Search results for "Apoptotic bodies"
showing 5 items of 5 documents
Parvovirus B19V Nonstructural Protein NS1 Induces Double-Stranded Deoxyribonucleic Acid Autoantibodies and End-Organ Damage in Nonautoimmune Mice
2018
Abstract Background Viral infection is implicated in development of autoimmunity. Parvovirus B19 (B19V) nonstructural protein, NS1, a helicase, covalently modifies self double-stranded deoxyribonucleic acid (dsDNA) and induces apoptosis. This study tested whether resulting apoptotic bodies (ApoBods) containing virally modified dsDNA could induce autoimmunity in an animal model. Methods BALB/c mice were inoculated with (1) pristane-induced, (2) B19V NS1-induced, or (3) staurosporine-induced ApoBods. Serum was tested for dsDNA autoantibodies by Crithidia luciliae staining and enzyme-linked immunosorbent assay. Brain, heart, liver, and kidney pathology was examined. Deposition of self-antigens…
Identification and Characterization of Extracellular Vesicles and Its DNA Cargo Secreted During Murine Embryo Development
2020
Extracellular vesicles (EVs) are known to transport DNA, but their implications in embryonic implantation are unknown. The aim of this study was to investigate EVs production and secretion by preimplantation embryos and assess their DNA cargo. Murine oocytes and embryos were obtained from six- to eight-week-old females, cultured until E4.5 and analyzed using transmission electron microscopy to examine EVs production. EVs were isolated from E4.5-day conditioned media and quantified by nanoparticle tracking analysis, characterized by immunogold, and their DNA cargo sequenced. Multivesicular bodies were observed in murine oocytes and preimplantation embryos together with the secretion of EVs t…
U937 variant cells as a model of apoptosis without cell disintegration
2012
AbstractThe variant cell line U937V was originally identified by a higher sensitivity to the cytocidal action of tumor necrosis factor alpha (TNFα) than that of its reference cell line, U937. We noticed that a typical morphological feature of dying U937V cells was the lack of cellular disintegration, which contrasts to the formation of apoptotic bodies seen with dying U937 cells. We found that both TNFα, which induces the extrinsic apoptotic pathway, and etoposide (VP-16), which induces the intrinsic apoptotic pathway, stimulated U937V cell death without cell disintegration. In spite of the distinct morphological differences between the U937 and U937V cells, the basic molecular events of ap…
Immune tolerance disruption by human parvovirus B19 viral infection mechanisms
2013
Virusinfektioita pidetään kasvavissa määrin suurimpana ympäristöperäisenä syynä, joka vaikuttaa autoimmuunisairauksien kehitykseen ja autoimmuniteetin muodostukseen. Esimerkiksi parvovirus B19 (B19V) on yhdistetty punahukkaan sekä nivelreumaan. On todettu, että B19V:n ei-rakenteellinen proteiini 1 (NS1) aiheuttaa apoptoosia soluissa, jotka eivät tavallisesti ole B19V infektion kohteena. Lisäksi hiljattain on osoitettu, että apoptoosin seurauksena muodostuvat apoptoottiset kappaleet kykenevät esittelemään antigeenejä niitä esittelemään erikoistuneille soluille, kuten makrofageille tai dendriittisoluille. Tämän tutkimuksen tarkoituksena on löytää B19V infektioon liittyviä autoantigeenejä sekä…
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…