Biology subjects

Mwandumba, H.

Publications and source records attributed to Mwandumba, H..

3 recordsLinked to original sources

bioRxiv2026

Screening of epigenetic modifiers identifies novel host-directed agents that suppress HIV-1 replication in primary human macrophages

Epigenetic modifications play a critical role in diverse biological processes, including HIV-1 replication in lymphoid and myeloid cells, particularly in the establishment and maintenance of latency. As such, epigenetic targets represent potential candidates for novel host directed therapy (HDT). In this study, we developed a novel in vitro screening platform using human primary macrophages, including both monocyte-derived macrophages and alveolar macrophages, infected with a replication-competent luminescent virus. In contrast to previous screens, this platform enables the identification of compounds and epigenetic targets that modulate viral replication during a spreading infection, capturing not only transcriptional regulation but other vulnerabilities across the complete HIV-1 life cycle. Our data reveal multiple novel compounds targeting distinct epigenetic regulators, effectively inhibiting viral replication at various stages in primary macrophages, which may serve as potential candidates/targets for HDT.

immunology↗

bioRxiv2025

Versatile HIV Rev-dependent reporter cell system for stringent and sensitive quantification of viral reservoirs, neutralizing antibodies, and restriction factors

Detecting and measuring HIV reservoirs, neutralizing antibodies, and restriction factors are important for HIV cure research and the development of new therapeutics and vaccines. Here we describe the development and validation of several HIV Rev-dependent indicator cell lines for these purposes. These reporter cells come from different T-lymphoblast cell lines, including MOLT-4-R5, SupT1-R5, CEM-SS, A3R5, and from the adherent TZM cell platform based on HeLa clone JC53. These cells express CD4, CXCR4, and various levels of CCR5. We compared these cell lines for responsiveness to both X4 and R5-tropic viruses, and confirmed that reporter expression in these cells is not affected by stimulation from mitogens but is responsive to HIV Tat and Rev, reducing non-specific reporter induction from the leaky LTR promoter. To validate the sensitivity of the Rev-dependent reporter cell systems, we conducted a viral dilution assay with three primary HIV-1 clade C swarms from an adult in Malawi. We also validated the systems for quantifying antibody neutralization and screening restriction factors; these systems are also sensitive for viral outgrowth assays for quantifying viral reservoirs in clinical and basic research settings. Given that the systems can measure HIV accurately in complex environments with mitogens or other substances, they can be used for versatile applications, such as quantifying latent reservoirs, testing inhibitory compounds, conducting neutralizing antibody assays, and identifying new restriction factors.

microbiology↗

bioRxiv2021

Genomic variation across a clinical Cryptococcus population linked to disease outcome

Cryptococcus neoformans is the causative agent of cryptococcosis, a disease with poor patient outcomes, accounting for approximately 180,000 deaths each year. Patient outcomes may be impacted by the underlying genetics of the infecting isolate; however, our current understanding of how genetic diversity contributes to clinical outcomes is limited. Here, we leverage clinical, in vitro growth and genomic data for 284 C. neoformans isolates to identify clinically relevant pathogen variants within a population of clinical isolates from patients with HIV-associated cryptococcosis in Malawi. Through a genome-wide association study (GWAS) approach, we identify variants associated with fungal burden and growth rate. We also find both small and large-scale variation, including aneuploidy, associated with alternate growth phenotypes, which may impact the course of infection. Genes impacted by these variants are involved in transcriptional regulation, signal transduction, glycosylation, sugar transport, and glycolysis. We show that growth within the CNS is reliant upon glycolysis in an animal model, and likely impacts patient mortality, as CNS yeast burden likely modulates patient outcome. Additionally, we find genes with roles in sugar transport are enriched in regions under selection in specific lineages of this clinical population. Further, we demonstrate that genomic variants in two genes identified by GWAS impact virulence in animal models. Our approach identifies links between genetic variation in C. neoformans and clinically relevant phenotypes and animal model pathogenesis; shedding light on specific survival mechanisms within the CNS and identifying pathways involved in yeast persistence. ImportanceInfection outcomes for cryptococcosis, most commonly caused by C. neoformans, are influenced by host immune responses, as well as host and pathogen genetics. Infecting yeast isolates are genetically diverse; however, we lack a deep understanding of how this diversity impacts patient outcomes. To better understand both clinical isolate diversity and how diversity contributes to infection outcome, we utilize a large collection of clinical C. neoformans samples, isolated from patients enrolled in a clinical trial across 3 hospitals in Malawi. By combining whole-genome sequence data, clinical data, and in vitro growth data, we utilize genome-wide association approaches to examine the genetic basis of virulence. Genes with significant associations display virulence attributes in both murine and rabbit models, demonstrating that our approach can identify potential links between genetic variants and patho-biologically significant phenotypes.

genomics↗