Search results for "hemocyte"
showing 10 items of 93 documents
Upregulated transcription of phenoloxidase genes in the pharynx and endostyle of Ciona intestinalis in response to LPS
2015
We investigated the role of phenoloxidases (POs) in ascidians inflammatory reaction, a components of a copper-containing protein family involved in invertebrate immune system. In Ciona intestinalis two phenoloxidases (CinPO-1, CinPO-2) have been sequenced. In the present study, real time PCR analysis showed that both CinPO-1 and CinPO-2 genes were modulated by LPS inoculation suggesting that they are inducible and highly expressed in the inflamed pharynx. In situ hybridization disclosed CinPO-1 and CinPO-2 transcripts in pharynx hemocytes (granulocytes) and, mainly, in unilocular refractile granulocytes (URG) which mainly populated the inflamed tunic matrix. Interestingly, the genes are als…
Ciona intestinalis interleukin 17-like genes expression is upregulated by LPS challenge
2015
In humans, IL-17 is a proinflammatory cytokine that plays a key role in the clearance of extracellular bacteria promoting cell infiltration and production of several cytokines and chemokines. Here, we report on three Ciona intestinalis IL-17 homologues (CiIL17-1, CiIL17-2, CiIL17-3). The gene organisation, phylogenetic tree and modelling supported the close relationship with the mammalian IL-17A and IL-17F suggesting that the C. intestinalis IL-17 genes share a common ancestor in the chordate lineages. Real time PCR analysis showed a prompt expression induced by LPS inoculation suggesting that they are involved in the first phase of inflammatory response. In situ hybridization assays disclo…
Enhanced expression of a cloned and sequenced Ciona intestinalis TNFa-like (CiTNFa) gene during the LPS-induced inflammatory response.
2008
A tumor necrosis factor-alpha (TNFalpha)-like gene from Ciona intestinalis (CiTNF alpha-like) body wall challenged with bacterial lipopolysaccharide (LPS) was cloned and sequenced 4 h after LPS inoculation. An open reading frame of 936 bp encoding a propeptide of 312 amino acids (35.4 kDa) displaying a transmembrane domain from positions 7 to 29, a TACE cleavage site, and a mature peptide domain of 185 amino acids (20.9 kDa), was determined with a predicted isoelectric point of 9.4. The phylogenetic tree based on deduced amino acid sequences of invertebrate TNF-like protein and vertebrate TNFs supported the divergence between the ascidian and vertebrate TNF families, whereas D. melanogaster…
FACIT collagen (1α-chain) is expressed by hemocytes and epidermis during the inflammatory response of the ascidian Ciona intestinalis
2007
Based on previous cloning and sequencing study, real-time PCR and in situ hybridization assays of the inflamed body wall of LPS-injected Ciona intestinalis showed the enhanced gene expression of a collagen with FACIT structural features (Ci-type IX-Col 1alpha-chain). By using specific antibodies raised against an opportunely chosen Ci-type IX-Col synthetic peptide, the fibroblast property of hemocytes challenged in vitro with LPS (at 4h) was displayed by flow cytometry, while immunocytochemistry identified hemocytes with large granules (morula cells) as collagen-producing cells. Hemocyte lysate supernatant analyzed in immunoblotting contained a 60 kDa band identifiable as 1alpha-chain-Ci-ty…
In vitro induction of cecropin genes — an immune response in a Drosophila blood cell line
1992
The Drosophila melanogaster cell line mbn-2 was explored as a model system to study insect immune responses in vitro. This cell line is of blood cell origin, derived from larval hemocytes of the mutant lethal (2) malignant blood neoplasm (1(2)mbn). The mbn-2 cells respond to microbial substances by the activation of cecropin genes, coding for bactericidal peptides. The response is stronger than that previously described for SL2 cells, and four other tested Drosophila cell lines were totally unresponsive. Bacterial lipopolysaccharide, algal laminarin (a beta-1,3-glucan), and bacterial flagellin were strong inducers, bacterial peptidoglycan fragments gave a weaker response, whereas a formyl-m…
Cloning and expression of a novel component of the CAP superfamily enhanced in the inflammatory response to LPS of the ascidian Ciona intestinalis.
