abstract: An estimated 267 million women worldwide are HSV-2 seropositive, including roughly 20% of reproductive-aged American women. HSV-2 is a neurotropic virus that establishes a persistent, life-long infection that increases risk for STI acquisition in individuals. The vaginal epithelium represents a critical first line of defense against infection, and during acute infection, underlying immune mechanisms in the epithelium may be critical to protect against disease pathogenesis. The recently identified pro-inflammatory cytokine IL-36gamma has been shown to be expressed at mucosal epithelia, including the female reproductive tract (FRT) and may be an important factor in host defense. Although IL-36gamma has been shown to be induced in the FRT after exposure to microbial products, the contributions of IL-36gamma to host defense mechanisms in response to this clinically relevant STI pathogen are not well understood. This dissertation describes the regulation of IL-36gamma in the FRT and explores its contribution to the host response against genital HSV-2 infection. To test the hypothesis that IL-36gamma is a key regulator of mucosal inflammation and immunity in the FRT, hormonal regulation of IL-36gamma in the FRT was investigated using estrogen- and progesterone-conditioned mice. From this preliminary study, it was shown that progesterone dampens IL36G expression relative to estrogen and may potentially increase susceptibility to infection. Next, the impact of IL-36gamma treatment on HSV-2 infection and replication in human 3-D vaginal epithelial cells was explored. In parallel, the impact of intravaginal IL-36gamma delivery on HSV-2 disease pathogenesis was evaluated using a lethal murine challenge model. IL-36gamma pre-treatment significantly limited HSV-2 replication in vitro and in vivo and was associated with transient neutrophil infiltration that corresponded with decreased disease severity and increased survival in mice. Last, the requirement for IL-36gamma in host defense was investigated utilizing IL-36gamma-/- mice in a lethal HSV-2 murine challenge model. Following infection, IL-36gamma-/- mice exhibited significantly impaired neutrophil recruitment, decreased overall survival time, and significantly increased viral neuroinvasion relative to wild type mice. Collectively, these data indicate that IL-36gamma is a crucial regulator of HSV-2-induced neutrophil infiltration and appears to function in a previously uncharacterized manner to limit viral neuroinvasion in genital HSV-2 disease pathogenesis. / Dissertation/Thesis / Doctoral Dissertation Molecular and Cellular Biology 2019

Toll-like receptor 4 (TLR4) belongs among chief bacteria-sensing Pattern recognition receptors. Endotoxin (lipopolysaccharide, LPS) recognition by TLR4 triggers signalling leading to release of cytokines that direct leukocyte infiltration into the inflammatory site and cause swelling. Effector mechanisms that ensure pathogen elimination include phagocytosis and oxidative burst. It has been repeatedly reported that the polymorphism in TLR4 may affect host resistance to various diseases. TLR4 may be, therefore, an important molecule in host-parasite co-evolution. Herein, I focused on TLR4 amino acid substitution Q549R which is associated with ornamentation in great tits. In tits I describe immune responsiveness to LPS stimulation on morphological and molecular level and examine effects of the Q549R substitution on inflammation and general body condition. In LPS- treated individuals I found decrease in heterophil-lymphocyte ratio (H/L) that might be caused by attraction of the blood-borne cells into the inflamed tissue. This is in striking contrast with increase in H/L in PBS-treated animals resulting from the stress response. There was no effect of Q549R on general condition and haematological parameters but I revealed a significant effect of the interaction between host Q549R genotype and the type...

