No description available.

No description available.

No description available.

No description available.

Highly active antiretroviral therapy (HAART) adherence rates of 70 ? 80% often appear in the literature. However, it is estimated that 95% adherence must be achieved to cause virologic failure. Furthermore, if viral replication is not suppressed by HAART, the virus can mutate and become resistant to the patient?s current regimen and render it ineffective. Previous work has indicated that psychosocial factors like mood and personality may be related to outcomes such as adherence and disease progression. Interventions may improve adherence through modification of mood. Moreover, personality may impact the extent to which interventions can effectively impact adherence. The present study evaluated the role of personality in a 10-week Cognitive-Behavioral Stress Management (CBSM) intervention designed to improve HAART adherence. Analyses were performed on 93 ethnically diverse men who have sex with men (MSM) living with HIV/AIDS who were on high-active antiretroviral therapy, had completed the NEO Personality Inventory ? Revised, and were enrolled in an ongoing group-based CBSM intervention study. Repeated measures ANCOVAs, with income and number of HIV symptoms as covariates, showed (1) the intervention had no effect on HIV viral load; (2) high Conscientiousness was related to better HAART adherence; (3) CBSM buffered a drop in HAART adherence, as well as an increase in depressed mood in those low in Conscientiousness across the intervention period; (4) low Conscientiousness, as well as high Neuroticism was related to higher levels of depressed mood through 15-months post randomization. However, while allowing for the further analysis of ethnic group interactions, the utilization of multiple imputation to account for missing data due to attrition changed several relationships between variables of interest, HAART adherence, and depressed mood. Linear regression, controlling for relevant variables, showed that (5) neither Conscientiousness nor Neuroticism were related to CBSM session or medication adherence training session attendance. These findings show that personality factors such as Conscientiousness and Neuroticism and ethnic group membership are related to changes in mood and behaviors (i.e., HAART adherence) relevant to the treatment of MSM living with HIV/AIDS.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 76-91).

>Magister Scientiae - MSc / Determination of CXCR4-usage patterns is essential in establishing suitability of CCR5 antagonist prescription in HIV-1 infected individuals to prevent treatment failure. Previous studies have suggested a switch to CXCR4-usage to be far less common in subtype C, yet recent studies have reported between 30 - 50% CXCR4-usage in this subtype. However, CXCR4-usage in subtype C is poorly characterised. Furthermore, the reliability of available genotypic algorithms is unknown for subtype C sequences. In this study, a comparative analysis of the predictive ability of several subtype B-modeled genotyping algorithms in subtype C tropism determination was undertaken. A total of 731 HIV-1 subtype C V3 sequences with phenotypically determined coreceptor tropism were collated from several sources. Datasets of 349 CCR5, 25 CXCR4 exclusive and 31 R5X4 (Dual) sequences were submitted to 11 various tropism prediction tools. The best performing tool was used to determine the tropism of 12,121 subtype C V3 sequences with unknown phenotypes, in order to characterise the prevalence and method of CXCR4 usage in HIV-1 subtype C. We determined that geno2pheno with a false positive rate of 5% is the best approach for predicting CXCR4-usage in subtype C sequences with an accuracy of 94% (89% sensitivity and 99% specificity). Contrary to what has been reported for subtype B, the optimal approaches for prediction of CXCR4-usage in sequence from viruses that use CXCR4 exclusively, also perform best at predicting CXCR4-use in dual-tropic viral variants. Furthermore, we find that a switch to CXCR4 usage is seen in subtype C for well over 20 years and has occurred consistently over time. At 5%, the frequency of CXCR4-usage in subtype C database records is lower than previous reports for both subtype C and B. The Geno2pheno coreceptor tool may be used as a reliable genotypic predictor in clinical settings to establish the viability of CCR5-antagonist therapies using drugs such as Maraviroc and provides a rapid and cost effective alternative to phenotypic testing in resource limited areas. A switch to CXCR4-usage in subtype C is constant but lower when compared to subtype B, a finding which may have broad implications for the design of intervention and treatment strategies for HIV-1 subtype C.

Human Immunodeficiency Virus (HIV) is the causative agent of AIDS, a disease which affects over 24 million people globally and for which there is neither curative treatment nor vaccine available. As an intracellular pathogen that encodes only 15 proteins HIV-1 is highly dependent upon its host's cellular machinery in order to complete its life cycle. Host-directed therapy thus represents a potentially lucrative strategy for the development of novel anti-HIV therapies. microRNAs (miRNAs) are short noncoding RNA molecules that function as part of the endogenous RNA interference system which governs post transcriptional gene regulation. Current knowledge has placed miRNAs at the crux of HIV-host interactions, yet the functional relevance of the majority of the human miRNAome with regards to HIV replication has remained unknown. A microscopy-based high content screening (HCS) approach was thus developed to systematically evaluate the significance of augmenting or inhibiting the function of individual host miRNAs on the replication dynamics of HIV. A bespoke image analysis and data mining pipeline recovered 56 host miRNAs associated with suppressed HIV replication and 28 host miRNAs associated with enhanced HIV replication. Notably, the HIV-modulating potential of 80 of these miRNAs was previously unknown. Furthermore, HCS also uncovered a novel role for the miR-200 family in the modulation of HIV replication. In silico miRNA target identification and pathway enrichment analysis identified 24 pathways associated exclusively with suppressed HIV replication, 10 pathways associated exclusively with enhanced HIV replication and 38 functional pathways enriched for both enhanced and suppressed viral replication. These included a number of pathways previously implicated in HIV replication such as the PI3K, MAPK, TNF and WNT signalling pathways but also revealed novel functional associations including that of the Hippo signalling pathway. Intriguingly pathway analysis revealed an enrichment for host factors associated with viral carcinogenesis and a convergence on host processes and functional targets classically associated with chemotherapy including host DNA damage repair, cell cycle and tyrosine kinase receptor-mediated signalling. Experimental validation confirmed that HIV replication induced an aberrant cell survival phenotype in response to chemically induced DNA damage but this effect was reversed when DNA damage was induced prior to HIV exposure. A series of compound-based validation screens were thus undertaken in order to verify the functional associations recovered by miRNA screening. A targeted collection of 293 small molecule inhibitors, including a number of FDA-approved chemotherapeutics, were screened for HIV modulating activity. Novel anti-HIV activity was recovered for over 40 compounds including a number of FDA-approved therapies. Compound-target enrichment analysis revealed a strong concordance with functional associations initially described by miRNA-based HCS including EGFR-mediated signalling and DNA damage repair. Concordant HIV-suppressive activity was also recovered for miRNAs and compounds with common functional targets. The outcomes of this study thus represent a significant and novel contribution to current knowledge on HIV-host interactions. Furthermore, these findings have characterised novel miRNA and small molecule candidates for the treatment of HIV and have successfully demonstrated the utility of miRNA-based HCS for novel-drug discovery and drug repositioning.

