SLO co-opts host cell glycosphingolipids to access cholesterol-rich lipid rafts for enhanced pore formation and cytotoxicity

被引：0

作者：

Sanduja, Pooja ^{[1
,2
]}

Schmieder, Stefanie S. ^{[2
,3
,4
]}

Baddal, Buket ^{[1
,2
,8
]}

Tian, Songhai ^{[5
,6
,7
,9
]}

Velarde, Jorge J. ^{[1
,2
,10
]}

Lencer, Wayne I. ^{[2
,3
,4
]}

Dong, Min ^{[5
,6
,7
]}

Wessels, Michael R. ^{[1
,2
]}

机构：

[1] Boston Childrens Hosp, Div Infect Dis, Boston, MA 02115 USA

[2] Harvard Med Sch, Dept Pediat, Boston, MA 02115 USA

[3] Boston Childrens Hosp, Div Gastroenterol, Boston, MA USA

[4] HARVARD DIGEST DIS CTR, BOSTON, MA USA

[5] Boston Childrens Hosp, Dept Urol, Boston, MA USA

[6] Harvard Med Sch, Dept Surg, Boston, MA USA

[7] Harvard Med Sch, Dept Microbiol, Boston, MA USA

[8] Near East Univ, Fac Med, Dept Med Microbiol & Clin Microbiol, Nicosia, Cyprus

[9] Peking Univ, State Key Lab Nat & Biomimet Drugs, Sch Pharmaceut Sci, Beijing, Peoples R China

[10] Sanofi, Cambridge, MA USA

来源：

MBIO | 2025年 / 16卷 / 03期

关键词：

Streptococcus pyogenes; group A Streptococcus; streptolysin O; toxin; cholesterol-dependent cytolysin; lipid raft; glycosphingolipid; glycan; receptor; CYTOLYSIN-MEDIATED TRANSLOCATION; SCALE CRISPR-CAS9 KNOCKOUT; DEPENDENT CYTOLYSINS; STREPTOCOCCUS-PYOGENES; RECEPTOR; PROTEIN; GENE; PNEUMOLYSIN; MECHANISM; VIRULENCE;

D O I：

10.1128/mbio.03777-24

中图分类号：

Q93 [微生物学];

学科分类号：

071005 ; 100705 ;

摘要：

Streptolysin O (SLO) is a virulence determinant of group A Streptococcus (S. pyogenes), the agent of streptococcal sore throat and severe invasive infections. SLO is a member of a family of bacterial pore-forming toxins known as cholesterol-dependent cytolysins, which require cell membrane cholesterol for pore formation. While cholesterol is essential for cytolytic activity, accumulating data suggest that cell surface glycans may also participate in the binding of SLO and other cholesterol-dependent cytolysins to host cells. Here, we find that unbiased CRISPR screens for host susceptibility factors for SLO cytotoxicity identified genes encoding enzymes involved in the earliest steps of glycosphingolipid (GSL) biosynthesis. Targeted knockouts of these genes conferred relative resistance to SLO cytotoxicity in two independent human cell lines. Inactiva tion of ugcg, which codes for UDP-glucose ceramide glucosyltransferase, the enzyme catalyzing the first glycosylation step in GSL biosynthesis, reduced the clustering of SLO on the cell surface. This result suggests that binding to GSLs serves to cluster SLO molecules at lipid rafts where both GSLs and cholesterol are abundant. SLO clustering and susceptibility to SLO cytotoxicity were restored by reconstituting the GSL content of ugcg knockout cells with ganglioside GM1, but susceptibility to SLO cytotoxicity was not restored by a GM1 variant that lacks an oligosaccharide head group required for SLO binding, nor by a variant with a "kinked" acyl chain that prevents efficient packing of the ganglioside ceramide moiety with cholesterol. Thus, SLO appears to co-opt cell surface glycosphingolipids to gain access to lipid rafts for increased efficiency of pore formation and cytotoxicity.

引用

页数：17