Biology subjects

Ortiz Canseco, J.

Publications and source records attributed to Ortiz Canseco, J..

3 recordsLinked to original sources

bioRxiv2026

ESX-1 remodels the Mycobacterium tuberculosis antigen storage compartment in macrophages

Mycobacterium tuberculosis (Mtb) secretes antigenic proteins that drive protective T cell responses, yet how Mtb intracellular localization affects the trafficking and spatiotemporal distribution of mycobacterial antigens in macrophages remains elusive. Here, we developed a split fluorescent protein reporter to monitor the dynamics of the TB vaccine lead antigen Ag85B in infected human macrophages. We discovered that Mtb triggers the formation and remodeling of two distinct types of Mtb Antigen Storage Compartment (MASC) that retains Ag85 within macrophage membranes. Using subcellular spatial proteomics, we profiled the composition of the MASC, identifying both the Mtb and macrophage proteins that constitute these compartments. Unexpectedly, MASCs are defined by metabolic compartmentalization and rewiring to lipid metabolism in both the macrophage and Mtb. Thus, Mtb builds via the ESX-1 system a metabolically distinct antigen storage compartment in immune cells, with potential implications for antigen selection and delivery in TB vaccine development.

cell biology↗

bioRxiv2022

Understanding emergence of antimycobacterial dose dependent resistance.

Concentration dependency of phenotypic and genotypic isoniazid-rifampicin resistance emergence was investigated to obtain a mechanistic understanding on how anti-mycobacterial drugs facilitate the emergence of bacterial populations that survive throughout treatment. Using static kill curve experiments, observing two evolution cycles, it was demonstrated that rifampicin resistance was the result of non-specific mechanisms and not associated with accumulation of drug resistance encoding SNPs. Whereas, part of isoniazid resistance could be accounted for by accumulation of specific SNPs, which was concentration dependent. Using a Hollow Fibre Infection Model it was demonstrated that emergence of genotypic resistance only occurs when antibiotic levels fall below MIC although MICs are typically maintained following clinical dosing provided that adherence to the regimen is good. This study showed that disentangling and quantifying concentration dependent emergence of resistance provides improved rational for drug and dose selection although further work on understanding underlying mechanisms is needed to improve the drug development pipeline. One Sentence SummaryDisentangling and quantifying concentration dependent emergence of resistance will contribute to better informed drug and dose selection for anti-mycobacterial combination therapy.

pharmacology and toxicology↗

bioRxiv2017

Polymersomes Targeting Mononuclear Phagocytes

Mononuclear phagocytes such as monocytes, tissue-specific macrophages and dendritic cells are primary actors in both innate and adaptive immunity, as well as tissue homoeostasis. They have key roles in a range of physiological and pathological processes, so any strategy targeting these cells will have wide-ranging impact. These phagocytes can be parasitized by intracellular bacteria, turning them from housekeepers to hiding places and favouring chronic and/or disseminated infection. One of the most infamous is the bacteria that cause tuberculosis, which is the most pandemic and one of the deadliest disease with one third of the worlds population infected, and 1.8 million deaths worldwide in 2015. Here we demonstrate the effective targeting and intracellular delivery of antibiotics to both circulating monocytes and resident macrophages, using pH sensitive nanoscopic polymersomes made of poly(2-(methacryloyloxy)ethyl phosphorylcholine)-co-poly(2-(di-isopropylamino)ethyl methacrylate) (PMPC-PDPA). Polymersome selectivity to mononuclear phagocytes is demonstrated and ascribed to the polymerised phosphorylcholine motifs affinity toward scavenger receptors. Finally, we demonstrate the successful exploitation of this targeting for the effective eradication of intracellular bacteria that cause tuberculosis Mycobacterium tuberculosis as well as other intracellular parasites including the Mycobacterium bovis, Mycobacterium marinum and the most common bacteria associated with antibiotic resistance, the Staphylococcus aureus.

immunology↗