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.

>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.

Background: Whether the non-inferior efficacy and safety results of switching virologically suppressed HIV-1-infected patients from nevirapine immediate-release (NVP-IR) to NVP extended-release (NVP-XR) demonstrated in the TRANxITION study conducted in Europe and North America are also applicable to virologically suppressed HIV-infected Taiwanese patients remains unknown. We evaluated the comparative safety and efficacy of continuing NVP-IR versus switching to NVP-XR in virologically suppressed HIV-infected Taiwanese adults receiving combined antiretroviral therapy (cART) regimens. Methods: We conducted a retrospective cohort study at Kaohsiung Veterans General Hospital from April 1, 2013, to March 31, 2015. Eighty-four virologically suppressed HIV-infected adults receiving NVP-IRcART were split into two groups: those continuing with NVP-IR (n = 49) and those being switched to NVP-XR (n = 35). Demographic characteristics, clinical variables, and laboratory findings were compared. Therapeutic drug monitoring of steady-state plasma NVP concentrations and genotype analysis of CYP2B6 516 were also performed in 22 participants. The primary endpoint was continued virological suppression at the end of the study. Secondary endpoints were time to loss of virological response and adverse events. Results: During a mean follow-up of 18.4 months, the NVP-XR group demonstrated similar success at maintaining virological response compared with the NVP-IR group (82.9% vs. 85.7%; P = 0.72). Cox regression analysis indicated that there were no significant differences between NVP regimens for time to loss of virological response (hazard ratio: 0.940; P = 0.754). Furthermore, there were no significant differences in adverse events between these two groups. In the 22 participants, there was a non-significantly lower level of steady-state plasma NVP concentrations in the NVP-XR group than in NVP-IR recipients (5145.0 ng/mL vs. 6775.0 ng/mL; P = 0.267). The prevalence of CYP2B6 516 GT was 86.6%, and there was no significant difference in the distribution of CYP2B6 516 between these two groups. Conclusions: We found that switching from NVP-IR to NVP-XR appeared to have similar safety and efficacy compared with continuing NVP-IR among virologically suppressed, HIV-infected Taiwanese patients. Our finding of higher C-trough levels in both groups compared with other studies conducted in Caucasian populations and the high prevalence of CYP2B6 516 GT requires further investigation in a larger Taiwanese cohort.

Orientador: Deilson Elgui de Oliveira / Banca: Ricardo Sobhie Diaz / Banca: Celso Teixeira Mendes Júnior / Resumo: A história natural de infecção pelo HIV e a progressão para a aids podem variar entre diferentes indivíduos, possivelmente devido a fatores genéticos, entre eles os polimorfismos de nucleotídeo simples (SNPs). SNPs localizados em regiões promotoras de genes que codificam citocinas podem afetar a síntese e a regulação dessas moléculas, resultando em alterações nas respostas imunitárias. O presente estudo buscou avaliar as frequências e os possíveis efeitos de SNPs nas posições -589 e -1098 da região promotora do gene da IL-4 e SNPs nas posições -238 e -862 da região promotora do gene do TNF-α em pacientes portadores do HIV. Amostras de DNA de 157 pacientes foram obtidas através de células mononucleares de sangue periférico e a genotipagem dos SNPs foi realizada pela técnica de High Resolution Melting (HRM). Foi observado que pacientes portadores de TT em SNP/pIL-4 -589 apresentaram contagem de linfócitos T CD8 + menor em relação aos portadores de CC (p=0.0104). Além disso, portadores de TT em SNP/pIL-4 -1098 apresentaram contagem de linfócitos T CD8 + maior em comparação aos portadores de GT (p=0.0053). Em relação a SNP/pTNF-α -238, as proporções de pacientes portadores de GG e GA diferiu entre os pacientes sem HAART e pacientes com HAART e sem falha terapêutica (p=0.0205). Assim, os resultados obtidos no presente estudo fortalecem a hipótese de que SNPs em genes de citocinas podem alterar a história natural da infecção pelo HIV e o curso clínico da doença, principalmente devido a alterações no balanço da produção de citocinas pro- e antiinflamatórias. / Abstract: The natural history of HIV infection and its progression towards aids may vary considerably among different individuals, possibly due to genetic factors, such as single nucleotide polymorphisms (SNPs). In cytokines genes promoters, SNPs may affect protein synthesis and regulation, resulting in more or less efficient immune responses against HIV. The present study evaluated the frequencies and possible effects of SNPs in the IL-4 gene promoter at positions -589 and -1098 and in the TNF-α gene promoter at positions -238 and -862 in HIV-infected patients from Brazil. DNA samples from 157 patients were obtained from peripheral blood mononuclear cells, and SNPs genotyping was performed by High Resolution Melting analysis (HRM). Patients carrying TT at SNP/pIL-4 -589 had lower circulating T CD8 + cells compared to CC carriers (p=0.0104). Moreover, carriers of TT at SNP/pIL-4 -1098 had more circulating T CD8 + cells compared to GT carriers (p=0.0053). Regarding SNP/pTNF-α -238, GG and GA proportions were significantly different between patients without HAART and patients on HAART without therapeutic failure (p=0.0205). In conclusion, these results provide compelling evidence that the presence of SNPs in cytokine-coding genes do modify the natural history of HIV infection, mainly due to changes in the balance between pro- and anti-inflammatory cytokines. / Mestre