2010
The CAP superfamily is a group of proteins that have been linked to several biological functions such as reproduction, cancer, and immune defense. A differential screening between lipopolysaccharide (LPS)-challenged and naive Ciona intestinalis has been performed to identify LPS-induced genes. This strategy has allowed the isolation of a full-length 1471-bp cDNA encoding for a 413-amino-acid protein (CiCAP). In silico analysis has shown that this polypeptide displays a modular structure with similarities to vertebrate CAP-superfamily proteins and to a collagen-binding adhesin of Streptococcus mutans. Domain organization analysis and alignment of CiCAP to other vertebrate CAP proteins have r…
Ciona intestinalis peroxinectin is a novel component of the peroxidase–cyclooxygenase gene superfamily upregulated by LPS
2013
Peroxinectins function as hemoperoxidase and cell adhesion factor involved in invertebrate immune reaction. In this study, the ascidian (Ciona intestinalis) peroxinectin gene (CiPxt) and its expression during the inflammatory response have been examined. CiPxt is a new member of the peroxidase-cyclooxygenase gene superfamily that contains both the peroxidase domain and the integrin KGD (Lys-Gly-Asp) binding motif. A phylogenetic tree showed that CiPxt is very close to the chordate group and appears to be the outgroup of mammalian MPO, EPO and TPO clades. The CiPxt molecular structure model resulted superimposable to the human myeloperoxidase. The CiPxt mRNA expression is upregulated by LPS …
Inducible galectins are expressed in the inflamed pharynx of the ascidian Ciona intestinalis
2011
Although ascidians belong to a key group in chordate phylogenesis, amino acid sequences of Ciona intestinalis galectin-CRDs (CiLgals-a and -b) have been retained too divergent from vertebrate galectins. In the present paper, to contribute in disclosing Bi-CRD galectin evolution a novel attempt was carried out on CiLgals-a and -b CRDs phylogenetic analysis, and their involvement in ascidian inflammatory responses was shown. CiLgals resulted aligned with Bi-CRD galectins from vertebrates (Xenopus tropicalis, Gallus gallus, Mus musculus, Homo sapiens), cephalochordates (Branchiostoma floridae), echinoderms (Strongylocentrotus purpuratus) and a mono-CRD galectin from the ascidian Clavelina pict…
Inflamed adult pharynx tissues and swimming larva of Ciona intestinalis share CiTNFalpha-producing cells.
2010
In situ hybridisation and immunohistochemistry analyses have shown that the Ciona intestinalis tumour necrosis factor alpha gene (CiTNFalpha), which has been previously cloned and sequenced, is expressed either during the inflammatory pharynx response to lipopolysaccharide (LPS) or during the swimming larval phase of development. Granulocytes with large granules and compartment/morula cells are CiTNFalpha-producing cells in both inflamed pharynx and larvae. Pharynx vessel endothelium also takes part in the inflammatory response. Haemocyte nodules in the vessel lumen or associated with the endothelium suggest the involvement of CiTNFalpha in recruiting lymphocyte-like cells and promoting the…
The prophenoloxidase system is activated during the tunic inflammatory reaction of Ciona intestinalis
2008
Phenoloxidase (PO) activity was examined in the tunic tissue of Ciona intestinalis following lipopolysaccharide (LPS) intratunic injection. Tunic homogenate supernatant (THS), assayed with the Dopa-MBTH reaction, displayed Ca(2+)-independent PO activity that was raised by LPS and further enhanced by proteases. Specific inhibitors (tropolone, phenylthiourea, diethylthiocarbamate) supported the specificity of the reaction. Assay with soybean trypsin inhibitor showed that, in the tunic, PO activation with trypsin was not significantly inhibited suggesting that proteases diverse from serine proteases were involved. In vivo experiments were carried out by injecting isosmotic medium or LPS, and T…