Calprotectin, an abundant cytosolic protein from human polymorphonuclear leukocytes, inhibits the growth of Borrelia burgdorferi.
We previously showed that numerous polymorphonuclear leukocyte (PMN) granule components efficiently kill Borrelia burgdorferi, the agent of Lyme disease. In addition, motile, granule-poor cytoplasts (U-Cyt) from human blood PMN can exert anti-Borrelia activity against opsonized B. burgdorferi independently of oxidative mechanisms. Here we show that lysates of U-Cyt also possess anti-Borrelia activity, a portion of which comes from the abundant cytosolic protein calprotectin. The anti-Borrelia activity of U-Cyt lysates and recombinant calprotectin was partially or completely reversed by specific antibody to calprotectin and by Zn(2+), a cation essential for the growth of B. burgdorferi and known to inhibit the antimicrobial activity of calprotectin. Quantitative microscopic and regrowth assays revealed that calprotectin acted in a bacteriostatic fashion against B. burgdorferi. We conclude that calprotectin, a potent bacteriostatic agent from a cell primarily recognized for its oxidative and granular antibacterial mechanisms, may play a modulatory role in infection by the Lyme spirochete, particularly at sites of acute inflammation.
Lusitani
Denise
D
Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut 06520, USA.
Malawista
Stephen E
SE
Montgomery
Ruth R
RR
D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D025065:Borrelia burgdorferi / Q000187:drug effects* / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity; D003600:Cytosol / Q000276:immunology; D006801:Humans; D066298:In Vitro Techniques; D039841:Leukocyte L1 Antigen Complex / Q000276:immunology / Q000302:isolation & purification / Q000494:pharmacology*; D009504:Neutrophils / Q000276:immunology* / Q000382:microbiology*; D015032:Zinc / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D000911:Antibodies, Monoclonal; D039841:Leukocyte L1 Antigen Complex; D015032:Zinc