Person: MacLeod, Iain
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MacLeod
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Iain
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MacLeod, Iain
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Publication Prevalence of oncogenic human papillomavirus genotypes in patients diagnosed with anogenital malignancies in Botswana(BioMed Central, 2017) Rantshabeng, Patricia S.; Moyo, Sikhulile; Moraka, Natasha O.; Ndlovu, Andrew; MacLeod, Iain; Gaseitsiwe, Simani; Kasvosve, IshmaelBackground: Human papillomavirus (HPV) associated malignancies are the leading cause of cancer death in Botswana. We sought to determine causative HPV types in patients with anogenital malignancies in Botswana to inform vaccine strategy. Methods: We used formalin-fixed and paraffin-embedded (FFPE) tissue blocks from patients diagnosed with anal, penile and vulvar squamous cell carcinomas between the years, 2014 and 2016. Presence of HPV 16, 18, or other high-risk (HR) types was detected using Abbott m2000 real-time PCR platform. Tissues with other high-risk types were subsequently analysed using a multiplex qPCR assay that includes 15 validated fluorophore probes. Results: A total of 126 tissue specimens, comprising of 21 anal (9 males, 12 females), 31 penile and 74 vulvar were studied. Ninety-three (73.8%) patients had their HIV status documented in the records while the rest did not. Eighty-three (83) out of 93 were HIV positive, a prevalence of 89.4% (95% CI: 81–94). HPV was detected in 68/126 (54%) tissues, of which 69% (95% CI: 54–79) had HPV 16 only, 28% (95% CI: 19–40) had other hr.-HPV types and 2.9% (95% CI, 3.5–10.1) were co-infected with HPV 16 and other hr.-types. Other high-risk types detected included HPV 26, 31, 33, 35, 39, 45, 51, 52, 66 and 68. HPV 18 was not detected. Multiple-type HPV infection was detected in 44 of 47 (93.6%) HIV positive participants co-infected with HPV. In HIV-negative individuals, only HPV 16 was detected. Conclusion: In our study, anogenital carcinomas were associated with HPV 16 and other hr.-HPV types besides HPV 16 and 18. HIV co-infected patients had multiple hr.-HPV types detected whereas in HIV-negative patients only HPV 16 was detected. Our study suggests that multivalent vaccines may be more suitable in this setting, especially for HIV-infected individuals.Publication Immune Activation Markers in Peripartum Women in Botswana: Association with Feeding Strategy and Maternal Morbidity(Public Library of Science (PLoS), 2014) Russell, Elizabeth S.; Mohammed, Terence; Smeaton, Laura; Jorowe, Baitshepi; MacLeod, Iain; Hoffman, Risa M.; Currier, Judith S.; Moyo, Sikhulile; Essex, Max; Lockman, ShahinHormone levels shift the immune state in HIV-uninfected pregnant and breastfeeding women away from Th1 responses and toward regulation to permit fetal tolerance. Limited data exist on inflammation during pregnancy or postpartum in HIV-infected women, though certain inflammatory markers are associated with adverse health outcomes among HIV-infected persons. We measured hsCRP, D-dimer, IFN-γ, IL-6, IL-10 and TNF-α at 34 weeks gestation and six months postpartum in HIV-infected women from the Botswana Mashi PMTCT trial who were randomized to breastfeeding or formula-feeding. Differences in inflammatory markers between gestation and postpartum periods, and by randomized feeding method, were estimated using generalized estimating equations, adjusting for baseline plasma HIV-1 viral load, CD4 count, calendar time, and antiretroviral treatment status. Additionally, we studied the association between marker concentrations at six months postpartum and major adverse clinical events over the following 4.5 years, using case-cohort sampling and adjusted Cox proportional hazards models. In 86 breastfeeding and 75 formula-feeding women, hsCRP and D-dimer decreased significantly between 34 weeks gestation and six months postpartum, while IFN-γ increased. There was no