The Slr protein of Streptococcus pyogenes is selectively expressed in vivo and is a target for protective antibodies
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Vaccine candidates are typically identified through characterization of microbial surface antigens expressed under laboratory conditions. Here, we studied the major human pathogen Streptococcus pyogenes and show that Slr, a lipoprotein encoded by all strains, is not detected on the bacterial surface during growth in broth but nevertheless is targeted by protective antibodies in vivo, as demonstrated by passive and active immunizations in a mouse model of invasive infection. The expression of Slr is governed by the zinc-controlled regulator AdcR, indicating that zinc depletion triggers surface expression of Slr in vivo. During infection in humans and mice, the antibody response to Slr is comparable to that elicited by the classical M protein and is, intriguingly, directed almost exclusively against a region with histidine-triad (HT) motifs, an outcome that may represent a mechanism of immune escape. For vaccine development, these data focus interest on Slr and other microbial surface proteins selectively expressed in vivo.
Date Issued
2026-08-12
Date Acceptance
2026-06-05
Citation
EMBO Molecular Medicine, 2026, 18 (8), pp.3086-3108
ISSN
1757-4676
Publisher
Springer Nature
Start Page
3086
End Page
3108
Journal / Book Title
EMBO Molecular Medicine
Volume
18
Issue
8
Copyright Statement
© The Author(s) 2026. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.
License URL
Identifier
10.1038/s44321-026-00470-0
Publication Status
Published
Date Publish Online
2026-06-15