Porcine DC-SIGN: Molecular cloning, gene structure, tissue distribution and binding characteristics

Abstract

DC-SIGN, a human C-type lectin, is involved in the transmission of many enveloped viruses. Here we report the cloning and characterization of the cDNA and gene encoding porcine DC-SIGN (pDC-SIGN). The full-length pDC-SIGN cDNA encodes a type II transmembrane protein of 240 amino acids. Phylogenetic analysis revealed that pDC-SIGN, together with bovine, canis and equine DC-SIGN, are more closely related to mouse SIGNR7 and SIGNR8 than to human DC-SIGN. pDC-SIGN has the same gene structure as bovine, canis DC-SIGN and mouse SIGNR8 with eight exons. pDC-SIGN mRNA expression was detected in pig spleen, thymus, lymph node, lung, bone marrow and muscles. pDC-SIGN protein was found to express on the surface of monocyte-derived macrophages and dendritic cells, alveolar macrophages, lymph node sinusoidal macrophage-like, dendritic-like and endothelial cells but not of monocytes, peripheral blood lymphocytes or lymph node lymphocytes. A BHK cell line stably expressing pDC-SIGN binds to human ICAM-3 and ICAM-2 immunoadhesins in a calcium-dependent manner, and enhances the transmission of porcine reproductive and respiratory syndrome virus (PRRSV) to target cells in trans. The results will help better understand the biological role(s) of DC-SIGN family in innate immunity during the evolutionary process.

The DC-SIGN of Zebrafish: Insights into the Existence of a CD209 Homologue in a Lower Vertebrate and Its Involvement in Adaptive Immunity

“…The latter may have significant implications for developing new ways of preventing pathogen infection (16). However, although numerous, the studies on DC-SIGN/CD209 have tended to be confined to a few mammals (11,(17)(18)(19), and the precise functional roles of this molecule remain elusive. For example, it is still controversial whether DC-SIGN/ICAM-3 interactions are required to establish lymphocyte activation and whether DC-SIGN/CD209 is DC specific, as previously implied (9, 20 -22).…”

Conserved arginine residues in the carboxyl terminus of the equine arteritis virus E protein may play a role in heparin binding but may not affect viral infectivity in equine endothelial cells

“…Similar to EAV, porcine arterivirus (PRRSV) has been shown to use at least six different cellular proteins to enter into host cells. These include CD151, CD163, sialoadhesin, heparan sulfate, dendritic cell-specific intercellular adhesion molecule-3-grabbing non-integrin (DC-SIGN; CD209) and vimentin [8,17,19,24,28,29]. It is also possible that in addition to the minor envelope protein E, other envelope proteins such as GP2, GP3, GP4, GP5 and M may also have the ability to bind to heparin.…”

Molecular cloning, characterization and expression analysis of a C-type lectin (Ec-CTL) in orange-spotted grouper, Epinephelus coioides

“…There are eight exons in the bovine and porcine DC-SIGN genes [24], while there are only five exons and four introns in the TCL-1 gene [9].…”

“…Livers were collected from healthy grouper or grouper infected with SGIV at different times (2,4,8,12,16,24,36, and 48 h) postinfection, and expression variation of Ec-CTL was investigated by Q-PCR (Fig. 4D).…”