Chemokines Expression In Vitro And Vivo Of Mice Infected With Streptococcus Suis Type2

Streptococcus suis type2(SS2) is an important swine pathogen and zoonosisagent which not only causes septicemia but also affects the central nervous system(CNS)and other tissues, leading to meningitis, enteritis, endocarditis, pneumonia andarthritis. Two large outbreak of SS2infections occurred in Sichuan and Jiangshu,China, not only causing great economic losses in the swine industry, but also resultingin more than50deaths of human. Over the past half-century, considerable attentionhas been given to the study of virulence factors and the pathogen-host interaction inSS2. However, little is known about the pathogenic mechanism of SS2. To shed lighton the evolution of pathogenicity of SS2, we must identify the new therapy target.Chemokines and G protein-coupled chemokine receptors are interesting therapeutictargets due to their involvement in various immune-related diseases, includingrheumatoid arthritis, multiple sclerosis, inflammatory bowel disease, chronicobstructive pulmonary disease.Here, we used SS2infected BALB/c mouse models in this study to identifyalterations in gene expression of mice infected via the gastrointestinal tract with SS2strain1330and ZY458. The genes expression of chemokines and cytokine in SS2(1330, ZY458)-infected BALB/c mice in vivo and inoculated J774A.1macrophagesin vitro were analyzed by quantitative real-time PCR (qRT-PCR) and enzyme-linkedimmunosorbent assay (ELISA) at different time points. In addition, adhered andinvaded SS2(1330, ZY458) in J774A.1macrophage were evaluated by transmissionelectron microscope (TEM) and scanning electron microscopy (SEM). Our resultsshow a marked effect of microbial colonization on the mRNA expression of intestinalchemokines (IL-12、CXCL10, et al) chemokine receptors (CCR3, CCR9, et al) andcytokine (INF-γ, TNF-a, et al) colon and jejunum of SS2infected BALB/c mice.Moreover, in vitro, as evidenced by adhesion and invasion SS2(1330, ZY458) inJ774A.1macrophage blot in J774A.1cells, also induce the secretion of cytokine and autophagy-lysosome. Together, this results indicated that the expression level ofchemokines, chemokine receptors, and cytokine genes that influence susceptibility orresistance to SS2(1330, ZY458) infection in vivo and vitro of BALB/c mice.