Ligand-activated signal transduction is a process critical to cell survival and function as it serves as a means of communication between the cells and their environment. Endocytosis is generally thought to down-regulate incoming signals by reducing the surface availability of receptors. However, increasing evidence in many systems suggests a notion which is referred to as the „signalling endosome" hypothesis - that endocytosis can also actively contribute to signalling apart from clearance of activated receptors and thereby attenuation of signalling. The functional aspect of signalling endosomes has been well-characterized in several pathways including RTK and TGF-β signalling. There are, however, various other signalling pathways where the active mechanism of endocytotic regulation is yet to be understood. In this study, we probe this aspect in the cytokine signalling system, where the receptors are known to internalize but the significance of such internalization and precise mechanism is unclear. My thesis aims to elucidate the function and molecular details of internalization of cytokine receptor using interleukin-4 receptor (IL-4R) signalling as a model. IL-4 and IL-13 ligands can induce assembly of three distinct complexes: IL4 induced IL-4Rα – IL-2Rγ (type I), IL-4 induced IL-4Rα – IL-13Rα1 (type II) or the IL-13 induced IL-13Rα1-IL-4Rα (type II). The formation of any of these complexes triggers signalling through the JAK/STAT pathway. However, models of how the oligomerization of the transmembrane receptors and activation takes place are very diverse and lack a clear molecular and biophysical understanding of the underlying receptor dynamics. Previous results of the lab had shown that the affinities between subunits are low, precluding complex formation at the plasma membrane at physiological concentrations. In addition, IL-4R subunits localize in to endosomal structures adjacent to the plasma membrane. It had already been shown that the shared IL-4R subunit IL-2Rγ is internalized by a specific, actin dependent, Rac1/Pak1 regulated endocytosis route in the IL-2 context. We could show that pharmacological suppression of this endocytosis pathway also prevented IL-4 induced JAK/STAT signalling, placing endocytosis upstream of signalling. Here I show using immuno-EM techniques that these endosomal structures are multivesicular bodies. Importantly, I could show that receptor subunits are highly enriched in the limiting membrane of these endosomes relative to the adjacent plasma membrane. Using quantitative loading assays I could furthermore demonstrate that this enrichment is achieved by constitutive internalization of receptors from the cell surface into cortical endosomes. The trafficking kinetics of the receptor subunits is independent of ligand occupancy. Pharmacological inhibition shows that receptors and ligand traffic via the previously identified Rac1/Pak1 pathway. Finally, Vav2 was identified as a candidate Guanine Exchange Factor (GEF) that may regulate Rac1 activity and thereby control the actin polymerization cascade driving IL-4R endocytosis. Immunoprecipitations showed that Vav2 interacts both with the cytoplasmic tail region of the receptors and the receptor associated 2 kinase JAK3. Vav2 may thus couple the receptor/JAK complexes to the Rac1/Pak1 mediated endocytosis route. Taken together, our results suggests that stable „signalling endosomes‟ adjacent to the plasma membrane act as enrichment centres, where ligand and receptor concentrations are locally increased by constitutive trafficking. The confined environment of the endosome then compensates for the weak affinities between the ligand and receptor and facilitates ligand-mediated receptor dimerization. Importantly, overexpression of both type II IL-4R subunits renders signal transduction resistant to endocytosis inhibition, strongly suggesting that the critical factor effecting signalling is sufficient concentration, which the endosomes facilitate achieving. The endosomes are thus dispensable as signalling scaffolds when the receptors are in sufficient concentration, where activated receptors could interact with downstream pathway components. Endocytosis thus provides a crucial means for the signalling process to overcome the thermodynamic hurdles for receptor oligomerization. In conclusion, our data propose a novel, purely thermodynamic role of endosomes in regulating cytokine receptor signalling not seen in any other signalling pathway.

Cutaneous melanoma is a very aggressive cancer with increasing incidence. It originates from transformed pigmented skin cells (melanocytes). The main risk factor for melanoma development is exposure to UV light and repeated sunburns. In approximately 10 % of cases, melanoma occurs on hereditary basis. Patients with cutaneous melanoma diagnosed in early stages have very good prognosis, with surgical resection of the primary tumour being mostly sufficient for treatment. In contrast, the advanced melanoma stages with metastases are often progressive and refractory to conventional therapies. Cutaneous melanoma is referred to as an immunogenic tumour that is frequently infiltrated by cells of the immune system. Tumours with immune cell infiltration show better prognosis. Spontaneous regression may occur. Over the last few years, progress has been made in the treatment of melanoma using checkpoints molecules (anti-CTLA-4 and anti-PD-1) to activate patients own immune system to recognize tumour lesions. In the tumour microenvironment, cytokines play an important role, enabling communication between cells and regulation of cell proliferation and migration and thus the tumour development. Cytokines (IL-2, IFNα) can be used in adjuvant therapy of melanoma. This work analysed levels of expressed cytokines in...

