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Interleukin-10 (IL-10) is a pleiotropic cytokine that plays an important role in immune system. In the present study, the IL-10 gene of African clawed frog (Xenopus tropicalis) was first cloned, and its expression pattern and 3D structure were also analyzed. The frog IL-10 mRNA encoded 172 amino acids which possessed several conserved features found in IL-10s from other species, including five-exon/four-intron genomic structure, conserved four cysteine residues, IL-10 family motif, and six α-helices. Real-time PCR showed that frog IL-10 mRNA was ubiquitous expressed in all examined tissues, highly in some immune related tissues including kidney, spleen, and intestine and lowly in heart, stomach, and liver. The frog IL-10 mRNA was upregulated at 24 h after LPS stimulation, indicating that it plays a part in the host immune response to bacterial infection. Another IL, termed as IL-20, was identified from the frog IL-10 locus, which might be the homologue of mammalian IL-19/20 according to the analysis results of the phylogenetic tree and the sequence identities.
Figure 1. Comparison of the gene organization of frog IL-10 gene with selected IL-10 molecules. The exons were indicated as black boxes and introns as black lines. The numbers above each box indicate the size (bp) of exons and the numbers below the lines indicate the size (bp) of introns. The gene organization of each gene was extracted from Ensembl Genome database.
Figure 2. Multiple alignment of vertebrate IL-10. The multiple alignment was produced using Clustal W, and conserved amino acids were shaded using GeneDoc software. The signal peptides predicted by SignalP 4.1 server were underlined. The conserved IL-10 family signature motifs were boxed. The four conserved cysteine residues existing in IL-10 were indicated by black cycles below the alignment and the six conserved cysteine residues in IL-19/20 were indicated by black arrows above the alignment. The accession numbers for sequence used in this alignment were listed in Figure 6.
Figure 3. Structure and molecular dynamics analysis of frog IL-10. (a) Superimposition of the frog IL-10 model with the human IL-10 (PDB: 2ILK). Frog IL-10 was shown in red color and human IL-10 was in white color; (b) RMSD of frog IL-10 postmolecular dynamics for 12âns. The MD analysis was performed by Gromacs 4.0 package [28] on an Inspur, 12âGHz PC, and results were analyzed using Origin 6.0 software.
Figure 4. Expression analysis of frog IL-10 in different tissues from healthy frog (a) and LPS stimulated frog (b). Six tissues including liver, spleen, kidney, intestine, heart, and stomach were sampled for real-time PCR analysis. The mean ± SD values were shown. The transcripts levels of IL-10 in healthy frog were relative to those of β-actin. The expression changes of IL-10 in LPS stimulated frog were expressed as fold change relative to the controls. P values generated by paired sample t-test between control and stimulated groups were shown above the bars. *P < 0.05.
Figure 5. Gene synteny of IL-10 loci in vertebrates. The gene synteny of human, chicken, and zebrafish IL-10 locus was analyzed using Genomicus (v75.02) software and human IL-10 was set as a reference to compare the conserved synteny between different species. The gene synteny of frog IL-10 locus was based on the results of GenScan and BLAST search against NCBI database.
Figure 6. Phylogenetic tree analysis of IL-10 family members from frog and other species. The tree was constructed by the âneighbor-joiningâ method using MEGA 6.0 software. Node values represent the percent of bootstrap confidence derived from 1,000 replicates. The accession number for each sequence followed the common species name.
Akdis,
Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases.
2011, Pubmed
Akdis,
Interleukins, from 1 to 37, and interferon-γ: receptors, functions, and roles in diseases.
2011,
Pubmed
Blumberg,
Interleukin 20: discovery, receptor identification, and role in epidermal function.
2001,
Pubmed
Burge,
Prediction of complete gene structures in human genomic DNA.
1997,
Pubmed
Commins,
The extended IL-10 superfamily: IL-10, IL-19, IL-20, IL-22, IL-24, IL-26, IL-28, and IL-29.
