Evidence map›Paper›PMID 42577437›Full record

ArticleFrontiers in microbiology2026

Systematic characterization of SARS-CoV-2 spike protein subunit trafficking and secretion reveals enhanced strategies for vaccine design and quantification.

Qian Zhang, Maria Hammond, Jie Song, Zongwei Fang, Hongxing Zhao, Maréne Landström, Ya-Fang Mei

Abstract read
In one paragraph

Article in Frontiers in microbiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

7 authors.

Qian Zhang *Department of Clinical Microbiology, Umeå University, Umeå, Sweden.
Maria Hammond *Department of Immunology, Genetics, Pathology, SciLifeLab; Proximity Proteomics Facility, Uppsala, Sweden.
Jie Song *Department of Medical Bioscience, Umeå University, Umeå, Sweden.
Zongwei FangDepartment of Clinical Microbiology, Umeå University, Umeå, Sweden.
Hongxing ZhaoDepartment of Immunology, Genetics, Pathology, SciLifeLab; Proximity Proteomics Facility, Uppsala, Sweden.
Maréne LandströmDepartment of Medical Bioscience, Umeå University, Umeå, Sweden.
Ya-Fang MeiDepartment of Clinical Microbiology, Umeå University, Umeå, Sweden.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Despite the widespread deployment of current COVID-19 vaccines, significant gaps remain in understanding the complete biological behavior of the SARS-CoV-2 spike (S) protein. Through systematic characterization of mammalian expression systems, this study shows that the full-length S protein exhibits a complex intracellular distribution, predominantly localizing not only to the cell membrane but also to the cytoplasm, nucleus, and extracellular compartments. Comparative analyses revealed distinct subunit-specific trafficking patterns. The S1 subunit showed increased intracellular accumulation and secretion compared to the full-length S protein, although with reduced surface expression. Conversely, the receptor-binding domain (RBD) and S2 domains were mainly associated with cytoskeletal (CS) structures. Notably, the signal sequence-enhanced RBD (SS-RBD) construct engineered in this study demonstrated dramatically enhanced extracellular accumulation, approximately 100-fold higher than the full-length S protein and 10-fold greater than S1, as measured by proximity extension assay (PEA). Signal peptide modification effectively redirected RBD from CS retention to efficient secretion, significantly improving detection sensitivity. PEA outperformed conventional methods such as flow cytometry (FACS), Western blotting (WB), and immunofluorescence, offering sensitivities several orders of magnitude higher. Consequently, these findings provide: (1) a structural framework for rational antigen design by distinguishing essential versus dispensable domains; (2) experimental support for SS-RBD as a promising vaccine candidate due to its high secretion efficiency and preservation of neutralizing epitopes; and (3) a robust platform using PEA for high-sensitivity antigen characterization. This study enhances the fundamental understanding of spike protein biology and offers actionable insights for developing next-generation vaccines targeting SARS-CoV-2 and related coronaviruses.

Indexed as

antigenicitycharacterizationPEA quantificationSARS-CoV-2secretionspike and subunitstraffickingvaccine candidate

Identifiers

PMID42577437
PMCPMC13454229

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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.