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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Activated macrophages: implications in HIV-associated disease pathogenesis

Killebrew, Deirdre Anne January 2005 (has links)
Mode of access: World Wide Web. / Thesis (Ph. D.)--University of Hawaii at Manoa, 2005. / Includes bibliographical references (leaves 158-166). / Electronic reproduction. / Also available by subscription via World Wide Web / xiii, 166 leaves, bound col. ill. 29 cm. +
2

Regulation of TRIM E3 Ligases and Cyclophilin A and the impact on HIV-1 replication and pathogenesis.

Singh, Ravesh. 26 October 2013 (has links)
No abstract available. / Thesis (Ph.D.)-University of KwaZulu-Natal, Durban, 2011.
3

A study of the molecular mechanism of progestin-induced regulation of IL-12 and IL-10 and implications for HIV pathogenesis

Louw, Renate 03 1900 (has links)
Thesis (PhD)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: Medroxyprogesterone acetate (MPA) and norethisterone (NET) and its derivatives (norethisterone enanthate (NET-EN); norethisterone acetate (NET-A)), designed to mimic the actions of the endogenous hormone progesterone (Prog), are extensively used by women as contraceptives and in hormone replacement therapy (HRT). A number of reports have indicated that these synthetic progestins affect immune function in the female genital tract thereby increasing the risk of acquiring sexual transmitted infections. Despite these findings, very little is known about their mechanism of action at the cellular level, in particular their steroid receptor-mediated effects on cytokine gene expression. In the first part of this thesis, the effect of Prog, MPA and NET-A on the expression of the endogenous pro-inflammatory cytokine gene, interleukin (IL)-12p40, and anti-inflammatory cytokine gene, IL-10, was investigated in a human ectocervical epithelial cell line, Ect1/E6E7. Quantitative realtime PCR (qPCR) showed that all three ligands significantly upregulated the tumor necrosis factor alpha (TNF )-induced IL-12p40 gene expression, while IL-10 gene expression was downregulated. Moreover, by reducing the glucocorticoid receptor (GR) levels with siRNA, these effects were shown to be mediated by the GR. A more detailed investigation into the molecular mechanism of the progestogen-induced upregulation of IL-12p40 gene expression, using chromatin immunoprecipitation (ChIP), siRNA, co-immunoprecipitation and re-ChIP analyses, showed that the progestogen-bound GR is recruited to the CCAAT enhancer binding protein (C/EBP)- regulatory element of the IL-12p40 promoter, most likely via an interaction with the transcription factor C/EBP . Similar experiments for the progestogen-induced downregulation of IL-10 gene expression showed that the progestogen-bound GR is recruited to the signal transducer and activator of transcription (STAT)-3 regulatory element of the IL-10 promoter, most likely via an interaction with the transcription factor STAT-3. The second part of this study elucidated the influence of the HIV-1 accessory viral protein R (Vpr) on progestogen-induced regulation of IL-12p40, IL-12p35 and IL-10 in the Ect1/E6E7 cell line. Results showed that in these cells, the overexpression of Vpr significantly modulated the effects of Prog, MPA and NET-A on the mRNA expression of IL- 12p40 and IL-10, while only the NET-A effect was modulated on IL-12p35. Moreover, reducing the GR protein levels by siRNA suggested that the GR is required by Vpr to mediate its effects. Taken together, these results show that Prog, MPA and NET-A promote the pro-inflammatory milieu in the ectocervical environment, and that during HIV-1 infections, this milieu is modulated. Furthermore, the results suggest that the use of MPA or NET in vivo may cause chronic inflammation of the ectocervical environment, which may have important implications for ectocervical immune function, and hence susceptibility to infections such as HIV-1. / AFRIKAANSE OPSOMMING: Medroksieprogesteroon asetaat (MPA), noretisteroon (NET) en derivate daarvan noretisteroon enantaat (NET-EN); noretisteroon asetaat (NET-A), ontwerp om die funksies van die natuurlike hormone progesteroon (Prog) na te boots, word wêreldwyd deur vroue as voorbehoedmiddels sowel as vir hormoon vervangingsterapie (HVT) gebruik. Daar is verskeie aanduidings dat hierdie sintetiese progestiene die immuunfunksie in die vroulike geslagskanaal kan beïnvloed en ook die moontlike vatbaarheid van seksueel oordraagbare infeksies kan verhoog. Ten spyte hiervan, is baie min bekend oor hulle meganisme van werking op ‘n molekulêre vlak, veral in die besonder hul effek op sitokinien geenuitdrukking. Die effek van Prog, MPA en NET-A op die geenuitdrukking van ’n endogene pro-inflammatoriese sitokinien, interleukin (IL)-12, en ’n anti-inflammatoriese sitokinien, IL-10, asook die onderliggend meganisme van werking, in ’n menslike ektoservikale sellyn, Ect1/E6E7, is in die eerste deel van hierdie studie ondersoek. Kwantitatiewe “realtime” polimerisasie ketting reaksie (PKR) het getoon dat al drie die ligande die tumor nekrosis faktor alfa (TNF- )-geïnduseerde IL-12p40 geenuitdrukking opreguleer en IL-10 geenuitdrukking onderdruk. Verder is gevind dat induksie van IL-12p40 en inhibisie van IL-10 deur Prog, MPA en NET-A deur die glukokortikoïed reseptor (GR) gedryf word, aangesien volledige opheffing van die effekte op hierdie sitokinien gene waargeneem is wanneer die GR proteïen vlakke deur middel van kort inmengende ribonukleïensuur (siRNS) verminder is. 'n Meer beskrywende ondersoek in die molekulêre meganisme is uitgevoer deur gebruik te maak van chromatien immunopresipitasie (ChIP), siRNS, mede-immunopresipitasie en her-ChIP analises. Hierdie resultate het voorgestel dat die progestogeen (Prog en die sintetiese progestiene)-gebonde GR tot die CCAAT verbeterende bindings protein (C/EBP)- regulatoriese element van die IL-12p40 promotor betrek word en dat die transkripsie faktor C/EBP benodig word om transkripsie van die IL-12p40 geen te aktiveer. Met betrekking tot IL-10, het die resultate voorgestel dat die progestogeen-gebonde GR tot die sein transduksie en aktiveerder van transkripsie (STAT)-3 regulatoriese element van die IL-10 promotor betrek word en dat die transkripsie faktor STAT-3 benodig word om transkripsie van die IL-10 geen te onderdruk. Die tweede deel van die studie het die invloed van die MIV-1 aksesorale virale proteïen R (Vpr) op sitokinien geenuitdrukking, spesifiek die progestogeen-geïnduseerde regulering van IL-12p40, IL-10 en IL-12p35, in die Ect1/E6E7 sellyn ondersoek. Resultate het getoon dat ooruitdrukking van Vpr in hierdie sellyn die effekte van Prog, MPA en NET-A op die mRNS uitdrukking van IL-12p40 en IL-10, en slegs die NET-A effek op IL-12p35, aansienlik moduleer. Vermindering van die GR proteïen vlakke deur middel van siRNS het getoon dat Vpr die GR benodig om hierdie veranderinge mee te bring. In samevatting, die resultate van hierdie proefskrif stel voor dat Prog, MPA en NET-A die pro-inflammatoriese milieu in die ektoservikale omgewing bevorder, en dat hierdie milieu gedurende MIV-1 infeksies verander. Verder, die resultate van hierdie studie impliseer dat die gebruik van MPA en NET in vivo nadelige lokale immuunonderdrukkende effekte mag hê wat kan lei tot kroniese inflammasie van die ektoservikale omgewing en ‘n moontlike verhoging in die vatbaarheid van infeksies soos MIV-1.
4

