Abstract
The present research was designed to study the effects of an extract from the edible cyanophyta Aphanizomenon flos-aquae on human natural killer (NK) cells. We have previously shown, using a double-blind randomized placebo-controlled crossover design, that ingestion of 1.5 g of dried whole A. flos-aquae resulted in a transient reduction in peripheral blood NK cells in 21 healthy human volunteers, suggesting increased NK cell homing into tissue. We have now identified an extract from A. flos-aquae (AFAe) that directly activates NK cells in vitro and modulates the chemokine receptor profile. NK cell activation was evaluated by expression of CD25 and CD69 on CD3 -CD56+ cells after 18 hours. Changes in CXCR3 and CXCR4 chemokine receptor expression after 5-60 minutes were evaluated by immunostaining and flow cytometry. AFAe induced the expression of CD69 on CD3-CD56+ NK cells, induced CD25 expression on 25% of these cells, and acted in synergy with interleukin 2. NK cells enriched by RosetteSep® (StemCell Technologies Inc., Vancouver, BC, Canada) were not activated by AFAe, indicating that the NK activation was dependent on other cells such as monocytes. The low-molecular-weight fraction <5,000 of AFAe was responsible for the most robust NK cell activation, suggesting novel compounds different from previously reported macrophage-activating large polysaccharides.
Original language | English (US) |
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Pages (from-to) | 435-441 |
Number of pages | 7 |
Journal | Journal of Medicinal Food |
Volume | 10 |
Issue number | 3 |
DOIs | |
State | Published - Sep 2007 |
Externally published | Yes |
Keywords
- Aphanizomenon flos-aquae
- Blue-green algae
- Human
- Immunomodulation
- Low-molecular-weight peptides
- Trafficking
ASJC Scopus subject areas
- Medicine (miscellaneous)
- Nutrition and Dietetics