Biology subjects

Zeeb, M.

Publications and source records attributed to Zeeb, M..

3 recordsLinked to original sources

bioRxiv2024

Rare twin cysteine residues in the HIV-1 envelope variable region 1 link to neutralization escape and breadth development

The identification of HIV-1 Envelope glycoprotein (Env) traits associated with development of neutralization cross-reactivity in natural infection is critical for vaccine design. Here we describe the presence of additional Cysteine (Cys) residues in V1 that are enriched among people with elite neutralization breadth. Using >65,000 V1 sequences from the CATNAP database, the AMP trials and three large longitudinal HIV infection cohorts, the SHCS, ZPHI and CAPRISA studies, we show that Env variants with extra V1 Cys are present at low levels throughout infection and fluctuate in frequency over time within participants. We demonstrate an independent association of extra V1 Cys with elite plasma neutralization, and a strong preference for two versus one extra Cys, suggesting certain Envs introduce an additional disulfide bond for stabilization. We observed high levels of neutralization resistance among Envs from 34 bNAb donors, of which 17.6% had elongated V1 regions with extra Cys. We show that extra V1 Cys moderately increase neutralization resistance in an Env from a V2- Apex bNAb-inducer. Modulation of the accessibility of bNAb epitopes on this Env by extra V1 Cys enhanced epitope shielding of several regions, but increased V2 exposure. This suggests that escape from autologous neutralizing activity drove insertion of the extra V1 Cys, creating a modified antigen that may have favored V2 bNAb induction in this donor. Overall, we identify a rare motif of twin Cys in V1 that confers increased neutralization resistance and Env stabilization, is associated with bNAb induction, and may hold potential for incorporation into future HIV bNAb immunogens.

immunology↗

bioRxiv2024

Comparative Evaluation of Bioinformatic Pipelines for Full-Length Viral Genome Assembly

The increasingly widespread application of next-generation sequencing (NGS) in clinical diagnostics and epidemiological research has generated a demand for robust, fast, automated, and user-friendly bioinformatic workflows. To guide the choice of tools for the assembly of full-length viral genomes from NGS datasets, we assessed the performance and applicability of four widely adopted bioinformatic pipelines (shiver - for which we created a user-friendly Dockerized version, referred to as dshiver; SmaltAlign, viral-ngs, and V-pipe) using both simulated datasets and real-world HIV-1 paired-end short- read sequences and default settings. All four pipelines produced high-quality consensus genome assemblies and minority variant calls when the reference sequence used for assembly had high similarity to the analyzed sample. However, while shiver and SmaltAlign showed robust performance also with more divergent samples (non-matching subtypes), viral-ngs and V-Pipe proved to be sensitive to genetic distance from the reference sequence. With empirical datasets, SmaltAlign and viral-ngs exhibited substantially shorter runtime compared to V-Pipe and shiver. In terms of applicability, V-Pipe provides the broadest functionalities; SmaltAlign and dshiver combine user-friendliness with robustness; while the use of viral-ngs requires a less computational resources compared to other tools. To conclude, all four pipelines can perform well in terms of quality metrics; however, the reference sequence needs to be adjusted to closely match the sample data for viral-ngs and V-Pipe. Differences in user-friendliness and runtime may guide the choice of the pipeline in a particular setting. The new Dockerized version of shiver offers ease of use in addition to the accuracy and robustness of the original pipeline.

bioinformatics↗

bioRxiv2023

Mycobacterium tuberculosis infection associated immune perturbations correlate with antiretroviral immunity

Infection with Mycobacterium tuberculosis (MTB) remains one of the most important opportunistic infections in people with HIV-1 (PWH). While active Tuberculosis (TB) leads to rapid progression of immunodeficiency in PWH, the interaction between MTB and HIV-1 during the asymptomatic phase of both infections remains poorly understood. In a cohort of individuals with HIV (PWH) with and without suppressed HIV-1 viral load, the transcriptomic profiles of peripheral blood mononuclear cells (PBMC) clustered in individuals infected with Mycobacterium tuberculosis (MTB) compared to carefully matched controls. Subsequent functional annotation analysis disclosed alterations in the IL-6, TNF, and KRAS pathways. Notably, MTB-associated genes demonstrated an inverse correlation with HIV-1 viremia, evident at both on individual gene level and when employed as a gene score. In sum, our data show that MTB infection in PWH is associated with a shift in the activation state of the immune system, displaying an inverse relationship with HIV-1 viral load. These results could provide an explanation for the observed increased antiretroviral control associated with MTB infection in PWH.

immunology↗