells and the inflammatory reaction induced in the footpad. To this end, male mice deficient in IL-12 and IL-23 (IL-12p40 KO) and wild-type mice (Wild-type/WT) were divided into the following groups: IL-12p40 KO mice suckled by infected mothers (IL-12p40 KO- SIM); IL-12p40 KO mice suckled by uninfected mothers (IL-12p40 KO); Wild-type mice suckled by infected mothers (SIM) and wild-type mice suckled by uninfected mothers (CONTROL). Fifty percent of animals in each group were immunized with OA in adjuvant. The other 50% remaining percent remained without immunization. In the SIM group was increased production of IgG2a, IL-5, TGF-β and IL-6, IL-17 with low levels compared to CONTROL. In animals IL-12p40 KO-SIM the production of IgG2a, IL-5 and TGF-β was higher than the IL-12p40 KO similar to group SIM, but IL-6 production was lower. The SIM group showed intense inflammatory infiltrate of eosinophils in the delayed hypersensitivity reaction (DTH), with severe edema compared with the less intense edema and inflammatory infiltration of neutrophils CONTROL group. The animals IL-12p40 KO and IL-12p40KO-SIM not have DTH, but the inflammatory reaction in the IL-12p40KO-SIM was less intense than in IL-12p40 KO. In conclusion, contact with parasite antigens, through breastfeeding, induced in adult offspring, better neutralizing antibody response, despite the deficiency in the production of IL-12 and IL-23. In this condition, though there has been a remarkable IL-5 production in lactating mothers infected with attenuated inflammatory response, probably via cross regulation between TGF-β and IL-6 modulate thereby the status of hyperactivation of these animals.

MYB30 est un facteur de transcription d’Arabidopsis thaliana connu pour son rôle de régulateur positif des défenses via la production d’acides gras à très longue chaîne (VLCFA). La cuticule, une couche hydrophobe protectrice qui recouvre les parties aériennes de la plante, est composée majoritairement de molécules lipidiques dérivées des VLCFA. Dans cette thèse, nous avons montré que le gène MYB30 est exprimé dans les cellules épidermiques de l’embryon, à une étape du développement qui coïncide avec la mise en place de la cuticule embryonnaire. Nos travaux révèlent que lors de l’embryogenèse, MYB30 contrôle l’expression de gènes de biosynthèse de la cuticule et la production de composés cuticulaires. En accord avec cela, nous avons montré que MYB30 est requis pour la formation d’une cuticule embryonnaire fonctionnelle. De plus, l’expression de MYB30 est dépendante de GASSHO1 et GASSHO2 (GSO1/2), deux récepteurs de type Receptor Like Kinase (RLK) impliqués dans une voie de signalisation spécifique à la graine, nécessaire pour la formation de la cuticule chez l’embryon. Nos données indiquent également que MYB30 régule négativement l’expression de GSO2, et que MYB30 pourrait agir en aval des deux RLK pour la formation de la cuticule embryonnaire. D’autre part, nous avons montré que ces deux RLK jouent également un rôle positif dans l’activation des réponses immunitaires de la plante adulte. Enfin, notre étude indique que MYB30 est aussi impliqué dans l’élongation cellulaire chez les plantules étiolées probablement via la régulation de la production de composés pariétaux. En conclusion, ces travaux identifient de nouveaux rôles pour MYB30, et le placent à l’interface entre les réponses de défense et le développement de la plante. / MYB30 is an Arabidopsis thaliana transcription factor known for its role of positive regulator of defense responses through the production of very long chain fatty acids (VLCFAs). The cuticle, a hydrophobic and protective layer that covers the aerial parts of the plant, is mainly composed of VLCFA-derived lipid molecules. In this thesis, we have shown that the MYB30 gene is expressed in the epidermal cells of the embryo, at a developmental stage that corresponds to the establishment of the embryonic cuticle. Our work reveals that during embryogenesis, MYB30 controls the expression of cuticle biosynthetic genes and the production of cuticular compounds. In agreement, we have shown that MYB30 is required for the formation of a functional embryonic cuticle. In addition, MYB30 expression is dependent on GASSHO1 and GASSHO2 (GSO1/2), two Receptor Like Kinases (RLKs) involved a seed-specific signaling pathway, necessary for the cuticle formation in the embryo. Our data also indicates that MYB30 negatively regulates GSO2 expression and that MYB30 may act downstream of the two RLKs in embryonic cuticle formation. Moreover, we have shown that these two RLKs also play a positive role in the activation of immune responses in adult plants. Finally, our study indicates that MYB30 is additionally involved in cell elongation in etiolated seedlings, likely by regulating the production of cell wall components. In conclusion, this work identifies new roles of MYB30, placing it at a crossroads between defense responses and plant development.

The global population is rapidly aging. It is estimated that over the next thirty years, the number of individuals >60 years of age will increase by over a billion, and the number of individuals over age 80 may increase by 300 million. As humans age, our immune system becomes progressively weaker through a process called immune senescence. This age-related decrease in immune function increases susceptibility to infection and chronic diseases. Sepsis is a leading cause of death worldwide. Over the past two decades, there has been an increased incidence of sepsis which is due, in part, to our aging population and immune senescence. The gut microbiome, which plays an essential role in health and disease, is altered in aging and sepsis. Specifically, the commensal microorganisms of the gut microbiota are replaced with potentially pathogenic bacteria. This contributes to immune dysfunction and worsened outcomes in critical illness. The innate immune system can be “trained” to respond more effectively to pathogens. We examined trained immunity as an approach to modulating immunosenescence and microbiome diversity in aging. We investigated the effect of trained immunity on: i) immune cells from healthy aging subjects and sepsis patients and ii) the diversity of the microbiome in aging and sepsis. Our results indicate that trained immunity is effective in combatting age-related immunosenescence. We found that β-glucan induced trained immunity enhances monocyte metabolism, increases functionality as well as alters the transcriptome and epigenome in aging individuals and sepsis patients. We also found that trained immunity induced the expansion of a unique population of myeloid cells in sepsis. These cells are defined as FSChi, CD11b+, GR-1hi and express high levels of immunosuppressive PD-L1. In addition, we found that trained immunity reversed age-related changes to the microbiome and prevented alterations to the microbiome in septic mice. We found that the Firmicutes/Bacteroidetes ratio increased in aging; however, trained immunity reversed this increase and increased Clostridia in aged mice. In sepsis, trained immunity prevented expansion of Proteobacteria observed in control mice. Thus, our results indicate that trained immunity may be effective in modulating immune senescence and the microbiome in aging and sepsis.

Background: Throughout human history infectious agents such as viruses have been one of the biggest threats to public health. One example of infectious agents that can cause severe malignant conditions in humans is the Epstein-Barr virus (EBV). This virus has been researched for decades but still a lot of its potential malignant functions remain to be elucidated. Autoimmunity, and especially multiple sclerosis (MS), has been strongly associated to EBV infection for a long time but the exact mechanisms behind this relationship are still largely unknown. Aim: The main aim of this study was to investigate the evidence connecting an EBV-specific dysregulated immune response to MS. Methods: This paper is written as a systematic review examining the latest science within the studied field. PubMed was searched for articles published between 2010-2020. Results: In total 15 studies were reviewed. Five out of seven studies found an altered antibody response towards EBV in patients with MS, while one demonstrated somewhat mixed results and one could not support such a pattern. Seven out of eight studies found an altered T cell response towards EBV in MS patients, while one could only support such a trend. Conclusions: This review confirms that there is strong evidence for a dysregulated EBV-specific immune response in MS patients. Evidence for a causal relationship between the failure to control a reactivated EBV infection and the progression of disease is suggestive, but this needs to be confirmed by further studies.