Comparison of the potency of a variety of β-glucans to induce cytokine production in human whole blood.
β-Glucans are components of fungal cell walls and potent stimulants of innate immunity. The majority of research on biological activities of glucans has focused on β-(1→3)-glucans, which have been implicated in relation to fungal exposure-associated respiratory symptoms and as important stimulatory agents in anti-fungal immune responses. Fungi-and bacteria and plants-produce a wide variety of glucans with vast differences in the proportion and arrangement of their β-(1→3)-, -(1→4)- and -(1→6)-glycosidic linkages. Thus far, the pro-inflammatory potential of different β-glucans has not been studied within the same experimental model. Therefore, we compared the potency of 13 different glucan preparations to induce in vitro production of IL-1β, IL-6, IL-8 and TNF-α in human, whole blood cultures. The strongest inducers of all cytokines were pustulan [β-(1→6)-glucan], lichenan [β-(1→3)-(1→4)-glucan], xyloglucan [β-(1→4)-glucan] and pullulan [α-(1→4)-(1→6)-glucan]. Moderate-to-strong cytokine production was observed for curdlan [β-(1→3)-glucan], baker's yeast glucan [β-(1→3)-(1→6)-glucan] and barley glucan [β-(1→3)-(1→4)-glucan], while all other glucan preparations induced very low, or no, detectable levels of cytokines. We therefore conclude that innate immunity reactions are not exclusively induced by β-(1→3)-glucans, but also by β-(1→6)- and β-(1→4)-structures. Thus, not only β-(1→3)-glucan, but also other β-glucans and particularly β-(1→6)-glucans should be considered in future research.
Institute for Risk Assessment Sciences, Utrecht University, Utrecht, the Netherlands.
Ilka
I
Noss
Gert
G
Doekes
Peter S
PS
Thorne
Dick J J
DJ
Heederik
Inge M
IM
Wouters
D001773:Blood Cells / Q000276:immunology* / Q000382:microbiology; D002473:Cell Wall / Q000378:metabolism; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D015536:Down-Regulation; D005658:Fungi / Q000276:immunology*; D006801:Humans; D007113:Immunity, Innate; D056747:Immunomodulation; D018836:Inflammation Mediators / Q000378:metabolism*; D047071:beta-Glucans / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*
D016207:Cytokines; D018836:Inflammation Mediators; D047071:beta-Glucans