Isolation and expression of a novel MBL-like collectin cDNA enhanced by LPS injection in the body wall of the ascidian Ciona intestinalis

Abstract

Collectins are a family of calcium-dependent lectins that are characterized by their collagen-like domains. Considerable interest has been focused on this class of proteins because of their ability to interact with components of the complement system activating a cascade of events responsible for the activation of the innate immune system. A differential screening between LPS-challenged and naïve Ciona intestinalis has been performed allowing the isolation of a full length cDNA encoding for a 221 AA protein. In silico analysis has shown that this polypeptide displays protein domains with similarities to mannose-binding lectins. A phylogenetic analysis suggested that C. intestinalis MBL has evolved early as a prototype of vertebrate MBL. Real-time PCR assay demonstrated that this gene is strongly activated after LPS injection in the tunica. In situ hybridization performed in LPS-induced animals has shown that this gene is expressed in granular amoebocytes and large granules hemocytes in the inflamed body wall tissue. Finally, an antimicrobial activity of the C. intestinalis MBL has been demonstrated.

Inducible galectins are expressed in the inflamed pharynx of the ascidian Ciona intestinalis

“…It is known that during a pathogenic infection, the expression of galectin genes is often upregulated and their production increase [2,4]. The LPS locally inoculated through the ascidian body wall directly permeates the underlying pharynx tissue and stimulates a prompt local inflammatory reaction including upregulation of collagen-IX-like, C3a [43], TNFalfa-like [23,24] and MBL-like genes [25], together with enhanced phenoloxidase activity [22,44] and an overproduction of galectin-like molecules with opsonic properties found in the hemolymph [27]. Here we show that LPS promptly upregulates CiLgals-a and -b genes being CiLgals-a more represented as shown by a higher expression rate.…”

Transforming growth factor β (CiTGF-β) gene expression is induced in the inflammatory reaction of Ciona intestinalis

“…The pharynx is the main hemopoietic organ in which circulating hemocyte populations are renewed, and it can be challenged by inoculating inflammatory agents and express immune related genes upregulated by lipopolysaccharide (LPS) such as MBL-like (Bonura et al, 2009), galectin-like (Vizzini et al, 2012), Interleukins 17 (Vizzini et al, 2015a). In the present paper, we report on the identification, characterisation and expression of the C. intestinalis TGF-b gene.…”

“…For this reason, they represent an intriguing model for studying the evolution of the innate immune system. In particular, the inflammatory reaction in the body wall of Ciona intestinalis is a well-established model for the analysis of inducible host defense molecules of the innate immune system: Type IX collagen-like , CAP-like (Bonura et al, 2010), MBL-like (Bonura et al, 2009), TNFa-like , galectin-like (Vizzini et al, 2012), peroxinectin (Vizzini et al, 2013b), Interleukin 17 (Vizzini et al, 2015a), and proPO-system Trapani et al, 2015., Vizzini et al, 2015b.…”

Molecular characterisation, evolution and expression analysis of g-type lysozymes in Ciona intestinalis

“…They are proto-chordates which possess an innate immune system, including inflammatory humoral and cellular responses. An inflammatory response induced by LPS injection in the body wall of C. intestinalis is a well-established model for the analysis of regulator and effector inducible host defense molecules of the innate immune system (Bonura et al, 2009;Parrinello et al, 2008Parrinello et al, , 2010Vizzini et al, 2012Vizzini et al, , 20132015a, 2015b2016). In the present paper, we report on the identification, characterization and expression of C. intestinalis g-type lysozymes.…”