Rab9 depletion enhances human adenovirus type 26 transduction efficiency through increased internalization and reduced late endosomal/lysosomal retention

Drašković, Isabela; Nestić, Davor; Lulić Horvat, Lucija; Martinčić, Jelena; Stojanović, Mario; Condezo, Gabriela N.; Kašnar, Klara; González-Almela, Esther; Lago, Darío; San Martín, Carmen; Custers, Jerome; Majhen, Dragomira (2026) Rab9 depletion enhances human adenovirus type 26 transduction efficiency through increased internalization and reduced late endosomal/lysosomal retention. PLOS Pathogens, 22 (8). ISSN 1553-7374

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Official URL: http://doi.org/10.1371/journal.ppat.1014028

Abstract

Understanding intracellular trafficking is central to decoding viral pathogenesis and engineering optimized viral vectors. How a virus or vector is routed through the endocytic pathway directly dictates its genome release, immune sensing, and overall transduction efficiency. Human adenovirus type 26 (HAdV-D26) presents a promising platform for vector design due to its low preexisting immunity, potent immune stimulation, scalable production, and versatile genetic engineering capacity. Although increasingly significant, the fundamental mechanisms governing HAdV-D26 intracellular trafficking are still not fully understood. Our study demonstrates that compared to well-described human adenovirus type 5 (HAdV-C5), HAdV-D26 undergoes prolonged intracellular trafficking, transiently localizing to early endosomes before residing in late endosomes/lysosomes for up to four hours post-infection. Inhibition of lysosomal acidification modestly enhances HAdV-D26 transduction efficiency, whereas blocking transport from early to late endosomes/lysosomes does not. Strikingly, Rab9 knockdown reduces HAdV-D26 late endosomal/lysosomal localization while increasing both virus internalization and genome delivery to the host cell nucleus. These findings indicate that late endosomal sorting pathways actively influence HAdV-D26 infection outcomes. By identifying a previously unappreciated role for Rab9 in adenovirus transduction, our results provide new mechanistic insight into HAdV-D26 intracellular trafficking, highlight serotype-specific differences in adenovirus entry pathways, and identify endosomal trafficking steps that may be targeted to improve adenoviral vector performance.

Item Type:

Article

Uncontrolled Keywords:

adenovirus,; endocytosis; rab9

Subjects:

NATURAL SCIENCES > Biology > Biochemistry and Molecular Biology
NATURAL SCIENCES > Biology > Microbiology

Divisions:

Division of Molecular Biology

Projects: