Heterogeneity of Oral Cavity Cancer with Special Attention to Immune Function of Clever-1

Various threats are fought off by human defense mechanisms each day. These threats may be foreign, such as microbes, or endogenous, such as cancer cells. Since cancer cells are essentially the host’s own by origin, anti-cancer defense is a challenging task for the immune system. This thesis work discusses the control of immunological responses, which may be dysregulated in the context of cancer, and the properties of cancer cells, which may determine their aggressiveness. This work focuses mainly on oral cavity squamous cell carcinoma. Special interest is shown to the Common Lymphatic Endothelial and Vascular Endothelial Receptor (Clever)-1, a scavenger receptor with multiple functions. Clever-1 is expressed in the tumor microenvironment of various solid tumors. Its inhibition by monoclonal antibodies or genetic deletion may inhibit tumor growth in mice. The exact mechanism by which Clever-1 targeting inhibits cancer growth is still incompletely understood. As a potential therapeutic target in cancer, its significance in normal immune responses demands investigation. The first part of this thesis focused on the function of the humoral immune response in Clever-1 deficient settings. The work revealed vigorous humoral responses in Clever-1 deficient mice, in particular towards polysaccharide type antigens. Accelerated antibody responses should not subject the individual to immune-mediated adverse events; they may even contribute to the anti-cancer effects of Clever-1 blocking therapies. The second part of my thesis project shows that high risk patients may be identified by immunohistochemical biomarkers. Clever-1 expression in these tumors was not clearly associated with clinicopathological parameters. Of the studied prognostic biomarkers, analysis of CD44 and Hypoxia Inducible Factor 1α allowed the identification of high risk patients, among unstratified patients with early stage OSCC. In my work I discovered a new association between Clever-1 and humoral immunity. I also identified a potential way to prognosticate early stage OSCC patients.Suuontelosyövän monimuotoisuus ja Clever-1:n merkitys puolustusmekanismeissa Immuunipuolustus torjuu monia uhkia. Nämä voivat olla peräisin ympäristöstä, kuten mikrobit, tai elimistöstä itsestään, kuten syöpäsolut. Syöpäsolujen torjunta on puolustusjärjestelmälle erityisen hankalaa, sillä ne ovat elimistön omia soluja. Tässä väitöskirjassa käsittelen immuunipuolustuksen säätelyä, joka voi olla viallinen syöpää sairastavilla potilailla, sekä syöpäsolujen ominaisuuksia, jotka saattavat määrätä syöpäkasvaimen aggressiivisuuden. Keskityn erityisesti suuontelosyöpään. Käsittelen myös Common lymphatic endothelial and vascular endothelial receptor (Clever)-1 -nimistä reseptoria, joka toimii immuunipuolustuksessa monin tavoin. Clever-1 ekspressoituu syöpäkasvaimissa monissa solutyypeissä, kuten verisuonissa ja valkosoluissa. Tuoreet tutkimukset ovat osoittaneet, että Clever-1:n toiminnan esto monoklonaalisilla vasta-aineilla tai geneettisellä manipulaatiolla voi hidastaa kasvainten kasvua hiirillä. Sen toimintamekanismia ei toistaiseksi täysin tunneta. Clever-1 on mahdollinen syöpähoidon kohde, joten tutkin tässä väitöskirjassa sen vaikutusta normaaliin immuunipuolustuksen toimintaan. Tämä on tärkeää ottaa huomioon jotta mahdollisen Clever-1:een kohdistuvan hoidon haittavaikutuksia voidaan arvioida. Työssä käytin Clever-1 -poistogeenistä hiirtä, joka mahdollisti Clever-1:n vaikutuksen joustavan ja spesifisen tutkimisen. Tulokset osoittivat, että Clever-1:n puutos tehosti vasta-ainevälitteistä puolustusreaktiota. Poikkeuksellisen voimakkaan vasta-ainevälitteisen puolustusreaktion ei uskota altistavan puolustusjärjestelmän toimintaan liittyville haittavaikutuksille, vaan se voi jopa tehostaa syöpään kohdistuvaa puolustusvastetta. Väitöskirjan muissa osajulkaisuissa totean, että korkean riskin suusyöpäpotilaat voidaan tunnistaa immunohistokemiallisten merkkiaineiden avulla. Näissä aineistoissa kasvaimissa tavattavan Clever-1:n määrä ei ollut yhteydessä ennusteeseen. Julkaisuissa raportoiduista ennusteellisista merkkiaineista CD44 ja Hypoxia Inducible Factor (HIF)-1α yhdessä helpottivat korkean uusiutumisriskin suuontelosyöpäpotilaiden tunnistamista varhain diagnosoitujen potilaiden joukosta. Väitöstyössä tunnistin uuden yhteyden Clever-1:n ja humoraalisen puolustusvasteen välillä. Löysin myös mahdollisen tavan arvioida varhaisvaiheen suuontelosyövän ennustetta.Siirretty Doriast

