<strong>Background. </strong> Previous evidence suggests that persons who have emigrated from HIV-endemic countries experience higher rates of HIV infection and delayed diagnosis. Despite this evidence, limited research has examined HIV testing in these populations. <br /><br /> <strong>Objectives. </strong> To examine factors associated with HIV testing, as well as motivations underlying testing behaviour, within five East African communities in Toronto. <br /><br /> <strong>Methods. </strong> Secondary data analyses were conducted using cross-sectional data collected in face-to-face interviews with people from Toronto's Ethiopian, Kenyan, Somali, Tanzanian, and Ugandan communities. Logistic regression techniques were employed to assess factors associated with "ever vs. never testing," "repeat vs. non-repeat testing," and "independent vs. directive testing. " Reasons provided for testing and not testing were described. <br /><br /> <strong>Results. </strong> Individuals from all five communities were interviewed (n=270). Males were slightly over-represented (55. 9%). The average age was 35. 7 yrs (range 17-71). Three-quarters (75. 6%) of the sample had been tested for HIV. Two-thirds (65. 7%) of testers had tested more than once and 40. 7% had independently decided to get their most recent test. 71. 1% of testers reporting previous testing for immigration purposes. Testing behaviour varied greatly across communities. Ethnicity was predictive of "ever" and "repeat" testing. Risk behaviour (including multiple sex partners, concurrent sex partners, condom non-use, and/or improper condom use) was overwhelmingly not associated with testing. Fear of exposure through sexual activity was the most frequent reason for independent testing. Immigration authorities were the most common person to initiate directive testing, followed by physicians. Low perceived risk was the most common reason for not testing. <br /><br /> <strong>Conclusions. </strong> Testing rates within this population were quite high and the immigration process heavily impacted upon testing behaviour. Many determinants and motivations of testing have been identified and should be used to inform the design of interventions to promote testing behaviour in these communities. Nevertheless, many gaps have been identified by the current research and should be addressed by future research.

Recent research of a cohort of HIV exposed sero-negative (HESN) female commercial sex workers in Nairobi has revealed an Immune Quiescent phenotype; characterized by reduced T cell activation and higher regulatory T cells (Tregs) in peripheral blood. HESN women also express lower levels of interferon regulatory factor-1 (IRF-1), a critical regulator known to negatively impact Treg development in mice. In this study, we analyzed the functional capacity of Tregs by an in vitro depletion assay and measured functionality by flow cytometry. Data showed Tregs suppressed CD4+ and CD8+ proliferation responses. We characterized the link between Tregs and IRF-1 in HESN and observed an inverse correlation between IRF-1 expression and Treg proportions. We also established reduced expression of IRF-1 in Tregs of healthy donors by flow cytometry. In a separate study, flow cytometric analysis of high-risk sex-workers revealed that CTLA-4 expression in memory CD4+cells, not Treg frequency, was associated with HIV seroconversion. / February 2017

The rational design of an HIV-1 vaccine immunogen able to induce potent, cross-reactive, neutralising antibodies remains one of the single greatest challenges in the field of vaccine research today. Roughly a dozen broadly neutralising monoclonal antibodies have been isolated to date, and their epitopes represent important vaccination targets. Interestingly, apart from three that identify over-lapping epitopes in gp41, all of the broadly neutralising monoclonal antibodies target epitopes apparent on different conformations of gp120 (including the epitopes of PG9/PG16). Thus the gp120 monomer remains the most ideal template for immunogen design. Recently, epitopes in the C3-V4 region of gp120 have been shown to be major targets for early strain-specific neutralising antibodies in subtype C infected individuals. Autologous neutralising antibodies identify vulnerable sites on the envelope, and understanding the nature of antigenic “hotspots” on gp120 will help to guide rational vaccine design. This study sought to confirm in four individuals that the C3-V4 epitope was in fact apparent on monomeric gp120, and thereafter to better characterise the nature of viral escape from these antibodies. Using magnetic beads coated with one of 16 different recombinant gp120 proteins it was confirmed that the C3-V4 response was aimed at a monomer-specific epitope in all four cases. In two instances these antibodies were shown to contribute to autologous neutralisation, while in a third the existence of quaternary structure specific antibodies that could not be adsorbed with monomeric gp120 made this link impossible. In the forth instance transfer of the C3-V4 region was shown to expose a normally occluded epitope in the CD4 binding site. This research also provided evidence for other epitopes for autologous neutralising antibodies in C3, overlapping with the CD4 binding site and V5. Lastly, by introducing relevant escape mutations into the parental recombinant gp120s and then comparing the ability of these proteins to adsorb out anti-C3 antibodies, it was shown that while these mutations conferred complete resistance to neutralisation they did not prevent the antibodies from binding to their respective epitopes. The extensive characterisation of C3-related epitopes such as those described in this research should no doubt contribute to the rational design of a gp120 based vaccine immunogen aimed at eliciting broad and potent neutralising antibody responses.

PhD, Virology, Faculty of Health Sciences, University of the Witwatersrand / HIV-associated cardiomyopathy is a multifactorial disease with a broad spectrum of aetiologies that arise due to chronic immunosupression during HIV infection. The intricate relationship between HIV infection and cardiac co-morbidity was investigated with the aid of HIV-neutralizing aptamers. These synthetic nucleic acid ligands with antibody-like properties are molecular tools with multifunctional applications ranging from drug discovery to diagnostics and therapeutics. The advent of the HIV/AIDS pandemic has naturally married the field of HIV therapy and diagnostics with that of aptamer technology. By employing a HIV-1 neutralizing aptamer, named UCLA1, raised against the viral surface envelope glycoprotein 120, I dissected some of the pathways leading to cardiomyocyte apoptosis in a cell culture system. In chapter one I investigated the potential cytotoxic effects of UCLA1 by comparing it against a panel of 17 antiretrovirals (ARVs) in clinical use with the goal of establishing a safety portfolio geared towards its use as a therapeutic agent. Using cultured human cardiomyocytes and primary peripheral blood mononuclear cells (PBMCs), I selected some of the major biological markers of ARV-induced cytotoxicity and found no measurable deleterious effect, especially when compared to other ARVs used in the same study. In chapter two, the permissiveness of cardiomyocytes to HIV infection as well as the relationship between virus-host interaction and caspase-mediated apoptosis were investigated. Non-productive, receptor and tropism-independent infection was observed, which was arrested after the reverse transcription stage. However, interaction between the virus gp120 and the host’s CXCR-4 chemokine receptor preferentially activated caspase-9 triggering robust mitochondria-mediated apoptosis. A shift from mitochondrial-initiated, caspase-9 mediated to Fas-ligand initiated, caspase-8 mediated was observed when CM were co-cultured with HIV-infected MDM. UCLA1 protected against caspase-9 mediated vii apoptosis but not caspase-8 mediated. Finally in chapter three I provided answers for the shift in caspase activation by showing that supraphysiological levels of IL-1β and IL-6 during HIV infection of MDM augment the effects of tumor necrosis factor (TNF). These observation provide new insight into the complex pathophysiology of HIVCM and highlight the potential of UCLA1 as a novel therapeutic agent to fight HIV and some of its associated diseases.

MSc (Med), Faculty of Health Sciences, University of the Witwatersrand, 2011 / BACKGROUND: Human Immunodeficiency Virus (HIV) is a global epidemic with growing numbers of people on highly active anti‐retroviral therapy (HAART) programmes. Effectiveness of treatment needs to be monitored to ensure the uncompromised well being of patients. This is currently done using both Viral Load (VL) and CD4 cell counts for HAART initiation and follow‐up. Although VL is the best predictor of disease progression it is often too expensive for monitoring patients in resource‐limited settings. There is thus a need for a cheaper, more accessible alternative to monitor long term patient response to therapy. METHODS: This study evaluated the use of a recently described flow cytometric assay of CD38 expression (previously developed at the Johannesburg Flow Cytometry Reference Laboratory) in a cohort of HIV+ patients failing 1st line therapy, who were subsequently enrolled onto 2nd line HAART. CD38 and CD8 were “piggy ‐backed” onto the PLG/CD4 protocol and mean fluorescence intensity (MFI) of the CD8/38 expression was monitored longitudinally. Patterns of CD38 expression were compared to 1st line treatment observations to establish equivalence in the predictive power of CD38 expression of fluctuation in viral load on 2nd line treatment patients. In addition, the effect of sample age on assay accuracy was tested before implementation of the CD38 assay at a secondary testing site. RESULTS: The patterns observed in the cohort of 2nd line therapy patients mirrored patterns previously seen in 1st line therapy with 55% of patients showing a continuous decline in CD38 MFI that mimicked changes in VL. The remaining 33% of patients had non‐specific increases in CD38 MFI without concurrent increases in VL and one patient showed irregular VL and CD38 MFI (non‐responder). The CD38 assay showed acceptable accuracy and reproducibility up to 48 hours after venesection (%CV<5%). Implementation at the secondary testing site was successful with 98% similarity (%CV<5%) compared to the reference laboratory. CONCLUSION: CD38 monitoring of 2nd line therapy patients showed comparable patterns to observations in 1st line therapy patients. The assay proved stable over time and easy to implement at another PLG/CD4 testing facility. As such, the CD38 assay offers a cost‐effective, reliable real time supplementary test to long‐term VL monitoring of HIV infected patients on the national ART programme.

Dissertation submitted to the Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of Master of Science in Medicine. Johannesburg, 2011 / The HIV-1 integrase (IN) enzyme is an integral part of the viral replication cycle and has no known human homologues, making it an ideal target for antiretroviral therapy. To date, only one inhibitor of IN strand transfer activity (Raltegravir, IsentressTM) is available for human use. However, the inevitable emergence of antiretroviral drug resistance requires ongoing research into new/novel therapies. There are currently no assays to screen for IN inhibitors against HIV-1 subtype C in South Africa (and worldwide), therefore, the overall objective of this study was to generate and characterize locally relevant, soluble, functional recombinant HIV-1 subtype C IN proteins for use in strand transfer assays. Recombinant integrase genes, including a soluble HIV-1 subtype C mutant (05ZAFV6 with C56S, C65S, W131D, F185D and C280S) and HIV-1 subtype C Y143C mutant (05ZAFV6 soluble with Y143C) were designed, generated and cloned in frame into pET15b. Optimal bacterial expression conditions for the expression of these constructs as well as an HIV-1 subtype C wild type (05ZAFV6), subtype B wild type (NL4-3), and subtype B soluble (NL4-3 with F185K and C280S; as controls) IN, in E.coli BL21 cells were determined. All five recombinant IN were successfully purified using nickel affinity chromatography, and subsequently used to establish a strand transfer assay to assess their activity and their response to two well-known integrase inhibitors, L-Chicoric acid and Raltegravir. All five recombinant IN proteins were found to be biologically active, with INY143C (116.67%) showing equivalent activity to INBwt (117.37%), while INCsol (52.96%) was the lowest. The IC50 values of L-Chicoric acid were higher than the expected values for all five recombinant IN, with the subtype B and C IN solubility mutations contributing to an increased resistance to inhibition by L-Chicoric acid. The dose responses to Raltegravir for INCwt and INBsol were as expected, with IC50’s in line with published data, and the INY143C mutant (known mutation conferring resistance to Raltegravir) was resistant to inhibition of strand transfer activity at all Raltegravir concentrations tested except the highest (50 μM). Finally, methods to complex the INY143C mutant to thiolated-DNA were evaluated, however definitive data could not be obtained. Future work should focus on optimization of the purification and characterization of the IN-DNA complexes. Overall, this study has led to the establishment of functional strand transfer assays based on HIV-1 subtype C recombinant IN proteins, and established a framework for screening of novel HIV-1 subtype C IN inhibitors.

PhD, Faculty of Health Sciences, University of the Witwatersrand / HIV/AIDS continues to be one of the greatest health challenges which South Africa faces. The epidemic in children is closely linked to that in women, the prevalence of which continues to grow according to antenatal statistics from the South African Department of Health (DOH). HIV is known to invade the central nervous system at the time of infection, and causes widespead damage. In children, this leads to a well-researched condition known as HIV encephalopathy, which affects all areas of neurodevelopment. The effects of timely initiation of antiretroviral therapy on alleviating the impact of encephalopathy have been well described. Neurodevelopmental delay is a stage four disease indicator according to the World Health Organisation (WHO), and therefore is a criterion for initiation of Highly Active Antiretroviral Therapy (HAART). HAART is often only administered according to the virologic and immunologic status of a child, as standardised neurodevelopmental assessment tools are not widely available in South African clinics. When HAART initation is dependent on immunologic status, it is often too late to prevent encephalopahy. To date, the only means of prevention of this condition is early initation of HAART, which has not been widely available in South Africa. Stringent guidelines for the commencement of this therapy according to the WHO, and the South African Department of Health (DOH) have had to be followed, leading to late initiation of HAART, and widespread central nervous system encephalopathy. Studies which have been carried out in South African clinics have demonstrated the high prevalence of this condition. Once there is evidence of encephalopathy, children should be referred for assessments in all facets of development, and where necessary, for rehabilitation. A standardised developmental screening tool which is suitable for use in a developing country is therefore necessary in order to screen for neurodevelopmental delays to allow for further assessment and referral to rehabilitation services, as well as providing an additional assessment criterion for initiation of HAART. Paediatric HIV clinics in developing countries are understaffed, and children may be seen by junior staff or screened by nurses due to the high numbers of clinic attendees. This often results in neurodevelopment being inadequately assessed and children are therefore not referred for intervention services. A standardised screening tool, which The Development of a Screening Tool to Evaluate Infants who are HIV Positive could be administered by clinic staff in order to ensure correct and timely referral of children for further assessment and intervention is therefore necessary. This is of importance both locally and internationally where a screening tool, which has been developed specifically for this purpose, does not exist. The aim of this study was therefore to evaluate the agreement between the Bayley-III Screening Test and the Bayley Scales of Infant Development (3rd version) in a population of HIV positive infants in order to evaluate its appropriateness for use in South Africa. The Bayley Scales of Infant Development have long been considered the ‘gold standard’ in infant developmental assessment, which is why this tool was chosen to evaluate the Bayley-III Screening Test against. The developmental scores in each facet (cognitive, motor or language) were evaluated to determine which should be included in an assessment tool for this population. Further objectives for the study were to adapt the screening tool to the needs of the population, or to develop a new screening tool should the Bayley-III Screening Test not prove suitable for use in this population. In order to meet the aims and objectives, a cross-sectional study was conducted where 112 HIV positive infants between the ages of six and eighteen months were assessed using the Bayley-III Screening Test and the Bayley Scales of Infant Development (3rd version) (BSID III). The infants were stratified into four age groups namely 6-8 months, 9- 12 months, 13-16 months, and 17-18 months. Children were recruited from Harriet Shezi Children’s Clinic at Chris Hani Baragwanath Hospital in Soweto. The agreement between the Bayley-III Screening Test and the Bayley Scales of Infant Development (3rd version) was analysed using Kappa, for the overall group, and for each age group. Overall agreement between the tools was as follows: K=0.58 for the Cognitive facet, K=0.82 for the Expressive Communication facet, K=0.76 for the Receptive Communication facet, K=0.44 for the Fine Motor facet and K=0.57 for the Gross Motor facet. These values indicate that the Bayley-III Screening Test is therefore not acceptable for clinical use, as excellent agreement (k≥0.75) in all facets would be necessary for this purpose. A new screening tool therefore had to be developed. The infant’s developmental scores from the BSID III were analysed to determine which facets of development were most severely affected, and therefore which facets should be included in a new screening tool. Gross motor function was demonstrated to be the area which was most severely affected, followed by cognitive function. A gross motor screening tool would therefore be suitable for use in this population, as no equipment would be necessary. Gross motor development is the most universally similar aspect of development, which is not completely dependent on cultural or socioeconomic factors which often have an influence on language and cognitive development. Item selection from the BSID III was undertaken to determine which items should be included in a brief screening tool. In each of the four age groups, item selection occurred as follows: Two items which discriminated the At-Risk, from Emerging and Competent groups (less than 20% in the At-Risk group, and 100% in the other groups) were selected. Two items, which discriminated between children in the ‘Emerging’ and ‘Competent’ categories on the BSID III were selected (0-5% of children who were At-Risk obtained credit, 30-50% of the Emerging group obtained credit, and 100% of the Competent group obtained credit). Lastly, two items were selected which discriminated the Competent group from the other two groups (100% or as high as possible in the Competent group, and 0% in the other groups). The new gross motor screening tool was assembled using the selected items, scoring was allocated, and it was tested against the scores obtained on the Gross Motor facet of the BSID III for the initial 112 infants. Agreement between the tools was analysed using Kappa, and refinements were made according to the discrepancies. This was done three times, until the Kappa value revealed excellent agreement between the tools (k = 0.87). A panel of experts was then invited to examine the new gross motor screening tool, and to comment on it, and further adjustments were made accordingly. Preliminary concurrent validity testing of the new gross motor screening tool was then carried out against the Gross Motor facet of the BSID III on 60 children, who were recruited from the Harriet Shezi Children’s Clinic at Chris Hani Baragwanath Hospital in Soweto. Statistical analysis revealed that the agreement between the BSID III and the new screening tool was excellent (k=0.85). The diagnostic properties of the new gross motor screening tool were as follows: sensitivity 97.4%, specificity 85.7%, positive predictive value 92.7%, and negative predictive value 94.7%. These values indicate that the statistical properties of the tool are excellent, and the tool will not be predisposed to underreferrals or over-referrals. Preliminary reliability testing was carried out on 15 children for test-retest/intrarater reliability and 15 children for interrater reliability. Interrater, test-retest and intrarater reliability were excellent (r=1, r=0.98, r=0.98 respectively). Further testing of reliablity and validity should be undertaken in order to establish these properties, and standardisation should also be carried out on healthy children. Given the need for an assessment tool of this nature in South Africa and other developing countries, and the statistical properties thus far, the tool may be used clinically for the purposes for which it was developed.

Ph.D., Faculty of Health Sciences, University of the Witwatersrand, 2011 / The HIV-­‐1 pandemic continues unabated. Although treatments exist that can substantially alleviate the morbidity and mortality associated with HIV, there is still a need for improved anti-­‐HIV treatments that reduce toxicities and administration frequency and mediate sustained inhibition of viral replication. Given the high mutability and variability of the virus, a strategy that is garnering increasing focus is the targeting of host factors that the virus requires to replicate, so-­‐called HIV-­‐dependency factors (HDFs). It is hoped this will reduce the emergence of viral drug resistance. A number of genome-­‐wide screens have been performed to identify HDFs, although many remain to be validated, particularly in relevant cells lines. An objective of this thesis was to validate three host factors as HDFs, in both TZM-­‐bl reporter and T cell-­‐derived cell lines, and to examine their potential as anti-­‐HIV-­‐1 therapeutic targets through exploitation of the cellular gene silencing pathway, RNA interference (RNAi). These were HIV-­‐1 Tat specific factor 1 (HTATSF1), DEAD (Asp-­‐Glu-­‐Ala-­‐Asp) box polypeptide 3, X-­‐ linked (DDX3X) and SWI/SNF related, matrix associated, actin dependent regulator of chromatin, subfamily b, member 1 (SMARCB1), selected because they had been previously implicated in HIV-­‐ 1 pathogenesis. The well-­‐characterised HDF, PC4 and SFRS1 interacting protein 1 (PSIP1)/lens epithelium-­‐derived growth factor (LEDGF)/p75, was included in the study as a positive control. Cassettes expressing short hairpin RNAs (shRNAs) targeting the four host proteins were generated, although shRNAs did not suppress endogenous ddx3x mRNA levels. The ability of shRNAs to inhibit HIV-­‐1 replication in the reporter cell line, TZM-­‐bl, was examined. These HeLa-­‐ derived cells are permissive for R5-­‐tropic HIV-­‐1 infection and contain an integrated luciferase gene driven by the viral promoter. shRNAs mediated a dose-­‐dependent inhibition of luciferase activity in cells infected with a HIV-­‐1 subtype B molecular clone and, although production of the viral protein p24 was unaltered, infectious particle production was decreased in cells treated with a shRNA suppressing HTATSF1. Little effect was observed with a shRNA targeting SMARCB1, suggesting that this may not function as an HDF under these conditions. No effect on infectious particle production was seen with the shRNA targeting PSIP1, which was a result of the long half-­‐ life of this protein, highlighting a limitation of using such reporter systems for HDF validation. Importantly, shRNAs were not associated with any cytotoxic effects in TZM-­‐bl cells. Whether HTATSF1 is a potential therapeutic target was interrogated further in the more relevant T cell-­‐derived SupT1 cell line. Lentiviruses were used to generate populations where >90% had one copy of the integrated shRNA expression cassette. Replication of the subtype B molecular clone p81A-­‐4 was significantly inhibited in the shH1-­‐expressing SupT1 cell line, which targets HTATSF1, for over 14 days post-­‐infection, although inhibition was not as pronounced asthat observed in the shP1-­‐expressing SupT1 cell line, which targets PSIP1. In contrast to a previous report, no change in the ratio of unspliced to singly-­‐ or multiply-­‐spliced HIV-­‐1 transcripts were detected in shH1-­‐expressing SupT1 cells, suggesting that HTATSF1 does not function as a splicing cofactor in this system. A slight rebound in p24 levels at 14 days post-­‐infection was accompanied by increased HTATSF1 expression and a decrease in the percentage of cells with transgene expression in the population. In addition, there was a slight decrease in shH1-­‐derived guide strand expression, but no change in transcription rates of the htatsf1 gene, suggesting that cells within the population with shH1 expression and HTATSF1 suppression may have a growth disadvantage. Thus, although this work demonstrates for the first time that HTATSF1 functions as an HDF in T cell-­‐derived SupT1 cells, it may not constitute a viable therapeutic target. A second objective of this thesis was to examine the feasibility of transcriptional gene silencing (TGS) of HDFs as an anti-­‐HIV strategy. TGS is a small RNA-­‐induced gene silencing pathway that operates through chromatin remodelling with the potential to mediate long-­‐term silencing of gene expression. Thus, its application may reduce the frequency of drug administration and associated toxicities. Short interfering RNAs (siRNAs) targeting the htatsf1 promoter were able to reduce target mRNA expression, which was accompanied by decreased htatsf1 transcription rates in HEK293T cells, suggesting silencing via a TGS mechanism. The htatsf1 silencing inhibited infectious HIV-­‐1 particle production from TZM-­‐bl cells. This work provides proof of principle that TGS induction at a HDF may inhibit HIV-­‐1 replication. siRNAs targeting the ddx3x promoter did not induce TGS. To examine whether gene susceptibility to TGS may be influenced by promoter architectures, 49 promoter features were examined for enrichment in genes at which small RNA-­‐induced TGS has been reported. Initially, the TGS group was compared to a random set of 2,000 promoters and then all other promoters in the genome. To control for gene activation, two further analyses were performed comparing the TGS group features to those from promoters active in the THP-­‐1 cell line and housekeeping genes. Whilst difficult to ascribe differences between the TGS group and the control groups to anything beyond a variation in the proportion of active genes within each group, there was enrichment for certain promoter features that are independent of activity; the TGS group was characterised by broad transcription start regions, high CpG content and a single expression profile. Moreover, the fraction of promoters with reported non-­‐coding RNA overlap was greater in the TGS group than the control groups. Thus, there is some evidence that a number of promoter features are associated with TGS susceptibility. It is hoped this novel analysis will facilitate selection of future TGS targets, including HDFs. In summary, the work presented in this thesis paves the way for development of improved anti-­‐HIV therapies involving HDF-­‐targeted TGS-­‐based gene therapies that mediate sustained inhibition of the virus.

