title: Inactivation of dipeptidyl peptidase IV attenuates the virulence of Streptococcus suis serotype 2 that causes streptococcal toxic shock syndrome.
abstract: Di-peptidyl peptidase IV (DPP IV), originally recognized as CD26 in eukaryotic cells, is distributed widely in microbial pathogens, including Streptococcus suis (S. suis), an emerging zoonotic agent. However, the role of DPP IV in S. suis virulence remains unclear. Here, we identified a dpp IV homologue from highly invasive isolate of S. suis 2 (SS2) causing streptococcal toxic shock syndrome (STSS). Enzymatic assays reproduced its enzymatic activity of dpp IV protein product as a functional DPP IV, and ELISA analysis demonstrated that SS2 DPP IV can interact with human fibronectin. An isogenic SS2 mutant of dpp IV, Delta dpp IV, was obtained by homologous recombination. Experimental animal infection suggested that an inactivation of dpp IV attenuates greatly its high virulence of Chinese virulent strains of SS2. Functional complementation can restore this defect in SS2 pathogenicity. To our knowledge, it may confirm, for the first time, that DPP IV contributes to SS2 virulence.
authors.affiliation: The College of Life Science, Nanjing Normal University, 210046, Nanjing, China.
authors.forename: Junchao
authors.initials: J
authors.lastname: Ge
authors.forename: Youjun
authors.initials: Y
authors.lastname: Feng
authors.forename: Hongfeng
authors.initials: H
authors.lastname: Ji
authors.forename: Huimin
authors.initials: H
authors.lastname: Zhang
authors.forename: Feng
authors.initials: F
authors.lastname: Zheng
authors.forename: Changjun
authors.initials: C
authors.lastname: Wang
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yin
authors.forename: Xiuzhen
authors.initials: X
authors.lastname: Pan
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Tang
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000032:analysis*; D002448:Cell Adhesion; D002460:Cell Line; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors* / Q000235:genetics; D005353:Fibronectins / Q000378:metabolism; D055786:Gene Knockout Techniques; D005816:Genetic Complementation Test; D006801:Humans; D051379:Mice; D011485:Protein Binding; D012772:Shock, Septic / Q000382:microbiology*; D017011:Streptococcus suis / Q000201:enzymology* / Q000235:genetics / Q000472:pathogenicity*; D016019:Survival Analysis; D014774:Virulence
chemical_list: D001426:Bacterial Proteins; D005353:Fibronectins; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases