Identification of the Primary Structure of Selenium-Containing Polysaccharides Selectively Inhibiting T-Cell...

Area of Science:

• Mycology
• Immunology
• Biochemistry

Background:

• Lentinula edodes mycelial cultures produce selenium-containing polysaccharide fractions with immunosuppressive activity.
• Previous studies identified these fractions as protein-containing mixtures of alpha- and beta-glucans.
• The specific component responsible for the non-typical immunosuppressive activity remained unidentified.

Purpose of the Study:

• To isolate and define the primary structure of individual polysaccharide components within the selenium-containing fraction.
• To investigate the biological activity of these isolated polysaccharides, specifically their effect on T- and B-cell proliferation.
• To compare the immunosuppressive effects of isolated polysaccharides with the original crude fraction.

Main Methods:

• Isolation and purification of four distinct selenium-polysaccharide components.
• Determination of the primary structure of each isolated polysaccharide.
• Assessment of the impact of isolated polysaccharides on T- and B-cell proliferation in vitro.

Main Results:

• Four unique Se-polysaccharides were identified: alpha-1,4-glucan, unbranched beta-1,6-d-glucan, unbranched beta-1,3-d-glucan, and beta-1,3-branched beta-1,6-d-glucan.
• These isolated polysaccharides are not typical cell wall components of Lentinula edodes.
• All isolated polysaccharides demonstrated biological activity, with a weaker yet more selective inhibitory effect on lymphocyte proliferation compared to the crude fraction.

Conclusions:

• The study successfully identified and characterized four novel selenium-polysaccharides from Lentinula edodes.
• These isolated polysaccharides exhibit distinct immunosuppressive properties, affecting lymphocyte proliferation selectively.
• The findings contribute to understanding the specific molecular mechanisms underlying the immunosuppressive activity of Lentinula edodes-derived compounds.