Treatment experience and HIV disease progression: findings from the Australian HIV observational database

Petoumenos, Kathy, Public Health & Community Medicine, Faculty of Medicine, UNSW January 2006 (has links)
The Australian HIV Observational Database (AHOD) is a collaboration of hospitals, sexual health clinics and specialist general practices throughout Australia, established in April 1999. Core data variables collected include demographic data, immunological and virological markers, AIDS diagnosis, antiretroviral and prophylactic treatment and cause of death. The first electronic data transfer occurred in September 1999 followed by six monthly data transfers thereafter. All analyses included in this thesis are based on patients recruited to AHOD by March 2004. By March 2004, 2329 patients had been recruited to AHOD from 27 sites throughout Australia. Of these, 352 (15%) patients were recruited from non-metropolitan clinics. The majority of patients were male (94%), and infected with HIV through male homosexual contact (73%). Almost 90% of AHOD patients are antiretroviral treatment experience, and the majority of patients are receiving triple therapy as mandated by standard of care guidelines in Australia. Antiretroviral treatment use has changed in Australia reflecting changes in the availability of new treatment strategies and agents. The crude mortality rate was 1.58 per 100 person years, and of the 105 deaths, more than half died from HIV-unrelated deaths. The prevalence of HBV and HCV in AHOD was 4.8% and 10.9%, respectively. HIV disease progression in the era of highly active antiretroviral treatment (HAART) among AHOD patients is consistent with what has been reported in developed countries. Common factors associated with HIV disease progression were low CD4 cell count, high viral load and prior treatment with mono or double therapy at the time of commencing HAART. This was demonstrated in AHOD in terms of long-term CD4 cell response, the rate of changing combination antiretroviral therapy and factors predicting death. HBV and HCV coinfection is also relatively common in AHOD, similar to other developed country cohorts. Coinfection does not appear to be serious impediments to the treatment of HIV infected patients. However, HIV disease outcome following HAART does appear to be adversely affected by HIV/HCV coinfection but not in terms of HIV/HBV coinfection. Patients attending non-metropolitan sites were found to be similar to those attending metropolitan sites in terms of both immunological response and survival.
5

