Identification and functional characterization of a bovine orthologue to DC-SIGN

Yamakawa, Y; Pennelegion, C; Willcocks, S; Stalker, A; MacHugh, N; Burt, D; Coffey, T J; Werling, D

Abstract

Dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) C-type lectin is almost exclusively expressed at the cell surface of DC. In addition to its normal function facilitating contact of DC with T cells, DC-SIGN has been shown to bind a variety of pathogens, including Mycobacterium bovis, and HIV-1 envelope protein gp120. In this study, we identified the bovine ortholog of the human DC-SIGN gene within the bovine genome, which exists as a single copy. PCR amplified a product, showing a 100% match with the predicted sequences as well as a sequence predicted to be similar to that of SIGNR7. Furthermore, a protein with the same molecular weight as human DC-SIGN was detected by Western blot in cell lysate derived from bovine DC. To characterize this molecule functionally, the uptake of FITC-labeled OVA and FITC-labeled gp120 (FITC-gp120) by bovine and human DC was assessed. FITC-gp120 was shown to bind to bovine DC in a time- and temperature-dependent manner. Binding was blocked by a polyclonal anti-DC-SIGN antibody but not by a control antibody. Furthermore, blocking of this molecule also reduced the binding of M. bovis bacillus Calmette-Guerin expressing GFP. Confocal microscopy showed that DC-SIGN was expressed on the surface of bovine DC. Subsequent pulse-chase studies revealed that FITC-gp120 was internalized by bovine monocyte-derived DC as early as 10 min. Thus, there is evidence of a DC-SIGN-like molecule expressed specifically by bovine DC. This molecule may play an important role in the infection of bovine (DC) cells with M. bovis.

Citation

Yamakawa, Y., Pennelegion, C., Willcocks, S., Stalker, A., MacHugh, N., Burt, D., …Werling, D. Identification and functional characterization of a bovine orthologue to DC-SIGN. Journal of Leukocyte Biology, 83(6), 1396-1403. https://doi.org/10.1189/jlb.0807523

• Journal Article Type: Article
• Deposit Date: Nov 11, 2014
• Journal: Journal of Leukocyte Biology
• Print ISSN: 0741-5400
• Publisher: Society for Leukocyte Biology
• Volume: 83
• Issue: 6
• Pages: 1396-1403
• DOI: https://doi.org/10.1189/jlb.0807523
• Public URL: https://rvc-repository.worktribe.com/output/1431598
• Additional Information: Corporate Creators : IAH, Roslin, Royal (Dick) School of Veterinary Studies