Extracellular Vesicle-Derived Spliced Leader RNA as a Minimally Invasive Molecular Biomarker for Leishmaniasis Detection.
- 1Department of Biological Sciences, University of Notre Dame, Notre Dame, IN 46556, USA.
- 2Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN 46556, USA.
Abstract
Leishmaniasis continues to be a major neglected tropical disease, particularly in endemic areas where reliable diagnosis remains challenging. Many existing diagnostic methods are invasive, lack sufficient sensitivity, or require equipment and expertise that may not be available in resource-limited settings. Parasite-derived spliced leader (SL) RNA has recently gained attention as a promising molecular marker because it may enable the sensitive detection of viable Leishmania parasites and help track changes in infection over time. Extracellular vesicles (EVs) are also of growing interest because they protect and transport stable biomolecules that may provide valuable diagnostic information and influence interactions between the parasite and its host. In this proof-of-concept study, we evaluated the feasibility of detecting Leishmania-derived SL-RNA in EV-enriched preparations from experimental leishmaniasis model systems. EV-enriched preparations were isolated from parasite-conditioned media (PCM), infected THP-1 macrophage (I-MP) cell-conditioned medium (CCM), and serum from experimentally infected mice using a precipitation method. As a complementary isolation approach, additional preparations were isolated from PCM by ultracentrifugation. An aliquot of each preparation was analyzed by nanoparticle tracking analysis to determine particle size and concentration, and the remaining portion was used for RNA extraction. RNA was reverse transcribed into cDNA and analyzed for SL-RNA amplification using quantitative polymerase chain reaction (qPCR). SL-RNA amplification was successfully detected in PCM, I-MP CCM, and serum from experimentally infected mice, while uninfected controls showed no specific amplification. These findings were independently confirmed via ddPCR analysis. Notably, EV-enriched preparations from infected mice yielded a stronger SL-RNA signal than serum alone, highlighting the diagnostic potential of targeting SL-RNA in EV-enriched human clinical samples, particularly in low-burden infections. Although these findings support the feasibility of EV-associated SL-RNA as a molecular biomarker for Leishmania infection, clinical validation with human samples is required.
Related
- Multiomic liquid biopsy: emerging applications in disease quantification, biomarker detection, molecular phenotyping, and cancer signal of origin prediction
- PCR Detection and Species Identification of Leishmania in Microscopy-Negative Smears from Suspected Cutaneous Leishmaniasis in Iran
- Performance of recombinase polymerase amplification assay for cutaneous leishmaniasis detection: a systematic review and meta-analysis.
- Urine-based detection of Leishmania donovani antibodies using recombinant aurora kinase and otubain cysteine peptidase for noninvasive diagnosis of visceral leishmaniasis
- Circulating hepatocyte-derived extracellular particles as potential biomarker of steatohepatitis progression to fibrogenesis: Exploring the impact of smoking
BibTeX
@article{oskouei2026extracellular,
title = {{Extracellular Vesicle-Derived Spliced Leader RNA as a Minimally Invasive Molecular Biomarker for Leishmaniasis Detection.}},
author = {Mohannasadat Sajjadi Oskouei and Juan P Gonzalez and Delis J Mattei-Lopez and Douglas A Shoue and Cristian Koepfli and Mary Ann McDowell},
journal = {Tropical medicine and infectious disease},
year = {2026},
month = oct,
doi = {10.3390/tropicalmed11100281},
url = {https://europepmc.org/article/MED/42931466},
note = {CC BY},
}
RIS
TY - JOUR
TI - Extracellular Vesicle-Derived Spliced Leader RNA as a Minimally Invasive Molecular Biomarker for Leishmaniasis Detection.
AU - Mohannasadat Sajjadi Oskouei
AU - Juan P Gonzalez
AU - Delis J Mattei-Lopez
AU - Douglas A Shoue
AU - Cristian Koepfli
AU - Mary Ann McDowell
PY - 2026
DA - 2026/10/03
JO - Tropical medicine and infectious disease
DO - 10.3390/tropicalmed11100281
UR - https://europepmc.org/article/MED/42931466
AB - Leishmaniasis continues to be a major neglected tropical disease, particularly in endemic areas where reliable diagnosis remains challenging. Many existing diagnostic methods are invasive, lack sufficient sensitivity, or require equipment and expertise that may not be available in resource-limited settings. Parasite-derived spliced leader (SL) RNA has recently gained attention as a promising molecular marker because it may enable the sensitive detection of viable Leishmania parasites and help track changes in infection over time. Extracellular vesicles (EVs) are also of growing interest because they protect and transport stable biomolecules that may provide valuable diagnostic information and influence interactions between the parasite and its host. In this proof-of-concept study, we evaluated the feasibility of detecting Leishmania-derived SL-RNA in EV-enriched preparations from experimental leishmaniasis model systems. EV-enriched preparations were isolated from parasite-conditioned media (PCM), infected THP-1 macrophage (I-MP) cell-conditioned medium (CCM), and serum from experimentally infected mice using a precipitation method. As a complementary isolation approach, additional preparations were isolated from PCM by ultracentrifugation. An aliquot of each preparation was analyzed by nanoparticle tracking analysis to determine particle size and concentration, and the remaining portion was used for RNA extraction. RNA was reverse transcribed into cDNA and analyzed for SL-RNA amplification using quantitative polymerase chain reaction (qPCR). SL-RNA amplification was successfully detected in PCM, I-MP CCM, and serum from experimentally infected mice, while uninfected controls showed no specific amplification. These findings were independently confirmed via ddPCR analysis. Notably, EV-enriched preparations from infected mice yielded a stronger SL-RNA signal than serum alone, highlighting the diagnostic potential of targeting SL-RNA in EV-enriched human clinical samples, particularly in low-burden infections. Although these findings support the feasibility of EV-associated SL-RNA as a molecular biomarker for Leishmania infection, clinical validation with human samples is required.
SN - 2414-6366
ER -