Protodyne: an immunostimulatory protein component, prepared from gram-positive Bacillus subtilis

Area of Science:

• Immunology
• Microbiology
• Biochemistry

Background:

• Protodyne, a protein from bacterial protoplasm, is known to boost non-specific immunity.
• Its preparation and immunomodulatory potential from Gram-positive bacteria remain less explored.

Purpose of the Study:

• To investigate the preparation of Protodyne from Gram-positive bacteria (Bacillus subtilis).
• To evaluate the immunomodulatory activities of Protodyne in various in vitro and in vivo assays.

Main Methods:

• Phenol extraction and ammonium sulfate precipitation were used to prepare Protodyne from Bacillus subtilis.
• Assays included mitogenic activity on spleen cells, induction of tumor necrosis factor (TNF) and interleukin-1 (IL-1), macrophage activation, phagocytosis, and survival studies in infected mice.

Main Results:

• Protodyne demonstrated significant mitogenic activity on mouse spleen cells.
• It potently induced TNF and IL-1 production in human peripheral blood mononuclear cells.
• Protodyne enhanced macrophage respiratory burst, intracellular parasite killing, and phagocytosis, while prolonging survival in immunosuppressed infected mice.

Conclusions:

• Protodyne can be effectively prepared from Gram-positive bacilli like Bacillus subtilis.
• Protodyne exhibits broad immunomodulatory activities, suggesting its potential as an immune-enhancing agent.
• Its mechanism involves inducing the release of soluble mediators such as TNF and IL-1, independent of lipopolysaccharide contamination.