2008,
Pubmed
Ding,
A single amino acid determines the immunostimulatory activity of interleukin 10.
2000,
Pubmed
Emami,
Role of interleukin-10 in the pathogenesis of necrotizing enterocolitis.
2012,
Pubmed
Fan,
Cytokine gene expression in normal human lymphocytes in response to stimulation.
1998,
Pubmed
Fiorentino,
Two types of mouse T helper cell. IV. Th2 clones secrete a factor that inhibits cytokine production by Th1 clones.
1989,
Pubmed
Grayfer,
Characterization and functional analysis of goldfish (Carassius auratus L.) interleukin-10.
2011,
Pubmed
Harun,
Sequencing of a second interleukin-10 gene in rainbow trout Oncorhynchus mykiss and comparative investigation of the expression and modulation of the paralogues in vitro and in vivo.
2011,
Pubmed
John,
Comparative protein structure modeling by iterative alignment, model building and model assessment.
2003,
Pubmed
Josephson,
Crystal structure of the IL-10/IL-10R1 complex reveals a shared receptor binding site.
2001,
Pubmed
Julenius,
Prediction, conservation analysis, and structural characterization of mammalian mucin-type O-glycosylation sites.
2005,
Pubmed
Kotenko,
IFN-lambdas mediate antiviral protection through a distinct class II cytokine receptor complex.
2003,
Pubmed
Kurowski,
GeneSilico protein structure prediction meta-server.
2003,
Pubmed
Nielsen,
Identification of prokaryotic and eukaryotic signal peptides and prediction of their cleavage sites.
1997,
Pubmed
Ouyang,
Regulation and functions of the IL-10 family of cytokines in inflammation and disease.
2011,
Pubmed
Qi,
Intron-containing type I and type III IFN coexist in amphibians: refuting the concept that a retroposition event gave rise to type I IFNs.
2010,
Pubmed
,
Xenbase
Qi,
Comparative study and expression analysis of the interferon gamma gene locus cytokines in Xenopus tropicalis.
2008,
Pubmed
,
Xenbase
Reimer,
poly(I:C) and LPS induce distinct IRF3 and NF-kappaB signaling during type-I IFN and TNF responses in human macrophages.
2008,
Pubmed
Robert,
Xenopus as an experimental model for studying evolution of hsp--immune system interactions.
2004,
Pubmed
,
Xenbase
Sabat,
Biology of interleukin-10.
2010,
Pubmed
Sahoo,
3D modeling and molecular dynamics simulation of an immune-regulatory cytokine, interleukin-10, from the Indian major carp, Catla catla.
2012,
Pubmed
Saraiva,
The regulation of IL-10 production by immune cells.
2010,
Pubmed
Shaw,
A conserved AU sequence from the 3' untranslated region of GM-CSF mRNA mediates selective mRNA degradation.
1986,
Pubmed
Solovyev,
Automatic annotation of eukaryotic genes, pseudogenes and promoters.
2006,
Pubmed
Tamura,
MEGA4: Molecular Evolutionary Genetics Analysis (MEGA) software version 4.0.
2007,
Pubmed
Thompson,
CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice.
1994,
Pubmed
Van Der Spoel,
GROMACS: fast, flexible, and free.
2005,
Pubmed
Wallner,
Pcons5: combining consensus, structural evaluation and fold recognition scores.
2005,
Pubmed
Walter,
Crystal structure of interleukin 10 reveals an interferon gamma-like fold.
1995,
Pubmed
Wang,
Cloning of a novel interleukin (IL)-20-like gene in rainbow trout Oncorhynchus mykiss gives an insight into the evolution of the IL-10 family.
2010,
Pubmed
Windsor,
Disulfide bond assignments and secondary structure analysis of human and murine interleukin 10.
1993,
Pubmed
Zdanov,
Structural features of the interleukin-10 family of cytokines.
2004,
Pubmed
Zou,
Identification of an interferon gamma homologue in Fugu, Takifugu rubripes.
2004,
Pubmed
