Search results for "infektiot"

Import and impact : characterization of parvovirus-nucleus interactions

2016

Virus-cell interactions as a pathological mechanism of parvovirus infection

2014

The activation of aggresomal pathway in Coxsackievirus B3 infection

2016

Aggresomin muodostuminen on yksi solun puolustusmekanismeista, joka pyrkii estämään proteiinien haitallisen aggregoitumisen solulimassa. Aikaisemmat kokeet ovat näyttäneet, että ihmisen enterovirus-infektio aiheuttaa muutoksia vimentiinissä, tyypin III välikokoisessa filamentissa (Turkki et al., julkaisematon data). Nämä muutokset ovat hyvin samankaltaisia aggresomin muodostumisen aikana tapahtuvien muutoksien kanssa. Tämän tutkimuksen tarkoituksena oli selvittää mahdollisen aggresomin muodostumisreitin aktivoituminen Coxsackievirus B3 (CVB3) -infektiossa, ja hypoteesimme oli, että häkkimäisten vimentiinirakenteiden muodostumisen lisäksi myös muita aggresomin muodostumisreitin aktivoitumise…

Pathogenic mechanisms of how human parvovirus breaks self-tolerance

2017

It is known that viral infections can cause acute, chronic, and autoimmune diseases (ADs). However, the mechanism of how a persistent viral infection contributes to ADs remains still unclear. In this thesis, pathological and immunological aspects of how common viruses can initiate autoimmunity were investigated, and human parvovirus B19 (B19V) was employed as a model virus. B19V non-structural protein 1 (NS1), a superfamily 3 (SF3) helicase, initiated DNA damage resulting in cellular apoptosis. The apoptotic bodies (ApoBods) induced by B19V NS1 were purified and characterized. These ApoBods contained viral NS1 proteins with modified autoimmune-associated self-antigens, e.g. DNA, Smith, Apol…

Soft X-ray Tomography Reveals HSV-1-Induced Remodeling of Human B Cells.

2022

Upon infection, viruses hijack the cell machinery and remodel host cell structures to utilize them for viral proliferation. Since viruses are about a thousand times smaller than their host cells, imaging virus-host interactions at high spatial resolution is like looking for a needle in a haystack. Scouting gross cellular changes with fluorescent microscopy is only possible for well-established viruses, where fluorescent tagging is developed. Soft X-ray tomography (SXT) offers 3D imaging of entire cells without the need for chemical fixation or labeling. Here, we use full-rotation SXT to visualize entire human B cells infected by the herpes simplex virus 1 (HSV-1). We have mapped the temporo…

Infection-induced chromatin modifications facilitate translocation of herpes simplex virus capsids to the inner nuclear membrane

2021

Herpes simplex virus capsids are assembled and packaged in the nucleus and move by diffusion through the nucleoplasm to the nuclear envelope for egress. Analyzing their motion provides conclusions not only on capsid transport but also on the properties of the nuclear environment during infection. We utilized live-cell imaging and single-particle tracking to characterize capsid motion relative to the host chromatin. The data indicate that as the chromatin was marginalized toward the nuclear envelope it presented a restrictive barrier to the capsids. However, later in infection this barrier became more permissive and the probability of capsids to enter the chromatin increased. Thus, although …

Quantitative microscopy reveals stepwise alteration of chromatin structure during herpesvirus infection

2019

During lytic herpes simplex virus 1 (HSV-1) infection, the expansion of the viral replication compartments leads to an enrichment of the host chromatin in the peripheral nucleoplasm. We have shown previously that HSV-1 infection induces the formation of channels through the compacted peripheral chromatin. Here, we used three-dimensional confocal and expansion microscopy, soft X-ray tomography, electron microscopy, and random walk simulations to analyze the kinetics of host chromatin redistribution and capsid localization relative to their egress site at the nuclear envelope. Our data demonstrated a gradual increase in chromatin marginalization, and the kinetics of chromatin smoothening arou…

Rearing background and exposure environment together explain higher survival of aquaculture fish during a bacterial outbreak

2019

1.Parasitic diseases represent one of the greatest challenges for aquaculture worldwide and there is an increasing emphasis on ecological solutions to prevent infections. One proposed solution is enriched rearing, where traditional stimulus‐poor rearing tanks are equipped with different types of structures to increase habitat complexity. Such spatial enrichment is known to increase survival of fish during parasite epidemics, but the underlying mechanisms are still unclear. 2.We studied whether enriched rearing affected infection of an important fish pathogen Flavobacterium columnare in young Atlantic salmon (Salmo salar) and sea‐migrating brown trout (Salmo trutta). First, we used natural b…