Background: Interactions between the neuroendocrine and immune system play an importatnt role in maintaining homeostasis. This communication is mediated by cytokines, neurotransmiters and hormones through endocrine, paracrine and autocrine signaling. Prolactin (PRL), hormone of anterior pituitary, is produced by a number of other tissues and cells of immune system. On periphery, PRL is cytokine. Sepsis is an inflamatory response of the organism to severe infection, Th1 immune response is activated and PRL could participate in it. Toll-like receptors (TLR) play a key role in a recognition of bacteial components and mediate a systemic response (with PRL secretion) during infection. It is supposed that activated immune system leads to increasing of PRL, TLR2 and TLR4 gene expression. We detected PRL, TLR2 a TLR4 mRNA levels in monocytes from patiens with system inflammation. We studied influence of single nucleotide polymorphism (SNP -1149 G/T) in PRL gene promotor, it supposed that G allele increases PRL expression. Materials and Methods: For the pilot study 30 patients diagnose with severe infectious event. Collectoin of patiens blood samples was performed consequently three times. Control group comprised 40 healthy individuals. One blood sample was taken from each healthy subject. For testing of...

Chikungunya virus (CHIKV) is classified as an alphavirus in the Togaviridae family. This virus is known to rely on Aedes arthropod vectors for its dissemination. Human infection is characterized by rash, high fever, and severe chronic polyarthritis that can last for years. Recently, efforts in developing animal models have been made in an attempt to better understand CHIKV pathogenesis. CHIKV infection starts with a 7 to 10 day long febrile acute phase, in which most of the symptoms occur (rash, fever, and incapacitating pain in joints and muscle). Once the immune system clears most of the viral infection, a chronic phase starts in as many as 70% of the infected patients. Long term virus-related polyarthralgia is the hallmark of the CHIKV chronic phase. It is believed that CHIKV-infected macrophages infiltrate the joints during the acute phase, and CHIKV infects joint tissue and persists in it. Research into the effects of CHIKV infection in human and murine macrophages revealed that CHIKV-infected human macrophages produce high amounts of virions as well as induce the production of pro-inflammatory cytokines and monocyte recruiting chemokines. This contrasts with murine macrophage infection where low quantities of the virus were detected as well as lower production of pro-inflammatory cytokines. This may contribute to the lack of polyarthritis in murine animal models. Current literature suggests that CHIKV’s viral proteins bind and interact with human host cell machinery promoting viral replication more efficiently in humans than in mice. CHIKV-related neuropathology is not the most common outcome of the disease. However, recent outbreaks suggest that this pathology is becoming more prevalent, affecting as many as 30% of confirmed patients. The role of adaptive and innate immunity in CHIKV disease amelioration has been extensively, yet separately, explored. A RAG2-/-γc-/- Balb/c mouse model was used to study the role of these immune pathways and their associated immune cells in CHIKV infection. The mice in this study developed local arthritis at the site of inoculation as well as showed signs of viral invasion in the brain. This study added to the hypothesis that both innate and adaptive immune responses are necessary to ameliorate the disease and that the lack of adequately matured lymphocytes and STAT6-activation deficient macrophages may result in more severe pathologies.

