ArticleJournal of virology2026
Human parainfluenza virus 3 fusion protein cleavage: a key determinant of infection and spread.
Article in Journal of virology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
0 citing papers in PubMed.
No citing paper in PubMed yet.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors.
Funding
Abstract
Human parainfluenza virus 3 (HPIV3) entry into target cells depends on a viral fusion complex composed of hemagglutinin-neuraminidase (HN) and fusion protein (F). In addition to attachment, HN activates F to mediate membrane fusion, while its neuraminidase activity promotes viral release. This creates a biological paradox: virions must repeatedly engage sialic acid-rich substrates in the airway without prematurely triggering F until they reach the target cell sialic acid receptor. Unlike the F proteins of laboratory strains that are cleaved intracellularly by furin to process F from its pro-protein to the active form that is essential for fusion, the F proteins of HPIV3 field strains lack a furin cleavage site and undergo partial cleavage mediated by extracellular serine proteases. We show that virions isolated directly from infected humans contain both cleaved and uncleaved F. In viral migration assays, reducing the proportion of cleaved F on virions increases the distance virions travel before infecting a cell. Even virions bearing only uncleaved F upon egress from infected cells can establish infection IMPORTANCE: Parainfluenza viruses employ their surface glycoproteins, the receptor-binding (hemagglutinin-neuraminidase) and fusion (F) proteins, to fuse with target cell membranes and infect the airway. F is made as an inactive precursor that is activated when host cell proteases cleave it to produce the fusion-competent form. Previous studies, utilizing laboratory-adapted viruses, assumed that F proteins are pre-cleaved on virus produced by infected people. We show that virions isolated directly from infected humans contain both cleaved and uncleaved F proteins. In viral migration assays, reducing the proportion of cleaved F on virions increases the distance virions travel before infecting a cell. The uncleaved F proteins enable virions to travel from their cell of origin without undergoing premature fusion protein activation, allowing virions to traverse the airway and infect the proper target cells. HPIV3 exploits host protease environments to produce a spectrum of virions suited to either local infection or intra-host spread.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.