Biology subjects

Kos, J.

Publications and source records attributed to Kos, J..

3 recordsLinked to original sources

bioRxiv2025

Development and validation of HIV SMRTcap for the characterization of HIV-1 reservoirs across tissues and subtypes

Human Immunodeficiency Virus type 1 (HIV-1) is responsible for the global HIV/AIDS epidemic and the establishment of an integrated HIV-1 reservoir remains the primary obstacle to cure. Upon therapy interruption, reactivation of the persistent HIV-1 reservoir propagates viral rebound and mediates continued immunological decline. While furthering understanding of the HIV-1 reservoir is essential for HIV-1 cure, commonly used sequencing strategies are often limited by the reliance on short-read sequencing across separate assays to determine integration sites and proviral integrity - something that does not always adequately resolve complex human genomic repeats or low complexity regions. Simultaneous identification of proviral integration sites and proviral integrity at the single molecule level would enable HIV-1 reservoir characterization with minimal imputation or bioinformatic reconstruction. Here we present HIV Single Molecule Real Time Capture (HIV SMRTcap), a novel molecular and computational pipeline that directly and simultaneously identifies HIV-1 integration sites, defines proviral integrity, and characterizes clonal expansion of HIV-1 provirus-containing cells with single molecule resolution. In combination with long-read, single-molecule, real-time (SMRT) sequencing and custom analytic pipelines, HIV SMRTcap enables a highly comprehensive characterization of HIV-1 reservoirs. Moreover, we demonstrate here that HIV SMRTcap performs robustly across the major global subtypes (HIV-1 subtype A, B, C, D and A/D recombinant viruses), and can use both cell- and tissue-derived inputs, including samples from antiretroviral therapy (ART) treated individuals with undetectable viral loads. Our results demonstrate that HIV SMRTcap serves as a comprehensive, robust method for unbiased HIV-1 reservoir characterization. Used alone, or in combination with single-cell based methods, HIV SMRTcap will enable novel exploration of viral reservoirs across subtypes and in tissue-specific compartments, providing critical information needed to inform HIV-1 cure.

genomics↗

bioRxiv2024

Pharmacological characterisation of allosteric modulators at human mGlu5

The metabotropic glutamate receptor 5 (mGlu5) is a Class C G protein-coupled receptor, ubiquitously expressed throughout the CNS. With major roles in cognition, learning and memory, mGlu5 dysfunction is linked with numerous neurodegenerative and neuropsychiatric disorders, presenting a viable therapeutic target. Allosteric modulators bind topographically distinct sites from glutamate and other orthosteric agonists and enhance (positive allosteric modulators, PAMs), inhibit (negative allosteric modulators, NAMs) or do not effect (neutral allosteric ligands, NALs) mGlu5 function. While mGlu5 modulators have efficacy in in vivo rodent models of CNS disorders, none have made it to the clinic. We hypothesise this lack of translatability is arises from preclinical optimisation using on non-human pharmacological data, as functional studies are predominantly performed using rat mGlu5 and non-human brain neuronal cultures. Here we assess and quantify the impact of eleven chemically and pharmacologically diverse mGlu5 PAMs, NAMs and NALs on human mGlu5 activity using radioligand binding, iCa2+ mobilisation and IP1 accumulation assays. By comparing to published and newly generated data for rat mGlu5 we show that while modulator pharmacology is relatively consistent across species, ligand dependent species differences in allosteric modulator affinity, cooperativity and probe dependence are evident. Additionally, we report PAM-dependent effects on orthosteric agonist kinetic profiles at human mGlu5. Together, these data highlight the importance of systematic evaluation of mGlu5 allosteric ligand activity at human mGlu5 to improve drug design and overcome potential barriers to translatability to clinical settings.

pharmacology and toxicology↗

bioRxiv2019

Therapeutic potential of inhibition of the neuroinflammation induced cathepsin X: in vivo evidence

Parkinsons disease (PD) is a progressive neurodegenerative disorder with unknown cause, but it has been postulated that chronic neuroinflammation may play a role in its pathogenesis. Microglia-derived lysosomal cathepsins have been increasingly recognized as important inflammatory mediators. Here, we analyzed the regional distribution and cellular localization of the cathepsin X in the rat brain with neuroinflammation-induced neurodegeneration. Unilateral injection of lipopolysaccharide (LPS) into the striatum induced strong upregulation of cathepsin X expression and its activity in the ipsilateral striatum. In addition to the striatum, cathepsin X overexpression was detected in other areas such as cerebral cortex, corpus callosum, subventricular zone and external globus pallidus mainly restricted to glial cells. Moreover, continuous administration of the cathepsin X specific inhibitor AMS36 showed protective effects against LPS-induced striatal degeneration, as seen by the decreased extent of striatal lesion and decreased expression of neuroinflammation marker. These results demonstrate that glial upregulated cathepsin X may play a role as a potential pathogenic factor in PD. Inhibition of cathepsin X enzymatic activity thus may be useful in preventing neuroinflammation-induced neurodegeneration.

molecular biology↗