Molecular cloning and comparative analysis of fibrinogen-related proteins from the soft tick Ornithodoros moubata and the hard tick Ixodes ricinus

Borreliae of the relapsing fever group (RFG) are heterogenous and can be divided mainly into three groups according to vectors, namely the soft-tick-borne relapsing fever (STBRF) Borreliae, the hard-tick-borne relapsing fever (HTBRF) Borreliae, the louse-borne relapsing fever (LBRF) Borreliae, and the avian relapsing fever ones. With respect to the geographical distribution, the STBRF Borreliae are further subdivided into Old World and New World strains. Except for the Avian relapsing fever group Borreliae, which cause avian spirochetosis, all the others share infectivity in humans. They are indeed the etiological agent of both endemic and epidemic forms of relapsing fever, causing high spirochaetemia and fever. Vectors are primarily soft ticks of Ornithodoros spp. in the STBRF group; hard ticks, notably Ixodes sp., Amblyomma sp., Dermacentor sp., and Rhipicephalus sp., in the HTBRF group; and the louse pediculus humanus humanus in the TBRF one. A recent hypothesis was supported for a common ancestor of RFG Borreliae, transmitted at the beginning by hard-body ticks. Accordingly, STBRF Borreliae switched to use soft-bodied ticks as a vector, which was followed by the use of lice by Borrelia recurrentis. There are also new candidate species of Borreliae, at present unclassified, which are also described in this review.

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Molecular Cloning and Characterization of Rat Contrapsin-Like Protease Inhibitor and Related Proteins1

The Journal of Biochemistry ◽

10.1093/oxfordjournals.jbchem.a123369 ◽

1991 ◽

Keyword(s):

Protease Inhibitor ◽

Molecular Cloning ◽

Related Proteins

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Molecular cloning and functional characterization of an aspartic protease from the hard tick Haemaphysalis longicornis

Insect Biochemistry and Molecular Biology ◽

10.1016/j.ibmb.2005.10.003 ◽

2006 ◽

Vol 36 (1) ◽

pp. 25-36 ◽

Cited By ~ 86

Author(s):

Damdinsuren Boldbaatar ◽

Chummy Sikalizyo Sikasunge ◽

Badgar Battsetseg ◽

Xuenan Xuan ◽

Kozo Fujisaki

Keyword(s):

Molecular Cloning ◽

Functional Characterization ◽

Aspartic Protease ◽

Hard Tick ◽

Haemaphysalis Longicornis

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The Immunomodulatory Effect of IrSPI, a Tick Salivary Gland Serine Protease Inhibitor Involved in Ixodes ricinus Tick Feeding

Vaccines ◽

10.3390/vaccines7040148 ◽

2019 ◽

Vol 7 (4) ◽

pp. 148 ◽

Cited By ~ 2

Author(s):

Adrien Blisnick ◽

Ladislav Šimo ◽

Catherine Grillon ◽

Fabienne Fasani ◽

Sébastien Brûlé ◽

...

Keyword(s):

Protease Inhibitor ◽

Serine Protease ◽

Ixodes Ricinus ◽

Serine Protease Inhibitor ◽

Blood Feeding ◽

Immunomodulatory Activity ◽

Hard Tick ◽

Tick Feeding ◽

Tick Saliva ◽

Elastase Inhibitor

Ticks are the most important vectors of pathogens affecting both domestic and wild animals worldwide. Hard tick feeding is a slow process—taking up to several days—and necessitates extended control over the host response. The success of the feeding process depends upon injection of tick saliva, which not only controls host hemostasis and wound healing, but also subverts the host immune response to avoid tick rejection that creates a favorable niche for the survival and propagation of diverse tick-borne pathogens. Here, we report on the molecular and biochemical features and functions of an Ixodes ricinus serine protease inhibitor (IrSPI). We characterize IrSPI as a Kunitz elastase inhibitor that is overexpressed in several tick organs—especially salivary glands—during blood-feeding. We also demonstrated that when IrSPI is injected into the host through saliva, it had no impact on tissue factor pathway-induced coagulation, fibrinolysis, endothelial cell angiogenesis or apoptosis, but the protein exhibits immunomodulatory activity. In particular, IrSPI represses proliferation of CD4+ T lymphocytes and proinflammatory cytokine secretion from both splenocytes and macrophages. Our study contributes valuable knowledge to tick-host interactions and provides insights that could be further exploited to design anti-tick vaccines targeting this immunomodulator implicated in I. ricinus feeding.

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