PUBLICATION
            Defense of zebrafish embryos against Streptococcus pneumoniae infection is dependent on the phagocytic activity of leukocytes
- Authors
 - Rounioja, S., Saralahti, A., Rantala, L., Parikka, M., Henriques-Normark, B., Silvennoinen, O., and Rämet, M.
 - ID
 - ZDB-PUB-110613-36
 - Date
 - 2012
 - Source
 - Developmental and comparative immunology 36(2): 342-8 (Journal)
 - Registered Authors
 - Keywords
 - zebrafish, streptococcus pneumoniae, innate immunity, host-pathogens interactions
 - MeSH Terms
 - 
    
        
        
            
                
- Microscopy, Fluorescence
 - Virulence Factors/genetics
 - Virulence Factors/immunology
 - Animals
 - Mutagenesis, Insertional/methods
 - RNA, Messenger/chemistry
 - RNA, Messenger/genetics
 - Host-Pathogen Interactions/immunology*
 - Embryo, Nonmammalian
 - Real-Time Polymerase Chain Reaction
 - Zebrafish
 - Streptococcus pneumoniae/immunology*
 - Reverse Transcriptase Polymerase Chain Reaction
 - Pneumococcal Infections/immunology*
 - Pneumococcal Infections/microbiology
 - Phagocytosis/immunology*
 
 - PubMed
 - 21658407 Full text @ Dev. Comp. Immunol.
 
            Citation
        
        
            Rounioja, S., Saralahti, A., Rantala, L., Parikka, M., Henriques-Normark, B., Silvennoinen, O., and Rämet, M. (2012) Defense of zebrafish embryos against Streptococcus pneumoniae infection is dependent on the phagocytic activity of leukocytes. Developmental and comparative immunology. 36(2):342-8.
        
    
                
                    
                        Abstract
                    
                    
                
                
            
        
        
    
        
            
            
 
    
    
        
    
    
    
        
                Severe community acquired pneumonia caused by Streptococcus pneumoniae is the most common cause of death from infection in developing countries. Serotype specific conjugate vaccines have decreased the incidence of invasive infections, but at the same time, disease due to non-vaccine serotypes have increased. New insights into host immune mechanisms against pneumococcus may provide better treatment and prevention strategies. Zebrafish is an attractive vertebrate model for studying host immune responses and infection biology. Here we show that an intravenous challenge with pneumococcus infects zebrafish embryos leading to death in a dose dependent manner. Survival rates correlate with the bacterial burden in the embryos. The production of proinflammatory cytokines is induced in zebrafish after pneumococcal exposure. Importantly, morpholino treated embryos lacking either myeloid cells or the ability to phagocytose bacteria have lowered survival rates compared to wild type embryos after pneumococcal challenge. These data suggest that the survival of zebrafish embryos upon intravenous infection with S. pneumoniae is dependent on the clearance of the bacteria by phagocytosing cells. Additionally, we demonstrate that mutant pneumococci lacking known virulence factors are attenuated in the zebrafish model. Our data demonstrate that zebrafish embryos can be used for study innate immune responses as well as virulence determinants in pneumococcal infections.
            
    
        
        
    
    
    
                
                    
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