In order to elucidate T. gondii infection in a regional hospital in southern Taiwan, serum samples were taken from 173 selected individuals. Among them, 91 serum samples were taken from uremic patients under regular hemodialysis, 34 from human immunodeficiency virus (HIV) infected patients and 48 from healthy adults. Of these 173 samples analyzed by commercial enzyme-linked immunosorbent assay (ELISA) kits including anti-T. gondii IgG and IgM, 21 were seropositive (12.1%) of T. gondii infection. Among 91 uremic patients, 11 (12.1%) were seropositive for IgG. Among 34 HIV-infected patients, 9 (26.5%) were seropositive for IgG and 3 (8.8%) were seropositive for IgM. ELISA data were tested by ANOVA and statistical significances were detected among these groups. The most common band revealed by Western blot assay was the 30 kDa antigen which appeared in 8 of 11 (72.7%) uremic IgG-positive patients and 4 of 9 (44.4%) HIV-infected patients. Serodiagnosis of T. gondii infection reveals a higher positive rate among HIV-infected patients, uremic patients under hemodialysis are also at risk for reactivation of latent toxoplasmal infection. Serological screening for anti-T. gondii antibodies among HIV-infected patients and hemodialytic patients as well as sustained follow-up to detect recent infection are extremely important.

Made available in DSpace on 2016-08-29T15:34:47Z (GMT). No. of bitstreams: 1 tese_4464_.pdf: 3204606 bytes, checksum: a23da35b5188c96d619b059f83d1577a (MD5) Previous issue date: 2010-12-15 / Os HPV são vírus epiteliotrópicos que infectam tecido cutâneo ou mucoso e estão relacionados com desenvolvimento de lesões que, no trato genital, variam de verrugas ao câncer cervical invasivo. As lesões são causadas por diferentes tipos de HPV, que são classificados em baixo e alto risco conforme sua associação com câncer cervical. Sabe-se que mulheres positivas para HIV são mais acometidas por infecções por HPV e estão mais propensas ao desenvolvimento de câncer cervical. O objetivo desse estudo foi avaliar a frequência de tipos de HPV em mulheres soropositivas e soronegativas para HIV. Para isso foram analisadas amostras de escovado cervical, mantidas congeladas, de mulheres conhecidamente positivas para HPV (n=87), atendidas no Centro de Referência DST/AIDS, em Vitória-ES, no período de março a dezembro de 2006. O DNA das amostras foi extraído utilizando kit comercial QIAamp® DNA Mini Kit ou através do método de isotiocinanato de guanidina e sílica. DNA do HPV foi amplificado por PCR utilizando os iniciadores degenerados MY09/MY11 e a genotipagem foi realizada por Restriction Fragment Length Polymorphism (RFLP) e por Reverse Line Blot (RLB). Do total de amostras, 97,7% foram genotipadas e 31 tipos distintos detectados: 6, 11, 13, 16, 18, 26, 31, 31b, 32, 33, 34, 35, 42, 44, 51, 52, 53, 55, 56, 58, 59, 61, 62, 64, 66, 68, 71, 81, 82, 83 e 84. O tipo mais prevalente foi o HPV16, tanto nas mulheres soropositivas quanto nas soronegativas para HIV, seguido pelos tipos 6, 53 e 11. O tipo 13, incomum em amostras cervicais, foi observado nesse estudo, porém a quantidade de amostras não foi suficiente para a realização de seqüenciamento para a confirmação deste tipo viral. Os tipos oncogênicos foram mais comuns nas amostras de mulheres soropositivas para HIV, porém com número semelhante e o número de infecções múltiplas foi maior entre as mulheres HIV positivas. Este estudo revelou uma grande diversidade de tipos de HPV na região. PALAVRAS CHAVES: Human papillomavirus (HPV), Human Immunodeficiency virus (HIV), Restriction Fragment Length Polymorphism (RFLP), Reverse Line Blot (RLB).

