WITHDRAWN: Exopolysaccharide from Bifidobacterium longum subsp. infantis E4: Structural analysis and immunoregulation...

Area of Science:

• Biochemistry
• Immunology
• Microbiology

Background:

• Exopolysaccharides (EPS) are known for their anti-inflammatory, antimicrobial, and immunomodulatory properties.
• Understanding the structural characteristics of EPS is crucial for elucidating their biological functions.

Purpose of the Study:

• To characterize the structures of EPS-1 and EPS-2.
• To investigate the immunomodulatory effects of EPS-1 and EPS-2 on cyclophosphamide (CTX)-induced immunocompromised mice.

Main Methods:

• Structural analysis using Fourier-transform infrared (FT-IR) spectroscopy, Congo red test, methylation, and nuclear magnetic resonance (NMR).
• Assessment of immune function in CTX-induced immunocompromised mice, including spleen and thymus indices, splenic lymphocyte proliferation, NK cell activity, T cell populations (Th1, Th2, Th17, Treg), and serum inflammatory cytokine levels (IFN-γ, IL-1β, IL-2, IL-6, IL-10, TNF-α).

Main Results:

• EPS-1 primarily comprised glucose and mannose, while EPS-2 consisted mainly of galactose, glucose, and mannose.
• Both EPS-1 and EPS-2 exhibited triple-helical conformations and alleviated the decrease in spleen and thymus indices in CTX-treated mice.
• EPS administration significantly increased splenic lymphocyte proliferation, NK cell activity, Th1, Th2, Th17, and Treg cell populations, and elevated serum inflammatory cytokine levels compared to the model control group.

Conclusions:

• EPS-1 and EPS-2 possess distinct structural features, including specific glycosidic linkages and triple-helical conformations.
• EPS-1 and EPS-2 demonstrate significant immunomodulatory potential by enhancing cellular and humoral immunity in a mouse model of immunosuppression.
• These findings highlight the therapeutic potential of EPS as agents for regulating and boosting immune function.