Peculiarities of immunocorrective effects of the bone marrow regulatory peptides (myelopeptides)

Area of Science:

• Immunology
• Biochemistry

Background:

• Myelopeptides (MPs) are low-molecular-weight peptides originating from bone marrow.
• These peptides possess immunoregulatory properties, influencing immune responses.

Purpose of the Study:

• To investigate the specific immunoregulatory effects of synthesized Myelopeptides (MPs), focusing on MP-1 and MP-2.
• To elucidate the mechanisms underlying the selective action of MPs on immune system components.

Main Methods:

• Synthesis of specific Myelopeptides (MPs), including MP-1 and MP-2.
• In vivo studies using cyclophosphamide (Cy)-treated mice to assess MP-1's effect on antibody production.
• Tumor inhibition assays in tumor-bearing organisms to evaluate MP-2's efficacy.
• Ligand-receptor interaction studies using FITC-labeled MP-1 and [3H]-labeled MP-2.
• Cytofluorimetric analysis to identify target cells for MP-1.

Main Results:

• MP-1 enhanced antibody production in immunosuppressed (Cy-treated) mice but had no effect in normal animals.
• MP-2 demonstrated an inhibitory effect on tumor growth, which was more pronounced with larger tumor sizes.
• MP-2's antitumor activity was attributed to the recovery of T lymphocyte function suppressed by tumor products.
• Specific binding of MP-1 and MP-2 to distinct cell populations was confirmed.
• Cytofluorimetric analysis identified CD4+ T lymphocytes (T helpers) as specific targets for MP-1.

Conclusions:

• Myelopeptides (MPs) exhibit selective immunocorrective effects, targeting damaged components of the immune system.
• The observed effects are mediated through specific ligand-receptor interactions.
• MPs function as endogenous immunoregulators involved in maintaining immune homeostasis.