Non-Primate Monocytes - CD14, CD16 - Ziegler-Heitbrock


Molecular characterization and expression of porcine Siglec-5.


In this study we describe the characterization of the porcine orthologue of Siglec-5. A cDNa clone was obtained from a porcine cDNa library derived from swine small intestine which encodes a 555 a-a type 1 transmembrane protein with sequence homology to human Siglec-5. This protein consists of four Ig-like domains, a transmembrane region, and a cytoplasmic tail with two tyrosine-based signalling motifs. When expressed as a recombinant protein fused to the Fc region of human IgG1, porcine Siglec-5 was able to bind porcine red blood cells in a sialic acid-dependent manner. Monoclonal antibodies (mAb) were developed against porcine Siglec-5 and used to analyse its expression in bone marrow and blood cells, and lymphoid tissues. Porcine Siglec-5 expression was mainly restricted to myelomonocytic cells and their precursors, being detected also, although at low levels, on plasmacytoid dendritic cells and B lymphocytes. In lymphoid tissues, ellipsoids of the spleen and subcapsular and medullar sinuses of lymph nodes were positive for Siglec-5. These mAbs were able to precipitate, from granulocyte lysates, a protein of approximately 85 kDa under non-reducing conditions, indicating that porcine Siglec-5 is expressed as a monomer in the plasma membrane.

Authors: Escalona Z, Álvarez B, Uenishi H, Toki D, Yuste M, Revilla C, Gómez del Moral M, Alonso F, Ezquerra A, Domínguez J
Journal: Dev. Comp. Immunol.; 2014 May; 44(1) 206-16. doi:10.1016/j.dci.2013.12.013
Year: 2014
PubMed: PMID: 24382335 (Go to PubMed)