significant association between inflammatory marker change and randomized feeding method after adjusting for multiple comparisons and removing outliers. In univariate analysis, TNF-α, D-dimer, and IFN-γ concentrations at six months postpartum were significant predictors of subsequent clinical events, and TNF-α remained significant in multivariate analysis (HR = 4.16, p = 0.001). In young HIV-infected women in Botswana inflammatory marker concentrations did not differ significantly between women who breast- vs. formula-fed. However, postpartum TNF-α level was predictive of subsequent adverse clinical event.Publication tat Exon 1 Exhibits Functional Diversity during HIV-1 Subtype C Primary Infection(American Society for Microbiology, 2013) Rossenkhan, R.; MacLeod, Iain; Sebunya, T. K.; Castro-Nallar, E.; McLane, Mary; Musonda, Rosemary; Gashe, B. A.; Novitsky, Vladimir; Essex, MyronHuman immunodeficiency virus type 1 (HIV-1) Tat is a mediator of viral transcription and is involved in the control of virus replication. However, associations between HIV-1 Tat diversity and functional effects during primary HIV-1 infection are still unclear. We estimated selection pressures in tat exon 1 using the mixed-effects model of evolution with 672 viral sequences generated from 20 patients infected with HIV-1 subtype C (HIV-1C) over 500 days postseroconversion. tat exon 1 residues 3, 4, 21, 24, 29, 39, and 68 were under positive selection, and we established that specific amino acid signature patterns were apparent in primary HIV-1C infection compared with chronic infection. We assessed the impact of these mutations on long terminal repeat (LTR) activity and found that Tat activity was negatively affected by the Ala21 substitution identified in 13/20 (65%) of patients, which reduced LTR activity by 88% (±1%) (P < 0.001). The greatest increase in Tat activity was seen with the Gln35/Lys39 double mutant that resulted in an additional 49% (±14%) production of LTR-driven luciferase (P = 0.012). There was a moderate positive correlation between Tat-mediated LTR activity and HIV-1 RNA in plasma (P = 0.026; r = 0.400) after 180 days postseroconversion that was reduced by 500 days postseroconversion (P = 0.043; r = 0.266). Although Tat activation of the LTR is not a strong predictor of these clinical variables, there are significant linear relationships between Tat transactivation and patients' plasma viral loads and CD4 counts, highlighting the complex interplay between Tat mutations in early HIV-1C infection.Publication Abacavir Alters the Transcription of Inflammatory Cytokines in Virologically Suppressed, HIV-Infected Women(International AIDS Society, 2012) MacLeod, Iain; Rowley, Christopher; Lockman, Shahin; Ogwu, Anthony; Moyo, Sikhulile; van Widenfelt, Erik; Mmalane, Mompati; Makhema, Joseph; Essex, Myron; Shapiro, RogerBackground: Abacavir (ABC) may be associated with a small, increased risk of myocardial infarction in HIV-infected adults, possibly related to cytokine-mediated inflammation. Methods: To evaluate the induction of inflammatory cytokine transcription by ABC, we used samples from women randomized to receive zidovudine/lamivudine/ABC (Trizivir) or lopinavir/ritonavir and zidovudine/lamividine (Kaletra/Combivir) from the third trimester through six-months postpartum for the prevention of mother-to-child transmission (PMTCT). Women were matched by CD4 count and baseline HIV RNA. All women attained viral suppression (<50 copies/ml) by the time of sampling. Results: Four cytokines showed a difference in expression between the treatment arms, all in a proinflammatory direction for the ABC arm: CD40LG 1.82-fold, (p=.027); IL-8 3.16-fold (p=.020); LTA 2.82-fold, (p=.008); and CCL5 −1.67-fold, (p=.035). At 12-months postpartum, 6-months after antiretroviral discontinuation, cytokine expression was similar by treatment arm. Conclusions: We conclude that ABC may upregulate proinflammatory cytokines at the transcriptional level in this population.