Iain J. MacLeod

Binding of Herpes Simplex Virus Type-1 Virions Leads to the Induction of Intracellular Signalling in the Absence of Virus Entry

The envelope of HSV-1 contains a number of glycoproteins, four of which are essential for virus entry. Virus particles lacking gB, gD, gH or gL are entry-defective, although these viruses retain the ability to bind to the plasma membrane via the remaining glycoproteins. Soluble forms of gD have been shown to trigger the nuclear translocation of the NF-κB transcriptional complex in addition to stimulating the production of Type I interferon. By taking advantage of the entry-defective phenotype of glycoprotein-deficient HSV-1 virus particles, the results presented here show that binding of virions to cellular receptors on the plasma membrane is sufficient to stimulate a change in cellular gene expression. Preliminary microarray studies, validated by quantitative real-time PCR, identified the differential expression of cellular genes associated with the NF-κB, PI3K/Akt, Jak/Stat and related Jak/Src pathways by virions lacking gB or gH but not gD. Gene induction occurred at a few particles per cell, corresponding to physiological conditions during primary infection. Reporter assay studies determined that NF-κB transcriptional activity is stimulated within an hour of HSV-1 binding, peaks between two and three hours post-binding and declines to background levels by five hours after induction. The immediate, transient nature of these signalling events suggests that HSV-1 glycoproteins, particularly gD, may alter the cellular environment pre-entry so as to condition the cell for viral replication.

Minor resistant variants in nevirapine-exposed infants may predict virologic failure on nevirapine-containing ART.

BACKGROUND Single-dose nevirapine (sdNVP) is widely used to prevent mother-to-child transmission (PMTCT) of HIV-1. This may result in NVP resistance in both mother and infant. The significance of low levels of NVP resistance mutations in infants treated with NVP-containing antiretroviral treatment (ART) is unknown. OBJECTIVES To determine the presence of pre-treatment NVP resistance in HIV-infected infants with and without prior NVP exposure. STUDY DESIGN 33 HIV-1-infected infants in a PMTCT trial received NVP-containing ART (26 infants with prior NVP exposure). Plasma and buffy coat samples obtained prior to ART initiation were evaluated for drug resistance by bulk sequencing and allele-specific PCR (ASPCR). RESULTS ViroSeq identified NVP resistance in 3 of 33 infants; all failed first-line therapy. Pre-ART plasma NVP resistance by ASPCR was detected in 9 of 16 children experiencing virologic failure compared to 4 of 17 children without virologic failure (risk ratio 2.4, CI 0.94-7.8, p=0.08). Proviral resistance was not associated with virologic failure (risk ratio 1.2, CI 0.8-2.0, p=0.40). In the nevirapine-exposed infants, those who started ART before 7 months had higher risk of virologic failure (RR 2.3, CI 0.96-9.2, p=0.11). CONCLUSIONS Low level drug resistance detected in plasma after NVP exposure prior to ART initiation may be associated with virologic failure on ART, while resistance in the DNA reservoir was not predictive of treatment outcome.

Prevalence of human papillomavirus genotypes and associated cervical squamous intraepithelial lesions in HIV-infected women in Botswana

Human papillomaviruses (HPV) constitute one of the most prevalent sexually transmitted infections and are the etiological agents for invasive cervical cancer, the predominant cancer among women in Botswana. However, the prevalence of HPV genotypes in Botswana has yet to be reported.

Sharp increase in rates of HIV transmitted drug resistance at antenatal clinics in Botswana demonstrates the need for routine surveillance

OBJECTIVES The aim of the study was to evaluate for the presence of drug resistance to HIV medications in treatment-naive individuals in Botswana. METHODS Two different populations were evaluated for evidence of HIV drug resistance at three different geographical locations in Botswana. In the first study population, consisting of pregnant females diagnosed with HIV during pregnancy, participants were enrolled at the time of their HIV diagnosis. The second population included pre-ART enrollees at Infectious Diseases Care Clinics (IDCCs) who had a CD4 T cell count >350 cells/μL. RESULTS A total of 422 genotypes were determined: 234 for samples from antenatal clinic (ANC) participants and 188 for samples from IDCC participants. Between 2012 and 2014, 6 of 172 (3.5%) genotypes from ANC participants exhibited transmitted drug resistance (TDR), with 3 (1.7%) showing resistance to first-line ART. In a subset of samples from Gaborone, Botswanas capital and largest city, the TDR rate was 3 in 105 (2.9%), but only 1 in 105 (1.0%) showed first-line ART resistance. Between December 2014 and April 2015, the rate of resistance to any ART in Gaborone was 6 in 62 (9.7%), with 5 (8.1%) exhibiting first-line ART resistance. CONCLUSIONS These data demonstrate that TDR rates for HIV differ geographically and temporally in Botswana, with significant increases in TDR observed at ANCs in Gaborone between 2012 and 2015. These findings stress the importance of continued testing for TDR, particularly as access to HIV treatment increases and guidelines recommend treatment at the time of HIV diagnosis.

Abacavir Alters the Transcription of Inflammatory Cytokines in Virologically Suppressed, HIV-Infected Women

Abacavir (ABC) may be associated with a small, increased risk of myocardial infarction in HIV‐infected adults, possibly related to cytokine‐mediated inflammation.

THE USE OF WHITE PHOSPHORUS AND THE LAW OF WAR

The controversy surrounding recent uses of white phosphorus (WP) to ‘flush-out’ suspected insurgents or in attacks against military targets in open ground has led to a renewed media interest in the legal status of WP-based munitions. An inherent public dislike for weapons that cause death or injury by fire is very natural, so one is entitled to ask whether humanity should not prevail when it comes to anti-personnel uses of such weapons. In the absence of a specific treaty dealing with the use of WP, this article, written jointly by a retired military lawyer and a scientist interested in the law, examines the use of such weapons in practice as well as the relevant legal and scientific background before attempting to reach conclusions about their legality. This involves a consideration of the reasons for the development of WP-based munitions, of their usual military uses and of some unconventional uses of such weapons. There follows an examination of the basic principles of customary international law as well as the treaty provisions dealing with incendiary weapons. Furthermore, because of the various harmful physiological interactions of WP, it was necessary to look closely at the legal provisions on poison, gas and chemical weapons. That demanded an interpretation of multiple aspects of the Chemical Weapons Convention before the legal status of WP could be fully determined. The convention is constructed in such a way that what at first sight appears to be a chemical weapon may not be as a matter of law unless it is consciously applied in a prohibited manner.

Current Status of Point-of-Care Testing for Human Immunodeficiency Virus Drug Resistance

&NA; Healthcare delivery has advanced due to the implementation of point‐of‐care testing, which is often performed within minutes to hours in minimally equipped laboratories or at home. Technologic advances are leading to point‐of‐care kits that incorporate nucleic acid‐based assays, including polymerase chain reaction, isothermal amplification, ligation, and hybridization reactions. As a limited number of single‐nucleotide polymorphisms are associated with clinically significant human immunodeficiency virus (HIV) drug resistance, assays to detect these mutations have been developed. Early versions of these assays have been used in research. This review summarizes the principles underlying each assay and discusses strategic needs for their incorporation into the management of HIV infection.

Immune activation markers in peripartum women in Botswana: association with feeding strategy and maternal morbidity.

Hormone 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.

Prevalence of oncogenic human papillomavirus genotypes in patients diagnosed with anogenital malignancies in Botswana

BackgroundHuman 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.MethodsWe 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.ResultsA 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.ConclusionIn 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.