Borrelia burgdorferi complement regulator-acquiring surface proteins (BbCRASPs): Expression patterns during the mammal–tick infection cycle

Abstract

Host complement is widely distributed throughout mammalian body fluids and can be activated immediately as part of the first line of defense against invading pathogens. The agent of Lyme disease, Borrelia burgdorferi sensu lato (s.l.), is naturally resistant to that innate immune defense system of its hosts. One resistance mechanism appears to involve binding fluid-phase regulators of complement to distinct borrelial outer surface molecules known as CRASPs (complement regulator acquiring surface proteins). Using sensitive molecular biology techniques, expression patterns of all three classes of genes encoding the CRASPs of B. burgdorferi sensu stricto (BbCRASPs) have been analyzed throughout the natural tick-mammal infection cycle. Each class shows a different expression profile in vivo and the results are summarized herein. Studies on the expression of B. burgdorferi genes using animal models of infection have advanced our knowledge on the ability of the causative agent to circumvent innate immune defenses, the contributions of CRASPs to spirochete infectivity, and the pathogenesis of Lyme disease.

BBA70 of Borrelia burgdorferi Is a Novel Plasminogen-binding Protein

“…CspA is expressed during the initial stages of mammalian infection. By contrast, CspZ, ErpP, ErpC, and ErpA are expressed during established mammalian infection (86). A previous study investigating expression of the BBA70-encoding gene during persistent infection of mice reported no detectable bba70 transcripts in ear tissues, although specific antibody responses to BBA70 were demonstrated at late stages of murine infection (87).…”

The Serology Diagnostic Schemes in Borrelia burgdorferi Sensu Lato Infections – Significance in Clinical Practice

“…The innate defense mechanisms are initiated as the first in the process of the immunological response of an organism against infection, in which as well as phagocytes as complement system, lysozyme and interferon take part. All disorders of the unspecific mechanisms in the early stage of the infection can prevent from an effective elimination of the pathogen in further stages of the immunological response, and consequently lead to the development of a chronic state of the illness (Bykowski et al, 2008;Siegel, et al, 2010). The diagnosis of the illness in patients with EM is usually made on the basis of a clinical picture without a confirmation of the serological tests, which results are frequently negative during this period.…”

Outer Surface Protein C Peptide Derived from Borrelia burgdorferi Sensu Stricto as a Target for Serodiagnosis of Early Lyme Disease

“…An ELISA (IR6) using a peptide derived from the VlsE protein of Borrelia has demonstrated greater specificity in the detection of Lyme disease than whole-cell ELISAs and has been approved for use by the FDA (19,23). However, C6, the peptide derived from VlsE, does not bind IgM particularly well, is derived from an antigen that is expressed only after infection is established (fewer than 1% of bacteria in the tick express VlsE, and transcription of the gene is suppressed prior to transmission of the bacteria), and the IR6 region of VlsE from which the peptide is derived has shown a greater degree of variability than originally thought (19,(23)(24)(25)(26). Though the IR6 assay represents a significant improvement, in terms of specificity, compared to the whole-cell ELISA (27), these concerns have precluded the use of the IR6 assay as a stand-alone diagnostic test for early Lyme disease.…”