Cloning, promoter analysis and expression in response to bacterial exposure of sea bass (Dicentrarchus labrax L.) interleukin-12 p40 and p35 subunits.
Interleukin-12 (IL-12) is a heterodimeric cytokine pivotal in resistance to microbial and viral infections. In the search for immunoregulatory genes in sea bass the genes for the two IL-12 subunits p40 and p35 were cloned and sequenced. Molecular characterization of these two genes was performed at both the cDNA and genomic levels. Sea bass IL-12 p40 and p35 conserve most cysteines involved in the intra-chain disulfide bonds of human IL-12 subunits as well as the important structural residues for human IL-12 heterodimerization. The gene organization of sea bass IL-12 p40 is similar to the human orthologue, whilst the sea bass IL-12 p35 gene structure, as reported for pufferfish, differs from the human one in containing an additional exon and lacking a second copy of a duplicated exon present in the mammalian genes. The promoter analysis of both sea bass and pufferfish IL-12 genes showed the presence of the main cis-acting elements involved in the transcriptional regulation of human and mouse orthologues. The involvement of IL-12 in sea bass anti-bacterial immune responses was demonstrated by investigating the expression profiles of IL-1beta, IL-12 p40 and p35 in the head-kidney and spleen following intraperitoneal injection of UV-killed and live Photobacterium damselae ssp. piscicida (Phdp). Finally, the importance of nuclear factor (NF)-kappaB on UV-killed Phdp-induced IL-12 p40 and p35 gene transcription was shown by the use of pyrrolidine dithiocarbamate (PDTC).
Nascimento
Diana S
DS
IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Rua do Campo Alegre 823, 4150-180 Porto, Portugal. de.nascimento@abdn.ac.uk
do Vale
Ana
A
Tomás
Ana M
AM
Zou
Jun
J
Secombes
Christopher J
CJ
dos Santos
Nuno M S
NM
D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass / Q000235:genetics* / Q000382:microbiology*; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D005786:Gene Expression Regulation; D006801:Humans; D053765:Interleukin-12 Subunit p35 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D053762:Interleukin-12 Subunit p40 / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D010776:Photobacterium / Q000502:physiology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D023721:Tetraodontiformes / Q000235:genetics
D053765:Interleukin-12 Subunit p35; D053762:Interleukin-12 Subunit p40; D012333:RNA, Messenger