Phenotypic and functional characterization of cytotoxic T lymphocytes in HIV-1 infected South African adults

Pillay, Santhoshan Thiagaraj 12 1900 (has links)
Bibliography / Thesis (MScMedSc (Pathology. Medical Virology))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: In just 25 years since the first reported cases in 1981, the number of Human Immunodeficiency virus (HIV) infected people has risen to 65 million, and over 25 million have died of acquired immunodeficiency syndrome (AIDS). Sub-Saharan Africa accounts for 67% of all people living with HIV and 72% of deaths in this region were AIDS related. Tuberculosis (TB) is one of the most common opportunistic infections in AIDS patients, particularly in developing countries, where 60 - 70% of TB cases occur in HIV-1-infected persons. HIV-1 is a high risk factor for the development of TB, the reactivation of a latent Mycobacterium tuberculosis infection and also progressive TB. CD8+ Cytotoxic T Lymphocytes (CTL) are pivotal in the host immune response to HIV infection. CTL are associated with resolution of acute infection and with reduction in viral load. Studies in macaques and humans indicate the importance of CTL in the control of HIV infection, where reduction in CD8+ T cell number has been correlated with progression to AIDS. The current study was a cross-sectional descriptive study of CD8+ T cells of HIV+ adult South Africans with and without TB co-infection (TB disease). The cohort consisted of anti-retroviral therapy (ART) naive patients and all CTL analyses were carried out on peripheral blood mononuclear cells (PBMCs). A total of 60 South African adults from the Western Cape were utilized in this study, including 15 healthy controls; 30 HIV+TB-individuals and 15 HIV+TB+ individuals. Expression of phenotypic, activation and functional markers were investigated by flow cytometry with the use of fluorochomeconjugated antibodies. The markers examined included the novel activation marker CD137, the CTL associated markers Perforin, Granzyme A, CD107a/b, Fas (CD95), and FasL (CD95L), intracellular cytokines IFN-y and TNF-a and the chronic HIV CTL dysfunction marker PD-1. HIV infection alone was associated with increased baseline expression of TNF-a, Perforin, Granzyme A, PD-1, Fas (CD95), and FasL (CD95L), but not CD137(4-1BB) or IFN-y as compared to uninfected controls. TB co-infection resulted in further increased baseline expression of TNF-a, perforin, PD-1, FasL (CD95L), as well as increased IFN-y. HIV-1 antigen (gag)-specific stimulation in vitro indicated that in HIV infection was associated with antigen-specific upregulation of activation and cytotoxicity markers CD137, IFN-y, TNF-a, Fas, FasL and CD107a/b. In TB co-infection a reduction in antigen-specific degranulation (CD107a/b up-regulation) and also Fas and FasL expression was observed. TB co-infection (in the form of active pulmonary TB) reduced antigen-specific CTL functional activity, but simultaneously there was an association with increased baseline PD-1 expression and also cytolytic marker expression (Fas, FasL, TNF-a). These cytolytic markers could be involved in non-antigen-specific bystander target cell death. The expression of the co-stimulatory molecule CD137 appeared to correlate with interferon-y production and levels of degranulation, confirming its usefulness as a putative surrogate marker of functional responsiveness. These data indicate that in addition to impacting on CD4 T cell function, TB co-infection leads to higher baseline expression of CTL-associated markers, but to dysfunctional antigen-specific CTL responses. / AFRIKAANSE OPSOMMING: Slegs vyf en twintig jaar na die eerste