<p>  </p> <p>Osteoarthritis (OA) is prevalent in equine and can be career-ending for performance horses due to lameness limitations and decreased quality of life. OA is a progressive, multifactorial disease that compromises the synovial joints' normal function, resulting in subchondral bone and articular cartilage deterioration over time. OA is a complex disease that impacts the entire joint, wherein activation of the innate immune system has an essential role in the disease progression and the development of pain. The synovial membrane, or the synovium, is a crucial contributor to the inflammation of diseased joints, regardless of the intra-articular tissue type initially affected. Synoviocytes are a predominant cell type of the synovium and contribute to inflammation by releasing key mediators and degradative enzymes, such as interleukin (IL)-6, IL-1β, a disintegrin, and metalloproteinase (ADAM) domains, and matrix metalloproteinases (MMPs). The production of pro-inflammatory molecules sequentially influences the expression of degradative enzymes and cartilage destruction. Therefore, the pathophysiological processes within synovial joints afflicted by OA can be further understood by studying the characteristics of synoviocytes.</p> <p>We aimed to investigate the inflammatory component of OA in an <em>in vitro</em> model using a primary cell line of equine fibroblast-like synoviocytes (eqFLS) stimulated with tumor necrosis factor-alpha (TNF-α) to represent an initial inflammatory stimulus. Our studies have shown that stimulating eqFLS with TNF-α for 24 hours significantly increased the gene expression of pro-inflammatory biomarkers. Among several pro-inflammatory candidate genes assayed, only pro-inflammatory cytokine IL-6 gene expression could be detected reproducibly following stimulation with the TNF-α gene in eqFLS. We characterized the pro-inflammatory response of eqFLS and utilized this system to examine the impact of novel therapeutic compounds designed <em>in-silico</em> with the goal of reducing the inflammatory response of eqFLS. A piperazine-based compound (C3) and its derivative (02-09) were primarily designed to mimic the interactions of the growth factor pigment epithelium-derived factor (PEDF) with its receptor, the non-integrin laminin receptor 1 (LAMR1). Based on previous <em>in vitro</em> studies in the laboratory, C3 and 02-09 had been proposed to have a strong potential for inhibiting inflammation while reducing angiogenesis and chondrocyte hypertrophy. The efficacy of these two novel compounds on eqFLS was examined in the present work by assessing the gene expression levels of inflammatory biomarkers, including IL-6, IL-1β, IL-8, ADAMs, and MMPs relative to a control housekeeping gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) in various study designs. An <em>in-vitro</em> screen with the IL-1β promoter driving a reporter green fluorescent protein (GFP) was also designed to detect and track the inflammatory response of eqFLS by imaging following stimulation with or without (+/-) TNF-α relative to controls. This screen will be utilized in future studies to potentially identify more effective compounds in the LAMR1-interacting series. The current findings suggest that the novel compounds, especially 02-09, might exhibit an anti-inflammatory effect on eqFLS; therefore, it is a potential therapeutic agent in modulating inflammation during OA development. </p> <p><br></p>

Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society. C1q/TNF-related protein 3 (CTRP3) is a relatively novel adipose tissue-derived cytokine (adipokine) which has been linked to improved glucose regulation and insulin sensitivity. However, the relationship between circulating CTRP3 levels and diabetes is controversial. CTRP3 can circulate in different oligomeric complexes: trimeric, hexameric, and high molecular weight (HMW) oligomeric complexes. However, the concentration of the different oligomeric complexes in human disease states has not been previously investigated. Therefore, the purpose of this study was to compare the levels of different oligomeric complexes of CTRP3 between type 2 diabetic and nondiabetic individuals. Additionally, the association between the oligomeric complexes and other serum factors was examined. CTRP3 primarily circulates in the HMW complex (>50%) and the hexametric multimer, with no CTRP3 detected in the trimeric complex or as a monomer. Further, no differences were observed in total, hexameric, or HMW CTRP3 levels regardless of diabetic status. Surprisingly, HMW CTRP3 was found to be positively correlated with circulating triglyceride levels. Combined, these data suggest that CTRP3 is associated with triglyceride regulation, not diabetic status. These data may explain some of the discrepancies in the literature as elevated triglyceride levels are often detected in patients with obesity and type 2 diabetes.