Made available in DSpace on 2014-06-11T19:27:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-26Bitstream added on 2014-06-13T19:56:56Z : No. of bitstreams: 1 leda_aro_me_botfm.pdf: 436850 bytes, checksum: e631607fe6c1cbb57e01981982378a57 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A história natural de infecção pelo HIV e a progressão para a aids podem variar entre diferentes indivíduos, possivelmente devido a fatores genéticos, entre eles os polimorfismos de nucleotídeo simples (SNPs). SNPs localizados em regiões promotoras de genes que codificam citocinas podem afetar a síntese e a regulação dessas moléculas, resultando em alterações nas respostas imunitárias. O presente estudo buscou avaliar as frequências e os possíveis efeitos de SNPs nas posições -589 e -1098 da região promotora do gene da IL-4 e SNPs nas posições -238 e -862 da região promotora do gene do TNF-α em pacientes portadores do HIV. Amostras de DNA de 157 pacientes foram obtidas através de células mononucleares de sangue periférico e a genotipagem dos SNPs foi realizada pela técnica de High Resolution Melting (HRM). Foi observado que pacientes portadores de TT em SNP/pIL-4 -589 apresentaram contagem de linfócitos T CD8 + menor em relação aos portadores de CC (p=0.0104). Além disso, portadores de TT em SNP/pIL-4 -1098 apresentaram contagem de linfócitos T CD8 + maior em comparação aos portadores de GT (p=0.0053). Em relação a SNP/pTNF-α -238, as proporções de pacientes portadores de GG e GA diferiu entre os pacientes sem HAART e pacientes com HAART e sem falha terapêutica (p=0.0205). Assim, os resultados obtidos no presente estudo fortalecem a hipótese de que SNPs em genes de citocinas podem alterar a história natural da infecção pelo HIV e o curso clínico da doença, principalmente devido a alterações no balanço da produção de citocinas pro- e antiinflamatórias. / The natural history of HIV infection and its progression towards aids may vary considerably among different individuals, possibly due to genetic factors, such as single nucleotide polymorphisms (SNPs). In cytokines genes promoters, SNPs may affect protein synthesis and regulation, resulting in more or less efficient immune responses against HIV. The present study evaluated the frequencies and possible effects of SNPs in the IL-4 gene promoter at positions -589 and -1098 and in the TNF-α gene promoter at positions -238 and -862 in HIV-infected patients from Brazil. DNA samples from 157 patients were obtained from peripheral blood mononuclear cells, and SNPs genotyping was performed by High Resolution Melting analysis (HRM). Patients carrying TT at SNP/pIL-4 -589 had lower circulating T CD8 + cells compared to CC carriers (p=0.0104). Moreover, carriers of TT at SNP/pIL-4 -1098 had more circulating T CD8 + cells compared to GT carriers (p=0.0053). Regarding SNP/pTNF-α -238, GG and GA proportions were significantly different between patients without HAART and patients on HAART without therapeutic failure (p=0.0205). In conclusion, these results provide compelling evidence that the presence of SNPs in cytokine-coding genes do modify the natural history of HIV infection, mainly due to changes in the balance between pro- and anti-inflammatory cytokines.