Ectopic germinal centers in the thymus accurately predict prognosis of myasthenia gravis after thymectomy

The ability of thymic histopathology to predict the long-term impact of thymectomy in non-thymomatous myasthenia gravis (NTMG) is mainly uncharted. We applied digital pathology to quantitatively characterize differences of thymic histology between early-onset (EOMG) and late-onset MG (LOMG) and to investigate the role of thymic changes for thymectomy outcomes in MG. We analyzed 83 thymic H&E slides from thymectomized NTMG patients, of which 69 had EOMG and 14 LOMG, using digital pathology open-access software QuPath. We compared the results to the retrospectively assessed clinical outcome at two years after thymectomy and at the last follow-up visit where complete stable remission and minimal use of medication were primary outcomes. The automated annotation pipeline was an effective and reliable way to analyze thymic H&E samples compared to manual annotation with mean intraclass correlation of 0.80. The ratio of thymic tissue to stroma and fat was increased in EOMG compared to LOMG (p = 8.7e-07), whereas no difference was observed in the ratio of medulla to cortex between these subtypes. AChRAb seropositivity correlated with the number of ectopic germinal centers (eGC; p = 0.00067) but not with other histological areas. Patients with an increased number of eGCs had better post-thymectomy outcomes at two years after thymectomy (p = 0.0035) and at the last follow-up (p = 0.0267). ROC analysis showed that eGC area predicts thymectomy outcome in EOMG with an AUC of 0.79. Digital pathology can thus help in providing a predictive tool to the clinician, the eGC number, to guide the post-thymectomy treatment decisions in EOMG patients.Peer reviewe

reChIP-seq reveals widespread bivalency of H3K4me3 and H3K27me3 in CD4+ memory T cells

The combinatorial action of co-localizing chromatin modifications and regulators determines chromatin structure and function. However, identifying co-localizing chromatin features in a high-throughput manner remains a technical challenge. Here we describe a novel reChIP-seq approach and tailored bioinformatic analysis tool, normR that allows for the sequential enrichment and detection of co-localizing DNA-associated proteins in an unbiased and genome-wide manner. We illustrate the utility of the reChIP-seq method and normR by identifying H3K4me3 or H3K27me3 bivalently modified nucleosomes in primary human CD4+ memory T cells. We unravel widespread bivalency at hypomethylated CpG-islands coinciding with inactive promoters of developmental regulators. reChIP-seq additionally uncovered heterogeneous bivalency in the population, which was undetectable by intersecting H3K4me3 and H3K27me3 ChIP- seq tracks. Finally, we provide evidence that bivalency is established and stabilized by an interplay between the genome and epigenome. Our reChIP-seq approach augments conventional ChIP-seq and is broadly applicable to unravel combinatorial modes of action

Experiencing Urban Air Mobility: How Passengers evaluate a simulated flight with an Air Taxi