There is increasing evidence that the effect of chemotherapy on tumor rejection is not cell autonomous but relies on the immune system. Indeed, several reports have shown that human and murine tumors respond to chemotherapeutic agents more efficiently when the host immune system is intact. In particular, we have shown that cyclophosphamide treatment of DBA/2 mice bearing P815 mastocytoma induces rejection and long term protection in a CD4- and CD8-dependent manner. We used this tumor model, as it is poorly immunogenic, expresses tumor-associated P1A and tumor-specific P1E antigens, encoded by germline and mutated genes, respectively, and allows the identification of some tumor-specific CD8+ T cells.We have previously reported that tumor regression correlates with selective infiltration of CD8+ T cells specific for P1E/H-2Kd antigen in tumor bed upon cyclophosphamide treatment. Unexpectedly, the proportion of CD8+ T cells specific for the tumor-associated antigen P1A in the context of H-2Ld decreases concomitantly, indicating that cyclophosphamide alters the repertoire of CD8+ T cells recognizing tumor antigens. Using P1A KO mice, we found that preferential activation of CD8+ T cells to P1E is not solely due to thymic negative selection. The major role of “mutated” antigens in tumor resistance has been recently highlighted in humans and raises an interesting question about the immune mechanisms of tumor rejection. Additionally to its effect on the specific immune response, cyclophosphamide promotes tumor infiltration by effector memory (P1E/H-2Kd)+ CD8+ T cells which are characterized by higher expression of KLRG1 and Eomes. Our data point to a role of IL-15 and type 1 IFNs for their development, as increased levels of IL-15 and IRF7 were measured in tumor after cyclophosphamide. IFNAR1 blockade interferes with the tumor rejection in 50% of mice and decreases the (P1E/H-2Kd)+ CD8+ T cell infiltration induced by cyclophosphamide, suggesting a role of this cytokine in the expansion and/or recruitment of (P1E/H-2Kd)+ CD8+ T cells in vivo.Altogether, our results suggest that type 1 IFNs and IL-15 induced after cyclophosphamide promote the reprogramming of CD8+ T cells specific for the “mutated” P1E/H-2Kd antigen into effector memory lymphocytes. / Option Biologie moléculaire du Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Les troubles du spectre autistique (TSA) sont un ensemble de pathologies neurodéveloppementales dont la prévalence est en constante augmentation. Ils sont caractérisés par des déficits de la communication et des interactions sociales, et par des comportements répétitifs et stéréotypés. A l’origine d’un handicap sévère, ces troubles se manifestent dès la petite enfance et persistent chez l’adulte. Cette entité recouvre des profils cliniques très hétérogènes, tant par le spectre de sévérité des symptômes que par la variété des comorbidités psychiatriques et somatiques associées sous tendues, en partie, par des dysfonctionnements immunitaires. Dans ce contexte, nous nous sommes de ce fait intéressés à l’identification et à la caractérisation de biomarqueurs à valence immunogénétique et immunologique afin d’en étudier l’implication physiopathologique et d’en déterminer les corrélats cliniques.De manière plus précise, nous avons évalué l’implication de la diversité génétique de molécules intervenant dans l’immunité innée (PRR, CLR, Dectin-1) et l’immunité adaptative (système HLA) dans le but d’apprécier le poids du terrain immunogénétique sur le développement de ces troubles. Puis, nous avons analysé les caractéristiques phénotypiques et fonctionnelles des cellules Natural Killer de patients atteints de TSA afin d’en déterminer l’influence potentielle sur l’état inflammatoire permanent rapporté chez certains patients TSA.Sur le plan immunogénétique, nous avons montré que la diversité génétique de Dectin-1 (CLEC7A), candidat sélectionné en raison de son implication dans la modulation de pathologies microbiennes intestinales, était associé à une forme particulière de TSA, le syndrome d’Asperger. Nous avons observé que le génotype CLEC7A rs2078178 GG ainsi que l’haplotype rs2078178/rs16910631 GG/GG étaient non seulement plus fréquents chez les Asperger mais aussi associées aux scores de quotient intellectuel (QI). Dans le cadre de l’analyse de la diversité génétique du système HLA, nous avons identifié un haplotype à risque (HLA-DRB1 *11-DQB1*07) et un haplotype de protection (HLA-DRB1 *17-DQB1*02). L’haplotype à risque étant également associé avec la sévérité de la maladie, reflétée par des scores défavorables dans les échelles cliniques psychiatriques testées.Dans la seconde partie de cette thèse nous avons exploré les modifications phénotypiques et fonctionnelles des cellules NK CD3- CD56+ chez les patients atteints d’autisme de haut niveau. Nous avons observé un état d’activation cellulaire permanent concomitant avec une capacité de dégranulation spontanée, une production soutenue d’IFN-?, et un état hypofonctionnel/épuisement cellulaire après stimulation in vitro. De plus, nous avons identifié un cluster spécifique de cellules NK, basé sur les paramètres HLA-DR, NKG2C, et KIR2DL1, et nous avons observé une augmentation inattendue des cellules NK NKG2C+ chez les sujets TSA en dehors de toute piste infectieuse connue. Enfin, nous avons observé que l’expression de KIR2DL1 et de HLA-DR était respectivement corrélée aux scores de QI et à ceux évaluant les CCA-LS et SAWR.Pris dans leur ensemble, ces données pourraient permettre de contribuer à une meilleure connaissance des mécanismes physiopathologiques associés au système immunitaire dans les TSA et par conséquent à une meilleure catégorisation des groupes de patients susceptibles de bénéficier de stratégies thérapeutiques immunologiques ciblées. / Autism spectrum disorders (ASD) are severe neurodevelopmental conditions characterized by deficits in communication and social interactions, and by repetitive and stereotyped behaviors and exhibiting a constant increase in terms of prevalence. Affecting ages ranging from the early post-natal period to adulthood, ASD are clinically heterogeneous and often associated with psychiatric and somatic comorbidities underlying, in part, by immune dysfunctions. In this context, we thus focused our attention on the analysis of immunogenetic and immunological characteristics potentially implicated in the disease risk and/or in the modulation their clinical phenotype. More precisely, we evaluated the potential implication of the genetic diversity of molecules involved in innate (PRR, CLR, Dectin-1) and adaptive (HLA) immune responses in disease risk. We then analyzed the phenotypic and functional characteristics of Natural Killer cells in patients with ASD, investigating their influence on the permanent inflammatory state often reported in ASD settings.On the immunogenetic point of view, we found that the genetic diversity of Dectin-1 (CLEC7A), a candidate selected because of its involvement in the modulation of intestinal microbial disorders, was associated with Asperger syndrome, a clinical form of ASD. We observed that the CLEC7A genotype rs2078178 GG and the rs2078178 / rs16910631 GG /GG haplotype were not only more frequent in Asperger but also associated with IQ scores.In terms of HLA diversity, we identified a risk haplotype (HLA-DRB1 * 11-DQB1 * 07) and a protective haplotype (HLA-DRB1 * 17-DQB1 * 02). The risk haplotype was also found to be associated with disease’s severity as reflected by unfavorable scores in the psychiatric clinical scales tested.In the second part of this thesis, we explored the phenotypic and functional modifications of CD3-CD56 + NK cells in patients with high-functioning autism. We observed a permanent cell activation state concomitant with spontaneous degranulation capacity, sustained IFN-? production and cellular hypofunction /exhaustion after in vitro stimulation. In addition, we identified a specific cluster of NK cells, based on the HLA-DR, NKG2C, and KIR2DL1 parameters, and we observed an unexpected increase of NK NKG2C + cells in ASD subjects independent of CMV infection. Finally, we observed that the expression of KIR2DL1 and HLA-DR were respectively correlated with the scores of IQ and those evaluating the CCA-LS and SAWR scales.Taken together, these data could contribute to a better knowledge of the pathophysiological mechanisms associated with the immune system in ASD and consequently to a better categorization of the groups of patients likely to benefit from targeted immunological therapeutic strategies.