berigte van die menslike immuniteitsgebrekvirus (MIV) in 1981, het die getal MIV-geinfekteerde individue gestyg tot 65 miljoen en het meer as 25 miljoen mense alreeds gesterf aan die verworwe immuniteitsgebrek sindroom (VIGS). Sub Sahara Afrika maak 67% uit van alle HIV gevalle en het `n MIVverwante doodsyfer van 72%. Een van die algemeenste opportunistiese infeksies in VIGS pasiente is Tuberkulose (TB). In ontwikkelende lande, veral, kom 60-70% van TB gevalle voor in MIV-1 geinfekteerde individue. MIV-1 is `n hoe risiko faktor vir die ontwikkeling van TB, die heraktivering van latente Mycobacterium tuberculosis infeksie en progressiewe TB. Die CD8+ sitotoksiese T Limfosiete (STL) se immuun reaksie teen `n MIV infeksie is noodsaaklik en word geassosieer met `n resolusie van die akute infeksie en `n afname in viruslading. Studies in die mens en macaque het getoon dat sitotoksiese T limfosiete belangrik is vir die beheer van MIV infeksies aangesien die afname in CD8+ sel getalle korreleer met die verloop tot VIGS. Hierdie deursnit-beskrywende studie het die CD8+ T selle van MIV+ volwasse Suid-Afrikaners, met of sonder`n TB mede-infeksie, ondersoek. STL analise is gedoen op die perifere bloed mono-nuklere selle (PBMS) van pasiente wat geen teen-retrovirale terapie (TRT) ontvang het nie. `n Totaal van sestig Suid-Afrikaanse volwassenes van die Wes-Kaap het deelgeneem aan die studie wat 15 gesonde kontroles; 30 MIV+TBen 15 MIV+TB+ individue ingesluit het. Die uitdrukking van fenotipiese, aktiverings en funksionele merkers is ondersoek deur middel van vloeisitometrie en fluorochroomgekonjugeerde teenliggaampies. Laasgenoemde het ingesluit die nuwe aktiversingsmerker CD 137, die STL geassosieerde merkers Perforien en Gransiem A, CD 107a/b, Fas (CD95) en FasL (CD95L), intrasellulere sitokiene IFN-y en TNF-a en PD-1, die merker vir chroniese MIV CTL disfunksie. Daar is gevind dat `n TB mede-infeksie (in die vorm van aktiewe pulmonere TB) die antigeen-spesifieke STL funksie verlaag en terselftertyd `n verhoging in die uitdrukking van PD-1 en sitolitiese merkers (Fas, FasL, TNF-a) bewerkstellig. Hierdie sitolitiese basislyn merkers is moontlik betrokke by die dood van nie-antigeen-spesifieke omstander teiken selle. Die uitdrukking van die mede-stimulatoriese molekule CD 137 blyk om te korreleer met die produksie van STL IFN-y en die vlakke van degranulasie. Dit bevestig die merker se bruikbaarheid as `n gewaande surrogaat merker vir funksionele reaksies. Die data toon verder dat `n TB mede-infeksie nie net `n effek het op die CD4 T sel funksie nie, dit lei ook tot `n verhoogde basislyn uitdrukking van STLgeassosieerde merkers, maar met disfunksionele antigeen-spesifieke STL reaksies. Hierdie studie het bepaal dat `n MIV infeksie verbind word met `n toename in die basislyn uitdrukking van TNF-a, Perforien, Gransiem A, PD-1, Fas (CD95) en FasL (CD95L). Dit is egter nie die geval wanneer die uitdrukking van CD 137 (4-1BB) of IFN-y vergelyk word met nie-geinfekteerde kontroles. `n TB mede-infeksie het `n verdere toename in die uitdrukking van TNF-a, Perforien, PD-1, FasL (CD95L) getoon, asook `n verhoging in IFN-y vanaf die basislyn. In vitro MIV-1 antigeen (gag)-spesifieke stimulasies het aangedui dat `n MIV infeksie met die antigeen-spesifieke op-regulasie van aktiverings en sitotoksiese merkers CD137, IFN-y, TNF-a, Fas, FasL en CD107a/b geassosieer word. In `n TB mede-infeksie, is `n verlaging van antigeen-spesifieke degranulasie (CD 107a/b op-regulasie) asook die uitdrukking van Fas en FasL waargeneem. / The Poliomyelitis Research Foundation / The National Health Laboratory Service

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