Protective niche for Borrelia burgdorferi to evade humoral immunity.
The Lyme disease spirochete, Borrelia burgdorferi, is an extracellular microbe that causes persistent infection despite the development of strong immune responses against the bacterium. B. burgdorferi expresses several ligand-binding lipoproteins, including the decorin-binding proteins (Dbps) A and B, which may mediate attachment to decorin, a major component of the host extracellular matrix during murine infection. We show that B. burgdorferi was better protected in the joints and skin, two tissues with a higher decorin expression, than in the urinary bladder and heart, two tissues with a lower decorin expression, during chronic infection of wild-type mice. Targeted disruption of decorin alone completely abolished the protective niche in chronically infected decorin-deficient mice but did not affect the spirochete burden during early infection. The nature of protection appeared to be specific because the spirochetes with higher outer surface protein C expression were not protected while the protective niche seemed to favor the spirochetes with a higher dbpA expression during chronic infection. These data suggest that spirochetal DbpA may interact with host decorin during infection and such interactions could be a mechanism that B. burgdorferi uses to evade humoral immunity and establish chronic infection.
Liang
Fang Ting
FT
Department of Internal Medicine, Section of Rheumatology, Yale University School of Medicine, New Haven, Connecticut, USA.
Brown
Eric L
EL
Wang
Tian
T
Iozzo
Renato V
RV
Fikrig
Erol
E
D018829:Adhesins, Bacterial / Q000502:physiology*; D000818:Animals; D000917:Antibody Formation; D001425:Bacterial Outer Membrane Proteins / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology*; D025065:Borrelia burgdorferi / Q000276:immunology*; D058575:Decorin; D016326:Extracellular Matrix Proteins; D006321:Heart / Q000382:microbiology / Q000503:physiopathology; D006720:Homozygote; D007596:Joints / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D008193:Lyme Disease / Q000276:immunology* / Q000382:microbiology; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D016513:Mice, SCID; D011509:Proteoglycans / Q000235:genetics / Q000502:physiology*; D012867:Skin / Q000276:immunology / Q000382:microbiology / Q000473:pathology; D001743:Urinary Bladder / Q000276:immunology / Q000382:microbiology / Q000473:pathology
D018829:Adhesins, Bacterial; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; C546879:Dcn protein, mouse; C112563:DdpA protein, Borrelia burgdorferi; C112557:DdpB protein, Borrelia burgdorferi; D058575:Decorin; D016326:Extracellular Matrix Proteins; D011509:Proteoglycans