A Protease do Vírus da Imunodeficiência Humana Tipo 1 (HIV-1 PR, EC 3.4.23.16) é um alvo macromolecular de grande importância no desenvolvimento de fármacos na terapia da Síndrome da Imunodeficiência Adquirida (AIDS). As maiores indústrias farmacêuticas do mundo concentram inúmeros esforços em estudos acerca desta proteína, que desde a introdução do saquinavir (Invirase&#174) na terapêutica em 1995, tem se mantido como um alvo fundamental para a descoberta de novos fármacos anti-HIV. A protease do vírus HIV-1 possui uma história rica de enorme sucesso no processo de descoberta e desenvolvimento de fármacos. A Química Medicinal moderna, de forte caráter multidisciplinar, fornece um arsenal de alternativas e estratégias racionais úteis no processo de planejamento de novos fármacos. Uma das tecnologias muito empregadas com sucesso é o estudo das relações quantitativas entre a estrutura e atividade (QSAR) para conjuntos de dados padrões. Os estudos de QSAR visam identificar e quantificar no complexo campo de modelagem as relações entre a estrutura e atividade de uma série de moléculas. Na presente dissertação de mestrado, foram realizados estudos de QSAR bi- (2D) e tridimensionais (3D) empregando, respectivamente, as técnicas holograma QSAR (HQSAR) e a análise comparativa dos campos moleculares (CoMFA), visando à geração de modelos preditivos para um conjunto de inibidores da protease do HIV-1. Os modelos gerados, associados às informações obtidas pelos mapas de contribuição 2D e de contorno 3D, são guias químico-medicinais úteis no planejamento de novos inibidores mais potentes e seletivos da protease do HIV-1. / The Human Immunodeficiency Virus Type 1 Protease (HIV-1 PR, EC 3.4.23.16) is a macromolecular target of great importance for the therapy of the Acquired Immunodeficiency Syndrome (AIDS). Major pharmaceutical companies around the world concentrate several efforts on studies concerning this enzyme, which since saquinavir (Invirase&#174) reached the market in 1995, has maintained its status as a fundamental target for anti-HIV drug discovery. HIV-1 protease has a rich history of enormous success in the drug discovery and development process. The strong multidisciplinary character of modern Medicinal Chemistry supplies an arsenal of useful rational strategies for the design of new drugs. One such technology is quantitative structure-activity relationships (QSAR), which has been successfully applied in a number of settings. QSAR studies aim to identify and quantify the relations between structure and activity of series of bioactive molecules organized within standard data sets. In the present master\'s dissertation, 2D and 3D QSAR studies were performed employing the hologram QSAR (HQSAR) and comparative molecular field analysis (CoMFA) techniques, respectively, in order to generate predictive models for a large set of HIV-1 PR inhibitors. The final models along with the information obtained from the 2D contribution and 3D contour maps should be useful in the design of new inhibitors with increased potency and selective within the chemical diversity of the data set.

