Laminarin from the brown seaweed Laminaria digitata is a linear β(1-3)-glucan with β(1-6)-linkages.
Laminarin can act either as a Dectin-1 antagonist or agonist [1]. It can bind to Dectin-1 without stimulating downstream signaling and is able to block binding to Dectin-1 of particulate β(1-3)-glucans, such as zymosan [2-3].
The activity of laminarin on Dectin-1 seems to vary depending on the purity of the laminarin preparation and the Dectin-1 isoform used [1, 4]. Cells expressing the human Dectin-1b isoform do not respond to laminarin, whereas cells expressing the human Dectin-1a isoform are highly responsive to laminarin [4].
The laminarin preparation provided by InvivoGen contains no detectable levels of endotoxin unlike other commercially available preparations [1].
References:
- Smith AJ. et al., 2017. Immunoregulatory Activity of the Natural Product Laminarin Varies Widely as a Result of Its Physical Properties. J Immunol. 200 (2):788-99.
- Goodridge HS. et al., 2011. Activation of the innate immune receptor Dectin-1 upon formation of a ‘phagocytic synapse’. Nature. 472(7344):471-5.
- Rothfuchs AG. et al., 2007. Dectin-1 Interaction with Mycobacterium tuberculosis Leads to Enhanced IL-12p40 Production by Splenic Dendritic Cells. J Immunol. 179(6):3463-71.
- InvivoGen insight. Summer 2013.