Staphylococcal enterotoxin-like X (SElX) is a unique superantigen with functional features of two major families of staphylococcal virulence factors

32Citations
Citations of this article
67Readers
Mendeley users who have this article in their library.

Abstract

Staphylococcus aureus is an opportunistic pathogen that produces many virulence factors. Two major families of which are the staphylococcal superantigens (SAgs) and the Staphylococcal Superantigen-Like (SSL) exoproteins. The former are immunomodulatory toxins that induce a Vβ-specific activation of T cells, while the latter are immune evasion molecules that interfere with a wide range of innate immune defences. The superantigenic properties of Staphylococcal enterotoxin-like X (SElX) have recently been established. We now reveal that SElX also possesses functional characteristics of the SSLs. A region of SElX displays high homology to the sialyl-lactosamine (sLacNac)-specific binding site present in a sub-family of SSLs. By analysing the interaction of SElX with sLacNac-containing glycans we show that SElX has an equivalent specificity and host cell binding range to the SSLs. Mutation of key amino acids in this conserved region affects the ability of SElX to bind to cells of myeloid origin and significantly reduces its ability to protect S. aureus from destruction in a whole blood killing (WBK) assay. Like the SSLs, SElX is up-regulated early during infection and is under the control of the S. aureus exotoxin expression (Sae) two component gene regulatory system. Additionally, the structure of SElX in complex with the sLacNac-containing tetrasaccharide sialyl Lewis X (sLeX) reveals that SElX is a unique single-domain SAg. In summary, SElX is an ‘SSL-like’ SAg.

Cite

CITATION STYLE

APA

Langley, R. J., Ting, Y. T., Clow, F., Young, P. G., Radcliff, F. J., Choi, J. M., … Fraser, J. D. (2017). Staphylococcal enterotoxin-like X (SElX) is a unique superantigen with functional features of two major families of staphylococcal virulence factors. PLoS Pathogens, 13(9). https://doi.org/10.1371/journal.ppat.1006549

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free