Increased Frequency of Inter-Subtype HIV-1 Recombinants Identified by Near Full-Length Virus Sequencing in Rwandan Acute Transmission Cohorts

Assessment of a diverse panel of transmitted/founder HIV-1 infectious molecular clones in a luciferase based CD8 T-cell mediated viral inhibition assay

Introduction

Immunological protection against human immunodeficiency virus-1 (HIV-1) infection is likely to require both humoral and cell-mediated immune responses, the latter involving cytotoxic CD8 T-cells. Characterisation of CD8 T-cell mediated direct anti-viral activity would provide understanding of potential correlates of immune protection and identification of critical epitopes associated with HIV-1 control.

Methods

The present report describes a functional viral inhibition assay (VIA) to assess CD8 T-cell-mediated inhibition of replication of a large and diverse panel of 45 HIV-1 infectious molecular clones (IMC) engineered with a Renilla reniformis luciferase reporter gene (LucR), referred to as IMC-LucR. HIV-1 IMC replication in CD4 T-cells and CD8 T-cell mediated inhibition was characterised in both ART naive subjects living with HIV-1 covering a broad human leukocyte antigen (HLA) distribution and compared with uninfected subjects.

Results & discussion

CD4 and CD8 T-cell lines were established from subjects vaccinated with a candidate HIV-1 vaccine and provided standard positive controls for both assay quality control and facilitating training and technology transfer. The assay was successfully established across 3 clinical research centres in Kenya, Uganda and the United Kingdom and shown to be reproducible. This IMC-LucR VIA enables characterisation of functional CD8 T-cell responses providing a tool for rational T-cell immunogen design of HIV-1 vaccine candidates and evaluation of vaccine-induced T-cell responses in HIV-1 clinical trials.

Pre-treatment HIV-1 drug resistance in antiretroviral therapy-naive adults in Eastern Africa: a systematic review and meta-analysis

BACKGROUND

Pre-treatment HIV drug resistance (PDR) may result in increased risk of virological failure and acquisition of new resistance mutations. With recently increasing ART coverage and periodic modifications of the guidelines for HIV treatment, there is a need for an updated systematic review to assess the levels of the PDR among adults newly initiating ART in Eastern Africa.

METHODS

We conducted a systematic search for studies published between 1 January 2017 and 30 April 2022 in the MEDLINE Complete and CINAHL Complete, searched simultaneously using EBSCOhost, and Web of Science. To determine the overall PDR prevalence estimates, we extracted data from eligible articles and analysed prevalence estimates using Stata 14.2.

RESULTS

A total of 22 eligible observation studies were selected. The studies included a total of 5852 ART-naive people living with HIV. The overall pooled prevalence of PDR was 10.0% (95% CI: 7.9%-12.0%, I2 = 88.9%) and 9.4% (95% CI: 7.0%-11.9%, I2 = 90.4%) for NNRTIs, 2.6% (95% CI: 1.8%-3.4%, I2 = 69.2%) for NRTIs and 0.7% (95% CI: 0.3%-1.2%, I2 = 29.0%) for PIs. No major integrase strand transfer inhibitors (INSTI)-related mutations were identified.

CONCLUSIONS

We observed a moderate overall PDR prevalence among new ART initiators in this study. PDR to NNRTIs is more prevalent, underscoring the importance of the current WHO recommendation for replacement of NNRTIs by INSTIs. PDR to NRTIs was low but notable, which warrants continuous surveillance of pre-existing resistance to the dolutegravir co-administered NRTI in Eastern Africa.