Mother-to-child transmission (MTCT) of HIV accounts for more than 90% of pediatric infections worldwide, yet the mechanism of vertical transfer remains unknown. The feline immunodeficiency virus (FIV)-infected cat is a cost-effective, small-animal model of HIV pathogenesis and MTCT, which produces a high rate of reproductive failure and fetal infection in litters delivered at early- and late-term gestation. Our previous data suggest that FIV infection may dysregulate placental cytokines and compromise pregnancy. We hypothesized that FIV-infection may cause dysregulation of placental cytokine expression, and aberrant expression of these cytokines may potentiate inflammation and transplacental infections. The purpose of this project was to evaluate feline placental immunopathology at the whole and cellular levels during early- and late-term gestation to understand how lentiviruses may perturb placental immune parameters. To determine whether placentas were vulnerable to FIV infection, we quantified the expression of the FIV receptors, CD134 and CXCR4, in RNA extracted from late-term placental tissue. We found higher expression of CD134 and CXCR4 in placentas from successful pregnancies. To evaluate relative cytokine expression in randomly-sampled, whole placental specimens, we quantified representative pro- and anti-inflammatory cytokines and a chemokine. IL-6 and IL-12p35 were increased in early-gestation, FIV-infected queens; IL-6 was increased in late-gestation, FIV-infected queens. To evaluate placental immunopathology at the cellular level, we developed a novel immunohistochemistry method to identify trophoblastic cells selectively. Trophoblasts were collected using laser capture microdissection, and RNA was extracted from captured cells. We detected expression of several anti- and pro-inflammatory cytokines and the chemokine receptor CXCR4 (the FIV co-receptor) in trophoblasts at both stages of gestation. However, we failed to detect expression of other cytokines and CD134, the FIV primary receptor. FIV infection slightly lowered expression of all cytokines at both early and late pregnancy, although only the decrease in IL-5, from early pregnancy, and IL-4 and IL-12p35, from late pregnancy, reached significant levels. Fetal non-viability was associated with decreased trophoblast expression of IL-4, IL-6, IL-12p35, and CXCR4 at early gestation and decreased expression of IL-4, IL-12p35, IL-12p40 at late gestation. Collectively, these data indicate that FIV infection negatively impacts pregnancy outcome and alters placental immunomodulation.

We are using the feline immunodeficiency virus (FIV)-infected cat to model HIV mother-to-child-transmission (MTCT). Vertical transmission of either virus may result not only in infected offspring, but also failed pregnancy.In HIV infections, maternal hematological and virological parameters predict MTCT.We hypothesized that such parameters would likewise be predictors of FIV vertical transfer. We inoculated ten cats with FIV-B-2542; 10 cats were uninoculated. Cats were allowed to breed naturally. Fetuses were delivered at approximately week 3 (early) gestation by cesarean section. Fetal and placental tissues were collected.Blood samples were collected from the day of inoculation through delivery. We quantified CD4:CD8 T cell ratios, proviral load, and plasma viremia, and monitored seroreactivity to FIV proteins in longitudinal sera from both groups of cats. We documented clinical and reproductive outcome. The infected group produced reduced litter size and more failed pregnancies; CD4:CD8 ratios were depressed by 3.5 months p.i.Proviral DNA was detected in 14 of 14 (100%) placentas tested and 12 of 14 (86%) fetuses. However, the parameters assessed were not predictive of reproductive outcome and suggested a role for placental immunopathology in compromised pregnancy.Regulatory T cells (Treg) are anti-inflammatory and essential in maintaining pregnancy.Th17 cells are pro-inflammatory and associated with pregnancy failure. The activation of these cell populations is regulated by the cytokines TGF-? and IL-6. We hypothesized that placental immunology may result from altered dynamics of these cell populations.Using immunofluorescence confocal microscopy to measure Treg and Th17 markers FoxP3 and ROR ? , respectively, we quantified these cells in placental specimens from FIV-infected and control cats at early and late (week 8) gestation.Significantly higher levels of ROR ? were measured in FIV-infected placentas at early pregnancy; these cells co-localized at the maternaletal interface. We quantified the expression of Treg immunomodulators by quantitative PCR, noting higher expression of TGF-? in infected queens.A positive correlation of ROR ? with IL-6 occurred in control placentas, as predicted, but not in infected placentas.Collectively, the data suggest that an inflammatory placental microenvironment at early pregnancy in infected queens may result, in part, from dysregulation of the Treg/Th17 balance.