title: CD44 deficiency enhanced Streptococcus equi ssp. zooepidemicus dissemination and inflammation response in a mouse model.
abstract: Streptococcus equi ssp. zooepidemicus (S. zooepidemicus) is responsible for peritonitis, septicemia, meningitis, arthritis and several other serious diseases in various species. Recent studies have demonstrated that CD44 is implicated in the process of host defense against pathogenic microorganisms. In the present study, the role of CD44 in the host response to S. zooepidemicus infection was investigated in a mouse model. Upon intraperitoneal infection with S. zooepidemicus, the expression of CD44 on the peritoneal exudate cells from wild-type (WT) mice was increased. CD44 deficiency accelerated mortality, which was accompanied by increased peritoneal bacterial growth and dissemination to distant body sites. CD44 knock-out (KO) mice showed enhanced early inflammatory cell recruitment into the peritoneal fluid on S. zooepidemicus infection. In line with this, the expression of proinflammatory cytokines, chemokines in peritoneal exudate cells and peritoneal macrophages of CD44 KO mice were increased compared with those of WT mice. In addition, CD44 deficiency was associated with reduced expression of A20, a negative regulator in TLR signaling. Overall, the present study suggests that CD44 plays a protective role in antibacterial defense against S. zooepidemicus in mice.
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China; School of Life Science, Foshan University, Guangdong 528231, PR China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Xiao
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
authors.forename: Yaosheng
authors.initials: Y
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China.
authors.forename: Zigong
authors.initials: Z
authors.lastname: Wei
authors.affiliation: State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou 510006, PR China. Electronic address: liuxh8@mail.sysu.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Liu
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D018960:Hyaluronan Receptors / Q000235:genetics*; D007249:Inflammation / Q000473:pathology*; D017737:Macrophages, Peritoneal; D051379:Mice; D018345:Mice, Knockout; D013290:Streptococcal Infections / Q000382:microbiology* / Q000473:pathology; D018502:Streptococcus equi / Q000187:drug effects*
chemical_list: C476399:Cd44 protein, mouse; D018960:Hyaluronan Receptors
keywords: Bacterial dissemination; CD44; Inflammatory cytokine production; Streptococcus equi ssp. zooepidemicus