Giraldi, I.M.E. Representações sobre o período da primeira internação hospitalar na perspectiva de mulheres HIV positivas, 2011 A aids foi relatada pela primeira vez em 1981 e atualmente a Organização Mundial da Saúde estima que aproximadamente 36 milhões de pessoas estejam infectadas pelo HIV em todo o mundo. No Brasil, entre as mulheres tem sido verificado o aumento da incidência de infecção a partir da segunda década da epidemia, indicando não apenas as dificuldades para oferecer respostas institucionais ao controle da epidemia, mas também, evidenciando as questões de gênero, em particular nas relações conjugais, como relações sexuais desprotegidas por falta de poder de negociação do preservativo e os comportamentos de risco adotados por seus parceiros, cuja assimetria provoca a vulnerabilização das mulheres à infecção. O adoecimento dessas mulheres leva a uma perspectiva preocupante, pois muitas vezes este adoecimento vem associado a responsabilidade dos cuidados de um parceiro e/ou de possíveis filhos infectados. Porém, quando os sintomas começam a aparecer, surgem ansiedade e medos que estavam aparentemente controlados. O processo de internação pode ocasionar reações que agravam o quadro dos pacientes internados. Neste sentido, este projeto teve por objetivos identificar, entre mulheres soropositivas para o HIV, algumas representações sociais sobre a primeira internação hospitalar motivada por manifestação de sintomas, adoecimento devido a fragilidade do sistema imunológico e/ou efeitos colaterais associados ao tratamento. Este estudo foi realizado com 10 mulheres soropositivas, com idade entre 32 e 46 anos, internadas numa unidade de tratamento específica - UETDI. A análise temática de conteúdo das transcrições de entrevistas individuais, semiestruturadas, audiogravadas foi sintetizada em Categorias e Subcategorias empíricas. Durante a internação, concretiza esta nova fase, sintomática, levando as participantes a encontrar novas formas de enfrentamento, representação do próprio corpo, novas perspectivas e, via contato com uma equipe adequada às suas necessidades e familiares, poder sair dessa hospitalização com novas possibilidades e representações de saúde. Por fim, pode-se indicar algumas reflexões acerca da complexidade da adesão do portador de HIV ao tratamento. / Giraldi, I.M.E. Representations about the first hospitalization period in the perspective of HIV-positive women, 2011 Aids was first reported in 1981; nowadays, the World Health Organization estimates that 36 million people are infected by the HIV worldwide. In Brazil, an increase of the infection\'s incidence has been observed in women since the epidemic\'s second decade. Such phenomenon indicates not only the difficulties for offering institutional responses in order to control the epidemics, but, also, it evidences genderrelated and more specifically conjugal questions, such as unsafe sexual relations occurring due to a lack of negotiation power for the use of condoms and risky behaviors adopted by partners, whose asymmetry leads to the increase of women\'s vulnerability to the infection. Women\'s process of sickening portrays a worrying panorama, for such process is associated to the responsibility for offering care to a partner or possible infected children. With the appearance of initial symptoms, though, anxiety and fears that were apparently under control arise, in contrast to an initial healthy state without weighty worries. In such context, the hospitalizing process can lead to reactions that aggravate the state of patients. The present study aimed to indentify some social representations of HIV-positive women regarding their first hospitalization due to symptom manifestation, immunologic fragility and/or treatment-related side effects. Ten women took part of the study, with ages between 32 and 46 years old, who were hospitalized in a specific treatment unity (UETDI). Thematic analysis of the recorded individual, semi-structured interviews\' contents was synthesized in empirical Categories and Subcategories. During hospitalization, a new, symptomatic stage becomes real, leading participants to find new strategies for coping, representing their own bodies, developing perspectives and, through the contact with health staff and family members, exiting the hospital with new possibilities and health-related representations. At last, some reflections are indicated regarding the complexity of adhesion to treatment process by people with HIV.