A Teleost Bactericidal Permeability-Increasing Protein Kills Gram-Negative Bacteria, Modulates Innate Immune Response, and Enhances Resistance against Bacterial and Viral Infection.
Bactericidal/permeability-increasing protein (BPI) is an important factor of innate immunity that in mammals is known to take part in the clearance of invading Gram-negative bacteria. In teleost, the function of BPI is unknown. In the present work, we studied the function of tongue sole (Cynoglossus semilaevis) BPI, CsBPI. We found that CsBPI was produced extracellularly by peripheral blood leukocytes (PBL). Recombinant CsBPI (rCsBPI) was able to bind to a number of Gram-negative bacteria but not Gram-positive bacteria. Binding to bacteria led to bacterial death through membrane permeabilization and structural destruction, and the bound bacteria were more readily taken up by PBL. In vivo, rCsBPI augmented the expression of a wide arrange of genes involved in antibacterial and antiviral immunity. Furthermore, rCsBPI enhanced the resistance of tongue sole against bacterial as well as viral infection. These results indicate for the first time that a teleost BPI possesses immunoregulatory effect and plays a significant role in antibacterial and antiviral defense.
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.|University of Chinese Academy of Sciences, Beijing, China.
Yuan-Yuan
YY
Sun
Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China.|Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.
Li
L
Sun
D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D001424:Bacterial Infections / Q000276:immunology*; D001798:Blood Proteins / Q000737:chemistry / Q000494:pharmacology*; D005399:Fishes; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D007113:Immunity, Innate / Q000187:drug effects*; D010587:Phagocytosis; D017386:Sequence Homology, Amino Acid; D014777:Virus Diseases / Q000276:immunology*
D023181:Antimicrobial Cationic Peptides; D001798:Blood Proteins; C021623:bactericidal permeability increasing protein