Specific serum Ig recognizing staphylococcal wall teichoic acid induces complement-mediated opsonophagocytosis against Staphylococcus aureus.
Wall teichoic acid (WTA) of Staphylococcus aureus is a major cell envelope-associated glycopolymer that is a key molecule in promoting colonization during S. aureus infection. The complement system plays a key role in the opsonization and clearance of pathogens. We recently reported that S. aureus WTA functions as a ligand of human serum mannose-binding lectin (MBL), a recognition molecule of the lectin complement pathway. Intriguingly, serum MBL in adults does not bind to WTA because of an inhibitory effect of serum anti-WTA-IgG. In this study, serum anti-WTA-IgG was purified to homogeneity using a purified S. aureus WTA-coupled affinity column to examine the biological function of human anti-WTA-IgG. The purified anti-WTA-IgG contained the IgG2 subclass as a major component and specifically induced C4 and C3 deposition on the S. aureus surface in the anti-WTA-IgG-depleted serum, but not in C1q-deficient serum. Furthermore, the anti-WTA-IgG-dependent C3 deposition induced phagocytosis of S. aureus cells by human polymorphonuclear leukocytes. These results demonstrate that serum anti-WTA-IgG is a real trigger for the induction of classical complement-dependent opsonophagocytosis against S. aureus. Our results also support the fact that a lack of the lectin complement pathway in MBL-deficient adults is compensated by Ag-specific, Ab-mediated adaptive immunity.
Global Research Laboratory of Insect Symbiosis, College of Pharmacy, Pusan National University, Jangjeon Dong, Gumjeong Gu, Busan 609-735, Korea.
Dong-Jun
DJ
Jung
Jang-Hyun
JH
An
Kenji
K
Kurokawa
Yoon-Chuel
YC
Jung
Min-Jung
MJ
Kim
Youko
Y
Aoyagi
Misao
M
Matsushita
Shinji
S
Takahashi
Hee-Seung
HS
Lee
Kazue
K
Takahashi
Bok Luel
BL
Lee
D000328:Adult; D000907:Antibodies, Bacterial / Q000276:immunology*; D000936:Antigen-Antibody Complex / Q000276:immunology; D002473:Cell Wall / Q000276:immunology*; D003176:Complement C3 / Q000276:immunology; D003181:Complement C4 / Q000276:immunology; D003171:Complement Pathway, Classical / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D009504:Neutrophils / Q000166:cytology / Q000276:immunology*; D010587:Phagocytosis / Q000276:immunology*; D013211:Staphylococcus aureus / Q000276:immunology*; D013682:Teichoic Acids / Q000276:immunology*
D000907:Antibodies, Bacterial; D000936:Antigen-Antibody Complex; C038245:C3 protein, human; D003176:Complement C3; D003181:Complement C4; D007074:Immunoglobulin G; D013682:Teichoic Acids