Magister Curationis - MCur / Background: In 2009, approximately 130 000 children in Southern Africa under the age of 15 were newly infected with HIV, with vertical transmission being the most common cause of HIV infection. HIV positive mothers are therefore faced with a unique dilemma about which infant feeding choice to make. Prior to 2006,formula feeding was the recommended feeding choice in an attempt to minimise vertical transmission of HIV. In 2006, the risks associated with formula feeding necessitated a change in the recommendations to allow for either exclusive formula feeding or exclusive breastfeeding. The clinical guidelines were reviewed in 2010, when research on the effectiveness of prevention of mother to child transmission efforts suggested a decrease in such transmissions, even when exclusive breastfeeding. Currently the recommendations focus on the contextual appropriateness of the infant feeding choice. The imminent withdrawal of free formula is a new development within the prevention efforts. Aims and Objectives: This study aimed to describe the infant feeding choices of HIV positive mothers on discharge from a level two hospital, in Cape Town. The study objectives included determining the infant feeding choice and the factors that influence HIV positive mothers’ infant feeding choice on discharge from the hospital. Research Methodology: A descriptive survey study design was used as it lends itself to the description of the new developments regarding prevention of mother to child transmission and the meaning it has for the infant feeding choices made by HIV positive mothers. A quantitative approach was used to establish the specified factors that currently affect HIV mothers’ infant feeding choices. A nonrandom consecutive sampling technique was used. The data collection method took the form of a questionnaire. Data analysis was performed through SPSS 20 to produce descriptive and inferential statistics to establish relationships between the independent and dependent variables. Results and Recommendations: The number of exclusive breastfeeding participants was higher (54%) than the exclusively formula feeding participants (46%), which is in keeping with the institution’s trends for the previous year (2011). Statistical significance was difficult to establish due to the small scale of the study, but clinical significance with the establishment of the factors influencing infant feeding choices was considered. These led to the following recommendations: reorientation of infant feeding counselling towards the criteria of acceptability, feasibility, affordability,sustainability and safety, in view of the withdrawal of free formula and promotion of exclusive breastfeeding as the single infant feeding strategy. Ethical Considerations: Ethical clearance was sought from the Ethics Committee of the University of the Western Cape, Research Committee of the level two hospital and informed consent was obtained from the participants.

Background : Host protein beta-2 microglobulin (β2m) is incorporated into the human immunodeficiency virus (HIV) -1 coat during budding. Antibodies directed to R7V, an epitope contained in β2m, increased with the duration of infection in long term non-progressor patients (LTNPs). Purified R7V antibodies neutralized HIV isolates and did not bind to human cells. These data suggested potential for R7V antibodies to be developed as therapeutic tools or prognostic markers and the R7V epitope as a vaccine candidate. However, the literature on R7V is still incomplete. For example, most published work on this epitope make no direct reference to HIV subtypes. The rationale for this study is the lack of information on whether all HIV-1 subtypes incorporate R7V and elicit immune responses to the same extent. In particular the response of HIV-1 subtype C infected individuals to R7V antigen is evaluated here. Methodology and results : A synthetic peptide of the R7V epitope of HIV-1 was synthesized and an “in-house” enzyme-linked immunosorbent assay (ELISA) developed. The peptide was able to detect antibodies generated during natural HIV-1 subtype C infection when used as antigen in the ELISA. This response was not as strong as that reported in the literature. A significantly lower ELISA response was observed for uninfected compared to infected sera (probability, p, value ≤ 0.000152), whereas no differences were noticed between antiretroviral (ARV) treated individuals compared to those who were treatment naïve or LTNPs compared to progressors. These data hold promise for the use of these antibodies as diagnostic rather than prognostic indicators. Polyclonal R7V antibodies produced in rabbits and recombinant R7V antibody fragments did not neutralize an HIV-1 subtype C isolate (Du151.2). However, the latter antibodies neutralized an HIV-1 subtype B strain (SF162), suggesting that the R7V epitope may be more exposed in this subtype. The recombinant R7V antibodies did not neutralize a vasicular stomatitis virus (VSV-G), indicating that no nonspecific neutralization occurred. Human immunodeficiency virus type 1 subtype C infected sera containing R7V antibodies (positive response in the R7V ELISA) neutralized Du151.2 while archive sera containing strong HIV-1 subtype C neutralizing antibodies did not recognize the R7V antigen ELISAs. The R7V peptide exogenously added to HIV-1 infected peripheral blood mononuclear cells (PBMCs) did not stimulate proliferation in vitro nor the production of interferon (IFN) gamma which if produced by CD8+ T-cells would have been indicative of a cellular immune response. The parent protein β2m could not initiate these responses either. Conclusion : Data collected here support a diagnostic rather than a prognostic application for R7V antibodies. R7V conjugated to keyhole limpet hemocyanin (KLH) induced non-neutralizing antibodies in rabbits, suggesting that other modifications (branching, lipid conjugation, etc.) may be needed before this epitope can be successfully utilized in vaccine studies. / Dissertation (MSc)--University of Pretoria, 2010. / Biochemistry / unrestricted