For the successful development and implementation of novel concepts and technology, the acceptance of potential users is crucial. Therefore, within the project HorizonUAM, we investigated passengers' acceptance of air taxis. One challenge is that not many people have real experiences with urban air mobility (UAM) at the moment and thus requirements formulated by potential users refer to rather abstract concepts. To allow participants to gain realistic impressions of UAM concepts, a Mixed Reality Air Taxi Simulator was set up. It allows participants to experience an inner-city business shuttle flight. A study with 30 participants assessed the information needs and the influence of another person on board on wellbeing in nominal situations (experiment 1) as well as one non-nominal situation (experiment 2). For the latter, participants experienced a re-routing of the flight due to an unavailability of landing sites at the vertidrome. During and after the flights, participants answered questionnaires and extensive interviews were conducted. The study produced first empirical data on relevant factors regarding interaction, information needs and comfort within an air taxi. The findings show that passengers want to be informed about intentions of the vehicle. The presence of a steward on board is not necessary but can increase wellbeing especially during non-nominal situations.Comment: 16 pages, 12 figures, 8 table

Enhanced Antibody Production in Clever-1/Stabilin-1–Deficient Mice

Clever-1, encoded by the Stab1 gene, is a scavenger and leukocyte trafficking receptor expressed by subsets of vascular and lymphatic endothelial cells and immunosuppressive macrophages. Monocyte Clever-1 also modulates T cell activation. However, nothing is known about the possible links between B cell function and Clever-1. Here, we found that Stab1 knockout mice (Stab1−/−) lacking the Clever-1 protein from all cells present with abnormally high antibody levels under resting conditions and show enhanced humoral immune responses after immunization with protein and carbohydrate antigens. Removal of the spleen does not abolish the augmented basal and post-immunization antibody levels in Clever-1–deficient mice. The increased IgG production is also present in mice in which Clever-1 is selectively ablated from macrophages. When compared to wildtype macrophages, Clever-1–deficient macrophages show increased TNF-α synthesis. In co-culture experiments, monocytes/macrophages deficient of Clever-1 support higher IgM production by B cells, which is blocked by TNF-α depletion. Collectively, our data show that the excessive inflammatory activity of monocytes/macrophages in the absence of Clever-1 results in augmented humoral immune responses in vivo

Lymphatic Endothelial Cell Activation and Dendritic Cell Transmigration Is Modified by Genetic Deletion of Clever-1

Clever-1 also known as Stabilin-1 and FEEL-1 is a scavenger molecule expressed on a subpopulation of anti-inflammatory macrophages and lymphatic endothelial cells (LECs). However, its role in regulating dendritic cell (DC) trafficking and subsequent effects on immunity have remained unexplored. In this study, we demonstrate that DC trafficking from the skin into the draining lymph nodes is compromised in the absence of Clever-1. By adoptive transfer approaches we further show that the poor trafficking is due to the impaired entrance of DCs into afferent lymphatics. Despite this, injections of ovalbumin-loaded DCs into the footpads induced a stronger proliferative response of OT II T cells in the draining lymph nodes. This could be explained by the increased MHC II expression on DCs and a less tolerogenic phenotype of LECs in lymph nodes of Clever-1 knockout mice. Thus, although fewer DCs reach the nodes, they are more active in creating antigen-specific immune responses. This suggests that the DCs migrating to the draining lymph node within Clever-1 positive lymphatics experience immunosuppressive interactions with LECs. In conclusion, besides being a trafficking molecule on lymphatic vasculature Clever-1 is immunosuppressive towards migrating DCs and thus, regulates the magnitude of immune responses created by incoming DCs in the draining lymph nodes

Loss-of-function mutation in IKZF2 leads to immunodeficiency with dysregulated germinal center reactions and reduction of MAIT cells

Peer reviewe

Loss-of-function mutation in IKZF2 leads to immunodeficiency with dysregulated germinal center reactions and reduction of MAIT cells

Peer reviewe

Using CEP-based blackboards for coordinating mobile RFID agents

In huge warehouses or stockrooms, it is often very difficult to find a certain item, because it has been misplaced and is therefore not at its assumed position. This position paper presents an approach on how to coordinate mobile RFID agents using a blackboard architecture based on Complex Event Processing